Small improvements (#588)

* Abort actions on exit

* Fix VideoRecorder state

* Add missing metering tests

* Fix default vertex shader definition

* Fix #582

* Make Camera2Engine more open

* Add timestampUs in Filter.draw signature

* Add timestampUs in BaseFilter.onPreDraw, onDraw, onPostDraw

* Change README

* Fix FrameProcessing segmentation fault

* Fix #590 by throwing

* Fix StackOverflowErrors in AudioMediaEncoder (Fixes #594)

* Enforce 100 character limits

* Improve encoder selection

* Simplify DeviceEncoders class

* Improve overlay add/remove

* Add changelog info

* Add more info

README.md

@@ -54,7 +54,7 @@ If you like the project, make profit from it, or simply want to thank back, plea
 [donating](https://natario1.github.io/CameraView/extra/donate) now! You can either make a one time
 donation or become a sponsor, in which case your company logo will immediately show up below.
 
-CameraView is trusted and supported by [ShareChat](https://sharechat.com/), a social media app with over 14 million daily active users. 
+CameraView is trusted and supported by [ShareChat](https://sharechat.com/), a social media app with over 100 million downloads. 
 
 <p align="center">
   <img src="docs/static/sharechat.png" width="100%">

cameraview/src/androidTest/java/com/otaliastudios/cameraview/CameraViewTest.java

@@ -930,6 +930,33 @@ public class CameraViewTest extends BaseTest {
         verify(cameraView.mOverlayLayout, never()).addView(overlay, params);
     }
 
+    @Test
+    public void testOverlays_removeOverlayView() {
+        // First add one.
+        cameraView.mOverlayLayout = spy(cameraView.mOverlayLayout);
+        View overlay = new View(getContext());
+        OverlayLayout.LayoutParams params = new OverlayLayout.LayoutParams(10, 10);
+        cameraView.addView(overlay, 0, params);
+        reset(cameraView.mOverlayLayout);
+        // Then remove.
+        cameraView.removeView(overlay);
+        verify(cameraView.mOverlayLayout, times(1)).isOverlay(params);
+        verify(cameraView.mOverlayLayout, times(1)).removeView(overlay);
+    }
+
+    @Test
+    public void testOverlays_dontRemoveOverlayView() {
+        // First add a view.
+        cameraView.mOverlayLayout = spy(cameraView.mOverlayLayout);
+        View notOverlay = new View(getContext());
+        ViewGroup.LayoutParams notOverlayParams = new ViewGroup.LayoutParams(10, 10);
+        cameraView.addView(notOverlay, notOverlayParams);
+        reset(cameraView.mOverlayLayout);
+        // Then remove.
+        cameraView.removeView(notOverlay);
+        verify(cameraView.mOverlayLayout, never()).removeView(notOverlay);
+    }
+
     //endregion
     // TODO: test permissions
 

cameraview/src/androidTest/java/com/otaliastudios/cameraview/engine/CameraIntegration1Test.java

@@ -27,4 +27,9 @@ public class CameraIntegration1Test extends CameraIntegrationTest {
     protected Engine getEngine() {
         return Engine.CAMERA1;
     }
+
+    @Override
+    protected long getMeteringTimeoutMillis() {
+        return Camera1Engine.AUTOFOCUS_END_DELAY_MILLIS;
+    }
 }

cameraview/src/androidTest/java/com/otaliastudios/cameraview/engine/CameraIntegration2Test.java

@@ -55,4 +55,9 @@ public class CameraIntegration2Test extends CameraIntegrationTest {
         }.start(engine);
         try { latch.await(); } catch (InterruptedException ignore) {}
     }
+
+    @Override
+    protected long getMeteringTimeoutMillis() {
+        return Camera2Engine.METER_TIMEOUT;
+    }
 }

cameraview/src/androidTest/java/com/otaliastudios/cameraview/engine/CameraIntegrationTest.java

@@ -658,8 +658,8 @@ public abstract class CameraIntegrationTest extends BaseTest {
         doEndOp(focus, 1).when(listener).onAutoFocusEnd(anyBoolean(), any(PointF.class));
 
         camera.startAutoFocus(1, 1);
-        // Stop is not guaranteed to be called, we use a delay. So wait at least the delay time.
-        PointF point = focus.await(1000 + Camera1Engine.AUTOFOCUS_END_DELAY_MILLIS);
+        // Stop routine can fail, so engines use a timeout. So wait at least the timeout time.
+        PointF point = focus.await(1000 + getMeteringTimeoutMillis());
         if (o.isAutoFocusSupported()) {
             assertNotNull(point);
             assertEquals(point, new PointF(1, 1));
@@ -668,6 +668,8 @@ public abstract class CameraIntegrationTest extends BaseTest {
         }
     }
 
+    protected abstract long getMeteringTimeoutMillis();
+
     //endregion
 
     //region capture
@@ -717,6 +719,24 @@ public abstract class CameraIntegrationTest extends BaseTest {
         openSync(true);
         camera.takePicture();
         waitForUiException();
+        camera.takePicture();
+
+    }
+
+    @Test
+    public void testCapturePicture_withMetering() {
+        openSync(true);
+        camera.setPictureMetering(true);
+        camera.takePicture();
+        waitForPictureResult(true);
+    }
+
+    @Test
+    public void testCapturePicture_withoutMetering() {
+        openSync(true);
+        camera.setPictureMetering(false);
+        camera.takePicture();
+        waitForPictureResult(true);
     }
 
     @Test
@@ -759,6 +779,22 @@ public abstract class CameraIntegrationTest extends BaseTest {
         assertTrue(result.isSnapshot());
     }
 
+    @Test
+    public void testCaptureSnapshot_withMetering() {
+        openSync(true);
+        camera.setPictureSnapshotMetering(true);
+        camera.takePictureSnapshot();
+        waitForPictureResult(true);
+    }
+
+    @Test
+    public void testCaptureSnapshot_withoutMetering() {
+        openSync(true);
+        camera.setPictureSnapshotMetering(false);
+        camera.takePictureSnapshot();
+        waitForPictureResult(true);
+    }
+
     //endregion
 
     //region Frame Processing

cameraview/src/androidTest/java/com/otaliastudios/cameraview/filter/BaseFilterTest.java

@@ -8,21 +8,16 @@ import androidx.test.ext.junit.runners.AndroidJUnit4;
 import androidx.test.filters.SmallTest;
 
 import com.otaliastudios.cameraview.BaseEglTest;
-import com.otaliastudios.cameraview.BaseTest;
 import com.otaliastudios.cameraview.internal.GlUtils;
 import com.otaliastudios.cameraview.internal.egl.EglViewport;
 
-import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
-import java.util.HashSet;
-
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.ArgumentMatchers.anyInt;
 import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.times;
@@ -108,10 +103,10 @@ public class BaseFilterTest extends BaseEglTest {
     public void testDraw_whenInvalid() {
         filter = spy(new TestFilter());
         float[] matrix = new float[16];
-        filter.draw(matrix);
-        verify(filter, never()).onPreDraw(matrix);
-        verify(filter, never()).onDraw();
-        verify(filter, never()).onPostDraw();
+        filter.draw(0L, matrix);
+        verify(filter, never()).onPreDraw(0L, matrix);
+        verify(filter, never()).onDraw(0L);
+        verify(filter, never()).onPostDraw(0L);
     }
 
     @Test
@@ -122,10 +117,10 @@ public class BaseFilterTest extends BaseEglTest {
         int texture = viewport.createTexture();
 
         float[] matrix = new float[16];
-        viewport.drawFrame(texture, matrix);
-        verify(filter, times(1)).onPreDraw(matrix);
-        verify(filter, times(1)).onDraw();
-        verify(filter, times(1)).onPostDraw();
+        viewport.drawFrame(0L, texture, matrix);
+        verify(filter, times(1)).onPreDraw(0L, matrix);
+        verify(filter, times(1)).onDraw(0L);
+        verify(filter, times(1)).onPostDraw(0L);
 
         viewport.release();
     }

cameraview/src/androidTest/java/com/otaliastudios/cameraview/filter/MultiFilterTest.java

@@ -3,7 +3,6 @@ package com.otaliastudios.cameraview.filter;
 
 import android.opengl.GLES20;
 
-import androidx.annotation.NonNull;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 import androidx.test.filters.SmallTest;
 
@@ -30,13 +29,13 @@ import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.atLeastOnce;
 import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.when;
 
 
 @RunWith(AndroidJUnit4.class)
@@ -146,7 +145,7 @@ public class MultiFilterTest extends BaseEglTest {
         EglViewport viewport = new EglViewport(multiFilter);
         int texture = viewport.createTexture();
         float[] matrix = new float[16];
-        viewport.drawFrame(texture, matrix);
+        viewport.drawFrame(0L, texture, matrix);
         viewport.release();
 
         // The child should have experienced the whole lifecycle.
@@ -154,7 +153,7 @@ public class MultiFilterTest extends BaseEglTest {
         verify(filter, atLeastOnce()).getFragmentShader();
         verify(filter, atLeastOnce()).setSize(anyInt(), anyInt());
         verify(filter, times(1)).onCreate(anyInt());
-        verify(filter, times(1)).draw(matrix);
+        verify(filter, times(1)).draw(0L, matrix);
         verify(filter, times(1)).onDestroy();
     }
 
@@ -181,7 +180,7 @@ public class MultiFilterTest extends BaseEglTest {
                 assertTrue(result[0] != 0);
                 return null;
             }
-        }).when(filter1).draw(matrix);
+        }).when(filter1).draw(0L, matrix);
 
         // Note: second filter is drawn with the identity matrix!
         doAnswer(new Answer() {
@@ -198,16 +197,16 @@ public class MultiFilterTest extends BaseEglTest {
                 return null;
 
             }
-        }).when(filter2).draw(any(float[].class));
+        }).when(filter2).draw(eq(0L), any(float[].class));
 
         EglViewport viewport = new EglViewport(multiFilter);
         int texture = viewport.createTexture();
-        viewport.drawFrame(texture, matrix);
+        viewport.drawFrame(0L, texture, matrix);
         viewport.release();
 
         // Verify that both are drawn.
-        verify(filter1, times(1)).draw(matrix);
-        verify(filter2, times(1)).draw(any(float[].class));
+        verify(filter1, times(1)).draw(0L, matrix);
+        verify(filter2, times(1)).draw(eq(0L), any(float[].class));
     }
 
 }

cameraview/src/androidTest/java/com/otaliastudios/cameraview/internal/DeviceEncodersTest.java

@@ -6,17 +6,13 @@ import android.media.MediaCodecInfo;
 import androidx.annotation.NonNull;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 import androidx.test.filters.MediumTest;
-import androidx.test.rule.ActivityTestRule;
 
 import com.otaliastudios.cameraview.BaseTest;
-import com.otaliastudios.cameraview.TestActivity;
-import com.otaliastudios.cameraview.controls.Grid;
 import com.otaliastudios.cameraview.size.AspectRatio;
 import com.otaliastudios.cameraview.size.Size;
 
 import org.junit.After;
 import org.junit.Before;
-import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
@@ -30,8 +26,6 @@ import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertSame;
 import static org.junit.Assert.assertTrue;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.when;
 
 @RunWith(AndroidJUnit4.class)
 @MediumTest
@@ -55,10 +49,11 @@ public class DeviceEncodersTest extends BaseTest {
 
     @NonNull
     private DeviceEncoders create() {
-        return new DeviceEncoders(
+        return new DeviceEncoders(DeviceEncoders.MODE_RESPECT_ORDER,
                 "video/avc",
                 "audio/mp4a-latm",
-                DeviceEncoders.MODE_TAKE_FIRST);
+                0,
+                0);
     }
 
     @Test
@@ -87,7 +82,7 @@ public class DeviceEncodersTest extends BaseTest {
         if (DeviceEncoders.ENABLED) {
             List<MediaCodecInfo> allEncoders = deviceEncoders.getDeviceEncoders();
             MediaCodecInfo encoder = deviceEncoders.findDeviceEncoder(allEncoders,
-                    "video/avc", DeviceEncoders.MODE_TAKE_FIRST);
+                    "video/avc", DeviceEncoders.MODE_RESPECT_ORDER, 0);
             assertNotNull(encoder);
             List<String> encoderTypes = Arrays.asList(encoder.getSupportedTypes());
             assertTrue(encoderTypes.contains("video/avc"));

cameraview/src/androidTest/java/com/otaliastudios/cameraview/overlay/OverlayDrawerTest.java

@@ -81,8 +81,9 @@ public class OverlayDrawerTest extends BaseEglTest {
         OverlayDrawer drawer = new OverlayDrawer(mock(Overlay.class), new Size(WIDTH, HEIGHT));
         drawer.mViewport = spy(drawer.mViewport);
         drawer.draw(Overlay.Target.PICTURE_SNAPSHOT);
-        drawer.render();
+        drawer.render(0L);
         verify(drawer.mViewport, times(1)).drawFrame(
+                0L,
                 drawer.mTextureId,
                 drawer.getTransform()
         );

cameraview/src/main/java/com/otaliastudios/cameraview/BitmapCallback.java

@@ -10,7 +10,7 @@ import androidx.annotation.UiThread;
 public interface BitmapCallback {
 
     /**
-     * Notifies that the bitmap was succesfully decoded.
+     * Notifies that the bitmap was successfully decoded.
      * This is run on the UI thread.
      * Returns a null object if a {@link OutOfMemoryError} was encountered.
      *

cameraview/src/main/java/com/otaliastudios/cameraview/CameraListener.java

@@ -48,8 +48,9 @@ public abstract class CameraListener {
      * Notifies that a picture previously captured with {@link CameraView#takePicture()}
      * or {@link CameraView#takePictureSnapshot()} is ready to be shown or saved to file.
      *
-     * If planning to show a bitmap, you can use {@link PictureResult#toBitmap(int, int, BitmapCallback)}
-     * to decode the byte array taking care about orientation and threading.
+     * If planning to show a bitmap, you can use
+     * {@link PictureResult#toBitmap(int, int, BitmapCallback)} to decode the byte array
+     * taking care about orientation and threading.
      *
      * @param result captured picture
      */
@@ -114,7 +115,9 @@ public abstract class CameraListener {
      * @param fingers finger positions that caused the event, null if not caused by touch
      */
     @UiThread
-    public void onZoomChanged(float newValue, @NonNull float[] bounds, @Nullable PointF[] fingers) { }
+    public void onZoomChanged(float newValue,
+                              @NonNull float[] bounds,
+                              @Nullable PointF[] fingers) { }
 
 
     /**
@@ -126,7 +129,9 @@ public abstract class CameraListener {
      * @param fingers finger positions that caused the event, null if not caused by touch
      */
     @UiThread
-    public void onExposureCorrectionChanged(float newValue, @NonNull float[] bounds, @Nullable PointF[] fingers) { }
+    public void onExposureCorrectionChanged(float newValue,
+                                            @NonNull float[] bounds,
+                                            @Nullable PointF[] fingers) { }
 
 
     /**

cameraview/src/main/java/com/otaliastudios/cameraview/CameraLogger.java

@@ -49,7 +49,10 @@ public final class CameraLogger {
          * @param message the log message
          * @param throwable an optional throwable
          */
-        void log(@LogLevel int level, @NonNull String tag, @NonNull String message, @Nullable Throwable throwable);
+        void log(@LogLevel int level,
+                 @NonNull String tag,
+                 @NonNull String message,
+                 @Nullable Throwable throwable);
     }
 
     @VisibleForTesting static String lastMessage;
@@ -60,7 +63,10 @@ public final class CameraLogger {
 
     @VisibleForTesting static Logger sAndroidLogger = new Logger() {
         @Override
-        public void log(int level, @NonNull String tag, @NonNull String message, @Nullable Throwable throwable) {
+        public void log(int level,
+                        @NonNull String tag,
+                        @NonNull String message,
+                        @Nullable Throwable throwable) {
             switch (level) {
                 case LEVEL_VERBOSE: Log.v(tag, message, throwable); break;
                 case LEVEL_INFO: Log.i(tag, message, throwable); break;

cameraview/src/main/java/com/otaliastudios/cameraview/CameraOptions.java

@@ -107,7 +107,8 @@ public class CameraOptions {
         zoomSupported = params.isZoomSupported();
 
         // autofocus
-        autoFocusSupported = params.getSupportedFocusModes().contains(Camera.Parameters.FOCUS_MODE_AUTO);
+        autoFocusSupported = params.getSupportedFocusModes()
+                .contains(Camera.Parameters.FOCUS_MODE_AUTO);
 
         // Exposure correction
         float step = params.getExposureCompensationStep();
@@ -135,7 +136,8 @@ public class CameraOptions {
                 supportedVideoAspectRatio.add(AspectRatio.of(width, height));
             }
         } else {
-            // StackOverflow threads seems to agree that if getSupportedVideoSizes is null, previews can be used.
+            // StackOverflow threads seems to agree that if getSupportedVideoSizes is null,
+            // previews can be used.
             List<Camera.Size> fallback = params.getSupportedPreviewSizes();
             for (Camera.Size size : fallback) {
                 int width = flipSizes ? size.height : size.width;
@@ -148,13 +150,16 @@ public class CameraOptions {
 
     // Camera2Engine constructor.
     @RequiresApi(Build.VERSION_CODES.LOLLIPOP)
-    public CameraOptions(@NonNull CameraManager manager, @NonNull String  cameraId, boolean flipSizes) throws CameraAccessException {
+    public CameraOptions(@NonNull CameraManager manager,
+                         @NonNull String cameraId,
+                         boolean flipSizes) throws CameraAccessException {
         Camera2Mapper mapper = Camera2Mapper.get();
         CameraCharacteristics cameraCharacteristics = manager.getCameraCharacteristics(cameraId);
 
         // Facing
         for (String cameraId1 : manager.getCameraIdList()) {
-            CameraCharacteristics cameraCharacteristics1 = manager.getCameraCharacteristics(cameraId1);
+            CameraCharacteristics cameraCharacteristics1 = manager
+                    .getCameraCharacteristics(cameraId1);
             Integer cameraFacing = cameraCharacteristics1.get(CameraCharacteristics.LENS_FACING);
             if (cameraFacing != null) {
                 Facing value = mapper.unmapFacing(cameraFacing);
@@ -163,7 +168,8 @@ public class CameraOptions {
         }
 
         // WB
-        int[] awbModes = cameraCharacteristics.get(CameraCharacteristics.CONTROL_AWB_AVAILABLE_MODES);
+        int[] awbModes = cameraCharacteristics.get(
+                CameraCharacteristics.CONTROL_AWB_AVAILABLE_MODES);
         //noinspection ConstantConditions
         for (int awbMode : awbModes) {
             WhiteBalance value = mapper.unmapWhiteBalance(awbMode);
@@ -174,7 +180,8 @@ public class CameraOptions {
         supportedFlash.add(Flash.OFF);
         Boolean hasFlash = cameraCharacteristics.get(CameraCharacteristics.FLASH_INFO_AVAILABLE);
         if (hasFlash != null && hasFlash) {
-            int[] aeModes = cameraCharacteristics.get(CameraCharacteristics.CONTROL_AE_AVAILABLE_MODES);
+            int[] aeModes = cameraCharacteristics.get(
+                    CameraCharacteristics.CONTROL_AE_AVAILABLE_MODES);
             //noinspection ConstantConditions
             for (int aeMode : aeModes) {
                 Set<Flash> flashes = mapper.unmapFlash(aeMode);
@@ -184,7 +191,8 @@ public class CameraOptions {
 
         // HDR
         supportedHdr.add(Hdr.OFF);
-        int[] sceneModes = cameraCharacteristics.get(CameraCharacteristics.CONTROL_AVAILABLE_SCENE_MODES);
+        int[] sceneModes = cameraCharacteristics.get(
+                CameraCharacteristics.CONTROL_AVAILABLE_SCENE_MODES);
         //noinspection ConstantConditions
         for (int sceneMode : sceneModes) {
             Hdr value = mapper.unmapHdr(sceneMode);
@@ -192,7 +200,8 @@ public class CameraOptions {
         }
 
         // Zoom
-        Float maxZoom = cameraCharacteristics.get(CameraCharacteristics.SCALER_AVAILABLE_MAX_DIGITAL_ZOOM);
+        Float maxZoom = cameraCharacteristics.get(
+                CameraCharacteristics.SCALER_AVAILABLE_MAX_DIGITAL_ZOOM);
         if(maxZoom != null) {
             zoomSupported = maxZoom > 1;
         }
@@ -205,24 +214,31 @@ public class CameraOptions {
         // What really matters in my opinion is the availability of regions.
         Integer afRegions = cameraCharacteristics.get(CameraCharacteristics.CONTROL_MAX_REGIONS_AF);
         Integer aeRegions = cameraCharacteristics.get(CameraCharacteristics.CONTROL_MAX_REGIONS_AE);
-        Integer awbRegions = cameraCharacteristics.get(CameraCharacteristics.CONTROL_MAX_REGIONS_AWB);
+        Integer awbRegions = cameraCharacteristics.get(
+                CameraCharacteristics.CONTROL_MAX_REGIONS_AWB);
         autoFocusSupported = (afRegions != null && afRegions > 0)
                 || (aeRegions != null && aeRegions > 0)
                 || (awbRegions != null && awbRegions > 0);
 
         // Exposure correction
-        Range<Integer> exposureRange = cameraCharacteristics.get(CameraCharacteristics.CONTROL_AE_COMPENSATION_RANGE);
-        Rational exposureStep = cameraCharacteristics.get(CameraCharacteristics.CONTROL_AE_COMPENSATION_STEP);
+        Range<Integer> exposureRange = cameraCharacteristics.get(
+                CameraCharacteristics.CONTROL_AE_COMPENSATION_RANGE);
+        Rational exposureStep = cameraCharacteristics.get(
+                CameraCharacteristics.CONTROL_AE_COMPENSATION_STEP);
         if (exposureRange != null && exposureStep != null && exposureStep.floatValue() != 0) {
             exposureCorrectionMinValue = exposureRange.getLower() / exposureStep.floatValue();
             exposureCorrectionMaxValue = exposureRange.getUpper() / exposureStep.floatValue();
         }
-        exposureCorrectionSupported = exposureCorrectionMinValue != 0 && exposureCorrectionMaxValue != 0;
+        exposureCorrectionSupported = exposureCorrectionMinValue != 0
+                && exposureCorrectionMaxValue != 0;
 
 
         // Picture Sizes
-        StreamConfigurationMap streamMap = cameraCharacteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);
-        if (streamMap == null) throw new RuntimeException("StreamConfigurationMap is null. Should not happen.");
+        StreamConfigurationMap streamMap = cameraCharacteristics.get(
+                CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);
+        if (streamMap == null) {
+            throw new RuntimeException("StreamConfigurationMap is null. Should not happen.");
+        }
         android.util.Size[] psizes = streamMap.getOutputSizes(ImageFormat.JPEG);
         for (android.util.Size size : psizes) {
             int width = flipSizes ? size.getHeight() : size.getWidth();
@@ -238,7 +254,8 @@ public class CameraOptions {
         Size videoMaxSize = new Size(profile.videoFrameWidth, profile.videoFrameHeight);
         android.util.Size[] vsizes = streamMap.getOutputSizes(MediaRecorder.class);
         for (android.util.Size size : vsizes) {
-            if (size.getWidth() <= videoMaxSize.getWidth() && size.getHeight() <= videoMaxSize.getHeight()) {
+            if (size.getWidth() <= videoMaxSize.getWidth()
+                    && size.getHeight() <= videoMaxSize.getHeight()) {
                 int width = flipSizes ? size.getHeight() : size.getWidth();
                 int height = flipSizes ? size.getWidth() : size.getHeight();
                 supportedVideoSizes.add(new Size(width, height));

cameraview/src/main/java/com/otaliastudios/cameraview/CameraUtils.java

@@ -108,7 +108,9 @@ public class CameraUtils {
      * @param callback a callback
      */
     @SuppressWarnings("WeakerAccess")
-    public static void writeToFile(@NonNull final byte[] data, @NonNull final File file, @NonNull final FileCallback callback) {
+    public static void writeToFile(@NonNull final byte[] data,
+                                   @NonNull final File file,
+                                   @NonNull final FileCallback callback) {
         final Handler ui = new Handler();
         WorkerHandler.execute(new Runnable() {
             @Override
@@ -149,7 +151,8 @@ public class CameraUtils {
      * @param callback a callback to be notified
      */
     @SuppressWarnings("WeakerAccess")
-    public static void decodeBitmap(@NonNull final byte[] source, @NonNull final BitmapCallback callback) {
+    public static void decodeBitmap(@NonNull final byte[] source,
+                                    @NonNull final BitmapCallback callback) {
         decodeBitmap(source, Integer.MAX_VALUE, Integer.MAX_VALUE, callback);
     }
     
@@ -167,7 +170,10 @@ public class CameraUtils {
      * @param callback a callback to be notified
      */
     @SuppressWarnings("WeakerAccess")
-    public static void decodeBitmap(@NonNull final byte[] source, final int maxWidth, final int maxHeight, @NonNull final BitmapCallback callback) {
+    public static void decodeBitmap(@NonNull final byte[] source,
+                                    final int maxWidth,
+                                    final int maxHeight,
+                                    @NonNull final BitmapCallback callback) {
         decodeBitmap(source, maxWidth, maxHeight, new BitmapFactory.Options(), callback);
     }
 
@@ -186,12 +192,20 @@ public class CameraUtils {
      * @param callback a callback to be notified
      */
     @SuppressWarnings("WeakerAccess")
-    public static void decodeBitmap(@NonNull final byte[] source, final int maxWidth, final int maxHeight, @NonNull final BitmapFactory.Options options, @NonNull final BitmapCallback callback) {
+    public static void decodeBitmap(@NonNull final byte[] source,
+                                    final int maxWidth,
+                                    final int maxHeight,
+                                    @NonNull final BitmapFactory.Options options,
+                                    @NonNull final BitmapCallback callback) {
         decodeBitmap(source, maxWidth, maxHeight, options, -1, callback);
     }
 
-    @SuppressWarnings("WeakerAccess")
-    static void decodeBitmap(@NonNull final byte[] source, final int maxWidth, final int maxHeight, @NonNull final BitmapFactory.Options options, final int rotation, @NonNull final BitmapCallback callback) {
+    static void decodeBitmap(@NonNull final byte[] source,
+                             final int maxWidth,
+                             final int maxHeight,
+                             @NonNull final BitmapFactory.Options options,
+                             final int rotation,
+                             @NonNull final BitmapCallback callback) {
         final Handler ui = new Handler();
         WorkerHandler.execute(new Runnable() {
             @Override
@@ -239,10 +253,13 @@ public class CameraUtils {
      * @param options the options to be passed to decodeByteArray
      * @return decoded bitmap or null if error is encountered
      */
-    @SuppressWarnings({"SuspiciousNameCombination", "WeakerAccess"})
+    @SuppressWarnings("WeakerAccess")
     @Nullable
     @WorkerThread
-    public static Bitmap decodeBitmap(@NonNull byte[] source, int maxWidth, int maxHeight, @NonNull BitmapFactory.Options options) {
+    public static Bitmap decodeBitmap(@NonNull byte[] source,
+                                      int maxWidth,
+                                      int maxHeight,
+                                      @NonNull BitmapFactory.Options options) {
         return decodeBitmap(source, maxWidth, maxHeight, options, -1);
     }
 
@@ -250,7 +267,11 @@ public class CameraUtils {
     // Ignores flipping, but it should be super rare.
     @SuppressWarnings("TryFinallyCanBeTryWithResources")
     @Nullable
-    private static Bitmap decodeBitmap(@NonNull byte[] source, int maxWidth, int maxHeight, @NonNull BitmapFactory.Options options, int rotation) {
+    private static Bitmap decodeBitmap(@NonNull byte[] source,
+                                       int maxWidth,
+                                       int maxHeight,
+                                       @NonNull BitmapFactory.Options options,
+                                       int rotation) {
         if (maxWidth <= 0) maxWidth = Integer.MAX_VALUE;
         if (maxHeight <= 0) maxHeight = Integer.MAX_VALUE;
         int orientation;
@@ -261,7 +282,8 @@ public class CameraUtils {
                 // http://sylvana.net/jpegcrop/exif_orientation.html
                 stream = new ByteArrayInputStream(source);
                 ExifInterface exif = new ExifInterface(stream);
-                int exifOrientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL);
+                int exifOrientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION,
+                        ExifInterface.ORIENTATION_NORMAL);
                 orientation = ExifHelper.readExifOrientation(exifOrientation);
                 flip = exifOrientation == ExifInterface.ORIENTATION_FLIP_HORIZONTAL ||
                         exifOrientation == ExifInterface.ORIENTATION_FLIP_VERTICAL ||
@@ -310,7 +332,8 @@ public class CameraUtils {
                 Matrix matrix = new Matrix();
                 matrix.setRotate(orientation);
                 Bitmap temp = bitmap;
-                bitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);
+                bitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(),
+                        bitmap.getHeight(), matrix, true);
                 temp.recycle();
             }
         } catch (OutOfMemoryError e) {

cameraview/src/main/java/com/otaliastudios/cameraview/CameraView.java

@@ -167,25 +167,36 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
         if (mInEditor) return;
 
         setWillNotDraw(false);
-        TypedArray a = context.getTheme().obtainStyledAttributes(attrs, R.styleable.CameraView, 0, 0);
+        TypedArray a = context.getTheme().obtainStyledAttributes(attrs, R.styleable.CameraView,
+                0, 0);
         ControlParser controls = new ControlParser(context, a);
 
         // Self managed
-        boolean playSounds = a.getBoolean(R.styleable.CameraView_cameraPlaySounds, DEFAULT_PLAY_SOUNDS);
-        boolean useDeviceOrientation = a.getBoolean(R.styleable.CameraView_cameraUseDeviceOrientation, DEFAULT_USE_DEVICE_ORIENTATION);
+        boolean playSounds = a.getBoolean(R.styleable.CameraView_cameraPlaySounds,
+                DEFAULT_PLAY_SOUNDS);
+        boolean useDeviceOrientation = a.getBoolean(
+                R.styleable.CameraView_cameraUseDeviceOrientation, DEFAULT_USE_DEVICE_ORIENTATION);
         mExperimental = a.getBoolean(R.styleable.CameraView_cameraExperimental, false);
         mPreview = controls.getPreview();
         mEngine = controls.getEngine();
 
         // Camera engine params
-        int gridColor = a.getColor(R.styleable.CameraView_cameraGridColor, GridLinesLayout.DEFAULT_COLOR);
-        long videoMaxSize = (long) a.getFloat(R.styleable.CameraView_cameraVideoMaxSize, 0);
-        int videoMaxDuration = a.getInteger(R.styleable.CameraView_cameraVideoMaxDuration, 0);
+        int gridColor = a.getColor(R.styleable.CameraView_cameraGridColor,
+                GridLinesLayout.DEFAULT_COLOR);
+        long videoMaxSize = (long) a.getFloat(R.styleable.CameraView_cameraVideoMaxSize,
+                0);
+        int videoMaxDuration = a.getInteger(R.styleable.CameraView_cameraVideoMaxDuration,
+                0);
         int videoBitRate = a.getInteger(R.styleable.CameraView_cameraVideoBitRate, 0);
         int audioBitRate = a.getInteger(R.styleable.CameraView_cameraAudioBitRate, 0);
-        long autoFocusResetDelay = (long) a.getInteger(R.styleable.CameraView_cameraAutoFocusResetDelay, (int) DEFAULT_AUTOFOCUS_RESET_DELAY_MILLIS);
-        boolean pictureMetering = a.getBoolean(R.styleable.CameraView_cameraPictureMetering, DEFAULT_PICTURE_METERING);
-        boolean pictureSnapshotMetering = a.getBoolean(R.styleable.CameraView_cameraPictureSnapshotMetering, DEFAULT_PICTURE_SNAPSHOT_METERING);
+        long autoFocusResetDelay = (long) a.getInteger(
+                R.styleable.CameraView_cameraAutoFocusResetDelay,
+                (int) DEFAULT_AUTOFOCUS_RESET_DELAY_MILLIS);
+        boolean pictureMetering = a.getBoolean(R.styleable.CameraView_cameraPictureMetering,
+                DEFAULT_PICTURE_METERING);
+        boolean pictureSnapshotMetering = a.getBoolean(
+                R.styleable.CameraView_cameraPictureSnapshotMetering,
+                DEFAULT_PICTURE_SNAPSHOT_METERING);
 
         // Size selectors and gestures
         SizeSelectorParser sizeSelectors = new SizeSelectorParser(a);
@@ -265,7 +276,8 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
     private void doInstantiateEngine() {
         LOG.w("doInstantiateEngine:", "instantiating. engine:", mEngine);
         mCameraEngine = instantiateCameraEngine(mEngine, mCameraCallbacks);
-        LOG.w("doInstantiateEngine:", "instantiated. engine:", mCameraEngine.getClass().getSimpleName());
+        LOG.w("doInstantiateEngine:", "instantiated. engine:",
+                mCameraEngine.getClass().getSimpleName());
         mCameraEngine.setOverlay(mOverlayLayout);
     }
 
@@ -278,7 +290,8 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
     void doInstantiatePreview() {
         LOG.w("doInstantiateEngine:", "instantiating. preview:", mPreview);
         mCameraPreview = instantiatePreview(mPreview, getContext(), this);
-        LOG.w("doInstantiateEngine:", "instantiated. preview:", mCameraPreview.getClass().getSimpleName());
+        LOG.w("doInstantiateEngine:", "instantiated. preview:",
+                mCameraPreview.getClass().getSimpleName());
         mCameraEngine.setPreview(mCameraPreview);
         if (mPendingFilter != null) {
             setFilter(mPendingFilter);
@@ -294,8 +307,11 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
      * @return the engine
      */
     @NonNull
-    protected CameraEngine instantiateCameraEngine(@NonNull Engine engine, @NonNull CameraEngine.Callback callback) {
-        if (mExperimental && engine == Engine.CAMERA2 && Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
+    protected CameraEngine instantiateCameraEngine(@NonNull Engine engine,
+                                                   @NonNull CameraEngine.Callback callback) {
+        if (mExperimental
+                && engine == Engine.CAMERA2
+                && Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
             return new Camera2Engine(callback);
         } else {
             mEngine = Engine.CAMERA1;
@@ -312,7 +328,9 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
      * @return the preview
      */
     @NonNull
-    protected CameraPreview instantiatePreview(@NonNull Preview preview, @NonNull Context context, @NonNull ViewGroup container) {
+    protected CameraPreview instantiatePreview(@NonNull Preview preview,
+                                               @NonNull Context context,
+                                               @NonNull ViewGroup container) {
         switch (preview) {
             case SURFACE:
                 return new SurfaceCameraPreview(context, container);
@@ -414,13 +432,15 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
             if (heightMode == AT_MOST && lp.height == MATCH_PARENT) heightMode = EXACTLY;
         }
 
-        LOG.i("onMeasure:", "requested dimensions are", "(" + widthValue + "[" + ms(widthMode) + "]x" +
-                heightValue + "[" + ms(heightMode) + "])");
-        LOG.i("onMeasure:",  "previewSize is", "(" + previewWidth + "x" + previewHeight + ")");
+        LOG.i("onMeasure:", "requested dimensions are (" + widthValue + "[" + ms(widthMode)
+                + "]x" + heightValue + "[" + ms(heightMode) + "])");
+        LOG.i("onMeasure:",  "previewSize is", "(" + previewWidth + "x"
+                + previewHeight + ")");
 
-        // (1) If we have fixed dimensions (either 300dp or MATCH_PARENT), there's nothing we should do,
-        // other than respect it. The preview will eventually be cropped at the sides (by PreviewImpl scaling)
-        // except the case in which these fixed dimensions manage to fit exactly the preview aspect ratio.
+        // (1) If we have fixed dimensions (either 300dp or MATCH_PARENT), there's nothing we
+        // should do, other than respect it. The preview will eventually be cropped at the sides
+        // (by Preview scaling) except the case in which these fixed dimensions manage to fit
+        // exactly the preview aspect ratio.
         if (widthMode == EXACTLY && heightMode == EXACTLY) {
             LOG.i("onMeasure:", "both are MATCH_PARENT or fixed value. We adapt.",
                     "This means CROP_CENTER.", "(" + widthValue + "x" + heightValue + ")");
@@ -440,8 +460,8 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
             return;
         }
 
-        // It's sure now that at least one dimension can be determined (either because EXACTLY or AT_MOST).
-        // This starts to seem a pleasant situation.
+        // It's sure now that at least one dimension can be determined (either because EXACTLY
+        // or AT_MOST). This starts to seem a pleasant situation.
 
         // (3) If one of the dimension is completely free (e.g. in a scrollable container),
         // take the other and fit the ratio.
@@ -457,16 +477,17 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
                 width = widthValue;
                 height = Math.round(width * ratio);
             }
-            LOG.i("onMeasure:", "one dimension was free, we adapted it to fit the aspect ratio.",
+            LOG.i("onMeasure:", "one dimension was free, we adapted it to fit the ratio.",
                     "(" + width + "x" + height + ")");
             super.onMeasure(MeasureSpec.makeMeasureSpec(width, EXACTLY),
                     MeasureSpec.makeMeasureSpec(height, EXACTLY));
             return;
         }
 
-        // (4) At this point both dimensions are either AT_MOST-AT_MOST, EXACTLY-AT_MOST or AT_MOST-EXACTLY.
-        // Let's manage this sanely. If only one is EXACTLY, we can TRY to fit the aspect ratio,
-        // but it is not guaranteed to succeed. It depends on the AT_MOST value of the other dimensions.
+        // (4) At this point both dimensions are either AT_MOST-AT_MOST, EXACTLY-AT_MOST or
+        // AT_MOST-EXACTLY. Let's manage this sanely. If only one is EXACTLY, we can TRY to fit
+        // the aspect ratio, but it is not guaranteed to succeed. It depends on the AT_MOST
+        // value of the other dimensions.
         if (widthMode == EXACTLY || heightMode == EXACTLY) {
             boolean freeWidth = widthMode == AT_MOST;
             int height, width;
@@ -724,8 +745,10 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
         boolean needsCamera = true;
         boolean needsAudio = audio == Audio.ON || audio == Audio.MONO || audio == Audio.STEREO;
 
-        needsCamera = needsCamera && c.checkSelfPermission(Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED;
-        needsAudio = needsAudio && c.checkSelfPermission(Manifest.permission.RECORD_AUDIO) != PackageManager.PERMISSION_GRANTED;
+        needsCamera = needsCamera && c.checkSelfPermission(Manifest.permission.CAMERA)
+                != PackageManager.PERMISSION_GRANTED;
+        needsAudio = needsAudio && c.checkSelfPermission(Manifest.permission.RECORD_AUDIO)
+                != PackageManager.PERMISSION_GRANTED;
 
         if (needsCamera || needsAudio) {
             requestPermissions(needsCamera, needsAudio);
@@ -742,13 +765,14 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
         if (audio == Audio.ON || audio == Audio.MONO || audio == Audio.STEREO) {
             try {
                 PackageManager manager = getContext().getPackageManager();
-                PackageInfo info = manager.getPackageInfo(getContext().getPackageName(), PackageManager.GET_PERMISSIONS);
+                PackageInfo info = manager.getPackageInfo(getContext().getPackageName(),
+                        PackageManager.GET_PERMISSIONS);
                 for (String requestedPermission : info.requestedPermissions) {
                     if (requestedPermission.equals(Manifest.permission.RECORD_AUDIO)) {
                         return;
                     }
                 }
-                String message = LOG.e("Permission error:", "When audio is enabled (Audio.ON),",
+                String message = LOG.e("Permission error: when audio is enabled (Audio.ON)" +
                         " the RECORD_AUDIO permission should be added to the app manifest file.");
                 throw new IllegalStateException(message);
             } catch (PackageManager.NameNotFoundException e) {
@@ -1272,8 +1296,12 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
      * @param y should be between 0 and getHeight()
      */
     public void startAutoFocus(float x, float y) {
-        if (x < 0 || x > getWidth()) throw new IllegalArgumentException("x should be >= 0 and <= getWidth()");
-        if (y < 0 || y > getHeight()) throw new IllegalArgumentException("y should be >= 0 and <= getHeight()");
+        if (x < 0 || x > getWidth()) {
+            throw new IllegalArgumentException("x should be >= 0 and <= getWidth()");
+        }
+        if (y < 0 || y > getHeight()) {
+            throw new IllegalArgumentException("y should be >= 0 and <= getHeight()");
+        }
         mCameraEngine.startAutoFocus(null, new PointF(x, y));
     }
 
@@ -1510,9 +1538,6 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
      * This will trigger {@link CameraListener#onPictureTaken(PictureResult)} if a listener
      * was registered.
      *
-     * Note that if sessionType is {@link Mode#VIDEO}, this
-     * might fall back to {@link #takePictureSnapshot()} (that is, we might capture a preview frame).
-     *
      * @see #takePictureSnapshot()
      */
     public void takePicture() {
@@ -2000,7 +2025,8 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
         }
 
         @Override
-        public void dispatchOnFocusStart(@Nullable final Gesture gesture, @NonNull final PointF point) {
+        public void dispatchOnFocusStart(@Nullable final Gesture gesture,
+                                         @NonNull final PointF point) {
             mLogger.i("dispatchOnFocusStart", gesture, point);
             mUiHandler.post(new Runnable() {
                 @Override
@@ -2020,7 +2046,8 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
         }
 
         @Override
-        public void dispatchOnFocusEnd(@Nullable final Gesture gesture, final boolean success,
+        public void dispatchOnFocusEnd(@Nullable final Gesture gesture,
+                                       final boolean success,
                                        @NonNull final PointF point) {
             mLogger.i("dispatchOnFocusEnd", gesture, success, point);
             mUiHandler.post(new Runnable() {
@@ -2096,7 +2123,8 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
 
         @Override
         public void dispatchFrame(@NonNull final Frame frame) {
-            // The getTime() below might crash if developers incorrectly release frames asynchronously.
+            // The getTime() below might crash if developers incorrectly release
+            // frames asynchronously.
             mLogger.v("dispatchFrame:", frame.getTime(), "processors:", mFrameProcessors.size());
             if (mFrameProcessors.isEmpty()) {
                 // Mark as released. This instance will be reused.
@@ -2106,7 +2134,8 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
                 mFrameProcessorsHandler.run(new Runnable() {
                     @Override
                     public void run() {
-                        mLogger.v("dispatchFrame: dispatching", frame.getTime(), "to processors.");
+                        mLogger.v("dispatchFrame: dispatching", frame.getTime(),
+                                "to processors.");
                         for (FrameProcessor processor : mFrameProcessors) {
                             try {
                                 processor.process(frame);
@@ -2173,7 +2202,6 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
         return super.generateLayoutParams(attributeSet);
     }
 
-    // We don't support removeView on overlays for now.
     @Override
     public void addView(View child, int index, ViewGroup.LayoutParams params) {
         if (!mInEditor && mOverlayLayout.isOverlay(params)) {
@@ -2183,6 +2211,16 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
         }
     }
 
+    @Override
+    public void removeView(View view) {
+        ViewGroup.LayoutParams params = view.getLayoutParams();
+        if (!mInEditor && params != null && mOverlayLayout.isOverlay(params)) {
+            mOverlayLayout.removeView(view);
+        } else {
+            super.removeView(view);
+        }
+    }
+
     //endregion
 
     //region Filters
@@ -2198,8 +2236,8 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
      * Use {@link NoFilter} to clear the existing filter,
      * and take a look at the {@link Filters} class for commonly used filters.
      *
-     * This method will throw an exception if the current preview does not support real-time filters.
-     * Make sure you use {@link Preview#GL_SURFACE} (the default).
+     * This method will throw an exception if the current preview does not support real-time
+     * filters. Make sure you use {@link Preview#GL_SURFACE} (the default).
      *
      * @see Filters
      * @param filter a new filter
@@ -2207,20 +2245,32 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
     public void setFilter(@NonNull Filter filter) {
         if (mCameraPreview == null) {
             mPendingFilter = filter;
-        } else if (!(filter instanceof NoFilter) && !mExperimental) {
-            throw new RuntimeException("Filters are an experimental features and need the experimental flag set.");
-        } else if (mCameraPreview instanceof FilterCameraPreview) {
-            ((FilterCameraPreview) mCameraPreview).setFilter(filter);
         } else {
-            throw new RuntimeException("Filters are only supported by the GL_SURFACE preview. Current:" + mPreview);
+            boolean isNoFilter = filter instanceof NoFilter;
+            boolean isFilterPreview = mCameraPreview instanceof FilterCameraPreview;
+            // If not experimental, we only allow NoFilter (called on creation).
+            if (!isNoFilter && !mExperimental) {
+                throw new RuntimeException("Filters are an experimental features and" +
+                        " need the experimental flag set.");
+            }
+            // If not a filter preview, we only allow NoFilter (called on creation).
+            if (!isNoFilter && !isFilterPreview) {
+                throw new RuntimeException("Filters are only supported by the GL_SURFACE preview." +
+                        " Current preview:" + mPreview);
+            }
+            // If we have a filter preview, apply.
+            if (isFilterPreview) {
+                ((FilterCameraPreview) mCameraPreview).setFilter(filter);
+            }
+            // No-op: !isFilterPreview && isNoPreview
         }
     }
 
     /**
      * Returns the current real-time filter applied to the camera preview.
      *
-     * This method will throw an exception if the current preview does not support real-time filters.
-     * Make sure you use {@link Preview#GL_SURFACE} (the default).
+     * This method will throw an exception if the current preview does not support real-time
+     * filters. Make sure you use {@link Preview#GL_SURFACE} (the default).
      *
      * @see #setFilter(Filter)
      * @return the current filter
@@ -2228,13 +2278,15 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
     @NonNull
     public Filter getFilter() {
         if (!mExperimental) {
-            throw new RuntimeException("Filters are an experimental features and need the experimental flag set.");
+            throw new RuntimeException("Filters are an experimental features and need " +
+                    "the experimental flag set.");
         } else if (mCameraPreview == null) {
             return mPendingFilter;
         } else if (mCameraPreview instanceof FilterCameraPreview) {
             return ((FilterCameraPreview) mCameraPreview).getCurrentFilter();
         } else {
-            throw new RuntimeException("Filters are only supported by the GL_SURFACE preview. Current:" + mPreview);
+            throw new RuntimeException("Filters are only supported by the GL_SURFACE preview. " +
+                    "Current:" + mPreview);
         }
 
     }

cameraview/src/main/java/com/otaliastudios/cameraview/PictureResult.java

@@ -137,7 +137,8 @@ public class PictureResult {
      * @param callback a callback to be notified of image decoding
      */
     public void toBitmap(int maxWidth, int maxHeight, @NonNull BitmapCallback callback) {
-        CameraUtils.decodeBitmap(getData(), maxWidth, maxHeight, new BitmapFactory.Options(), rotation, callback);
+        CameraUtils.decodeBitmap(getData(), maxWidth, maxHeight, new BitmapFactory.Options(),
+                rotation, callback);
     }
 
     /**

cameraview/src/main/java/com/otaliastudios/cameraview/VideoResult.java

@@ -185,7 +185,8 @@ public class VideoResult {
 
     /**
      * Returns the reason why the recording was stopped.
-     * @return one of {@link #REASON_USER}, {@link #REASON_MAX_DURATION_REACHED} or {@link #REASON_MAX_SIZE_REACHED}.
+     * @return one of {@link #REASON_USER}, {@link #REASON_MAX_DURATION_REACHED}
+     *         or {@link #REASON_MAX_SIZE_REACHED}.
      */
     public int getTerminationReason() {
         return endReason;

cameraview/src/main/java/com/otaliastudios/cameraview/controls/ControlParser.java

@@ -25,16 +25,19 @@ public class ControlParser {
     private int engine;
 
     public ControlParser(@NonNull Context context, @NonNull TypedArray array) {
-        this.preview = array.getInteger(R.styleable.CameraView_cameraPreview, Preview.DEFAULT.value());
-        this.facing = array.getInteger(R.styleable.CameraView_cameraFacing, Facing.DEFAULT(context).value());
-        this.flash = array.getInteger(R.styleable.CameraView_cameraFlash, Flash.DEFAULT.value());
-        this.grid = array.getInteger(R.styleable.CameraView_cameraGrid, Grid.DEFAULT.value());
-        this.whiteBalance = array.getInteger(R.styleable.CameraView_cameraWhiteBalance, WhiteBalance.DEFAULT.value());
-        this.mode = array.getInteger(R.styleable.CameraView_cameraMode, Mode.DEFAULT.value());
-        this.hdr = array.getInteger(R.styleable.CameraView_cameraHdr, Hdr.DEFAULT.value());
-        this.audio = array.getInteger(R.styleable.CameraView_cameraAudio, Audio.DEFAULT.value());
-        this.videoCodec = array.getInteger(R.styleable.CameraView_cameraVideoCodec, VideoCodec.DEFAULT.value());
-        this.engine = array.getInteger(R.styleable.CameraView_cameraEngine, Engine.DEFAULT.value());
+        preview = array.getInteger(R.styleable.CameraView_cameraPreview, Preview.DEFAULT.value());
+        facing = array.getInteger(R.styleable.CameraView_cameraFacing,
+                Facing.DEFAULT(context).value());
+        flash = array.getInteger(R.styleable.CameraView_cameraFlash, Flash.DEFAULT.value());
+        grid = array.getInteger(R.styleable.CameraView_cameraGrid, Grid.DEFAULT.value());
+        whiteBalance = array.getInteger(R.styleable.CameraView_cameraWhiteBalance,
+                WhiteBalance.DEFAULT.value());
+        mode = array.getInteger(R.styleable.CameraView_cameraMode, Mode.DEFAULT.value());
+        hdr = array.getInteger(R.styleable.CameraView_cameraHdr, Hdr.DEFAULT.value());
+        audio = array.getInteger(R.styleable.CameraView_cameraAudio, Audio.DEFAULT.value());
+        videoCodec = array.getInteger(R.styleable.CameraView_cameraVideoCodec,
+                VideoCodec.DEFAULT.value());
+        engine = array.getInteger(R.styleable.CameraView_cameraEngine, Engine.DEFAULT.value());
     }
 
     @NonNull

cameraview/src/main/java/com/otaliastudios/cameraview/engine/Camera1Engine.java

@@ -76,7 +76,8 @@ public class Camera1Engine extends CameraEngine implements
     public void onError(int error, Camera camera) {
         if (error == Camera.CAMERA_ERROR_SERVER_DIED) {
             // Looks like this is recoverable.
-            LOG.w("Recoverable error inside the onError callback.", "CAMERA_ERROR_SERVER_DIED");
+            LOG.w("Recoverable error inside the onError callback.",
+                    "CAMERA_ERROR_SERVER_DIED");
             restart();
             return;
         }
@@ -118,7 +119,10 @@ public class Camera1Engine extends CameraEngine implements
     @Override
     protected boolean collectCameraInfo(@NonNull Facing facing) {
         int internalFacing = mMapper.mapFacing(facing);
-        LOG.i("collectCameraInfo", "Facing:", facing, "Internal:", internalFacing, "Cameras:", Camera.getNumberOfCameras());
+        LOG.i("collectCameraInfo",
+                "Facing:", facing,
+                "Internal:", internalFacing,
+                "Cameras:", Camera.getNumberOfCameras());
         Camera.CameraInfo cameraInfo = new Camera.CameraInfo();
         for (int i = 0, count = Camera.getNumberOfCameras(); i < count; i++) {
             Camera.getCameraInfo(i, cameraInfo);
@@ -150,10 +154,12 @@ public class Camera1Engine extends CameraEngine implements
         // Set parameters that might have been set before the camera was opened.
         LOG.i("onStartEngine:", "Applying default parameters.");
         Camera.Parameters params = mCamera.getParameters();
-        mCameraOptions = new CameraOptions(params, getAngles().flip(Reference.SENSOR, Reference.VIEW));
+        mCameraOptions = new CameraOptions(params, getAngles()
+                .flip(Reference.SENSOR, Reference.VIEW));
         applyAllParameters(params);
         mCamera.setParameters(params);
-        mCamera.setDisplayOrientation(getAngles().offset(Reference.SENSOR, Reference.VIEW, Axis.ABSOLUTE)); // <- not allowed during preview
+        mCamera.setDisplayOrientation(getAngles().offset(Reference.SENSOR, Reference.VIEW,
+                Axis.ABSOLUTE)); // <- not allowed during preview
         LOG.i("onStartEngine:", "Ended");
         return Tasks.forResult(null);
     }
@@ -194,14 +200,19 @@ public class Camera1Engine extends CameraEngine implements
         mPreview.setStreamSize(previewSize.getWidth(), previewSize.getHeight());
 
         Camera.Parameters params = mCamera.getParameters();
-        params.setPreviewFormat(ImageFormat.NV21); // should be the default, but let's make sure, since YuvImage will only support this & a few others
-        params.setPreviewSize(mPreviewStreamSize.getWidth(), mPreviewStreamSize.getHeight()); // not allowed during preview
+        // NV21 should be the default, but let's make sure, since YuvImage will only support this
+        // and a few others
+        params.setPreviewFormat(ImageFormat.NV21);
+        // setPreviewSize is not allowed during preview
+        params.setPreviewSize(mPreviewStreamSize.getWidth(), mPreviewStreamSize.getHeight());
         if (getMode() == Mode.PICTURE) {
-            params.setPictureSize(mCaptureSize.getWidth(), mCaptureSize.getHeight()); // allowed during preview
+            // setPictureSize is allowed during preview
+            params.setPictureSize(mCaptureSize.getWidth(), mCaptureSize.getHeight());
         } else {
-            // mCaptureSize in this case is a video size. The available video sizes are not necessarily
-            // a subset of the picture sizes, so we can't use the mCaptureSize value: it might crash.
-            // However, the setPictureSize() passed here is useless : we don't allow HQ pictures in video mode.
+            // mCaptureSize in this case is a video size. The available video sizes are not
+            // necessarily a subset of the picture sizes, so we can't use the mCaptureSize value:
+            // it might crash. However, the setPictureSize() passed here is useless : we don't allow
+            // HQ pictures in video mode.
             // While this might be lifted in the future, for now, just use a picture capture size.
             Size pictureSize = computeCaptureSize(Mode.PICTURE);
             params.setPictureSize(pictureSize.getWidth(), pictureSize.getHeight());
@@ -298,7 +309,8 @@ public class Camera1Engine extends CameraEngine implements
     @WorkerThread
     @Override
     protected void onTakePicture(@NonNull PictureResult.Stub stub, boolean doMetering) {
-        stub.rotation = getAngles().offset(Reference.SENSOR, Reference.OUTPUT, Axis.RELATIVE_TO_SENSOR);
+        stub.rotation = getAngles().offset(Reference.SENSOR, Reference.OUTPUT,
+                Axis.RELATIVE_TO_SENSOR);
         stub.size = getPictureSize(Reference.OUTPUT);
         mPictureRecorder = new Full1PictureRecorder(stub, Camera1Engine.this, mCamera);
         mPictureRecorder.take();
@@ -306,10 +318,13 @@ public class Camera1Engine extends CameraEngine implements
 
     @WorkerThread
     @Override
-    protected void onTakePictureSnapshot(@NonNull PictureResult.Stub stub, @NonNull AspectRatio outputRatio, boolean doMetering) {
-        stub.size = getUncroppedSnapshotSize(Reference.OUTPUT); // Not the real size: it will be cropped to match the view ratio
-        stub.rotation = getAngles().offset(Reference.SENSOR, Reference.OUTPUT, Axis.RELATIVE_TO_SENSOR); // Actually it will be rotated and set to 0.
-
+    protected void onTakePictureSnapshot(@NonNull PictureResult.Stub stub,
+                                         @NonNull AspectRatio outputRatio,
+                                         boolean doMetering) {
+        // Not the real size: it will be cropped to match the view ratio
+        stub.size = getUncroppedSnapshotSize(Reference.OUTPUT);
+        // Actually it will be rotated and set to 0.
+        stub.rotation = getAngles().offset(Reference.SENSOR, Reference.OUTPUT, Axis.RELATIVE_TO_SENSOR);
         if (mPreview instanceof GlCameraPreview && Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
             mPictureRecorder = new SnapshotGlPictureRecorder(stub, this, (GlCameraPreview) mPreview, outputRatio);
         } else {
@@ -324,8 +339,10 @@ public class Camera1Engine extends CameraEngine implements
 
     @Override
     protected void onTakeVideo(@NonNull VideoResult.Stub stub) {
-        stub.rotation = getAngles().offset(Reference.SENSOR, Reference.OUTPUT, Axis.RELATIVE_TO_SENSOR);
-        stub.size = getAngles().flip(Reference.SENSOR, Reference.OUTPUT) ? mCaptureSize.flip() : mCaptureSize;
+        stub.rotation = getAngles().offset(Reference.SENSOR, Reference.OUTPUT,
+                Axis.RELATIVE_TO_SENSOR);
+        stub.size = getAngles().flip(Reference.SENSOR, Reference.OUTPUT) ? mCaptureSize.flip()
+                : mCaptureSize;
         // Unlock the camera and start recording.
         try {
             mCamera.unlock();
@@ -342,12 +359,13 @@ public class Camera1Engine extends CameraEngine implements
     @SuppressLint("NewApi")
     @WorkerThread
     @Override
-    protected void onTakeVideoSnapshot(@NonNull VideoResult.Stub stub, @NonNull AspectRatio outputRatio) {
+    protected void onTakeVideoSnapshot(@NonNull VideoResult.Stub stub,
+                                       @NonNull AspectRatio outputRatio) {
         if (!(mPreview instanceof GlCameraPreview)) {
-            throw new IllegalStateException("Video snapshots are only supported with GlCameraPreview.");
+            throw new IllegalStateException("Video snapshots are only supported with GL_SURFACE.");
         }
         if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN_MR2) {
-            throw new IllegalStateException("Video snapshots are only supported starting from API 18.");
+            throw new IllegalStateException("Video snapshots are only supported on API 18+.");
         }
         GlCameraPreview glPreview = (GlCameraPreview) mPreview;
         Size outputSize = getUncroppedSnapshotSize(Reference.OUTPUT);
@@ -370,7 +388,8 @@ public class Camera1Engine extends CameraEngine implements
         LOG.i("onTakeVideoSnapshot", "rotation:", stub.rotation, "size:", stub.size);
 
         // Start.
-        mVideoRecorder = new SnapshotVideoRecorder(Camera1Engine.this, glPreview, getOverlay(), stub.rotation);
+        mVideoRecorder = new SnapshotVideoRecorder(Camera1Engine.this, glPreview,
+                getOverlay(), stub.rotation);
         mVideoRecorder.start(stub);
     }
 
@@ -494,7 +513,8 @@ public class Camera1Engine extends CameraEngine implements
         });
     }
 
-    private boolean applyWhiteBalance(@NonNull Camera.Parameters params, @NonNull WhiteBalance oldWhiteBalance) {
+    private boolean applyWhiteBalance(@NonNull Camera.Parameters params,
+                                      @NonNull WhiteBalance oldWhiteBalance) {
         if (mCameraOptions.supports(mWhiteBalance)) {
             params.setWhiteBalance(mMapper.mapWhiteBalance(mWhiteBalance));
             return true;
@@ -573,7 +593,8 @@ public class Camera1Engine extends CameraEngine implements
                     if (applyExposureCorrection(params, old)) {
                         mCamera.setParameters(params);
                         if (notify) {
-                            mCallback.dispatchOnExposureCorrectionChanged(mExposureCorrectionValue, bounds, points);
+                            mCallback.dispatchOnExposureCorrectionChanged(mExposureCorrectionValue,
+                                    bounds, points);
                         }
                     }
                 }
@@ -582,7 +603,8 @@ public class Camera1Engine extends CameraEngine implements
         });
     }
 
-    private boolean applyExposureCorrection(@NonNull Camera.Parameters params, float oldExposureCorrection) {
+    private boolean applyExposureCorrection(@NonNull Camera.Parameters params,
+                                            float oldExposureCorrection) {
         if (mCameraOptions.isExposureCorrectionSupported()) {
             // Just make sure we're inside boundaries.
             float max = mCameraOptions.getExposureCorrectionMaxValue();
@@ -591,7 +613,8 @@ public class Camera1Engine extends CameraEngine implements
             val = val < min ? min : val > max ? max : val; // cap
             mExposureCorrectionValue = val;
             // Apply.
-            int indexValue = (int) (mExposureCorrectionValue / params.getExposureCompensationStep());
+            int indexValue = (int) (mExposureCorrectionValue
+                    / params.getExposureCompensationStep());
             params.setExposureCompensation(indexValue);
             return true;
         }
@@ -692,7 +715,8 @@ public class Camera1Engine extends CameraEngine implements
                         viewWidthF, viewHeightF, offset);
                 List<Camera.Area> meteringAreas1 = meteringAreas2.subList(0, 1);
 
-                // At this point we are sure that camera supports auto focus... right? Look at CameraView.onTouchEvent().
+                // At this point we are sure that camera supports auto focus... right?
+                // Look at CameraView.onTouchEvent().
                 Camera.Parameters params = mCamera.getParameters();
                 int maxAF = params.getMaxNumFocusAreas();
                 int maxAE = params.getMaxNumMeteringAreas();
@@ -702,8 +726,8 @@ public class Camera1Engine extends CameraEngine implements
                 mCamera.setParameters(params);
                 mCallback.dispatchOnFocusStart(gesture, p);
 
-                // The auto focus callback is not guaranteed to be called, but we really want it to be.
-                // So we remove the old runnable if still present and post a new one.
+                // The auto focus callback is not guaranteed to be called, but we really want it
+                // to be. So we remove the old runnable if still present and post a new one.
                 if (mFocusEndRunnable != null) mHandler.remove(mFocusEndRunnable);
                 mFocusEndRunnable = new Runnable() {
                     @Override
@@ -778,7 +802,11 @@ public class Camera1Engine extends CameraEngine implements
         int bottom = (int) Math.min(centerY + delta, 1000);
         int left = (int) Math.max(centerX - delta, -1000);
         int right = (int) Math.min(centerX + delta, 1000);
-        LOG.i("focus:", "computeMeteringArea:", "top:", top, "left:", left, "bottom:", bottom, "right:", right);
+        LOG.i("focus:", "computeMeteringArea:",
+                "top:", top,
+                "left:", left,
+                "bottom:", bottom,
+                "right:", right);
         return new Rect(left, top, right, bottom);
     }
 

cameraview/src/main/java/com/otaliastudios/cameraview/engine/Camera2Engine.java

@@ -27,6 +27,7 @@ import android.view.SurfaceHolder;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.annotation.RequiresApi;
+import androidx.annotation.VisibleForTesting;
 import androidx.annotation.WorkerThread;
 
 import com.google.android.gms.tasks.Task;
@@ -81,7 +82,7 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
 
     private static final int FRAME_PROCESSING_FORMAT = ImageFormat.NV21;
     private static final int FRAME_PROCESSING_INPUT_FORMAT = ImageFormat.YUV_420_888;
-    private static final long METER_TIMEOUT = 2500;
+    @VisibleForTesting static final long METER_TIMEOUT = 2500;
 
     private final CameraManager mManager;
     private String mCameraId;
@@ -96,17 +97,19 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
     private Size mFrameProcessingSize;
     private ImageReader mFrameProcessingReader; // need this or the reader surface is collected
     private final WorkerHandler mFrameConversionHandler;
+    private final Object mFrameProcessingImageLock = new Object();
     private Surface mFrameProcessingSurface;
 
     // Preview
     private Surface mPreviewStreamSurface;
 
     // Video recording
-    private VideoResult.Stub mFullVideoPendingStub; // When takeVideo is called, we have to reset the session.
+    // When takeVideo is called, we restart the session.
+    private VideoResult.Stub mFullVideoPendingStub;
 
     // Picture capturing
     private ImageReader mPictureReader;
-    private final boolean mPictureCaptureStopsPreview = false; // can make configurable at some point
+    private final boolean mPictureCaptureStopsPreview = false; // can be configurable at some point
 
     // Actions
     private final List<Action> mActions = new ArrayList<>();
@@ -135,32 +138,46 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
         return value == null ? fallback : value;
     }
 
-    @SuppressWarnings("DuplicateBranchesInSwitch")
     @NonNull
     private CameraException createCameraException(@NonNull CameraAccessException exception) {
         int reason;
         switch (exception.getReason()) {
-            case CameraAccessException.CAMERA_DISABLED: reason = CameraException.REASON_FAILED_TO_CONNECT; break;
-            case CameraAccessException.CAMERA_ERROR: reason = CameraException.REASON_DISCONNECTED; break;
-            case CameraAccessException.CAMERA_DISCONNECTED: reason = CameraException.REASON_DISCONNECTED; break;
-            case CameraAccessException.CAMERA_IN_USE: reason = CameraException.REASON_FAILED_TO_CONNECT; break;
-            case CameraAccessException.MAX_CAMERAS_IN_USE: reason = CameraException.REASON_FAILED_TO_CONNECT; break;
-            default: reason = CameraException.REASON_UNKNOWN; break;
+            case CameraAccessException.CAMERA_DISABLED:
+            case CameraAccessException.CAMERA_IN_USE:
+            case CameraAccessException.MAX_CAMERAS_IN_USE: {
+                reason = CameraException.REASON_FAILED_TO_CONNECT;
+                break;
+            }
+            case CameraAccessException.CAMERA_ERROR:
+            case CameraAccessException.CAMERA_DISCONNECTED: {
+                reason = CameraException.REASON_DISCONNECTED;
+                break;
+            }
+            default: {
+                reason = CameraException.REASON_UNKNOWN;
+                break;
+            }
         }
         return new CameraException(exception, reason);
     }
 
-    @SuppressWarnings("DuplicateBranchesInSwitch")
     @NonNull
     private CameraException createCameraException(int stateCallbackError) {
         int reason;
         switch (stateCallbackError) {
-            case CameraDevice.StateCallback.ERROR_CAMERA_DISABLED: reason = CameraException.REASON_FAILED_TO_CONNECT; break; // Device policy
-            case CameraDevice.StateCallback.ERROR_CAMERA_DEVICE: reason = CameraException.REASON_FAILED_TO_CONNECT; break; // Fatal error
-            case CameraDevice.StateCallback.ERROR_CAMERA_SERVICE: reason = CameraException.REASON_FAILED_TO_CONNECT; break; // Fatal error, device might have to be restarted
-            case CameraDevice.StateCallback.ERROR_CAMERA_IN_USE: reason = CameraException.REASON_FAILED_TO_CONNECT; break;
-            case CameraDevice.StateCallback.ERROR_MAX_CAMERAS_IN_USE: reason = CameraException.REASON_FAILED_TO_CONNECT; break;
-            default: reason = CameraException.REASON_UNKNOWN; break;
+            case CameraDevice.StateCallback.ERROR_CAMERA_DISABLED: // Device policy
+            case CameraDevice.StateCallback.ERROR_CAMERA_DEVICE: // Fatal error
+            case CameraDevice.StateCallback.ERROR_CAMERA_SERVICE: // Fatal error, might have to
+                // restart the device
+            case CameraDevice.StateCallback.ERROR_CAMERA_IN_USE:
+            case CameraDevice.StateCallback.ERROR_MAX_CAMERAS_IN_USE: {
+                reason = CameraException.REASON_FAILED_TO_CONNECT;
+                break;
+            }
+            default: {
+                reason = CameraException.REASON_UNKNOWN;
+                break;
+            }
         }
         return new CameraException(reason);
     }
@@ -173,7 +190,8 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
      */
     @SuppressWarnings("UnusedReturnValue")
     @NonNull
-    private CaptureRequest.Builder createRepeatingRequestBuilder(int template) throws CameraAccessException {
+    private CaptureRequest.Builder createRepeatingRequestBuilder(int template)
+            throws CameraAccessException {
         CaptureRequest.Builder oldBuilder = mRepeatingRequestBuilder;
         mRepeatingRequestBuilder = mCamera.createCaptureRequest(template);
         mRepeatingRequestBuilder.setTag(template);
@@ -199,8 +217,7 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
     }
 
     /**
-     * Sets up the repeating request builder with default surfaces and extra ones
-     * if needed (like a video recording surface).
+     * Removes default surfaces from the repeating request builder.
      */
     private void removeRepeatingRequestBuilderSurfaces() {
         mRepeatingRequestBuilder.removeTarget(mPreviewStreamSurface);
@@ -209,17 +226,6 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
         }
     }
 
-    private void applyRepeatingRequestBuilderAsSingle() {
-        if (getPreviewState() == STATE_STARTED) {
-            try {
-                mSession.capture(mRepeatingRequestBuilder.build(),
-                        mRepeatingRequestCallback, null);
-            } catch (CameraAccessException e) {
-                throw createCameraException(e);
-            }
-        }
-    }
-
     /**
      * Applies the repeating request builder to the preview, assuming we actually have a preview
      * running. Can be called after changing parameters to the builder.
@@ -228,7 +234,8 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
      * it should be set before calling this method, for example by calling
      * {@link #createRepeatingRequestBuilder(int)}.
      */
-    private void applyRepeatingRequestBuilder() {
+    @SuppressWarnings("WeakerAccess")
+    protected void applyRepeatingRequestBuilder() {
         applyRepeatingRequestBuilder(true, CameraException.REASON_DISCONNECTED);
     }
 
@@ -284,7 +291,8 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
     protected List<Size> getPreviewStreamAvailableSizes() {
         try {
             CameraCharacteristics characteristics = mManager.getCameraCharacteristics(mCameraId);
-            StreamConfigurationMap streamMap = characteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);
+            StreamConfigurationMap streamMap =
+                    characteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);
             if (streamMap == null) {
                 throw new RuntimeException("StreamConfigurationMap is null. Should not happen.");
             }
@@ -309,7 +317,7 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
     }
 
     @Override
-    protected boolean collectCameraInfo(@NonNull Facing facing) {
+    protected final boolean collectCameraInfo(@NonNull Facing facing) {
         int internalFacing = mMapper.mapFacing(facing);
         String[] cameraIds = null;
         try {
@@ -325,7 +333,8 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
         for (String cameraId : cameraIds) {
             try {
                 CameraCharacteristics characteristics = mManager.getCameraCharacteristics(cameraId);
-                if (internalFacing == readCharacteristic(characteristics, CameraCharacteristics.LENS_FACING, -99)) {
+                if (internalFacing == readCharacteristic(characteristics,
+                        CameraCharacteristics.LENS_FACING, -99)) {
                     mCameraId = cameraId;
                     int sensorOffset = readCharacteristic(characteristics,
                             CameraCharacteristics.SENSOR_ORIENTATION, 0);
@@ -372,12 +381,13 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
 
                 @Override
                 public void onDisconnected(@NonNull CameraDevice camera) {
-                    // Not sure if this is called INSTEAD of onOpened() or can be called after as well.
-                    // However, using trySetException should address this problem - it will only trigger
-                    // if the task has no result.
+                    // Not sure if this is called INSTEAD of onOpened() or can be called after
+                    // as well. However, using trySetException should address this problem -
+                    // it will only trigger if the task has no result.
                     //
-                    // Docs say to release this camera instance, however, since we throw an unrecoverable
-                    // CameraException, this will trigger a stop() through the exception handler.
+                    // Docs say to release this camera instance, however, since we throw an
+                    // unrecoverable CameraException, this will trigger a stop() through the
+                    // exception handler.
                     task.trySetException(new CameraException(CameraException.REASON_DISCONNECTED));
                 }
 
@@ -463,8 +473,11 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
         // 4. FRAME PROCESSING
         if (hasFrameProcessors()) {
             // Choose the size.
-            StreamConfigurationMap streamMap = mCameraCharacteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);
-            if (streamMap == null) throw new RuntimeException("StreamConfigurationMap is null. Should not happen.");
+            StreamConfigurationMap streamMap = mCameraCharacteristics
+                    .get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);
+            if (streamMap == null) {
+                throw new RuntimeException("StreamConfigurationMap is null. Should not happen.");
+            }
             android.util.Size[] aSizes = streamMap.getOutputSizes(FRAME_PROCESSING_INPUT_FORMAT);
             List<Size> sizes = new ArrayList<>();
             for (android.util.Size aSize : aSizes) {
@@ -479,7 +492,8 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
                     mFrameProcessingSize.getHeight(),
                     FRAME_PROCESSING_INPUT_FORMAT,
                     2);
-            mFrameProcessingReader.setOnImageAvailableListener(this, mFrameConversionHandler.getHandler());
+            mFrameProcessingReader.setOnImageAvailableListener(this,
+                    mFrameConversionHandler.getHandler());
             mFrameProcessingSurface = mFrameProcessingReader.getSurface();
             outputSurfaces.add(mFrameProcessingSurface);
         } else {
@@ -500,7 +514,7 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
 
                 @Override
                 public void onConfigureFailed(@NonNull CameraCaptureSession session) {
-                    // I would say this should be a library error and as such we throw a Runtime Exception.
+                    // This SHOULD be a library error so we throw a RuntimeException.
                     String message = LOG.e("onConfigureFailed! Session", session);
                     throw new RuntimeException(message);
                 }
@@ -529,13 +543,14 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
 
         LOG.i("onStartPreview", "Starting preview.");
         addRepeatingRequestBuilderSurfaces();
-        applyRepeatingRequestBuilder(false, CameraException.REASON_FAILED_TO_START_PREVIEW);
+        applyRepeatingRequestBuilder(false,
+                CameraException.REASON_FAILED_TO_START_PREVIEW);
         LOG.i("onStartPreview", "Started preview.");
 
         // Start delayed video if needed.
         if (mFullVideoPendingStub != null) {
-            // Do not call takeVideo/onTakeVideo. It will reset some stub parameters that the recorder sets.
-            // Also we are posting this so that doTakeVideo sees a started preview.
+            // Do not call takeVideo/onTakeVideo. It will reset some stub parameters that
+            // the recorder sets. Also we are posting so that doTakeVideo sees a started preview.
             LOG.i("onStartPreview", "Posting doTakeVideo call.");
             final VideoResult.Stub stub = mFullVideoPendingStub;
             mFullVideoPendingStub = null;
@@ -594,7 +609,12 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
         mCaptureSize = null;
         mFrameProcessingSize = null;
         if (mFrameProcessingReader != null) {
+            synchronized (mFrameProcessingImageLock) {
+                // This call synchronously releases all Images and their underlying properties.
+                // This can cause a segmentation fault while converting the Image to NV21.
+                // So we use this lock for the two operations.
                 mFrameProcessingReader.close();
+            }
             mFrameProcessingReader = null;
         }
         if (mPictureReader != null) {
@@ -611,7 +631,6 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
     @NonNull
     @Override
     protected Task<Void> onStopEngine() {
-        LOG.i("onStopEngine:", "About to clean up.");
         try {
             LOG.i("onStopEngine:", "Clean up.", "Releasing camera.");
             mCamera.close();
@@ -620,6 +639,16 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
             LOG.w("onStopEngine:", "Clean up.", "Exception while releasing camera.", e);
         }
         mCamera = null;
+
+        // After engine is stopping, the repeating request builder will be null,
+        // so the ActionHolder.getBuilder() contract would be broken. Same for characteristics.
+        // This can cause crashes if some ongoing Action queries the holder. So we abort them.
+        LOG.i("onStopEngine:", "Aborting actions.");
+        for (Action action : mActions) {
+            action.abort(this);
+        }
+
+        mCameraCharacteristics = null;
         mCameraOptions = null;
         mVideoRecorder = null;
         mRepeatingRequestBuilder = null;
@@ -633,7 +662,9 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
 
     @WorkerThread
     @Override
-    protected void onTakePictureSnapshot(@NonNull final PictureResult.Stub stub, @NonNull final AspectRatio outputRatio, boolean doMetering) {
+    protected void onTakePictureSnapshot(@NonNull final PictureResult.Stub stub,
+                                         @NonNull final AspectRatio outputRatio,
+                                         boolean doMetering) {
         if (doMetering) {
             LOG.i("onTakePictureSnapshot:", "doMetering is true. Delaying.");
             Action action = Actions.timeout(METER_TIMEOUT, createMeterAction(null));
@@ -653,7 +684,8 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
             // stub.size is not the real size: it will be cropped to the given ratio
             // stub.rotation will be set to 0 - we rotate the texture instead.
             stub.size = getUncroppedSnapshotSize(Reference.OUTPUT);
-            stub.rotation = getAngles().offset(Reference.SENSOR, Reference.OUTPUT, Axis.RELATIVE_TO_SENSOR);
+            stub.rotation = getAngles().offset(Reference.SENSOR, Reference.OUTPUT,
+                    Axis.RELATIVE_TO_SENSOR);
             mPictureRecorder = new Snapshot2PictureRecorder(stub, this,
                     (GlCameraPreview) mPreview, outputRatio);
             mPictureRecorder.take();
@@ -674,21 +706,24 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
             action.start(this);
         } else {
             LOG.i("onTakePicture:", "doMetering is false. Performing.");
-            stub.rotation = getAngles().offset(Reference.SENSOR, Reference.OUTPUT, Axis.RELATIVE_TO_SENSOR);
+            stub.rotation = getAngles().offset(Reference.SENSOR, Reference.OUTPUT,
+                    Axis.RELATIVE_TO_SENSOR);
             stub.size = getPictureSize(Reference.OUTPUT);
             try {
                 if (mPictureCaptureStopsPreview) {
-                    // These two are present in official samples and are probably meant to speed things up?
-                    // But from my tests, they actually make everything slower. So this is disabled by default
-                    // with a boolean flag. Maybe in the future we can make this configurable as some
-                    // people might want to stop the preview while picture is being taken even if it
-                    // increases the latency.
+                    // These two are present in official samples and are probably meant to
+                    // speed things up? But from my tests, they actually make everything slower.
+                    // So this is disabled by default with a boolean flag. Maybe in the future
+                    // we can make this configurable as some people might want to stop the preview
+                    // while picture is being taken even if it increases the latency.
                     mSession.stopRepeating();
                     mSession.abortCaptures();
                 }
-                CaptureRequest.Builder builder = mCamera.createCaptureRequest(CameraDevice.TEMPLATE_STILL_CAPTURE);
+                CaptureRequest.Builder builder
+                        = mCamera.createCaptureRequest(CameraDevice.TEMPLATE_STILL_CAPTURE);
                 applyAllParameters(builder, mRepeatingRequestBuilder);
-                mPictureRecorder = new Full2PictureRecorder(stub, this, builder, mPictureReader);
+                mPictureRecorder = new Full2PictureRecorder(stub, this, builder,
+                        mPictureReader);
                 mPictureRecorder.take();
             } catch (CameraAccessException e) {
                 throw createCameraException(e);
@@ -721,8 +756,10 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
     @Override
     protected void onTakeVideo(@NonNull VideoResult.Stub stub) {
         LOG.i("onTakeVideo", "called.");
-        stub.rotation = getAngles().offset(Reference.SENSOR, Reference.OUTPUT, Axis.RELATIVE_TO_SENSOR);
-        stub.size = getAngles().flip(Reference.SENSOR, Reference.OUTPUT) ? mCaptureSize.flip() : mCaptureSize;
+        stub.rotation = getAngles().offset(Reference.SENSOR, Reference.OUTPUT,
+                Axis.RELATIVE_TO_SENSOR);
+        stub.size = getAngles().flip(Reference.SENSOR, Reference.OUTPUT) ?
+                mCaptureSize.flip() : mCaptureSize;
         // We must restart the session at each time.
         // Save the pending data and restart the session.
         LOG.w("onTakeVideo", "calling restartBind.");
@@ -752,9 +789,10 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
 
     @WorkerThread
     @Override
-    protected void onTakeVideoSnapshot(@NonNull VideoResult.Stub stub, @NonNull AspectRatio outputRatio) {
+    protected void onTakeVideoSnapshot(@NonNull VideoResult.Stub stub,
+                                       @NonNull AspectRatio outputRatio) {
         if (!(mPreview instanceof GlCameraPreview)) {
-            throw new IllegalStateException("Video snapshots are only supported with GlCameraPreview.");
+            throw new IllegalStateException("Video snapshots are only supported with GL_SURFACE.");
         }
         GlCameraPreview glPreview = (GlCameraPreview) mPreview;
         Size outputSize = getUncroppedSnapshotSize(Reference.OUTPUT);
@@ -779,18 +817,21 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
         // Start.
         // The overlay rotation should alway be VIEW-OUTPUT, just liek Camera1Engine.
         int overlayRotation = getAngles().offset(Reference.VIEW, Reference.OUTPUT, Axis.ABSOLUTE);
-        mVideoRecorder = new SnapshotVideoRecorder(this, glPreview, getOverlay(), overlayRotation);
+        mVideoRecorder = new SnapshotVideoRecorder(this, glPreview, getOverlay(),
+                overlayRotation);
         mVideoRecorder.start(stub);
     }
 
+    /**
+     * When video ends we must stop the recorder and remove the recorder surface from
+     * camera outputs. This is done in onVideoResult. However, on some devices, order matters.
+     * If we stop the recorder and AFTER send camera frames to it, the camera will try to fill
+     * the recorder "abandoned" Surface and on some devices with a poor internal implementation
+     * (HW_LEVEL_LEGACY) this crashes. So if the conditions are met, we restore here. Issue #549.
+     */
     @Override
     public void onVideoRecordingEnd() {
         super.onVideoRecordingEnd();
-        // When video ends we must stop the recorder and remove the recorder surface from camera outputs.
-        // This is done in onVideoResult. However, on some devices, order matters. If we stop the recorder
-        // and AFTER send camera frames to it, the camera will try to fill the recorder "abandoned"
-        // Surface and on some devices with a poor internal implementation (HW_LEVEL_LEGACY) this crashes.
-        // So if the conditions are met, we restore here. Issue #549.
         boolean needsIssue549Workaround = (mVideoRecorder instanceof Full2VideoRecorder) ||
                 (readCharacteristic(CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL, -1)
                         == CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL_LEGACY);
@@ -806,7 +847,7 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
     }
 
     /**
-     * Some video recorders might change the camera template to {@link CameraDevice#TEMPLATE_RECORD}.
+     * Video recorders might change the camera template to {@link CameraDevice#TEMPLATE_RECORD}.
      * After the video is taken, we should restore the template preview, which also means that
      * we'll remove any extra surface target that was added by the video recorder.
      *
@@ -846,26 +887,34 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
             // We might be in a metering operation, or the old builder might have some special
             // metering parameters. Copy these special keys over to the new builder.
             // These are the keys changed by metering.Parameters, or by us in applyFocusForMetering.
-            builder.set(CaptureRequest.CONTROL_AF_REGIONS, oldBuilder.get(CaptureRequest.CONTROL_AF_REGIONS));
-            builder.set(CaptureRequest.CONTROL_AE_REGIONS, oldBuilder.get(CaptureRequest.CONTROL_AE_REGIONS));
-            builder.set(CaptureRequest.CONTROL_AWB_REGIONS, oldBuilder.get(CaptureRequest.CONTROL_AWB_REGIONS));
-            builder.set(CaptureRequest.CONTROL_AF_MODE, oldBuilder.get(CaptureRequest.CONTROL_AF_MODE));
+            builder.set(CaptureRequest.CONTROL_AF_REGIONS,
+                    oldBuilder.get(CaptureRequest.CONTROL_AF_REGIONS));
+            builder.set(CaptureRequest.CONTROL_AE_REGIONS,
+                    oldBuilder.get(CaptureRequest.CONTROL_AE_REGIONS));
+            builder.set(CaptureRequest.CONTROL_AWB_REGIONS,
+                    oldBuilder.get(CaptureRequest.CONTROL_AWB_REGIONS));
+            builder.set(CaptureRequest.CONTROL_AF_MODE,
+                    oldBuilder.get(CaptureRequest.CONTROL_AF_MODE));
             // Do NOT copy exposure or focus triggers!
         }
     }
 
-    private void applyDefaultFocus(@NonNull CaptureRequest.Builder builder) {
-        int[] modesArray = readCharacteristic(CameraCharacteristics.CONTROL_AF_AVAILABLE_MODES, new int[]{});
+    @SuppressWarnings("WeakerAccess")
+    protected void applyDefaultFocus(@NonNull CaptureRequest.Builder builder) {
+        int[] modesArray = readCharacteristic(CameraCharacteristics.CONTROL_AF_AVAILABLE_MODES,
+                new int[]{});
         List<Integer> modes = new ArrayList<>();
         for (int mode : modesArray) { modes.add(mode); }
         if (getMode() == Mode.VIDEO &&
                 modes.contains(CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_VIDEO)) {
-            builder.set(CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_VIDEO);
+            builder.set(CaptureRequest.CONTROL_AF_MODE,
+                    CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_VIDEO);
             return;
         }
 
         if (modes.contains(CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE)) {
-            builder.set(CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);
+            builder.set(CaptureRequest.CONTROL_AF_MODE,
+                    CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);
             return;
         }
 
@@ -882,10 +931,18 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
         }
     }
 
-    private void applyFocusForMetering(@NonNull CaptureRequest.Builder builder) {
-        // All focus modes support the AF trigger, except OFF and EDOF.
-        // However, unlike the preview, we'd prefer AUTO to any CONTINUOUS value.
-        int[] modesArray = readCharacteristic(CameraCharacteristics.CONTROL_AF_AVAILABLE_MODES, new int[]{});
+    /**
+     * All focus modes support the AF trigger, except OFF and EDOF.
+     * However, unlike the preview, we'd prefer AUTO to any CONTINUOUS value.
+     * An AUTO value means that focus is locked unless we run the focus trigger,
+     * which is what metering does.
+     *
+     * @param builder builder
+     */
+    @SuppressWarnings("WeakerAccess")
+    protected void applyFocusForMetering(@NonNull CaptureRequest.Builder builder) {
+        int[] modesArray = readCharacteristic(CameraCharacteristics.CONTROL_AF_AVAILABLE_MODES,
+                new int[]{});
         List<Integer> modes = new ArrayList<>();
         for (int mode : modesArray) { modes.add(mode); }
         if (modes.contains(CaptureRequest.CONTROL_AF_MODE_AUTO)) {
@@ -894,12 +951,14 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
         }
         if (getMode() == Mode.VIDEO &&
                 modes.contains(CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_VIDEO)) {
-            builder.set(CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_VIDEO);
+            builder.set(CaptureRequest.CONTROL_AF_MODE,
+                    CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_VIDEO);
             return;
         }
 
         if (modes.contains(CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE)) {
-            builder.set(CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);
+            builder.set(CaptureRequest.CONTROL_AF_MODE,
+                    CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);
             //noinspection UnnecessaryReturnStatement
             return;
         }
@@ -916,13 +975,14 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
                     boolean shouldApply = applyFlash(mRepeatingRequestBuilder, old);
                     boolean needsWorkaround = getPreviewState() == STATE_STARTED;
                     if (needsWorkaround) {
-                        // Runtime changes to the flash value are not correctly handled by the driver.
-                        // See https://stackoverflow.com/q/53003383/4288782 for example.
+                        // Runtime changes to the flash value are not correctly handled by the
+                        // driver. See https://stackoverflow.com/q/53003383/4288782 for example.
                         // For this reason, we go back to OFF, capture once, then go to the new one.
                         mFlash = Flash.OFF;
                         applyFlash(mRepeatingRequestBuilder, old);
                         try {
-                            mSession.capture(mRepeatingRequestBuilder.build(), null, null);
+                            mSession.capture(mRepeatingRequestBuilder.build(), null,
+                                    null);
                         } catch (CameraAccessException e) {
                             throw createCameraException(e);
                         }
@@ -946,17 +1006,18 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
      * - {@link CaptureRequest#CONTROL_AE_MODE_ON_ALWAYS_FLASH}
      *
      * The API offers a high level control through {@link CaptureRequest#CONTROL_AE_MODE},
-     * which is what the mapper looks at. It will trigger (if specified) flash only for still captures
-     * which is exactly what we want.
+     * which is what the mapper looks at. It will trigger (if specified) flash only for
+     * still captures which is exactly what we want.
      *
      * However, we set CONTROL_AE_MODE to ON/OFF (depending
      * on which is available) with both {@link Flash#OFF} and {@link Flash#TORCH}.
      *
-     * When CONTROL_AE_MODE is ON or OFF, the low level control, called {@link CaptureRequest#FLASH_MODE},
-     * becomes effective, and that's where we can actually distinguish between a turned off flash
-     * and a torch flash.
+     * When CONTROL_AE_MODE is ON or OFF, the low level control, called
+     * {@link CaptureRequest#FLASH_MODE}, becomes effective, and that's where we can actually
+     * distinguish between a turned off flash and a torch flash.
      */
-    private boolean applyFlash(@NonNull CaptureRequest.Builder builder,
+    @SuppressWarnings("WeakerAccess")
+    protected boolean applyFlash(@NonNull CaptureRequest.Builder builder,
                                  @NonNull Flash oldFlash) {
         if (mCameraOptions.supports(mFlash)) {
             int[] availableAeModesArray = readCharacteristic(
@@ -996,7 +1057,8 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
         });
     }
 
-    private boolean applyLocation(@NonNull CaptureRequest.Builder builder,
+    @SuppressWarnings("WeakerAccess")
+    protected boolean applyLocation(@NonNull CaptureRequest.Builder builder,
                                     @SuppressWarnings("unused") @Nullable Location oldLocation) {
         if (mLocation != null) {
             builder.set(CaptureRequest.JPEG_GPS_LOCATION, mLocation);
@@ -1021,7 +1083,8 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
         });
     }
 
-    private boolean applyWhiteBalance(@NonNull CaptureRequest.Builder builder,
+    @SuppressWarnings("WeakerAccess")
+    protected boolean applyWhiteBalance(@NonNull CaptureRequest.Builder builder,
                                         @NonNull WhiteBalance oldWhiteBalance) {
         if (mCameraOptions.supports(mWhiteBalance)) {
             int whiteBalance = mMapper.mapWhiteBalance(mWhiteBalance);
@@ -1049,8 +1112,8 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
         });
     }
 
-
-    private boolean applyHdr(@NonNull CaptureRequest.Builder builder, @NonNull Hdr oldHdr) {
+    @SuppressWarnings("WeakerAccess")
+    protected boolean applyHdr(@NonNull CaptureRequest.Builder builder, @NonNull Hdr oldHdr) {
         if (mCameraOptions.supports(mHdr)) {
             int hdr = mMapper.mapHdr(mHdr);
             builder.set(CaptureRequest.CONTROL_SCENE_MODE, hdr);
@@ -1080,9 +1143,11 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
         });
     }
 
-    private boolean applyZoom(@NonNull CaptureRequest.Builder builder, float oldZoom) {
+    @SuppressWarnings("WeakerAccess")
+    protected boolean applyZoom(@NonNull CaptureRequest.Builder builder, float oldZoom) {
         if (mCameraOptions.isZoomSupported()) {
-            float maxZoom = readCharacteristic(CameraCharacteristics.SCALER_AVAILABLE_MAX_DIGITAL_ZOOM, 1F);
+            float maxZoom = readCharacteristic(
+                    CameraCharacteristics.SCALER_AVAILABLE_MAX_DIGITAL_ZOOM, 1F);
             // converting 0.0f-1.0f zoom scale to the actual camera digital zoom scale
             // (which will be for example, 1.0-10.0)
             float calculatedZoom = (mZoomValue * (maxZoom - 1.0f)) + 1.0f;
@@ -1096,8 +1161,8 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
 
     @NonNull
     private Rect getZoomRect(float zoomLevel, float maxDigitalZoom) {
-        Rect activeRect = readCharacteristic(CameraCharacteristics.SENSOR_INFO_ACTIVE_ARRAY_SIZE, new Rect());
-
+        Rect activeRect = readCharacteristic(CameraCharacteristics.SENSOR_INFO_ACTIVE_ARRAY_SIZE,
+                new Rect());
         int minW = (int) (activeRect.width() / maxDigitalZoom);
         int minH = (int) (activeRect.height() / maxDigitalZoom);
         int difW = activeRect.width() - minW;
@@ -1107,11 +1172,15 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
         // When zoom is maxZoom, we want to return a centered rect with minW and minH
         int cropW = (int) (difW * (zoomLevel - 1) / (maxDigitalZoom - 1) / 2F);
         int cropH = (int) (difH * (zoomLevel - 1) / (maxDigitalZoom - 1) / 2F);
-        return new Rect(cropW, cropH, activeRect.width() - cropW, activeRect.height() - cropH);
+        return new Rect(cropW, cropH, activeRect.width() - cropW,
+                activeRect.height() - cropH);
     }
 
     @Override
-    public void setExposureCorrection(final float EVvalue, @NonNull final float[] bounds, @Nullable final PointF[] points, final boolean notify) {
+    public void setExposureCorrection(final float EVvalue,
+                                      @NonNull final float[] bounds,
+                                      @Nullable final PointF[] points,
+                                      final boolean notify) {
         final float old = mExposureCorrectionValue;
         mExposureCorrectionValue = EVvalue;
         mHandler.run(new Runnable() {
@@ -1130,11 +1199,15 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
         });
     }
 
-    private boolean applyExposureCorrection(@NonNull CaptureRequest.Builder builder, float oldEVvalue) {
+    @SuppressWarnings("WeakerAccess")
+    protected boolean applyExposureCorrection(@NonNull CaptureRequest.Builder builder,
+                                              float oldEVvalue) {
         if (mCameraOptions.isExposureCorrectionSupported()) {
-            Rational exposureCorrectionStep = readCharacteristic(CameraCharacteristics.CONTROL_AE_COMPENSATION_STEP,
+            Rational exposureCorrectionStep = readCharacteristic(
+                    CameraCharacteristics.CONTROL_AE_COMPENSATION_STEP,
                     new Rational(1, 1));
-            int exposureCorrectionSteps = Math.round(mExposureCorrectionValue * exposureCorrectionStep.floatValue());
+            int exposureCorrectionSteps = Math.round(mExposureCorrectionValue
+                    * exposureCorrectionStep.floatValue());
             builder.set(CaptureRequest.CONTROL_AE_EXPOSURE_COMPENSATION, exposureCorrectionSteps);
             return true;
         }
@@ -1165,6 +1238,7 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
             LOG.w("onImageAvailable", "no byte buffer!");
             return;
         }
+        LOG.v("onImageAvailable", "trying to acquire Image.");
         Image image = null;
         try {
             image = reader.acquireLatestImage();
@@ -1174,9 +1248,11 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
             getFrameManager().onBufferUnused(data);
             return;
         }
-        LOG.i("onImageAvailable", "we have both a byte buffer and an Image.");
+        LOG.v("onImageAvailable", "we have both a byte buffer and an Image.");
         try {
+            synchronized (mFrameProcessingImageLock) {
                 ImageHelper.convertToNV21(image, data);
+            }
         } catch (Exception e) {
             LOG.w("onImageAvailable", "error while converting.");
             getFrameManager().onBufferUnused(data);
@@ -1188,7 +1264,8 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
             // After preview, the frame manager is correctly set up
             Frame frame = getFrameManager().getFrame(data,
                     System.currentTimeMillis(),
-                    getAngles().offset(Reference.SENSOR, Reference.OUTPUT, Axis.RELATIVE_TO_SENSOR));
+                    getAngles().offset(Reference.SENSOR, Reference.OUTPUT,
+                            Axis.RELATIVE_TO_SENSOR));
             mCallback.dispatchFrame(frame);
         } else {
             getFrameManager().onBufferUnused(data);
@@ -1197,18 +1274,35 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
 
     @Override
     public void setHasFrameProcessors(final boolean hasFrameProcessors) {
-        super.setHasFrameProcessors(hasFrameProcessors);
-        LOG.i("setHasFrameProcessors", "changed to", hasFrameProcessors, "posting.");
+        LOG.i("setHasFrameProcessors", "changing to", hasFrameProcessors, "posting.");
+        Camera2Engine.super.setHasFrameProcessors(hasFrameProcessors);
         mHandler.run(new Runnable() {
             @Override
             public void run() {
-                LOG.i("setHasFrameProcessors", "changed to", hasFrameProcessors, "executing. BindState:", getBindState());
-                if (getBindState() == STATE_STARTED) {
-                    LOG.i("setHasFrameProcessors", "triggering a restart.");
-                    // TODO if taking video, this stops it.
+                LOG.i("setHasFrameProcessors", "changing to", hasFrameProcessors,
+                        "executing. BindState:", getBindState(),
+                        "PreviewState:", getPreviewState());
+
+                // Frame processing is set up partially when binding and partially when starting
+                // the preview. We don't want to only check bind state or startPreview can fail.
+                if (getBindState() == STATE_STOPPED) {
+                    LOG.i("setHasFrameProcessors", "not bound so won't restart.");
+                } else if (getPreviewState() == STATE_STARTED) {
+                    // This needs a restartBind(). NOTE: if taking video, this stops it.
+                    LOG.i("setHasFrameProcessors", "bound with preview.",
+                            "Calling restartBind().");
                     restartBind();
                 } else {
-                    LOG.i("setHasFrameProcessors", "not bound so won't restart.");
+                    // Bind+Preview is not completely started yet not completely stopped.
+                    // This can happen if the user adds a frame processor in onCameraOpened().
+                    // Supporting this would add lot of complexity to this class, and
+                    // this should be discouraged anyway since changing the frame processor number
+                    // at this time requires restarting the camera when it was just opened.
+                    // For these reasons, let's throw.
+                    throw new IllegalStateException("Added/removed a FrameProcessor at illegal " +
+                            "time. These operations should be done before opening the camera, or " +
+                            "before closing it - NOT when it just opened, for example during the " +
+                            "onCameraOpened() callback.");
                 }
             }
         });
@@ -1225,8 +1319,9 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
             @Override
             public void run() {
                 LOG.i("startAutoFocus", "executing. Preview state:", getPreviewState());
-                // This will only work when we have a preview, since it launches the preview in the end.
-                // Even without this it would need the bind state at least, since we need the preview size.
+                // This will only work when we have a preview, since it launches the preview
+                // in the end. Even without this it would need the bind state at least,
+                // since we need the preview size.
                 if (getPreviewState() < STATE_STARTED) return;
 
                 // The camera options API still has the auto focus API but it really
@@ -1244,7 +1339,8 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
                         mCallback.dispatchOnFocusEnd(gesture, action.isSuccessful(), point);
                         mHandler.remove(mUnlockAndResetMeteringRunnable);
                         if (shouldResetAutoFocus()) {
-                            mHandler.post(getAutoFocusResetDelay(), mUnlockAndResetMeteringRunnable);
+                            mHandler.post(getAutoFocusResetDelay(),
+                                    mUnlockAndResetMeteringRunnable);
                         }
                     }
                 });
@@ -1263,7 +1359,8 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
         // The last one is under our control because the library has no focus API.
         // So let's set a good af mode here. This operation is reverted during onMeteringReset().
         applyFocusForMetering(mRepeatingRequestBuilder);
-        mMeterAction = new MeterAction(Camera2Engine.this, point, point == null);
+        mMeterAction = new MeterAction(Camera2Engine.this, point,
+                point == null);
         return mMeterAction;
     }
 
@@ -1282,8 +1379,10 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
                         protected void onStart(@NonNull ActionHolder holder) {
                             super.onStart(holder);
                             applyDefaultFocus(holder.getBuilder(this));
-                            holder.getBuilder(this).set(CaptureRequest.CONTROL_AE_LOCK, false);
-                            holder.getBuilder(this).set(CaptureRequest.CONTROL_AWB_LOCK, false);
+                            holder.getBuilder(this)
+                                    .set(CaptureRequest.CONTROL_AE_LOCK, false);
+                            holder.getBuilder(this)
+                                    .set(CaptureRequest.CONTROL_AWB_LOCK, false);
                             holder.applyBuilder(this);
                             setState(STATE_COMPLETED);
                             // TODO should wait results?
@@ -1348,7 +1447,8 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
     }
 
     @Override
-    public void applyBuilder(@NonNull Action source, @NonNull CaptureRequest.Builder builder) throws CameraAccessException {
+    public void applyBuilder(@NonNull Action source, @NonNull CaptureRequest.Builder builder)
+            throws CameraAccessException {
         mSession.capture(builder.build(), mRepeatingRequestCallback, null);
     }
 

cameraview/src/main/java/com/otaliastudios/cameraview/engine/CameraEngine.java

@@ -64,8 +64,10 @@ import java.util.concurrent.TimeUnit;
  * Setting up the Camera is usually a 4 steps process:
  * 1. Setting up the Surface. Done by {@link CameraPreview}.
  * 2. Starting the camera. Done by us. See {@link #startEngine()}, {@link #onStartEngine()}.
- * 3. Binding the camera to the surface. Done by us. See {@link #startBind()}, {@link #onStartBind()}
- * 4. Streaming the camera preview.      Done by us. See {@link #startPreview()}, {@link #onStartPreview()}
+ * 3. Binding the camera to the surface. Done by us. See {@link #startBind()},
+ *    {@link #onStartBind()}
+ * 4. Streaming the camera preview. Done by us. See {@link #startPreview()},
+ *    {@link #onStartPreview()}
  *
  * The first two steps can actually happen at the same time, anyway
  * the order is not guaranteed, we just get a callback from the Preview when 1 happens.
@@ -80,14 +82,16 @@ import java.util.concurrent.TimeUnit;
  * STATE
  * We only expose generic {@link #start()} and {@link #stop()} calls to the outside.
  * The external users of this class are most likely interested in whether we have completed step 2
- * or not, since that tells us if we can act on the camera or not, rather than knowing about steps 3 and 4.
+ * or not, since that tells us if we can act on the camera or not, rather than knowing about
+ * steps 3 and 4.
  *
  * So in the {@link CameraEngine} notation,
- * - {@link #start()}: ASYNC - starts the engine (S2). When possible, at a later time, S3 and S4 are also performed.
+ * - {@link #start()}: ASYNC - starts the engine (S2). When possible, at a later time,
+ *                     S3 and S4 are also performed.
  * - {@link #stop()}: ASYNC - stops everything: undoes S4, then S3, then S2.
  * - {@link #restart()}: ASYNC - completes a stop then a start.
- * - {@link #destroy()}: SYNC - performs a {@link #stop()} that will go on no matter the exceptions, without throwing.
- *                              Makes the engine unusable and clears resources.
+ * - {@link #destroy()}: SYNC - performs a {@link #stop()} that will go on no matter the exceptions,
+ *                       without throwing. Makes the engine unusable and clears resources.
  *
  * For example, we expose the engine (S2) state through {@link #getEngineState()}. It will be:
  * - {@link #STATE_STARTING} if we're into step 2
@@ -109,13 +113,13 @@ import java.util.concurrent.TimeUnit;
  *
  *
  * ERROR HANDLING
- * THe {@link #mHandler} thread has a special {@link Thread.UncaughtExceptionHandler} that handles exceptions
- * and dispatches error to the callback (instead of crashing the app). This lets subclasses run code
- * safely and directly throw {@link CameraException}s when needed.
+ * THe {@link #mHandler} thread has a special {@link Thread.UncaughtExceptionHandler} that handles
+ * exceptions and dispatches error to the callback (instead of crashing the app).
+ * This lets subclasses run code safely and directly throw {@link CameraException}s when needed.
  *
- * For convenience, the two main method {@link #onStartEngine()} and {@link #onStopEngine()} are already
- * called on the engine thread, but they can still be asynchronous by returning a Google's
- * {@link com.google.android.gms.tasks.Task}.
+ * For convenience, the two main method {@link #onStartEngine()} and {@link #onStopEngine()}
+ * are already called on the engine thread, but they can still be asynchronous by returning a
+ * Google's {@link com.google.android.gms.tasks.Task}.
  */
 public abstract class CameraEngine implements
         CameraPreview.SurfaceCallback,
@@ -133,7 +137,9 @@ public abstract class CameraEngine implements
         void dispatchOnFocusStart(@Nullable Gesture trigger, @NonNull PointF where);
         void dispatchOnFocusEnd(@Nullable Gesture trigger, boolean success, @NonNull PointF where);
         void dispatchOnZoomChanged(final float newValue, @Nullable final PointF[] fingers);
-        void dispatchOnExposureCorrectionChanged(float newValue, @NonNull float[] bounds, @Nullable PointF[] fingers);
+        void dispatchOnExposureCorrectionChanged(float newValue,
+                                                 @NonNull float[] bounds,
+                                                 @Nullable PointF[] fingers);
         void dispatchFrame(@NonNull Frame frame);
         void dispatchError(CameraException exception);
         void dispatchOnVideoRecordingStart();
@@ -186,8 +192,10 @@ public abstract class CameraEngine implements
     private int mAudioBitRate;
     private boolean mHasFrameProcessors;
     private long mAutoFocusResetDelayMillis;
-    private int mSnapshotMaxWidth = Integer.MAX_VALUE; // in REF_VIEW for consistency with SizeSelectors
-    private int mSnapshotMaxHeight = Integer.MAX_VALUE; // in REF_VIEW for consistency with SizeSelectors
+    // in REF_VIEW, for consistency with SizeSelectors
+    private int mSnapshotMaxWidth = Integer.MAX_VALUE;
+    // in REF_VIEW, for consistency with SizeSelectors
+    private int mSnapshotMaxHeight = Integer.MAX_VALUE;
     private Overlay overlay;
 
     // Steps
@@ -205,9 +213,11 @@ public abstract class CameraEngine implements
 
     // Ops used for testing.
     @VisibleForTesting(otherwise = VisibleForTesting.PROTECTED) Op<Void> mZoomOp = new Op<>();
-    @VisibleForTesting(otherwise = VisibleForTesting.PROTECTED) Op<Void> mExposureCorrectionOp = new Op<>();
+    @VisibleForTesting(otherwise = VisibleForTesting.PROTECTED) Op<Void> mExposureCorrectionOp
+            = new Op<>();
     @VisibleForTesting(otherwise = VisibleForTesting.PROTECTED) Op<Void> mFlashOp = new Op<>();
-    @VisibleForTesting(otherwise = VisibleForTesting.PROTECTED) Op<Void> mWhiteBalanceOp = new Op<>();
+    @VisibleForTesting(otherwise = VisibleForTesting.PROTECTED) Op<Void> mWhiteBalanceOp
+            = new Op<>();
     @VisibleForTesting(otherwise = VisibleForTesting.PROTECTED) Op<Void> mHdrOp = new Op<>();
     @VisibleForTesting(otherwise = VisibleForTesting.PROTECTED) Op<Void> mLocationOp = new Op<>();
     @VisibleForTesting(otherwise = VisibleForTesting.PROTECTED) Op<Void> mPlaySoundsOp = new Op<>();
@@ -258,9 +268,9 @@ public abstract class CameraEngine implements
 
     /**
      * Handles exceptions coming from either runtime errors on the {@link #mHandler} code that is
-     * not caught (using the {@link CrashExceptionHandler}), as might happen during standard mHandler.post()
-     * operations that subclasses might do, OR for errors caught by tasks and continuations that
-     * we launch here.
+     * not caught (using the {@link CrashExceptionHandler}), as might happen during standard
+     * mHandler.post() operations that subclasses might do, OR for errors caught by tasks and
+     * continuations that we launch here.
      *
      * In the first case, the thread is about to be terminated. In the second case,
      * we can actually keep using it.
@@ -269,7 +279,9 @@ public abstract class CameraEngine implements
      * @param throwable the throwable
      * @param fromExceptionHandler true if coming from exception handler
      */
-    private void handleException(@NonNull Thread thread, final @NonNull Throwable throwable, final boolean fromExceptionHandler) {
+    private void handleException(@NonNull Thread thread,
+                                 final @NonNull Throwable throwable,
+                                 final boolean fromExceptionHandler) {
         if (!(throwable instanceof CameraException)) {
             // This is unexpected, either a bug or something the developer should know.
             // Release and crash the UI thread so we get bug reports.
@@ -290,7 +302,8 @@ public abstract class CameraEngine implements
         }
 
         final CameraException cameraException = (CameraException) throwable;
-        LOG.e("uncaughtException:", "Got CameraException:", cameraException, "on engine state:", getEngineStateName());
+        LOG.e("uncaughtException:", "Got CameraException:", cameraException,
+                "on engine state:", getEngineStateName());
         if (fromExceptionHandler) {
             // Got to restart the handler.
             thread.interrupt();
@@ -478,7 +491,8 @@ public abstract class CameraEngine implements
             @Override
             public void run() {
                 LOG.w("restartBind", "executing stopPreview.");
-                stopPreview(false).continueWithTask(mHandler.getExecutor(), new Continuation<Void, Task<Void>>() {
+                stopPreview(false).continueWithTask(mHandler.getExecutor(),
+                        new Continuation<Void, Task<Void>>() {
                     @Override
                     public Task<Void> then(@NonNull Task<Void> task) {
                         LOG.w("restartBind", "executing stopBind.");
@@ -525,7 +539,9 @@ public abstract class CameraEngine implements
     @NonNull
     @WorkerThread
     private Task<Void> stopPreview(boolean swallowExceptions) {
-        LOG.i("stopPreview", "needsStopPreview:", needsStopPreview(), "swallowExceptions:", swallowExceptions);
+        LOG.i("stopPreview",
+                "needsStopPreview:", needsStopPreview(),
+                "swallowExceptions:", swallowExceptions);
         if (needsStopPreview()) {
             mPreviewStep.doStop(swallowExceptions, new Callable<Task<Void>>() {
                 @Override
@@ -595,7 +611,8 @@ public abstract class CameraEngine implements
 
     @Override
     public final void onSurfaceChanged() {
-        LOG.i("onSurfaceChanged:", "Size is", getPreviewSurfaceSize(Reference.VIEW), "Posting.");
+        LOG.i("onSurfaceChanged:", "Size is", getPreviewSurfaceSize(Reference.VIEW),
+                "Posting.");
         mHandler.run(new Runnable() {
             @Override
             public void run() {
@@ -608,9 +625,11 @@ public abstract class CameraEngine implements
                 // Compute a new camera preview size and apply.
                 Size newSize = computePreviewStreamSize();
                 if (newSize.equals(mPreviewStreamSize)) {
-                    LOG.i("onSurfaceChanged:", "The computed preview size is identical. No op.");
+                    LOG.i("onSurfaceChanged:",
+                            "The computed preview size is identical. No op.");
                 } else {
-                    LOG.i("onSurfaceChanged:", "Computed a new preview size. Calling onPreviewStreamSizeChanged().");
+                    LOG.i("onSurfaceChanged:",
+                            "Computed a new preview size. Calling onPreviewStreamSizeChanged().");
                     mPreviewStreamSize = newSize;
                     onPreviewStreamSizeChanged();
                 }
@@ -633,7 +652,8 @@ public abstract class CameraEngine implements
         mHandler.run(new Runnable() {
             @Override
             public void run() {
-                stopPreview(false).onSuccessTask(mHandler.getExecutor(), new SuccessContinuation<Void, Void>() {
+                stopPreview(false).onSuccessTask(mHandler.getExecutor(),
+                        new SuccessContinuation<Void, Void>() {
                     @NonNull
                     @Override
                     public Task<Void> then(@Nullable Void aVoid) {
@@ -663,7 +683,8 @@ public abstract class CameraEngine implements
         // Stop if needed, synchronously and silently.
         // Cannot use Tasks.await() because we might be on the UI thread.
         final CountDownLatch latch = new CountDownLatch(1);
-        stop(true).addOnCompleteListener(mHandler.getExecutor(), new OnCompleteListener<Void>() {
+        stop(true).addOnCompleteListener(mHandler.getExecutor(),
+                new OnCompleteListener<Void>() {
             @Override
             public void onComplete(@NonNull Task<Void> task) {
                 latch.countDown();
@@ -695,14 +716,17 @@ public abstract class CameraEngine implements
             @Override
             public void run() {
                 LOG.w("Start:", "executing runnable. AllState is", mAllStep.getState());
-                // It's better to schedule anyway. allStep might be STARTING and we might be tempted to early return here,
-                // But the truth is that there might be a stop already scheduled when the STARTING op ends.
+                // It's better to schedule anyway. allStep might be STARTING and we might be
+                // tempted to early return here, but the truth is that there might be a stop
+                // already scheduled when the STARTING op ends.
                 // if (mAllStep.isStoppingOrStopped()) {
-                //     LOG.i("Start:", "executing runnable. AllState is STOPPING or STOPPED, so we schedule a start.");
+                //     LOG.i("Start:", "executing runnable. AllState is STOPPING or STOPPED,
+                //     so we schedule a start.");
                     mAllStep.doStart(false, new Callable<Task<Void>>() {
                         @Override
                         public Task<Void> call() {
-                            return startEngine().addOnFailureListener(mHandler.getExecutor(), new OnFailureListener() {
+                            return startEngine().addOnFailureListener(mHandler.getExecutor(),
+                                    new OnFailureListener() {
                                 @Override
                                 public void onFailure(@NonNull Exception e) {
                                     outTask.trySetException(e);
@@ -725,7 +749,8 @@ public abstract class CameraEngine implements
                     });
                 // } else {
                 //     // NOTE: this returns early if we were STARTING.
-                //     LOG.i("Start:", "executing runnable. AllState is STARTING or STARTED, so we return early.");
+                //     LOG.i("Start:",
+                //     "executing runnable. AllState is STARTING or STARTED, so we return early.");
                 //     outTask.trySetResult(null);
                 // }
             }
@@ -746,14 +771,17 @@ public abstract class CameraEngine implements
             @Override
             public void run() {
                 LOG.w("Stop:", "executing runnable. AllState is", mAllStep.getState());
-                // It's better to schedule anyway. allStep might be STOPPING and we might be tempted to early return here,
-                // But the truth is that there might be a start already scheduled when the STOPPING op ends.
+                // It's better to schedule anyway. allStep might be STOPPING and we might be
+                // tempted to early return here, but the truth is that there might be a start
+                // already scheduled when the STOPPING op ends.
                 // if (mAllStep.isStartedOrStarting()) {
-                //     LOG.i("Stop:", "executing runnable. AllState is STARTING or STARTED, so we schedule a stop.");
+                //     LOG.i("Stop:", "executing runnable. AllState is STARTING or STARTED,
+                //     so we schedule a stop.");
                     mAllStep.doStop(swallowExceptions, new Callable<Task<Void>>() {
                         @Override
                         public Task<Void> call() {
-                            return stopPreview(swallowExceptions).continueWithTask(mHandler.getExecutor(), new Continuation<Void, Task<Void>>() {
+                            return stopPreview(swallowExceptions).continueWithTask(
+                                    mHandler.getExecutor(), new Continuation<Void, Task<Void>>() {
                                 @Override
                                 public Task<Void> then(@NonNull Task<Void> task) {
                                     return stopBind(swallowExceptions);
@@ -779,7 +807,8 @@ public abstract class CameraEngine implements
                     });
                 // } else {
                 //     // NOTE: this returns early if we were STOPPING.
-                //     LOG.i("Stop:", "executing runnable. AllState is STOPPING or STOPPED, so we return early.");
+                //     LOG.i("Stop:", "executing runnable.
+                //     AllState is STOPPING or STOPPED, so we return early.");
                 //     outTask.trySetResult(null);
                 // }
             }
@@ -800,7 +829,6 @@ public abstract class CameraEngine implements
         return overlay;
     }
 
-    @SuppressWarnings("WeakerAccess")
     public final Angles getAngles() {
         return mAngles;
     }
@@ -888,9 +916,13 @@ public abstract class CameraEngine implements
         return mSnapshotMaxHeight;
     }
 
-    public final void setAutoFocusResetDelay(long delayMillis) { mAutoFocusResetDelayMillis = delayMillis; }
+    public final void setAutoFocusResetDelay(long delayMillis) {
+        mAutoFocusResetDelayMillis = delayMillis;
+    }
 
-    public final long getAutoFocusResetDelay() { return mAutoFocusResetDelayMillis; }
+    public final long getAutoFocusResetDelay() {
+        return mAutoFocusResetDelayMillis;
+    }
 
     /**
      * Sets a new facing value. This will restart the session (if there's any)
@@ -1039,8 +1071,8 @@ public abstract class CameraEngine implements
      * Camera is about to be opened. Implementors should look into available cameras
      * and see if anyone matches the given {@link Facing value}.
      *
-     * If so, implementors should set {@link Angles#setSensorOffset(Facing, int)} and any other information
-     * (like camera ID) needed to start the engine.
+     * If so, implementors should set {@link Angles#setSensorOffset(Facing, int)}
+     * and any other information (like camera ID) needed to start the engine.
      *
      * @param facing the facing value
      * @return true if we have one
@@ -1059,7 +1091,10 @@ public abstract class CameraEngine implements
     public abstract void setZoom(float zoom, @Nullable PointF[] points, boolean notify);
 
     // If closed, no-op. If opened, check supported and apply.
-    public abstract void setExposureCorrection(float EVvalue, @NonNull float[] bounds, @Nullable PointF[] points, boolean notify);
+    public abstract void setExposureCorrection(float EVvalue,
+                                               @NonNull float[] bounds,
+                                               @Nullable PointF[] points,
+                                               boolean notify);
 
     // If closed, keep. If opened, check supported and apply.
     public abstract void setFlash(@NonNull Flash flash);
@@ -1091,7 +1126,8 @@ public abstract class CameraEngine implements
         mHandler.run(new Runnable() {
             @Override
             public void run() {
-                LOG.v("takePicture", "performing. BindState:", getBindState(), "isTakingPicture:", isTakingPicture());
+                LOG.v("takePicture", "performing. BindState:", getBindState(),
+                        "isTakingPicture:", isTakingPicture());
                 if (mMode == Mode.VIDEO) {
                     throw new IllegalStateException("Can't take hq pictures while in VIDEO mode");
                 }
@@ -1115,7 +1151,8 @@ public abstract class CameraEngine implements
         mHandler.run(new Runnable() {
             @Override
             public void run() {
-                LOG.v("takePictureSnapshot", "performing. BindState:", getBindState(), "isTakingPicture:", isTakingPicture());
+                LOG.v("takePictureSnapshot", "performing. BindState:",
+                        getBindState(), "isTakingPicture:", isTakingPicture());
                 if (getBindState() < STATE_STARTED) return;
                 if (isTakingPicture()) return;
                 stub.location = mLocation;
@@ -1141,7 +1178,8 @@ public abstract class CameraEngine implements
             mCallback.dispatchOnPictureTaken(result);
         } else {
             LOG.e("onPictureResult", "result is null: something went wrong.", error);
-            mCallback.dispatchError(new CameraException(error, CameraException.REASON_PICTURE_FAILED));
+            mCallback.dispatchError(new CameraException(error,
+                    CameraException.REASON_PICTURE_FAILED));
         }
     }
 
@@ -1154,7 +1192,8 @@ public abstract class CameraEngine implements
         mHandler.run(new Runnable() {
             @Override
             public void run() {
-                LOG.v("takeVideo", "performing. BindState:", getBindState(), "isTakingVideo:", isTakingVideo());
+                LOG.v("takeVideo", "performing. BindState:", getBindState(),
+                        "isTakingVideo:", isTakingVideo());
                 if (getBindState() < STATE_STARTED) return;
                 if (isTakingVideo()) return;
                 if (mMode == Mode.PICTURE) {
@@ -1179,12 +1218,14 @@ public abstract class CameraEngine implements
      * @param stub a video stub
      * @param file the output file
      */
-    public final void takeVideoSnapshot(final @NonNull VideoResult.Stub stub, @NonNull final File file) {
+    public final void takeVideoSnapshot(@NonNull final VideoResult.Stub stub,
+                                        @NonNull final File file) {
         LOG.v("takeVideoSnapshot", "scheduling");
         mHandler.run(new Runnable() {
             @Override
             public void run() {
-                LOG.v("takeVideoSnapshot", "performing. BindState:", getBindState(), "isTakingVideo:", isTakingVideo());
+                LOG.v("takeVideoSnapshot", "performing. BindState:", getBindState(),
+                        "isTakingVideo:", isTakingVideo());
                 if (getBindState() < STATE_STARTED) return;
                 if (isTakingVideo()) return;
                 stub.file = file;
@@ -1215,10 +1256,13 @@ public abstract class CameraEngine implements
         });
     }
 
+    @SuppressWarnings("WeakerAccess")
     protected void onStopVideo() {
         if (mVideoRecorder != null) {
             mVideoRecorder.stop(false);
-            mVideoRecorder = null;
+            // Do not null this, so we respond correctly to isTakingVideo(),
+            // which checks for recorder presence and recorder.isRecording().
+            // It will be nulled in onVideoResult.
         }
     }
 
@@ -1230,7 +1274,8 @@ public abstract class CameraEngine implements
             mCallback.dispatchOnVideoTaken(result);
         } else {
             LOG.e("onVideoResult", "result is null: something went wrong.", exception);
-            mCallback.dispatchError(new CameraException(exception, CameraException.REASON_VIDEO_FAILED));
+            mCallback.dispatchError(new CameraException(exception,
+                    CameraException.REASON_VIDEO_FAILED));
         }
     }
 
@@ -1248,10 +1293,13 @@ public abstract class CameraEngine implements
     protected abstract void onTakePicture(@NonNull PictureResult.Stub stub, boolean doMetering);
 
     @WorkerThread
-    protected abstract void onTakePictureSnapshot(@NonNull PictureResult.Stub stub, @NonNull AspectRatio outputRatio, boolean doMetering);
+    protected abstract void onTakePictureSnapshot(@NonNull PictureResult.Stub stub,
+                                                  @NonNull AspectRatio outputRatio,
+                                                  boolean doMetering);
 
     @WorkerThread
-    protected abstract void onTakeVideoSnapshot(@NonNull VideoResult.Stub stub, @NonNull AspectRatio outputRatio);
+    protected abstract void onTakeVideoSnapshot(@NonNull VideoResult.Stub stub,
+                                                @NonNull AspectRatio outputRatio);
 
     @WorkerThread
     protected abstract void onTakeVideo(@NonNull VideoResult.Stub stub);
@@ -1286,7 +1334,8 @@ public abstract class CameraEngine implements
     private Size getPreviewSurfaceSize(@NonNull Reference reference) {
         CameraPreview preview = mPreview;
         if (preview == null) return null;
-        return getAngles().flip(Reference.VIEW, reference) ? preview.getSurfaceSize().flip() : preview.getSurfaceSize();
+        return getAngles().flip(Reference.VIEW, reference) ? preview.getSurfaceSize().flip()
+                : preview.getSurfaceSize();
     }
 
     /**
@@ -1295,7 +1344,7 @@ public abstract class CameraEngine implements
      * levels so we don't want to perform the op here.
      *
      * The base snapshot size is based on PreviewStreamSize (later cropped with view ratio). Why?
-     * One might be tempted to say that it is the SurfaceSize (which already matches the view ratio).
+     * One might be tempted to say that it's the SurfaceSize (which already matches the view ratio).
      *
      * The camera sensor will capture preview frames with PreviewStreamSize and that's it. Then they
      * are hardware-scaled by the preview surface, but this does not affect the snapshot, as the
@@ -1367,7 +1416,8 @@ public abstract class CameraEngine implements
         List<Size> list = new ArrayList<>(sizes);
         Size result = selector.select(list).get(0);
         if (!list.contains(result)) {
-            throw new RuntimeException("SizeSelectors must not return Sizes other than those in the input list.");
+            throw new RuntimeException("SizeSelectors must not return Sizes other than " +
+                    "those in the input list.");
         }
         LOG.i("computeCaptureSize:", "result:", result, "flip:", flip, "mode:", mode);
         if (flip) result = result.flip(); // Go back to REF_SENSOR
@@ -1395,13 +1445,17 @@ public abstract class CameraEngine implements
             sizes.add(flip ? size.flip() : size);
         }
 
-        // Create our own default selector, which will be used if the external mPreviewStreamSizeSelector
-        // is null, or if it fails in finding a size.
+        // Create our own default selector, which will be used if the external
+        // mPreviewStreamSizeSelector is null, or if it fails in finding a size.
         Size targetMinSize = getPreviewSurfaceSize(Reference.VIEW);
-        if (targetMinSize == null) throw new IllegalStateException("targetMinSize should not be null here.");
+        if (targetMinSize == null) {
+            throw new IllegalStateException("targetMinSize should not be null here.");
+        }
         AspectRatio targetRatio = AspectRatio.of(mCaptureSize.getWidth(), mCaptureSize.getHeight());
         if (flip) targetRatio = targetRatio.flip();
-        LOG.i("computePreviewStreamSize:", "targetRatio:", targetRatio, "targetMinSize:", targetMinSize);
+        LOG.i("computePreviewStreamSize:",
+                "targetRatio:", targetRatio,
+                "targetMinSize:", targetMinSize);
         SizeSelector matchRatio = SizeSelectors.and( // Match this aspect ratio and sort by biggest
                 SizeSelectors.aspectRatio(targetRatio, 0),
                 SizeSelectors.biggest());
@@ -1426,7 +1480,8 @@ public abstract class CameraEngine implements
         }
         Size result = selector.select(sizes).get(0);
         if (!sizes.contains(result)) {
-            throw new RuntimeException("SizeSelectors must not return Sizes other than those in the input list.");
+            throw new RuntimeException("SizeSelectors must not return Sizes other than " +
+                    "those in the input list.");
         }
         if (flip) result = result.flip();
         LOG.i("computePreviewStreamSize:", "result:", result, "flip:", flip);

cameraview/src/main/java/com/otaliastudios/cameraview/engine/LogAction.java

@@ -15,12 +15,14 @@ import com.otaliastudios.cameraview.engine.action.BaseAction;
 @RequiresApi(Build.VERSION_CODES.LOLLIPOP)
 class LogAction extends BaseAction {
 
-    private final static CameraLogger LOG = CameraLogger.create(Camera2Engine.class.getSimpleName());
+    private final static CameraLogger LOG
+            = CameraLogger.create(Camera2Engine.class.getSimpleName());
 
     private String lastLog;
 
     @Override
-    public void onCaptureCompleted(@NonNull ActionHolder holder, @NonNull CaptureRequest request,
+    public void onCaptureCompleted(@NonNull ActionHolder holder,
+                                   @NonNull CaptureRequest request,
                                    @NonNull TotalCaptureResult result) {
         super.onCaptureCompleted(holder, request, result);
         Integer aeMode = result.get(CaptureResult.CONTROL_AE_MODE);
@@ -34,29 +36,14 @@ class LogAction extends BaseAction {
                 " afState: " + afState + " afTriggerState: " + afTriggerState;
         if (!log.equals(lastLog)) {
             lastLog = log;
-            LOG.w(log);
+            LOG.i(log);
+        }
     }
 
-        // START
-        // aeMode: 3 aeLock: false aeState: 4 aeTriggerState: 0 afState: 2 afTriggerState: 0
-        //
-        // DURING metering (focus skips)
-        // aeMode: 3 aeLock: false aeState: 4 aeTriggerState: 0 afState: 0 afTriggerState: 0
-        // aeMode: 3 aeLock: false aeState: 5 aeTriggerState: 1 afState: 0 afTriggerState: 0
-        //
-        // DURING locking (focus skips)
-        // aeMode: 3 aeLock: false aeState: 4 aeTriggerState: 1 afState: 0 afTriggerState: 0
-        // aeMode: 3 aeLock: true aeState: 5 aeTriggerState: 1 afState: 0 afTriggerState: 0
-        //
-        // AFTER locked
-        // aeMode: 3 aeLock: true aeState: 3 aeTriggerState: 1 afState: 0 afTriggerState: 0
-        //
-        // AFTER super.take() called
-        // aeMode: 1 aeLock: true aeState: 5 aeTriggerState: 1 afState: 0 afTriggerState: 0
-        // aeMode: 1 aeLock: true aeState: 3 aeTriggerState: 1 afState: 0 afTriggerState: 0
-        //
-        // Reverting flash changes + reset lock + reset metering
-        // aeMode: 3 aeLock: false aeState: 4 aeTriggerState: 2(1 now) afState: 2 afTriggerState: 0
-        // aeMode: 3 aeLock: false aeState: 1 aeTriggerState: 2(1 now) afState: 2 afTriggerState: 0
+    @Override
+    protected void onCompleted(@NonNull ActionHolder holder) {
+        super.onCompleted(holder);
+        setState(0); // set another state.
+        start(holder); // restart.
     }
 }

cameraview/src/main/java/com/otaliastudios/cameraview/engine/Step.java

@@ -105,17 +105,21 @@ class Step {
         return doStart(swallowExceptions, op, null);
     }
 
-    Task<Void> doStart(final boolean swallowExceptions, final @NonNull Callable<Task<Void>> op, final @Nullable Runnable onStarted) {
+    Task<Void> doStart(final boolean swallowExceptions,
+                       final @NonNull Callable<Task<Void>> op,
+                       final @Nullable Runnable onStarted) {
         LOG.i(name, "doStart", "Called. Enqueuing.");
         task = task.continueWithTask(callback.getExecutor(), new Continuation<Void, Task<Void>>() {
             @Override
             public Task<Void> then(@NonNull Task<Void> task) throws Exception {
                 LOG.i(name, "doStart", "About to start. Setting state to STARTING");
                 setState(STATE_STARTING);
-                return op.call().addOnFailureListener(callback.getExecutor(), new OnFailureListener() {
+                return op.call().addOnFailureListener(callback.getExecutor(),
+                        new OnFailureListener() {
                     @Override
                     public void onFailure(@NonNull Exception e) {
-                        LOG.w(name, "doStart", "Failed with error", e, "Setting state to STOPPED");
+                        LOG.w(name, "doStart", "Failed with error", e,
+                                "Setting state to STOPPED");
                         setState(STATE_STOPPED);
                         if (!swallowExceptions) callback.handleException(e);
                     }
@@ -139,17 +143,21 @@ class Step {
         return doStop(swallowExceptions, op, null);
     }
 
-    Task<Void> doStop(final boolean swallowExceptions, final @NonNull Callable<Task<Void>> op, final @Nullable Runnable onStopped) {
+    Task<Void> doStop(final boolean swallowExceptions,
+                      final @NonNull Callable<Task<Void>> op,
+                      final @Nullable Runnable onStopped) {
         LOG.i(name, "doStop", "Called. Enqueuing.");
         task = task.continueWithTask(callback.getExecutor(), new Continuation<Void, Task<Void>>() {
             @Override
             public Task<Void> then(@NonNull Task<Void> task) throws Exception {
                 LOG.i(name, "doStop", "About to stop. Setting state to STOPPING");
                 state = STATE_STOPPING;
-                return op.call().addOnFailureListener(callback.getExecutor(), new OnFailureListener() {
+                return op.call().addOnFailureListener(callback.getExecutor(),
+                        new OnFailureListener() {
                     @Override
                     public void onFailure(@NonNull Exception e) {
-                        LOG.w(name, "doStop", "Failed with error", e, "Setting state to STOPPED");
+                        LOG.w(name, "doStop", "Failed with error", e,
+                                "Setting state to STOPPED");
                         state = STATE_STOPPED;
                         if (!swallowExceptions) callback.handleException(e);
                     }

cameraview/src/main/java/com/otaliastudios/cameraview/engine/action/Action.java

@@ -13,8 +13,8 @@ import androidx.annotation.RequiresApi;
 /**
  * The Action class encapsulates logic for completing an action in a Camera2 environment.
  * In this case, we are often interested in constantly receiving the {@link CaptureResult}
- * and {@link CaptureRequest} callbacks, as well as applying changes to a {@link CaptureRequest.Builder}
- * and having them applied to the sensor.
+ * and {@link CaptureRequest} callbacks, as well as applying changes to a
+ * {@link CaptureRequest.Builder} and having them applied to the sensor.
  *
  * The Action class receives the given callbacks and can operate over the engine
  * through the {@link ActionHolder} object.
@@ -61,25 +61,32 @@ public interface Action {
     void removeCallback(@NonNull ActionCallback callback);
 
     /**
-     * Called from {@link CaptureCallback#onCaptureStarted(CameraCaptureSession, CaptureRequest, long, long)}.
+     * Called from {@link CaptureCallback#onCaptureStarted(CameraCaptureSession, CaptureRequest,
+     * long, long)}.
      * @param holder the holder
      * @param request the request
      */
     void onCaptureStarted(@NonNull ActionHolder holder, @NonNull CaptureRequest request);
 
     /**
-     * Called from {@link CaptureCallback#onCaptureProgressed(CameraCaptureSession, CaptureRequest, CaptureResult)}.
+     * Called from {@link CaptureCallback#onCaptureProgressed(CameraCaptureSession, CaptureRequest,
+     * CaptureResult)}.
      * @param holder the holder
      * @param request the request
      * @param result the result
      */
-    void onCaptureProgressed(@NonNull ActionHolder holder, @NonNull CaptureRequest request, @NonNull CaptureResult result);
+    void onCaptureProgressed(@NonNull ActionHolder holder,
+                             @NonNull CaptureRequest request,
+                             @NonNull CaptureResult result);
 
     /**
-     * Called from {@link CaptureCallback#onCaptureCompleted(CameraCaptureSession, CaptureRequest, TotalCaptureResult)}.
+     * Called from {@link CaptureCallback#onCaptureCompleted(CameraCaptureSession, CaptureRequest,
+     * TotalCaptureResult)}.
      * @param holder the holder
      * @param request the request
      * @param result the result
      */
-    void onCaptureCompleted(@NonNull ActionHolder holder, @NonNull CaptureRequest request, @NonNull TotalCaptureResult result);
+    void onCaptureCompleted(@NonNull ActionHolder holder,
+                            @NonNull CaptureRequest request,
+                            @NonNull TotalCaptureResult result);
 }

cameraview/src/main/java/com/otaliastudios/cameraview/engine/action/ActionHolder.java

@@ -77,5 +77,6 @@ public interface ActionHolder {
      * @param builder builder
      * @throws CameraAccessException camera exception
      */
-    void applyBuilder(@NonNull Action source, @NonNull CaptureRequest.Builder builder) throws CameraAccessException;
+    void applyBuilder(@NonNull Action source, @NonNull CaptureRequest.Builder builder)
+            throws CameraAccessException;
 }

cameraview/src/main/java/com/otaliastudios/cameraview/engine/action/ActionWrapper.java

@@ -50,13 +50,17 @@ public abstract class ActionWrapper extends BaseAction {
     }
 
     @Override
-    public void onCaptureProgressed(@NonNull ActionHolder holder, @NonNull CaptureRequest request, @NonNull CaptureResult result) {
+    public void onCaptureProgressed(@NonNull ActionHolder holder,
+                                    @NonNull CaptureRequest request,
+                                    @NonNull CaptureResult result) {
         super.onCaptureProgressed(holder, request, result);
         getAction().onCaptureProgressed(holder, request, result);
     }
 
     @Override
-    public void onCaptureCompleted(@NonNull ActionHolder holder, @NonNull CaptureRequest request, @NonNull TotalCaptureResult result) {
+    public void onCaptureCompleted(@NonNull ActionHolder holder,
+                                   @NonNull CaptureRequest request,
+                                   @NonNull TotalCaptureResult result) {
         super.onCaptureCompleted(holder, request, result);
         getAction().onCaptureCompleted(holder, request, result);
     }

cameraview/src/main/java/com/otaliastudios/cameraview/engine/action/BaseAction.java

@@ -78,12 +78,16 @@ public abstract class BaseAction implements Action {
     }
 
     @Override
-    public void onCaptureProgressed(@NonNull ActionHolder holder, @NonNull CaptureRequest request, @NonNull CaptureResult result) {
+    public void onCaptureProgressed(@NonNull ActionHolder holder,
+                                    @NonNull CaptureRequest request,
+                                    @NonNull CaptureResult result) {
         // Overrideable
     }
 
     @Override
-    public void onCaptureCompleted(@NonNull ActionHolder holder, @NonNull CaptureRequest request, @NonNull TotalCaptureResult result) {
+    public void onCaptureCompleted(@NonNull ActionHolder holder,
+                                   @NonNull CaptureRequest request,
+                                   @NonNull TotalCaptureResult result) {
         // Overrideable
     }
 
@@ -92,7 +96,7 @@ public abstract class BaseAction implements Action {
      * this removes this action from the holder.
      * @param newState new state
      */
-    protected void setState(int newState) {
+    protected final void setState(int newState) {
         if (newState != state) {
             state = newState;
             for (ActionCallback callback : callbacks) {

cameraview/src/main/java/com/otaliastudios/cameraview/engine/action/SequenceAction.java

@@ -75,7 +75,8 @@ class SequenceAction extends BaseAction {
     }
 
     @Override
-    public void onCaptureProgressed(@NonNull ActionHolder holder, @NonNull CaptureRequest request,
+    public void onCaptureProgressed(@NonNull ActionHolder holder,
+                                    @NonNull CaptureRequest request,
                                     @NonNull CaptureResult result) {
         super.onCaptureProgressed(holder, request, result);
         if (runningAction >= 0) {
@@ -84,7 +85,8 @@ class SequenceAction extends BaseAction {
     }
 
     @Override
-    public void onCaptureCompleted(@NonNull ActionHolder holder, @NonNull CaptureRequest request,
+    public void onCaptureCompleted(@NonNull ActionHolder holder,
+                                   @NonNull CaptureRequest request,
                                    @NonNull TotalCaptureResult result) {
         super.onCaptureCompleted(holder, request, result);
         if (runningAction >= 0) {

cameraview/src/main/java/com/otaliastudios/cameraview/engine/action/TogetherAction.java

@@ -65,7 +65,8 @@ class TogetherAction extends BaseAction {
     }
 
     @Override
-    public void onCaptureProgressed(@NonNull ActionHolder holder, @NonNull CaptureRequest request,
+    public void onCaptureProgressed(@NonNull ActionHolder holder,
+                                    @NonNull CaptureRequest request,
                                     @NonNull CaptureResult result) {
         super.onCaptureProgressed(holder, request, result);
         for (BaseAction action : actions) {
@@ -74,7 +75,8 @@ class TogetherAction extends BaseAction {
     }
 
     @Override
-    public void onCaptureCompleted(@NonNull ActionHolder holder, @NonNull CaptureRequest request,
+    public void onCaptureCompleted(@NonNull ActionHolder holder,
+                                   @NonNull CaptureRequest request,
                                    @NonNull TotalCaptureResult result) {
         super.onCaptureCompleted(holder, request, result);
         for (BaseAction action : actions) {

cameraview/src/main/java/com/otaliastudios/cameraview/engine/lock/ExposureLock.java

@@ -20,7 +20,8 @@ public class ExposureLock extends BaseLock {
 
     @Override
     protected boolean checkIsSupported(@NonNull ActionHolder holder) {
-        boolean isNotLegacy = readCharacteristic(CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL, -1)
+        boolean isNotLegacy = readCharacteristic(
+                CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL, -1)
                 != CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL_LEGACY;
         // Not sure we should check aeMode as well, probably all aeModes support locking,
         // but this should not be a big issue since we're not even using different AE modes.
@@ -30,7 +31,8 @@ public class ExposureLock extends BaseLock {
                         || aeMode == CameraCharacteristics.CONTROL_AE_MODE_ON_ALWAYS_FLASH
                         || aeMode == CameraCharacteristics.CONTROL_AE_MODE_ON_AUTO_FLASH
                         || aeMode == CameraCharacteristics.CONTROL_AE_MODE_ON_AUTO_FLASH_REDEYE
-                        || aeMode == 5 /* CameraCharacteristics.CONTROL_AE_MODE_ON_EXTERNAL_FLASH, API 28 */);
+                        || aeMode == 5
+                        /* CameraCharacteristics.CONTROL_AE_MODE_ON_EXTERNAL_FLASH, API 28 */);
         boolean result = isNotLegacy && isAEOn;
         LOG.i("checkIsSupported:", result);
         return result;
@@ -49,13 +51,16 @@ public class ExposureLock extends BaseLock {
         int cancelTrigger = Build.VERSION.SDK_INT >= 23
                 ? CaptureRequest.CONTROL_AE_PRECAPTURE_TRIGGER_CANCEL
                 : CaptureRequest.CONTROL_AE_PRECAPTURE_TRIGGER_IDLE;
-        holder.getBuilder(this).set(CaptureRequest.CONTROL_AE_PRECAPTURE_TRIGGER, cancelTrigger);
+        holder.getBuilder(this).set(CaptureRequest.CONTROL_AE_PRECAPTURE_TRIGGER,
+                cancelTrigger);
         holder.getBuilder(this).set(CaptureRequest.CONTROL_AE_LOCK, true);
         holder.applyBuilder(this);
     }
 
     @Override
-    public void onCaptureCompleted(@NonNull ActionHolder holder, @NonNull CaptureRequest request, @NonNull TotalCaptureResult result) {
+    public void onCaptureCompleted(@NonNull ActionHolder holder,
+                                   @NonNull CaptureRequest request,
+                                   @NonNull TotalCaptureResult result) {
         super.onCaptureCompleted(holder, request, result);
         Integer aeState = result.get(CaptureResult.CONTROL_AE_STATE);
         LOG.i("processCapture:", "aeState:", aeState);

cameraview/src/main/java/com/otaliastudios/cameraview/engine/lock/FocusLock.java

@@ -22,7 +22,8 @@ public class FocusLock extends BaseLock {
     protected boolean checkIsSupported(@NonNull ActionHolder holder) {
         // We'll lock by changing the AF mode to AUTO.
         // In that mode, AF won't change unless someone starts a trigger operation.
-        int[] modes = readCharacteristic(CameraCharacteristics.CONTROL_AF_AVAILABLE_MODES, new int[]{});
+        int[] modes = readCharacteristic(CameraCharacteristics.CONTROL_AF_AVAILABLE_MODES,
+                new int[]{});
         for (int mode : modes) {
             if (mode == CameraCharacteristics.CONTROL_AF_MODE_AUTO) {
                 return true;
@@ -50,13 +51,17 @@ public class FocusLock extends BaseLock {
 
     @Override
     protected void onStarted(@NonNull ActionHolder holder) {
-        holder.getBuilder(this).set(CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_AUTO);
-        holder.getBuilder(this).set(CaptureRequest.CONTROL_AF_TRIGGER, CaptureRequest.CONTROL_AF_TRIGGER_CANCEL);
+        holder.getBuilder(this).set(CaptureRequest.CONTROL_AF_MODE,
+                CaptureRequest.CONTROL_AF_MODE_AUTO);
+        holder.getBuilder(this).set(CaptureRequest.CONTROL_AF_TRIGGER,
+                CaptureRequest.CONTROL_AF_TRIGGER_CANCEL);
         holder.applyBuilder(this);
     }
 
     @Override
-    public void onCaptureCompleted(@NonNull ActionHolder holder, @NonNull CaptureRequest request, @NonNull TotalCaptureResult result) {
+    public void onCaptureCompleted(@NonNull ActionHolder holder,
+                                   @NonNull CaptureRequest request,
+                                   @NonNull TotalCaptureResult result) {
         super.onCaptureCompleted(holder, request, result);
         Integer afState = result.get(CaptureResult.CONTROL_AF_STATE);
         Integer afMode = result.get(CaptureResult.CONTROL_AF_MODE);

cameraview/src/main/java/com/otaliastudios/cameraview/engine/lock/WhiteBalanceLock.java

@@ -20,10 +20,13 @@ public class WhiteBalanceLock extends BaseLock {
 
     @Override
     protected boolean checkIsSupported(@NonNull ActionHolder holder) {
-        boolean isNotLegacy = readCharacteristic(CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL, -1)
+        boolean isNotLegacy = readCharacteristic(
+                CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL, -1)
                 != CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL_LEGACY;
         Integer awbMode = holder.getBuilder(this).get(CaptureRequest.CONTROL_AWB_MODE);
-        boolean result = isNotLegacy && awbMode != null && awbMode == CaptureRequest.CONTROL_AWB_MODE_AUTO;
+        boolean result = isNotLegacy
+                && awbMode != null
+                && awbMode == CaptureRequest.CONTROL_AWB_MODE_AUTO;
         LOG.i("checkIsSupported:", result);
         return result;
     }
@@ -43,7 +46,9 @@ public class WhiteBalanceLock extends BaseLock {
     }
 
     @Override
-    public void onCaptureCompleted(@NonNull ActionHolder holder, @NonNull CaptureRequest request, @NonNull TotalCaptureResult result) {
+    public void onCaptureCompleted(@NonNull ActionHolder holder,
+                                   @NonNull CaptureRequest request,
+                                   @NonNull TotalCaptureResult result) {
         super.onCaptureCompleted(holder, request, result);
         Integer awbState = result.get(CaptureResult.CONTROL_AWB_STATE);
         LOG.i("processCapture:", "awbState:", awbState);

cameraview/src/main/java/com/otaliastudios/cameraview/engine/meter/BaseReset.java

@@ -29,7 +29,8 @@ public abstract class BaseReset extends BaseAction {
         super.onStart(holder);
         MeteringRectangle area = null;
         if (resetArea) {
-            Rect rect = readCharacteristic(CameraCharacteristics.SENSOR_INFO_ACTIVE_ARRAY_SIZE, new Rect());
+            Rect rect = readCharacteristic(CameraCharacteristics.SENSOR_INFO_ACTIVE_ARRAY_SIZE,
+                    new Rect());
             area = new MeteringRectangle(rect, MeteringRectangle.METERING_WEIGHT_DONT_CARE);
         }
         onStarted(holder, area);

cameraview/src/main/java/com/otaliastudios/cameraview/engine/meter/ExposureMeter.java

@@ -32,7 +32,8 @@ public class ExposureMeter extends BaseMeter {
     @Override
     protected boolean checkIsSupported(@NonNull ActionHolder holder) {
         // In our case, this means checking if we support the AE precapture trigger.
-        boolean isNotLegacy = readCharacteristic(CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL, -1)
+        boolean isNotLegacy = readCharacteristic(
+                CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL, -1)
                 != CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL_LEGACY;
         Integer aeMode = holder.getBuilder(this).get(CaptureRequest.CONTROL_AE_MODE);
         boolean isAEOn = aeMode != null &&
@@ -40,7 +41,8 @@ public class ExposureMeter extends BaseMeter {
                         || aeMode == CameraCharacteristics.CONTROL_AE_MODE_ON_ALWAYS_FLASH
                         || aeMode == CameraCharacteristics.CONTROL_AE_MODE_ON_AUTO_FLASH
                         || aeMode == CameraCharacteristics.CONTROL_AE_MODE_ON_AUTO_FLASH_REDEYE
-                        || aeMode == 5 /* CameraCharacteristics.CONTROL_AE_MODE_ON_EXTERNAL_FLASH, API 28 */);
+                        || aeMode == 5
+                        /* CameraCharacteristics.CONTROL_AE_MODE_ON_EXTERNAL_FLASH, API 28 */);
         boolean result = isNotLegacy && isAEOn;
         LOG.i("checkIsSupported:", result);
         return result;
@@ -63,7 +65,8 @@ public class ExposureMeter extends BaseMeter {
                 CaptureRequest.CONTROL_AE_PRECAPTURE_TRIGGER_START);
 
         // Check the regions.
-        int maxRegions = readCharacteristic(CameraCharacteristics.CONTROL_MAX_REGIONS_AE, 0);
+        int maxRegions = readCharacteristic(CameraCharacteristics.CONTROL_MAX_REGIONS_AE,
+                0);
         if (!areas.isEmpty() && maxRegions > 0) {
             int max = Math.min(maxRegions, areas.size());
             holder.getBuilder(this).set(CaptureRequest.CONTROL_AE_REGIONS,
@@ -103,8 +106,8 @@ public class ExposureMeter extends BaseMeter {
                     // PRECAPTURE is a transient state. Being here might mean that precapture run
                     // and was successful, OR that the trigger was not even received yet. To
                     // distinguish, check the trigger state.
-                    if (aeTriggerState != null
-                            && aeTriggerState == CaptureResult.CONTROL_AE_PRECAPTURE_TRIGGER_START) {
+                    if (aeTriggerState != null && aeTriggerState
+                            == CaptureResult.CONTROL_AE_PRECAPTURE_TRIGGER_START) {
                         setSuccessful(true);
                         setState(STATE_COMPLETED);
                     }

cameraview/src/main/java/com/otaliastudios/cameraview/engine/meter/ExposureReset.java

@@ -29,29 +29,32 @@ public class ExposureReset extends BaseReset {
 
     @Override
     protected void onStarted(@NonNull ActionHolder holder, @Nullable MeteringRectangle area) {
-        int maxRegions = readCharacteristic(CameraCharacteristics.CONTROL_MAX_REGIONS_AE, 0);
+        int maxRegions = readCharacteristic(CameraCharacteristics.CONTROL_MAX_REGIONS_AE,
+                0);
         if (area != null && maxRegions > 0) {
             holder.getBuilder(this).set(CaptureRequest.CONTROL_AE_REGIONS,
                     new MeteringRectangle[]{area});
         }
 
         // NOTE: precapture might not be supported, in which case I think it will be ignored.
-        Integer trigger = holder.getLastResult(this).get(CaptureResult.CONTROL_AE_PRECAPTURE_TRIGGER);
+        Integer trigger = holder.getLastResult(this)
+                .get(CaptureResult.CONTROL_AE_PRECAPTURE_TRIGGER);
         LOG.i("onStarted:", "last precapture trigger is", trigger);
         if (trigger != null && trigger == CaptureRequest.CONTROL_AE_PRECAPTURE_TRIGGER_START) {
             LOG.i("onStarted:", "canceling precapture.");
             int newTrigger = Build.VERSION.SDK_INT >= 23
                     ? CaptureRequest.CONTROL_AE_PRECAPTURE_TRIGGER_CANCEL
                     : CaptureRequest.CONTROL_AE_PRECAPTURE_TRIGGER_IDLE;
-            holder.getBuilder(this).set(CaptureRequest.CONTROL_AE_PRECAPTURE_TRIGGER, newTrigger);
+            holder.getBuilder(this).set(CaptureRequest.CONTROL_AE_PRECAPTURE_TRIGGER,
+                    newTrigger);
         }
 
         // Documentation about CONTROL_AE_PRECAPTURE_TRIGGER says that, if it was started but not
         // followed by a CAPTURE_INTENT_STILL_PICTURE request, the internal AE routine might remain
         // locked unless we unlock manually.
-        // This is often the case for us, since the snapshot picture recorder does not use the intent
-        // and anyway we use the precapture sequence for touch metering as well.
-        // To reset, docs suggest the use of CONTROL_AE_PRECAPTURE_TRIGGER_CANCEL, which we do above,
+        // This is often the case for us, since the snapshot picture recorder does not use the
+        // intent and anyway we use the precapture sequence for touch metering as well.
+        // To reset docs suggest the use of CONTROL_AE_PRECAPTURE_TRIGGER_CANCEL, which we do above,
         // or the technique used below: locking then unlocking. This proved to be the ONLY method
         // to unlock reliably, unlike the cancel trigger (which we'll run anyway).
         holder.getBuilder(this).set(CaptureRequest.CONTROL_AE_LOCK, true);

cameraview/src/main/java/com/otaliastudios/cameraview/engine/meter/FocusMeter.java

@@ -53,7 +53,8 @@ public class FocusMeter extends BaseMeter {
         LOG.i("onStarted:", "with areas:", areas);
         holder.getBuilder(this).set(CaptureRequest.CONTROL_AF_TRIGGER,
                 CaptureRequest.CONTROL_AF_TRIGGER_START);
-        int maxRegions = readCharacteristic(CameraCharacteristics.CONTROL_MAX_REGIONS_AF, 0);
+        int maxRegions = readCharacteristic(CameraCharacteristics.CONTROL_MAX_REGIONS_AF,
+                0);
         if (!areas.isEmpty() && maxRegions > 0) {
             int max = Math.min(maxRegions, areas.size());
             holder.getBuilder(this).set(CaptureRequest.CONTROL_AF_REGIONS,

cameraview/src/main/java/com/otaliastudios/cameraview/engine/meter/FocusReset.java

@@ -27,7 +27,8 @@ public class FocusReset extends BaseReset {
     @Override
     protected void onStarted(@NonNull ActionHolder holder, @Nullable MeteringRectangle area) {
         boolean changed = false;
-        int maxRegions = readCharacteristic(CameraCharacteristics.CONTROL_MAX_REGIONS_AF, 0);
+        int maxRegions = readCharacteristic(CameraCharacteristics.CONTROL_MAX_REGIONS_AF,
+                0);
         if (area != null && maxRegions > 0) {
             holder.getBuilder(this).set(CaptureRequest.CONTROL_AF_REGIONS,
                     new MeteringRectangle[]{area});

cameraview/src/main/java/com/otaliastudios/cameraview/engine/meter/MeterAction.java

@@ -82,8 +82,8 @@ public class MeterAction extends ActionWrapper {
         List<MeteringRectangle> areas = new ArrayList<>();
         if (point != null) {
             // This is a good Q/A. https://stackoverflow.com/a/33181620/4288782
-            // At first, the point is relative to the View system and does not account our own cropping.
-            // Will keep updating these two below.
+            // At first, the point is relative to the View system and does not account
+            // our own cropping. Will keep updating these two below.
             final PointF referencePoint = new PointF(point.x, point.y);
             Size referenceSize = engine.getPreview().getSurfaceSize();
 
@@ -132,7 +132,7 @@ public class MeterAction extends ActionWrapper {
         Size previewStreamSize = engine.getPreviewStreamSize(Reference.VIEW);
         Size previewSurfaceSize = referenceSize;
         if (previewStreamSize == null) {
-            throw new IllegalStateException("getPreviewStreamSize should not be null at this point.");
+            throw new IllegalStateException("getPreviewStreamSize should not be null here.");
         }
         int referenceWidth = previewSurfaceSize.getWidth();
         int referenceHeight = previewSurfaceSize.getHeight();
@@ -142,13 +142,15 @@ public class MeterAction extends ActionWrapper {
             if (previewStreamAspectRatio.toFloat() > previewSurfaceAspectRatio.toFloat()) {
                 // Stream is larger. The x coordinate must be increased: a touch on the left side
                 // of the surface is not on the left size of stream (it's more to the right).
-                float scale = previewStreamAspectRatio.toFloat() / previewSurfaceAspectRatio.toFloat();
+                float scale = previewStreamAspectRatio.toFloat()
+                        / previewSurfaceAspectRatio.toFloat();
                 referencePoint.x += previewSurfaceSize.getWidth() * (scale - 1F) / 2F;
                 referenceWidth = Math.round(previewSurfaceSize.getWidth() * scale);
             } else {
                 // Stream is taller. The y coordinate must be increased: a touch on the top side
                 // of the surface is not on the top size of stream (it's a bit lower).
-                float scale = previewSurfaceAspectRatio.toFloat() / previewStreamAspectRatio.toFloat();
+                float scale = previewSurfaceAspectRatio.toFloat()
+                        / previewStreamAspectRatio.toFloat();
                 referencePoint.y += previewSurfaceSize.getHeight() * (scale - 1F) / 2F;
                 referenceHeight = Math.round(previewSurfaceSize.getHeight() * scale);
             }
@@ -169,7 +171,8 @@ public class MeterAction extends ActionWrapper {
 
     @SuppressWarnings("SuspiciousNameCombination")
     @NonNull
-    private Size applyPreviewToSensorRotation(@NonNull Size referenceSize, @NonNull PointF referencePoint) {
+    private Size applyPreviewToSensorRotation(@NonNull Size referenceSize,
+                                              @NonNull PointF referencePoint) {
         // Not elegant, but the sin/cos way was failing for some reason.
         int angle = engine.getAngles().offset(Reference.SENSOR, Reference.VIEW, Axis.ABSOLUTE);
         boolean flip = angle % 180 != 0;
@@ -194,12 +197,13 @@ public class MeterAction extends ActionWrapper {
     }
 
     @NonNull
-    private Size applyCropRegionCoordinates(@NonNull Size referenceSize, @NonNull PointF referencePoint) {
+    private Size applyCropRegionCoordinates(@NonNull Size referenceSize,
+                                            @NonNull PointF referencePoint) {
         // The input point and size refer to the stream rect.
         // The stream rect is part of the 'crop region', as described below.
         // https://source.android.com/devices/camera/camera3_crop_reprocess.html
         Rect cropRect = holder.getBuilder(this).get(CaptureRequest.SCALER_CROP_REGION);
-        // For now, we don't care about x and y position. Rect should be non-null, but let's be safe.
+        // For now we don't care about x and y position. Rect should not be null, but let's be safe.
         int cropRectWidth = cropRect == null ? referenceSize.getWidth() : cropRect.width();
         int cropRectHeight = cropRect == null ? referenceSize.getHeight() : cropRect.height();
         // The stream is always centered inside the crop region, and one of the dimensions
@@ -210,16 +214,19 @@ public class MeterAction extends ActionWrapper {
     }
 
     @NonNull
-    private Size applyActiveArrayCoordinates(@NonNull Size referenceSize, @NonNull PointF referencePoint) {
+    private Size applyActiveArrayCoordinates(@NonNull Size referenceSize,
+                                             @NonNull PointF referencePoint) {
         // The input point and size refer to the scaler crop region.
         // We can query for the crop region position inside the active array, so this is easy.
         Rect cropRect = holder.getBuilder(this).get(CaptureRequest.SCALER_CROP_REGION);
         referencePoint.x += cropRect == null ? 0 : cropRect.left;
         referencePoint.y += cropRect == null ? 0 : cropRect.top;
         // Finally, get the active rect width and height from characteristics.
-        Rect activeRect = holder.getCharacteristics(this).get(CameraCharacteristics.SENSOR_INFO_ACTIVE_ARRAY_SIZE);
+        Rect activeRect = holder.getCharacteristics(this)
+                .get(CameraCharacteristics.SENSOR_INFO_ACTIVE_ARRAY_SIZE);
         if (activeRect == null) { // Should never happen
-            activeRect = new Rect(0, 0, referenceSize.getWidth(), referenceSize.getHeight());
+            activeRect = new Rect(0, 0, referenceSize.getWidth(),
+                    referenceSize.getHeight());
         }
         return new Size(activeRect.width(), activeRect.height());
     }

cameraview/src/main/java/com/otaliastudios/cameraview/engine/meter/WhiteBalanceMeter.java

@@ -27,10 +27,13 @@ public class WhiteBalanceMeter extends BaseMeter {
 
     @Override
     protected boolean checkIsSupported(@NonNull ActionHolder holder) {
-        boolean isNotLegacy = readCharacteristic(CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL, -1)
+        boolean isNotLegacy = readCharacteristic(
+                CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL, -1)
                 != CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL_LEGACY;
         Integer awbMode = holder.getBuilder(this).get(CaptureRequest.CONTROL_AWB_MODE);
-        boolean result = isNotLegacy && awbMode != null && awbMode == CaptureRequest.CONTROL_AWB_MODE_AUTO;
+        boolean result = isNotLegacy
+                && awbMode != null
+                && awbMode == CaptureRequest.CONTROL_AWB_MODE_AUTO;
         LOG.i("checkIsSupported:", result);
         return result;
     }
@@ -46,7 +49,8 @@ public class WhiteBalanceMeter extends BaseMeter {
     @Override
     protected void onStarted(@NonNull ActionHolder holder, @NonNull List<MeteringRectangle> areas) {
         LOG.i("onStarted:", "with areas:", areas);
-        int maxRegions = readCharacteristic(CameraCharacteristics.CONTROL_MAX_REGIONS_AWB, 0);
+        int maxRegions = readCharacteristic(CameraCharacteristics.CONTROL_MAX_REGIONS_AWB,
+                0);
         if (!areas.isEmpty() && maxRegions > 0) {
             int max = Math.min(maxRegions, areas.size());
             holder.getBuilder(this).set(CaptureRequest.CONTROL_AWB_REGIONS,
@@ -56,7 +60,8 @@ public class WhiteBalanceMeter extends BaseMeter {
     }
 
     @Override
-    public void onCaptureCompleted(@NonNull ActionHolder holder, @NonNull CaptureRequest request,
+    public void onCaptureCompleted(@NonNull ActionHolder holder,
+                                   @NonNull CaptureRequest request,
                                    @NonNull TotalCaptureResult result) {
         super.onCaptureCompleted(holder, request, result);
         Integer awbState = result.get(CaptureResult.CONTROL_AWB_STATE);

cameraview/src/main/java/com/otaliastudios/cameraview/engine/meter/WhiteBalanceReset.java

@@ -30,9 +30,11 @@ public class WhiteBalanceReset extends BaseReset {
     @Override
     protected void onStarted(@NonNull ActionHolder holder, @Nullable MeteringRectangle area) {
         LOG.w("onStarted:", "with area:", area);
-        int maxRegions = readCharacteristic(CameraCharacteristics.CONTROL_MAX_REGIONS_AWB, 0);
+        int maxRegions = readCharacteristic(CameraCharacteristics.CONTROL_MAX_REGIONS_AWB,
+                0);
         if (area != null && maxRegions > 0) {
-            holder.getBuilder(this).set(CaptureRequest.CONTROL_AWB_REGIONS, new MeteringRectangle[]{area});
+            holder.getBuilder(this).set(CaptureRequest.CONTROL_AWB_REGIONS,
+                    new MeteringRectangle[]{area});
             holder.applyBuilder(this);
         }
         setState(STATE_COMPLETED);

cameraview/src/main/java/com/otaliastudios/cameraview/engine/offset/Axis.java

@@ -21,7 +21,7 @@ public enum Axis {
      * This rotation axis takes into account the current
      * {@link com.otaliastudios.cameraview.controls.Facing} value.
      *
-     * - for {@link com.otaliastudios.cameraview.controls.Facing#BACK}, this equals {@link #ABSOLUTE}
+     * - for {@link com.otaliastudios.cameraview.controls.Facing#BACK}, this is {@link #ABSOLUTE}
      * - for {@link com.otaliastudios.cameraview.controls.Facing#FRONT}, this is inverted
      */
     RELATIVE_TO_SENSOR

cameraview/src/main/java/com/otaliastudios/cameraview/filter/BaseFilter.java

@@ -36,7 +36,8 @@ import java.nio.FloatBuffer;
  * NOTE - the {@link android.graphics.SurfaceTexture} restrictions apply:
  * We only support the {@link android.opengl.GLES11Ext#GL_TEXTURE_EXTERNAL_OES} texture target
  * and it must be specified in the fragment shader as a samplerExternalOES texture.
- * You also have to explicitly require the extension: see {@link #createDefaultFragmentShader(String)}.
+ * You also have to explicitly require the extension: see
+ * {@link #createDefaultFragmentShader(String)}.
  *
  */
 public abstract class BaseFilter implements Filter {
@@ -44,31 +45,42 @@ public abstract class BaseFilter implements Filter {
     private final static String TAG = BaseFilter.class.getSimpleName();
     private final static CameraLogger LOG = CameraLogger.create(TAG);
 
-    private final static String DEFAULT_VERTEX_POSITION_NAME = "aPosition";
-    private final static String DEFAULT_VERTEX_TEXTURE_COORDINATE_NAME = "aTextureCoord";
-    private final static String DEFAULT_VERTEX_MVP_MATRIX_NAME = "uMVPMatrix";
-    private final static String DEFAULT_VERTEX_TRANSFORM_MATRIX_NAME = "uTexMatrix";
-    private final static String DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME = "vTextureCoord";
+    @SuppressWarnings("WeakerAccess")
+    protected final static String DEFAULT_VERTEX_POSITION_NAME = "aPosition";
+
+    @SuppressWarnings("WeakerAccess")
+    protected final static String DEFAULT_VERTEX_TEXTURE_COORDINATE_NAME = "aTextureCoord";
+
+    @SuppressWarnings("WeakerAccess")
+    protected final static String DEFAULT_VERTEX_MVP_MATRIX_NAME = "uMVPMatrix";
+
+    @SuppressWarnings("WeakerAccess")
+    protected final static String DEFAULT_VERTEX_TRANSFORM_MATRIX_NAME = "uTexMatrix";
+    protected final static String DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME = "vTextureCoord";
 
     @NonNull
-    private static String createDefaultVertexShader(@NonNull String vertexPositionName,
+    private static String createDefaultVertexShader(
+            @NonNull String vertexPositionName,
             @NonNull String vertexTextureCoordinateName,
             @NonNull String vertexModelViewProjectionMatrixName,
             @NonNull String vertexTransformMatrixName,
             @NonNull String fragmentTextureCoordinateName) {
-        return "uniform mat4 "+vertexModelViewProjectionMatrixName+";\n" +
-                "uniform mat4 "+vertexTransformMatrixName+";\n" +
-                "attribute vec4 "+vertexPositionName+";\n" +
-                "attribute vec4 "+vertexTextureCoordinateName+";\n" +
-                "varying vec2 "+fragmentTextureCoordinateName+";\n" +
-                "void main() {\n" +
-                "    gl_Position = "+vertexModelViewProjectionMatrixName+" * "+vertexPositionName+";\n" +
-                "    vTextureCoord = ("+vertexTransformMatrixName+" * "+vertexTextureCoordinateName+").xy;\n" +
-                "}\n";
+        return "uniform mat4 "+vertexModelViewProjectionMatrixName+";\n"
+                + "uniform mat4 "+vertexTransformMatrixName+";\n"
+                + "attribute vec4 "+vertexPositionName+";\n"
+                + "attribute vec4 "+vertexTextureCoordinateName+";\n"
+                + "varying vec2 "+fragmentTextureCoordinateName+";\n"
+                + "void main() {\n"
+                + "    gl_Position = " +vertexModelViewProjectionMatrixName+" * "
+                + vertexPositionName+";\n"
+                + "    "+fragmentTextureCoordinateName+" = ("+vertexTransformMatrixName+" * "
+                + vertexTextureCoordinateName+").xy;\n"
+                + "}\n";
     }
 
     @NonNull
-    private static String createDefaultFragmentShader(@NonNull String fragmentTextureCoordinateName) {
+    private static String createDefaultFragmentShader(
+            @NonNull String fragmentTextureCoordinateName) {
         return "#extension GL_OES_EGL_image_external : require\n"
                 + "precision mediump float;\n"
                 + "varying vec2 "+fragmentTextureCoordinateName+";\n"
@@ -94,7 +106,7 @@ public abstract class BaseFilter implements Filter {
     });
 
     private int vertexModelViewProjectionMatrixLocation = -1;
-    private int vertexTranformMatrixLocation = -1;
+    private int vertexTransformMatrixLocation = -1;
     private int vertexPositionLocation = -1;
     private int vertexTextureCoordinateLocation = -1;
     @VisibleForTesting int programHandle = -1;
@@ -121,6 +133,7 @@ public abstract class BaseFilter implements Filter {
                 fragmentTextureCoordinateName);
     }
 
+    @SuppressWarnings("WeakerAccess")
     @NonNull
     protected String createDefaultFragmentShader() {
         return createDefaultFragmentShader(fragmentTextureCoordinateName);
@@ -131,12 +144,16 @@ public abstract class BaseFilter implements Filter {
         this.programHandle = programHandle;
         vertexPositionLocation = GLES20.glGetAttribLocation(programHandle, vertexPositionName);
         GlUtils.checkLocation(vertexPositionLocation, vertexPositionName);
-        vertexTextureCoordinateLocation = GLES20.glGetAttribLocation(programHandle, vertexTextureCoordinateName);
+        vertexTextureCoordinateLocation = GLES20.glGetAttribLocation(programHandle,
+                vertexTextureCoordinateName);
         GlUtils.checkLocation(vertexTextureCoordinateLocation, vertexTextureCoordinateName);
-        vertexModelViewProjectionMatrixLocation = GLES20.glGetUniformLocation(programHandle, vertexModelViewProjectionMatrixName);
-        GlUtils.checkLocation(vertexModelViewProjectionMatrixLocation, vertexModelViewProjectionMatrixName);
-        vertexTranformMatrixLocation = GLES20.glGetUniformLocation(programHandle, vertexTransformMatrixName);
-        GlUtils.checkLocation(vertexTranformMatrixLocation, vertexTransformMatrixName);
+        vertexModelViewProjectionMatrixLocation = GLES20.glGetUniformLocation(programHandle,
+                vertexModelViewProjectionMatrixName);
+        GlUtils.checkLocation(vertexModelViewProjectionMatrixLocation,
+                vertexModelViewProjectionMatrixName);
+        vertexTransformMatrixLocation = GLES20.glGetUniformLocation(programHandle,
+                vertexTransformMatrixName);
+        GlUtils.checkLocation(vertexTransformMatrixLocation, vertexTransformMatrixName);
     }
 
     @Override
@@ -145,7 +162,7 @@ public abstract class BaseFilter implements Filter {
         vertexPositionLocation = -1;
         vertexTextureCoordinateLocation = -1;
         vertexModelViewProjectionMatrixLocation = -1;
-        vertexTranformMatrixLocation = -1;
+        vertexTransformMatrixLocation = -1;
     }
 
     @NonNull
@@ -160,48 +177,53 @@ public abstract class BaseFilter implements Filter {
     }
 
     @Override
-    public void draw(float[] transformMatrix) {
+    public void draw(long timestampUs, float[] transformMatrix) {
         if (programHandle == -1) {
-            LOG.w("Filter.draw() called after destroying the filter. This can happen rarely because of threading.");
+            LOG.w("Filter.draw() called after destroying the filter. " +
+                    "This can happen rarely because of threading.");
         } else {
-            onPreDraw(transformMatrix);
-            onDraw();
-            onPostDraw();
+            onPreDraw(timestampUs, transformMatrix);
+            onDraw(timestampUs);
+            onPostDraw(timestampUs);
         }
     }
 
-    protected void onPreDraw(float[] transformMatrix) {
+    protected void onPreDraw(long timestampUs, float[] transformMatrix) {
         // Copy the model / view / projection matrix over.
-        GLES20.glUniformMatrix4fv(vertexModelViewProjectionMatrixLocation, 1, false, GlUtils.IDENTITY_MATRIX, 0);
+        GLES20.glUniformMatrix4fv(vertexModelViewProjectionMatrixLocation, 1,
+                false, GlUtils.IDENTITY_MATRIX, 0);
         GlUtils.checkError("glUniformMatrix4fv");
 
         // Copy the texture transformation matrix over.
-        GLES20.glUniformMatrix4fv(vertexTranformMatrixLocation, 1, false, transformMatrix, 0);
+        GLES20.glUniformMatrix4fv(vertexTransformMatrixLocation, 1,
+                false, transformMatrix, 0);
         GlUtils.checkError("glUniformMatrix4fv");
 
         // Enable the "aPosition" vertex attribute.
         // Connect vertexBuffer to "aPosition".
         GLES20.glEnableVertexAttribArray(vertexPositionLocation);
         GlUtils.checkError("glEnableVertexAttribArray: " + vertexPositionLocation);
-        GLES20.glVertexAttribPointer(vertexPositionLocation, 2, GLES20.GL_FLOAT, false, 8, vertexPosition);
+        GLES20.glVertexAttribPointer(vertexPositionLocation, 2, GLES20.GL_FLOAT,
+                false, 8, vertexPosition);
         GlUtils.checkError("glVertexAttribPointer");
 
         // Enable the "aTextureCoord" vertex attribute.
         // Connect texBuffer to "aTextureCoord".
         GLES20.glEnableVertexAttribArray(vertexTextureCoordinateLocation);
         GlUtils.checkError("glEnableVertexAttribArray");
-        GLES20.glVertexAttribPointer(vertexTextureCoordinateLocation, 2, GLES20.GL_FLOAT, false, 8, textureCoordinates);
+        GLES20.glVertexAttribPointer(vertexTextureCoordinateLocation, 2, GLES20.GL_FLOAT,
+                false, 8, textureCoordinates);
         GlUtils.checkError("glVertexAttribPointer");
     }
 
     @SuppressWarnings("WeakerAccess")
-    protected void onDraw() {
+    protected void onDraw(long timestampUs) {
         GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, 4);
         GlUtils.checkError("glDrawArrays");
     }
 
     @SuppressWarnings("WeakerAccess")
-    protected void onPostDraw() {
+    protected void onPostDraw(long timestampUs) {
         GLES20.glDisableVertexAttribArray(vertexPositionLocation);
         GLES20.glDisableVertexAttribArray(vertexTextureCoordinateLocation);
     }

cameraview/src/main/java/com/otaliastudios/cameraview/filter/Filter.java

@@ -67,9 +67,10 @@ public interface Filter {
      * Called to render the actual texture. The given transformation matrix
      * should be applied.
      *
+     * @param timestampUs timestamp in microseconds
      * @param transformMatrix matrix
      */
-    void draw(float[] transformMatrix);
+    void draw(long timestampUs, float[] transformMatrix);
 
     /**
      * Called anytime the output size changes.

cameraview/src/main/java/com/otaliastudios/cameraview/filter/MultiFilter.java

@@ -26,8 +26,9 @@ import java.util.Map;
  * New filters can be added at any time through {@link #addFilter(Filter)}, but currently they
  * can not be removed because we can not easily ensure that they would be correctly released.
  *
- * The {@link MultiFilter} does also implement {@link OneParameterFilter} and {@link TwoParameterFilter},
- * dispatching all the parameter calls to child filters, assuming they support it.
+ * The {@link MultiFilter} does also implement {@link OneParameterFilter} and
+ * {@link TwoParameterFilter}, dispatching all the parameter calls to child filters,
+ * assuming they support it.
  *
  * There are some important technical caveats when using {@link MultiFilter}:
  * - each child filter requires the allocation of a GL framebuffer. Using a large number of filters
@@ -146,11 +147,17 @@ public class MultiFilter implements Filter, OneParameterFilter, TwoParameterFilt
             state.textureId = textureArray[0];
 
             GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, state.textureId);
-            GLES20.glTexImage2D(GLES20.GL_TEXTURE_2D, 0, GLES20.GL_RGBA, state.size.getWidth(), state.size.getHeight(), 0, GLES20.GL_RGBA, GLES20.GL_UNSIGNED_BYTE, null);
-            GLES20.glTexParameterf(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_LINEAR);
-            GLES20.glTexParameterf(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_LINEAR);
-            GLES20.glTexParameterf(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_S, GLES20.GL_CLAMP_TO_EDGE);
-            GLES20.glTexParameterf(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_T, GLES20.GL_CLAMP_TO_EDGE);
+            GLES20.glTexImage2D(GLES20.GL_TEXTURE_2D, 0, GLES20.GL_RGBA,
+                    state.size.getWidth(), state.size.getHeight(), 0, GLES20.GL_RGBA,
+                    GLES20.GL_UNSIGNED_BYTE, null);
+            GLES20.glTexParameterf(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER,
+                    GLES20.GL_LINEAR);
+            GLES20.glTexParameterf(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER,
+                    GLES20.GL_LINEAR);
+            GLES20.glTexParameterf(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_S,
+                    GLES20.GL_CLAMP_TO_EDGE);
+            GLES20.glTexParameterf(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_T,
+                    GLES20.GL_CLAMP_TO_EDGE);
             GLES20.glBindFramebuffer(GLES20.GL_FRAMEBUFFER, state.framebufferId);
             GLES20.glFramebufferTexture2D(GLES20.GL_FRAMEBUFFER,
                     GLES20.GL_COLOR_ATTACHMENT0,
@@ -230,7 +237,7 @@ public class MultiFilter implements Filter, OneParameterFilter, TwoParameterFilt
     }
 
     @Override
-    public void draw(float[] transformMatrix) {
+    public void draw(long timestampUs, float[] transformMatrix) {
         synchronized (lock) {
             for (int i = 0; i < filters.size(); i++) {
                 boolean isFirst = i == 0;
@@ -258,9 +265,9 @@ public class MultiFilter implements Filter, OneParameterFilter, TwoParameterFilt
                 // The first filter should apply all the transformations. Then,
                 // since they are applied, we should use a no-op matrix.
                 if (isFirst) {
-                    filter.draw(transformMatrix);
+                    filter.draw(timestampUs, transformMatrix);
                 } else {
-                    filter.draw(GlUtils.IDENTITY_MATRIX);
+                    filter.draw(timestampUs, GlUtils.IDENTITY_MATRIX);
                 }
 
                 // Set the input for the next cycle:

cameraview/src/main/java/com/otaliastudios/cameraview/filters/AutoFixFilter.java

@@ -24,7 +24,7 @@ public class AutoFixFilter extends BaseFilter implements OneParameterFilter {
             + "float hist_scale;\n"
             + "float density_offset;\n"
             + "float density_scale;\n"
-            + "varying vec2 vTextureCoord;\n"
+            + "varying vec2 "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+";\n"
             + "void main() {\n"
             + "  shift_scale = " + (1.0f / 256f) + ";\n"
             + "  hist_offset = " + (0.5f / 766f) + ";\n"
@@ -32,7 +32,8 @@ public class AutoFixFilter extends BaseFilter implements OneParameterFilter {
             + "  density_offset = " + (0.5f / 1024f) + ";\n"
             + "  density_scale = " + (1023f / 1024f) + ";\n"
             + "  const vec3 weights = vec3(0.33333, 0.33333, 0.33333);\n"
-            + "  vec4 color = texture2D(tex_sampler_0, vTextureCoord);\n"
+            + "  vec4 color = texture2D(tex_sampler_0, "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME
+            + ");\n"
             + "  float energy = dot(color.rgb, weights);\n"
             + "  float mask_value = energy - 0.5;\n"
             + "  float alpha;\n"
@@ -116,8 +117,8 @@ public class AutoFixFilter extends BaseFilter implements OneParameterFilter {
     }
 
     @Override
-    protected void onPreDraw(float[] transformMatrix) {
-        super.onPreDraw(transformMatrix);
+    protected void onPreDraw(long timestampUs, float[] transformMatrix) {
+        super.onPreDraw(timestampUs, transformMatrix);
         GLES20.glUniform1f(scaleLocation, scale);
         GlUtils.checkError("glUniform1f");
     }

cameraview/src/main/java/com/otaliastudios/cameraview/filters/BlackAndWhiteFilter.java

@@ -11,9 +11,9 @@ public class BlackAndWhiteFilter extends BaseFilter {
 
     private final static String FRAGMENT_SHADER = "#extension GL_OES_EGL_image_external : require\n"
             + "precision mediump float;\n"
-            + "varying vec2 vTextureCoord;\n"
+            + "varying vec2 "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+";\n"
             + "uniform samplerExternalOES sTexture;\n" + "void main() {\n"
-            + "  vec4 color = texture2D(sTexture, vTextureCoord);\n"
+            + "  vec4 color = texture2D(sTexture, "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+");\n"
             + "  float colorR = (color.r + color.g + color.b) / 3.0;\n"
             + "  float colorG = (color.r + color.g + color.b) / 3.0;\n"
             + "  float colorB = (color.r + color.g + color.b) / 3.0;\n"

cameraview/src/main/java/com/otaliastudios/cameraview/filters/BrightnessFilter.java

@@ -17,9 +17,9 @@ public class BrightnessFilter extends BaseFilter implements OneParameterFilter {
             + "precision mediump float;\n"
             + "uniform samplerExternalOES sTexture;\n"
             + "uniform float brightness;\n"
-            + "varying vec2 vTextureCoord;\n"
+            + "varying vec2 "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+";\n"
             + "void main() {\n"
-            + "  vec4 color = texture2D(sTexture, vTextureCoord);\n"
+            + "  vec4 color = texture2D(sTexture, "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+");\n"
             + "  gl_FragColor = brightness * color;\n"
             + "}\n";
 
@@ -86,8 +86,8 @@ public class BrightnessFilter extends BaseFilter implements OneParameterFilter {
     }
 
     @Override
-    protected void onPreDraw(float[] transformMatrix) {
-        super.onPreDraw(transformMatrix);
+    protected void onPreDraw(long timestampUs, float[] transformMatrix) {
+        super.onPreDraw(timestampUs, transformMatrix);
         GLES20.glUniform1f(brightnessLocation, brightness);
         GlUtils.checkError("glUniform1f");
     }

cameraview/src/main/java/com/otaliastudios/cameraview/filters/ContrastFilter.java

@@ -17,9 +17,9 @@ public class ContrastFilter extends BaseFilter implements OneParameterFilter {
             + "precision mediump float;\n"
             + "uniform samplerExternalOES sTexture;\n"
             + "uniform float contrast;\n"
-            + "varying vec2 vTextureCoord;\n"
+            + "varying vec2 "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+";\n"
             + "void main() {\n"
-            + "  vec4 color = texture2D(sTexture, vTextureCoord);\n"
+            + "  vec4 color = texture2D(sTexture, "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+");\n"
             + "  color -= 0.5;\n"
             + "  color *= contrast;\n"
             + "  color += 0.5;\n"
@@ -88,8 +88,8 @@ public class ContrastFilter extends BaseFilter implements OneParameterFilter {
     }
 
     @Override
-    protected void onPreDraw(float[] transformMatrix) {
-        super.onPreDraw(transformMatrix);
+    protected void onPreDraw(long timestampUs, float[] transformMatrix) {
+        super.onPreDraw(timestampUs, transformMatrix);
         GLES20.glUniform1f(contrastLocation, contrast);
         GlUtils.checkError("glUniform1f");
     }

cameraview/src/main/java/com/otaliastudios/cameraview/filters/CrossProcessFilter.java

@@ -13,9 +13,9 @@ public class CrossProcessFilter extends BaseFilter {
     private final static String FRAGMENT_SHADER = "#extension GL_OES_EGL_image_external : require\n"
             + "precision mediump float;\n"
             + "uniform samplerExternalOES sTexture;\n"
-            + "varying vec2 vTextureCoord;\n"
+            + "varying vec2 "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+";\n"
             + "void main() {\n"
-            + "  vec4 color = texture2D(sTexture, vTextureCoord);\n"
+            + "  vec4 color = texture2D(sTexture, "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+");\n"
             + "  vec3 ncolor = vec3(0.0, 0.0, 0.0);\n"
             + "  float value;\n"
             + "  if (color.r < 0.5) {\n"

cameraview/src/main/java/com/otaliastudios/cameraview/filters/DocumentaryFilter.java

@@ -22,7 +22,7 @@ public class DocumentaryFilter extends BaseFilter {
             + "float stepsize;\n"
             + "uniform float inv_max_dist;\n"
             + "uniform vec2 scale;\n"
-            + "varying vec2 vTextureCoord;\n"
+            + "varying vec2 "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+";\n"
             + "float rand(vec2 loc) {\n"
             + "  float theta1 = dot(loc, vec2(0.9898, 0.233));\n"
             + "  float theta2 = dot(loc, vec2(12.0, 78.0));\n"
@@ -41,8 +41,8 @@ public class DocumentaryFilter extends BaseFilter {
             + "  stepsize = " + 1.0f / 255.0f + ";\n"
 
             // black white
-            + "  vec4 color = texture2D(sTexture, vTextureCoord);\n"
-            + "  float dither = rand(vTextureCoord + seed);\n"
+            + "  vec4 color = texture2D(sTexture, "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+");\n"
+            + "  float dither = rand("+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+" + seed);\n"
             + "  vec3 xform = clamp(2.0 * color.rgb, 0.0, 1.0);\n"
             + "  vec3 temp = clamp(2.0 * (color.rgb + stepsize), 0.0, 1.0);\n"
             + "  vec3 new_color = clamp(xform + (temp - xform) * (dither - 0.5), 0.0, 1.0);\n"
@@ -50,7 +50,7 @@ public class DocumentaryFilter extends BaseFilter {
             + "  float gray = dot(new_color, vec3(0.299, 0.587, 0.114));\n"
             + "  new_color = vec3(gray, gray, gray);\n"
             // vignette
-            + "  vec2 coord = vTextureCoord - vec2(0.5, 0.5);\n"
+            + "  vec2 coord = "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+" - vec2(0.5, 0.5);\n"
             + "  float dist = length(coord * scale);\n"
             + "  float lumen = 0.85 / (1.0 + exp((dist * inv_max_dist - 0.83) * 20.0)) + 0.15;\n"
             + "  gl_FragColor = vec4(new_color * lumen, color.a);\n"
@@ -93,8 +93,8 @@ public class DocumentaryFilter extends BaseFilter {
     }
 
     @Override
-    protected void onPreDraw(float[] transformMatrix) {
-        super.onPreDraw(transformMatrix);
+    protected void onPreDraw(long timestampUs, float[] transformMatrix) {
+        super.onPreDraw(timestampUs, transformMatrix);
         float[] scale = new float[2];
         if (mWidth > mHeight) {
             scale[0] = 1f;

cameraview/src/main/java/com/otaliastudios/cameraview/filters/DuotoneFilter.java

@@ -20,9 +20,9 @@ public class DuotoneFilter extends BaseFilter implements TwoParameterFilter {
             + "uniform samplerExternalOES sTexture;\n"
             + "uniform vec3 first;\n"
             + "uniform vec3 second;\n"
-            + "varying vec2 vTextureCoord;\n"
+            + "varying vec2 "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+";\n"
             + "void main() {\n"
-            + "  vec4 color = texture2D(sTexture, vTextureCoord);\n"
+            + "  vec4 color = texture2D(sTexture, "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+");\n"
             + "  float energy = (color.r + color.g + color.b) * 0.3333;\n"
             + "  vec3 new_color = (1.0 - energy) * first + energy * second;\n"
             + "  gl_FragColor = vec4(new_color.rgb, color.a);\n"
@@ -137,8 +137,8 @@ public class DuotoneFilter extends BaseFilter implements TwoParameterFilter {
     }
 
     @Override
-    protected void onPreDraw(float[] transformMatrix) {
-        super.onPreDraw(transformMatrix);
+    protected void onPreDraw(long timestampUs, float[] transformMatrix) {
+        super.onPreDraw(timestampUs, transformMatrix);
         float[] first = new float[]{
                 Color.red(mFirstColor) / 255f,
                 Color.green(mFirstColor) / 255f,

cameraview/src/main/java/com/otaliastudios/cameraview/filters/FillLightFilter.java

@@ -18,10 +18,10 @@ public class FillLightFilter extends BaseFilter implements OneParameterFilter {
             + "uniform samplerExternalOES sTexture;\n"
             + "uniform float mult;\n"
             + "uniform float igamma;\n"
-            + "varying vec2 vTextureCoord;\n"
+            + "varying vec2 "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+";\n"
             + "void main() {\n"
             + "  const vec3 color_weights = vec3(0.25, 0.5, 0.25);\n"
-            + "  vec4 color = texture2D(sTexture, vTextureCoord);\n"
+            + "  vec4 color = texture2D(sTexture, "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+");\n"
             + "  float lightmask = dot(color.rgb, color_weights);\n"
             + "  float backmask = (1.0 - lightmask);\n"
             + "  vec3 ones = vec3(1.0, 1.0, 1.0);\n"
@@ -95,8 +95,8 @@ public class FillLightFilter extends BaseFilter implements OneParameterFilter {
     }
 
     @Override
-    protected void onPreDraw(float[] transformMatrix) {
-        super.onPreDraw(transformMatrix);
+    protected void onPreDraw(long timestampUs, float[] transformMatrix) {
+        super.onPreDraw(timestampUs, transformMatrix);
         float amount = 1.0f - strength;
         float multiplier = 1.0f / (amount * 0.7f + 0.3f);
         GLES20.glUniform1f(multiplierLocation, multiplier);

cameraview/src/main/java/com/otaliastudios/cameraview/filters/GammaFilter.java

@@ -15,11 +15,12 @@ public class GammaFilter extends BaseFilter implements OneParameterFilter {
 
     private final static String FRAGMENT_SHADER = "#extension GL_OES_EGL_image_external : require\n"
             + "precision mediump float;\n"
-            + "varying vec2 vTextureCoord;\n"
+            + "varying vec2 "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+";\n"
             + "uniform samplerExternalOES sTexture;\n"
             + "uniform float gamma;\n"
             + "void main() {\n"
-            + "  vec4 textureColor = texture2D(sTexture, vTextureCoord);\n"
+            + "  vec4 textureColor = texture2D(sTexture, "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME
+            + ");\n"
             + "  gl_FragColor = vec4(pow(textureColor.rgb, vec3(gamma)), textureColor.w);\n"
             + "}\n";
 
@@ -82,8 +83,8 @@ public class GammaFilter extends BaseFilter implements OneParameterFilter {
     }
 
     @Override
-    protected void onPreDraw(float[] transformMatrix) {
-        super.onPreDraw(transformMatrix);
+    protected void onPreDraw(long timestampUs, float[] transformMatrix) {
+        super.onPreDraw(timestampUs, transformMatrix);
         GLES20.glUniform1f(gammaLocation, gamma);
         GlUtils.checkError("glUniform1f");
     }

cameraview/src/main/java/com/otaliastudios/cameraview/filters/GrainFilter.java

@@ -19,7 +19,7 @@ public class GrainFilter extends BaseFilter implements OneParameterFilter {
     private final static String FRAGMENT_SHADER = "#extension GL_OES_EGL_image_external : require\n"
             + "precision mediump float;\n"
             + "vec2 seed;\n"
-            + "varying vec2 vTextureCoord;\n"
+            + "varying vec2 "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+";\n"
             + "uniform samplerExternalOES tex_sampler_0;\n"
             + "uniform samplerExternalOES tex_sampler_1;\n"
             + "uniform float scale;\n"
@@ -40,18 +40,25 @@ public class GrainFilter extends BaseFilter implements OneParameterFilter {
             + "void main() {\n"
             + "  seed[0] = " + RANDOM.nextFloat() + ";\n"
             + "  seed[1] = " + RANDOM.nextFloat() + ";\n"
-            + "  float noise = texture2D(tex_sampler_1, vTextureCoord + vec2(-stepX, -stepY)).r * 0.224;\n"
-            + "  noise += texture2D(tex_sampler_1, vTextureCoord + vec2(-stepX, stepY)).r * 0.224;\n"
-            + "  noise += texture2D(tex_sampler_1, vTextureCoord + vec2(stepX, -stepY)).r * 0.224;\n"
-            + "  noise += texture2D(tex_sampler_1, vTextureCoord + vec2(stepX, stepY)).r * 0.224;\n"
+            + "  float noise = texture2D(tex_sampler_1, "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME
+            + " + vec2(-stepX, -stepY)).r * 0.224;\n"
+            + "  noise += texture2D(tex_sampler_1, "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME
+            + " + vec2(-stepX, stepY)).r * 0.224;\n"
+            + "  noise += texture2D(tex_sampler_1, "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME
+            + " + vec2(stepX, -stepY)).r * 0.224;\n"
+            + "  noise += texture2D(tex_sampler_1, "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME
+            + " + vec2(stepX, stepY)).r * 0.224;\n"
             + "  noise += 0.4448;\n"
             + "  noise *= scale;\n"
-            + "  vec4 color = texture2D(tex_sampler_0, vTextureCoord);\n"
+            + "  vec4 color = texture2D(tex_sampler_0, "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME
+            + ");\n"
             + "  float energy = 0.33333 * color.r + 0.33333 * color.g + 0.33333 * color.b;\n"
             + "  float mask = (1.0 - sqrt(energy));\n"
             + "  float weight = 1.0 - 1.333 * mask * noise;\n"
             + "  gl_FragColor = vec4(color.rgb * weight, color.a);\n"
-            + "  gl_FragColor = gl_FragColor+vec4(rand(vTextureCoord + seed), rand(vTextureCoord + seed),rand(vTextureCoord + seed),1);\n"
+            + "  gl_FragColor = gl_FragColor+vec4(rand("+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME
+            + " + seed), rand("+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+" + seed),rand("
+            + DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+" + seed),1);\n"
             + "}\n";
 
     private float strength = 0.5f;
@@ -61,7 +68,6 @@ public class GrainFilter extends BaseFilter implements OneParameterFilter {
     private int stepXLocation = -1;
     private int stepYLocation = -1;
 
-    @SuppressWarnings("WeakerAccess")
     public GrainFilter() { }
 
     @Override
@@ -132,8 +138,8 @@ public class GrainFilter extends BaseFilter implements OneParameterFilter {
     }
 
     @Override
-    protected void onPreDraw(float[] transformMatrix) {
-        super.onPreDraw(transformMatrix);
+    protected void onPreDraw(long timestampUs, float[] transformMatrix) {
+        super.onPreDraw(timestampUs, transformMatrix);
         GLES20.glUniform1f(strengthLocation, strength);
         GlUtils.checkError("glUniform1f");
         GLES20.glUniform1f(stepXLocation, 0.5f / width);

cameraview/src/main/java/com/otaliastudios/cameraview/filters/GrayscaleFilter.java

@@ -12,9 +12,9 @@ public class GrayscaleFilter extends BaseFilter {
     private final static String FRAGMENT_SHADER = "#extension GL_OES_EGL_image_external : require\n"
             + "precision mediump float;\n"
             + "uniform samplerExternalOES sTexture;\n"
-            + "varying vec2 vTextureCoord;\n"
+            + "varying vec2 "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+";\n"
             + "void main() {\n"
-            + "  vec4 color = texture2D(sTexture, vTextureCoord);\n"
+            + "  vec4 color = texture2D(sTexture, "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+");\n"
             + "  float y = dot(color, vec4(0.299, 0.587, 0.114, 0));\n"
             + "  gl_FragColor = vec4(y, y, y, color.a);\n"
             + "}\n";

cameraview/src/main/java/com/otaliastudios/cameraview/filters/HueFilter.java

@@ -15,7 +15,7 @@ public class HueFilter extends BaseFilter implements OneParameterFilter {
 
     private final static String FRAGMENT_SHADER = "#extension GL_OES_EGL_image_external : require\n"
             + "precision mediump float;\n"
-            + "varying vec2 vTextureCoord;\n"
+            + "varying vec2 "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+";\n"
             + "uniform samplerExternalOES sTexture;\n"
             + "uniform float hue;\n"
             + "void main() {\n"
@@ -25,7 +25,7 @@ public class HueFilter extends BaseFilter implements OneParameterFilter {
             + "  vec4 kYIQToR = vec4 (1.0, 0.9563, 0.6210, 0.0);\n"
             + "  vec4 kYIQToG = vec4 (1.0, -0.2721, -0.6474, 0.0);\n"
             + "  vec4 kYIQToB = vec4 (1.0, -1.1070, 1.7046, 0.0);\n"
-            + "  vec4 color = texture2D(sTexture, vTextureCoord);\n"
+            + "  vec4 color = texture2D(sTexture, "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+");\n"
             + "  float YPrime = dot(color, kRGBToYPrime);\n"
             + "  float I = dot(color, kRGBToI);\n"
             + "  float Q = dot(color, kRGBToQ);\n"
@@ -96,8 +96,8 @@ public class HueFilter extends BaseFilter implements OneParameterFilter {
     }
 
     @Override
-    protected void onPreDraw(float[] transformMatrix) {
-        super.onPreDraw(transformMatrix);
+    protected void onPreDraw(long timestampUs, float[] transformMatrix) {
+        super.onPreDraw(timestampUs, transformMatrix);
         // map it on 360 degree circle
         float shaderHue = ((hue - 45) / 45f + 0.5f) * -1;
         GLES20.glUniform1f(hueLocation, shaderHue);

cameraview/src/main/java/com/otaliastudios/cameraview/filters/InvertColorsFilter.java

@@ -11,10 +11,10 @@ public class InvertColorsFilter extends BaseFilter {
 
     private final static String FRAGMENT_SHADER = "#extension GL_OES_EGL_image_external : require\n"
             + "precision mediump float;\n"
-            + "varying vec2 vTextureCoord;\n"
+            + "varying vec2 "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+";\n"
             + "uniform samplerExternalOES sTexture;\n"
             + "void main() {\n"
-            + "  vec4 color = texture2D(sTexture, vTextureCoord);\n"
+            + "  vec4 color = texture2D(sTexture, "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+");\n"
             + "  float colorR = (1.0 - color.r) / 1.0;\n"
             + "  float colorG = (1.0 - color.g) / 1.0;\n"
             + "  float colorB = (1.0 - color.b) / 1.0;\n"

cameraview/src/main/java/com/otaliastudios/cameraview/filters/LomoishFilter.java

@@ -7,7 +7,6 @@ import androidx.annotation.NonNull;
 import com.otaliastudios.cameraview.filter.BaseFilter;
 import com.otaliastudios.cameraview.internal.GlUtils;
 
-import java.util.Date;
 import java.util.Random;
 
 /**
@@ -25,7 +24,7 @@ public class LomoishFilter extends BaseFilter {
             + "uniform float inv_max_dist;\n"
             + "vec2 seed;\n"
             + "float stepsize;\n"
-            + "varying vec2 vTextureCoord;\n"
+            + "varying vec2 "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+";\n"
             + "float rand(vec2 loc) {\n"
             + "  float theta1 = dot(loc, vec2(0.9898, 0.233));\n"
             + "  float theta2 = dot(loc, vec2(12.0, 78.0));\n"
@@ -44,18 +43,18 @@ public class LomoishFilter extends BaseFilter {
             // sharpen
             + "  vec3 nbr_color = vec3(0.0, 0.0, 0.0);\n"
             + "  vec2 coord;\n"
-            + "  vec4 color = texture2D(sTexture, vTextureCoord);\n"
-            + "  coord.x = vTextureCoord.x - 0.5 * stepsizeX;\n"
-            + "  coord.y = vTextureCoord.y - stepsizeY;\n"
+            + "  vec4 color = texture2D(sTexture, "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+");\n"
+            + "  coord.x = "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+".x - 0.5 * stepsizeX;\n"
+            + "  coord.y = "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+".y - stepsizeY;\n"
             + "  nbr_color += texture2D(sTexture, coord).rgb - color.rgb;\n"
-            + "  coord.x = vTextureCoord.x - stepsizeX;\n"
-            + "  coord.y = vTextureCoord.y + 0.5 * stepsizeY;\n"
+            + "  coord.x = "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+".x - stepsizeX;\n"
+            + "  coord.y = "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+".y + 0.5 * stepsizeY;\n"
             + "  nbr_color += texture2D(sTexture, coord).rgb - color.rgb;\n"
-            + "  coord.x = vTextureCoord.x + stepsizeX;\n"
-            + "  coord.y = vTextureCoord.y - 0.5 * stepsizeY;\n"
+            + "  coord.x = "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+".x + stepsizeX;\n"
+            + "  coord.y = "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+".y - 0.5 * stepsizeY;\n"
             + "  nbr_color += texture2D(sTexture, coord).rgb - color.rgb;\n"
-            + "  coord.x = vTextureCoord.x + stepsizeX;\n"
-            + "  coord.y = vTextureCoord.y + 0.5 * stepsizeY;\n"
+            + "  coord.x = "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+".x + stepsizeX;\n"
+            + "  coord.y = "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+".y + 0.5 * stepsizeY;\n"
             + "  nbr_color += texture2D(sTexture, coord).rgb - color.rgb;\n"
             + "  vec3 s_color = vec3(color.rgb + 0.3 * nbr_color);\n"
             // cross process
@@ -85,12 +84,12 @@ public class LomoishFilter extends BaseFilter {
             + "  }\n"
             + "  c_color.b = s_color.b * 0.5 + 0.25;\n"
             // blackwhite
-            + "  float dither = rand(vTextureCoord + seed);\n"
+            + "  float dither = rand("+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+" + seed);\n"
             + "  vec3 xform = clamp((c_color.rgb - 0.15) * 1.53846, 0.0, 1.0);\n"
             + "  vec3 temp = clamp((color.rgb + stepsize - 0.15) * 1.53846, 0.0, 1.0);\n"
             + "  vec3 bw_color = clamp(xform + (temp - xform) * (dither - 0.5), 0.0, 1.0);\n"
             // vignette
-            + "  coord = vTextureCoord - vec2(0.5, 0.5);\n"
+            + "  coord = "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+" - vec2(0.5, 0.5);\n"
             + "  float dist = length(coord * scale);\n"
             + "  float lumen = 0.85 / (1.0 + exp((dist * inv_max_dist - 0.73) * 20.0)) + 0.15;\n"
             + "  gl_FragColor = vec4(bw_color * lumen, color.a);\n"
@@ -142,8 +141,8 @@ public class LomoishFilter extends BaseFilter {
     }
 
     @Override
-    protected void onPreDraw(float[] transformMatrix) {
-        super.onPreDraw(transformMatrix);
+    protected void onPreDraw(long timestampUs, float[] transformMatrix) {
+        super.onPreDraw(timestampUs, transformMatrix);
         float[] scale = new float[2];
         if (width > height) {
             scale[0] = 1f;

cameraview/src/main/java/com/otaliastudios/cameraview/filters/PosterizeFilter.java

@@ -12,8 +12,8 @@ public class PosterizeFilter extends BaseFilter {
     private final static String FRAGMENT_SHADER = "#extension GL_OES_EGL_image_external : require\n"
             + "precision mediump float;\n"
             + "uniform samplerExternalOES sTexture;\n"
-            + "varying vec2 vTextureCoord;\n" + "void main() {\n"
-            + "  vec4 color = texture2D(sTexture, vTextureCoord);\n"
+            + "varying vec2 "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+";\n" + "void main() {\n"
+            + "  vec4 color = texture2D(sTexture, "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+");\n"
             + "  vec3 pcolor;\n"
             + "  pcolor.r = (color.r >= 0.5) ? 0.75 : 0.25;\n"
             + "  pcolor.g = (color.g >= 0.5) ? 0.75 : 0.25;\n"

cameraview/src/main/java/com/otaliastudios/cameraview/filters/SaturationFilter.java

@@ -20,21 +20,24 @@ public class SaturationFilter extends BaseFilter implements OneParameterFilter {
             + "uniform vec3 exponents;\n"
             + "float shift;\n"
             + "vec3 weights;\n"
-            + "varying vec2 vTextureCoord;\n"
+            + "varying vec2 "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+";\n"
             + "void main() {\n"
             + "  weights[0] = " + 2f / 8f + ";\n"
             + "  weights[1] = " + 5f / 8f + ";\n"
             + "  weights[2] = " + 1f / 8f + ";\n"
             + "  shift = " + 1.0f / 255.0f + ";\n"
-            + "  vec4 oldcolor = texture2D(sTexture, vTextureCoord);\n"
+            + "  vec4 oldcolor = texture2D(sTexture, "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME
+            + ");\n"
             + "  float kv = dot(oldcolor.rgb, weights) + shift;\n"
             + "  vec3 new_color = scale * oldcolor.rgb + (1.0 - scale) * kv;\n"
             + "  gl_FragColor = vec4(new_color, oldcolor.a);\n"
-            + "  vec4 color = texture2D(sTexture, vTextureCoord);\n"
+            + "  vec4 color = texture2D(sTexture, "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME
+            + ");\n"
             + "  float de = dot(color.rgb, weights);\n"
             + "  float inv_de = 1.0 / de;\n"
             + "  vec3 verynew_color = de * pow(color.rgb * inv_de, exponents);\n"
-            + "  float max_color = max(max(max(verynew_color.r, verynew_color.g), verynew_color.b), 1.0);\n"
+            + "  float max_color = max(max(max(verynew_color.r, verynew_color.g), "
+            + "verynew_color.b), 1.0);\n"
             + "  gl_FragColor = gl_FragColor+vec4(verynew_color / max_color, color.a);\n"
             + "}\n";
 
@@ -103,8 +106,8 @@ public class SaturationFilter extends BaseFilter implements OneParameterFilter {
     }
 
     @Override
-    protected void onPreDraw(float[] transformMatrix) {
-        super.onPreDraw(transformMatrix);
+    protected void onPreDraw(long timestampUs, float[] transformMatrix) {
+        super.onPreDraw(timestampUs, transformMatrix);
         if (scale > 0.0f) {
             GLES20.glUniform1f(scaleLocation, 0F);
             GlUtils.checkError("glUniform1f");

cameraview/src/main/java/com/otaliastudios/cameraview/filters/SepiaFilter.java

@@ -13,7 +13,7 @@ public class SepiaFilter extends BaseFilter {
             + "precision mediump float;\n"
             + "uniform samplerExternalOES sTexture;\n"
             + "mat3 matrix;\n"
-            + "varying vec2 vTextureCoord;\n"
+            + "varying vec2 "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+";\n"
             + "void main() {\n"
             + "  matrix[0][0]=" + 805.0f / 2048.0f + ";\n"
             + "  matrix[0][1]=" + 715.0f / 2048.0f + ";\n"
@@ -24,7 +24,7 @@ public class SepiaFilter extends BaseFilter {
             + "  matrix[2][0]=" + 387.0f / 2048.0f + ";\n"
             + "  matrix[2][1]=" + 344.0f / 2048.0f + ";\n"
             + "  matrix[2][2]=" + 268.0f / 2048.0f + ";\n"
-            + "  vec4 color = texture2D(sTexture, vTextureCoord);\n"
+            + "  vec4 color = texture2D(sTexture, "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+");\n"
             + "  vec3 new_color = min(matrix * color.rgb, 1.0);\n"
             + "  gl_FragColor = vec4(new_color.rgb, color.a);\n"
             + "}\n";

cameraview/src/main/java/com/otaliastudios/cameraview/filters/SharpnessFilter.java

@@ -19,22 +19,22 @@ public class SharpnessFilter extends BaseFilter implements OneParameterFilter {
             + "uniform float scale;\n"
             + "uniform float stepsizeX;\n"
             + "uniform float stepsizeY;\n"
-            + "varying vec2 vTextureCoord;\n"
+            + "varying vec2 "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+";\n"
             + "void main() {\n"
             + "  vec3 nbr_color = vec3(0.0, 0.0, 0.0);\n"
             + "  vec2 coord;\n"
-            + "  vec4 color = texture2D(sTexture, vTextureCoord);\n"
-            + "  coord.x = vTextureCoord.x - 0.5 * stepsizeX;\n"
-            + "  coord.y = vTextureCoord.y - stepsizeY;\n"
+            + "  vec4 color = texture2D(sTexture, "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+");\n"
+            + "  coord.x = "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+".x - 0.5 * stepsizeX;\n"
+            + "  coord.y = "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+".y - stepsizeY;\n"
             + "  nbr_color += texture2D(sTexture, coord).rgb - color.rgb;\n"
-            + "  coord.x = vTextureCoord.x - stepsizeX;\n"
-            + "  coord.y = vTextureCoord.y + 0.5 * stepsizeY;\n"
+            + "  coord.x = "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+".x - stepsizeX;\n"
+            + "  coord.y = "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+".y + 0.5 * stepsizeY;\n"
             + "  nbr_color += texture2D(sTexture, coord).rgb - color.rgb;\n"
-            + "  coord.x = vTextureCoord.x + stepsizeX;\n"
-            + "  coord.y = vTextureCoord.y - 0.5 * stepsizeY;\n"
+            + "  coord.x = "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+".x + stepsizeX;\n"
+            + "  coord.y = "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+".y - 0.5 * stepsizeY;\n"
             + "  nbr_color += texture2D(sTexture, coord).rgb - color.rgb;\n"
-            + "  coord.x = vTextureCoord.x + stepsizeX;\n"
-            + "  coord.y = vTextureCoord.y + 0.5 * stepsizeY;\n"
+            + "  coord.x = "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+".x + stepsizeX;\n"
+            + "  coord.y = "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+".y + 0.5 * stepsizeY;\n"
             + "  nbr_color += texture2D(sTexture, coord).rgb - color.rgb;\n"
             + "  gl_FragColor = vec4(color.rgb - 2.0 * scale * nbr_color, color.a);\n"
             + "}\n";
@@ -116,8 +116,8 @@ public class SharpnessFilter extends BaseFilter implements OneParameterFilter {
     }
 
     @Override
-    protected void onPreDraw(float[] transformMatrix) {
-        super.onPreDraw(transformMatrix);
+    protected void onPreDraw(long timestampUs, float[] transformMatrix) {
+        super.onPreDraw(timestampUs, transformMatrix);
         GLES20.glUniform1f(scaleLocation, scale);
         GlUtils.checkError("glUniform1f");
         GLES20.glUniform1f(stepSizeXLocation, 1.0F / width);

cameraview/src/main/java/com/otaliastudios/cameraview/filters/TemperatureFilter.java

@@ -17,9 +17,9 @@ public class TemperatureFilter extends BaseFilter implements OneParameterFilter
             + "precision mediump float;\n"
             + "uniform samplerExternalOES sTexture;\n"
             + "uniform float scale;\n"
-            + "varying vec2 vTextureCoord;\n"
+            + "varying vec2 "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+";\n"
             + "void main() {\n"
-            + "  vec4 color = texture2D(sTexture, vTextureCoord);\n"
+            + "  vec4 color = texture2D(sTexture, "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+");\n"
             + "  vec3 new_color = color.rgb;\n"
             + "  new_color.r = color.r + color.r * ( 1.0 - color.r) * scale;\n"
             + "  new_color.b = color.b - color.b * ( 1.0 - color.b) * scale;\n"
@@ -94,8 +94,8 @@ public class TemperatureFilter extends BaseFilter implements OneParameterFilter
     }
 
     @Override
-    protected void onPreDraw(float[] transformMatrix) {
-        super.onPreDraw(transformMatrix);
+    protected void onPreDraw(long timestampUs, float[] transformMatrix) {
+        super.onPreDraw(timestampUs, transformMatrix);
         GLES20.glUniform1f(scaleLocation, scale);
         GlUtils.checkError("glUniform1f");
     }

cameraview/src/main/java/com/otaliastudios/cameraview/filters/TintFilter.java

@@ -21,12 +21,12 @@ public class TintFilter extends BaseFilter implements OneParameterFilter {
             + "uniform samplerExternalOES sTexture;\n"
             + "uniform vec3 tint;\n"
             + "vec3 color_ratio;\n"
-            + "varying vec2 vTextureCoord;\n"
+            + "varying vec2 "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+";\n"
             + "void main() {\n"
             + "  color_ratio[0] = " + 0.21f + ";\n"
             + "  color_ratio[1] = " + 0.71f + ";\n"
             + "  color_ratio[2] = " + 0.07f + ";\n"
-            + "  vec4 color = texture2D(sTexture, vTextureCoord);\n"
+            + "  vec4 color = texture2D(sTexture, "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+");\n"
             + "  float avg_color = dot(color_ratio, color.rgb);\n"
             + "  vec3 new_color = min(0.8 * avg_color + 0.2 * tint, 1.0);\n"
             + "  gl_FragColor = vec4(new_color.rgb, color.a);\n" + "}\n";
@@ -91,8 +91,8 @@ public class TintFilter extends BaseFilter implements OneParameterFilter {
     }
 
     @Override
-    protected void onPreDraw(float[] transformMatrix) {
-        super.onPreDraw(transformMatrix);
+    protected void onPreDraw(long timestampUs, float[] transformMatrix) {
+        super.onPreDraw(timestampUs, transformMatrix);
         float[] channels = new float[]{
                 Color.red(tint) / 255f,
                 Color.green(tint) / 255f,

cameraview/src/main/java/com/otaliastudios/cameraview/filters/VignetteFilter.java

@@ -21,13 +21,14 @@ public class VignetteFilter extends BaseFilter implements TwoParameterFilter {
             + "uniform float inv_max_dist;\n"
             + "uniform float shade;\n"
             + "uniform vec2 scale;\n"
-            + "varying vec2 vTextureCoord;\n"
+            + "varying vec2 "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+";\n"
             + "void main() {\n"
             + "  const float slope = 20.0;\n"
-            + "  vec2 coord = vTextureCoord - vec2(0.5, 0.5);\n"
+            + "  vec2 coord = "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+" - vec2(0.5, 0.5);\n"
             + "  float dist = length(coord * scale);\n"
-            + "  float lumen = shade / (1.0 + exp((dist * inv_max_dist - range) * slope)) + (1.0 - shade);\n"
-            + "  vec4 color = texture2D(sTexture, vTextureCoord);\n"
+            + "  float lumen = shade / (1.0 + exp((dist * inv_max_dist - range) * slope)) "
+            + "+ (1.0 - shade);\n"
+            + "  vec4 color = texture2D(sTexture, "+DEFAULT_FRAGMENT_TEXTURE_COORDINATE_NAME+");\n"
             + "  gl_FragColor = vec4(color.rgb * lumen, color.a);\n"
             + "}\n";
 
@@ -144,8 +145,8 @@ public class VignetteFilter extends BaseFilter implements TwoParameterFilter {
     }
 
     @Override
-    protected void onPreDraw(float[] transformMatrix) {
-        super.onPreDraw(transformMatrix);
+    protected void onPreDraw(long timestampUs, float[] transformMatrix) {
+        super.onPreDraw(timestampUs, transformMatrix);
         float[] scale = new float[2];
         if (mWidth > mHeight) {
             scale[0] = 1f;

cameraview/src/main/java/com/otaliastudios/cameraview/frame/Frame.java

@@ -44,8 +44,8 @@ public class Frame {
         if (!hasContent()) {
             LOG.e("Frame is dead! time:", mTime, "lastTime:", mLastTime);
             throw new RuntimeException("You should not access a released frame. " +
-                    "If this frame was passed to a FrameProcessor, you can only use its contents synchronously, " +
-                    "for the duration of the process() method.");
+                    "If this frame was passed to a FrameProcessor, you can only use its contents " +
+                    "synchronously, for the duration of the process() method.");
         }
     }
 

cameraview/src/main/java/com/otaliastudios/cameraview/frame/FrameManager.java

@@ -28,18 +28,20 @@ import java.util.concurrent.LinkedBlockingQueue;
  * For both byte buffers and frames to get back to the FrameManager pool, all you have to do
  * is call {@link Frame#release()} when done.
  *
- * Other than this, the FrameManager can work in two modes, depending on whether a {@link BufferCallback}
- * is passed to the constructor. The modes changes the buffer behavior.
+ * Other than this, the FrameManager can work in two modes, depending on whether a
+ * {@link BufferCallback} is passed to the constructor. The modes changes the buffer behavior.
  *
  * 1. {@link #BUFFER_MODE_DISPATCH}: in this mode, as soon as we have a buffer, it is dispatched to
  *    the {@link BufferCallback}. The callback should then fill the buffer, and finally call
  *    {@link #getFrame(byte[], long, int)} to receive a frame.
  *    This is used for Camera1.
  *
- * 2. {@link #BUFFER_MODE_ENQUEUE}: in this mode, the manager internally keeps a queue of byte buffers,
- *    instead of handing them to the callback. The users can ask for buffers through {@link #getBuffer()}.
- *    This buffer can be filled with data and used to get a frame {@link #getFrame(byte[], long, int)},
- *    or, in case it was not filled, returned to the queue using {@link #onBufferUnused(byte[])}.
+ * 2. {@link #BUFFER_MODE_ENQUEUE}: in this mode, the manager internally keeps a queue of byte
+ *    buffers, instead of handing them to the callback. The users can ask for buffers through
+ *    {@link #getBuffer()}.
+ *    This buffer can be filled with data and used to get a frame
+ *    {@link #getFrame(byte[], long, int)}, or, in case it was not filled, returned to the queue
+ *    using {@link #onBufferUnused(byte[])}.
  *    This is used for Camera2.
  */
 public class FrameManager {
@@ -149,7 +151,8 @@ public class FrameManager {
     @Nullable
     public byte[] getBuffer() {
         if (mBufferMode != BUFFER_MODE_ENQUEUE) {
-            throw new IllegalStateException("Can't call getBuffer() when not in BUFFER_MODE_ENQUEUE.");
+            throw new IllegalStateException("Can't call getBuffer() " +
+                    "when not in BUFFER_MODE_ENQUEUE.");
         }
         return mBufferQueue.poll();
     }
@@ -161,7 +164,8 @@ public class FrameManager {
      */
     public void onBufferUnused(@NonNull byte[] buffer) {
         if (mBufferMode != BUFFER_MODE_ENQUEUE) {
-            throw new IllegalStateException("Can't call onBufferUnused() when not in BUFFER_MODE_ENQUEUE.");
+            throw new IllegalStateException("Can't call onBufferUnused() " +
+                    "when not in BUFFER_MODE_ENQUEUE.");
         }
 
         if (isSetUp()) {
@@ -188,7 +192,8 @@ public class FrameManager {
     @NonNull
     public Frame getFrame(@NonNull byte[] data, long time, int rotation) {
         if (!isSetUp()) {
-            throw new IllegalStateException("Can't call getFrame() after releasing or before setUp.");
+            throw new IllegalStateException("Can't call getFrame() after releasing " +
+                    "or before setUp.");
         }
 
         Frame frame = mFrameQueue.poll();

cameraview/src/main/java/com/otaliastudios/cameraview/gesture/Gesture.java

@@ -8,7 +8,8 @@ import androidx.annotation.NonNull;
 
 /**
  * Gestures listen to finger gestures over the {@link CameraView} bounds and can be mapped
- * to one or more camera controls using XML attributes or {@link CameraView#mapGesture(Gesture, GestureAction)}.
+ * to one or more camera controls using XML attributes or {@link CameraView#mapGesture(Gesture,
+ * GestureAction)}.
  *
  * Not every gesture can control a certain action. For example, pinch gestures can only control
  * continuous values, such as zoom or AE correction. Single point gestures, on the other hand,

cameraview/src/main/java/com/otaliastudios/cameraview/gesture/GestureAction.java

@@ -2,6 +2,7 @@ package com.otaliastudios.cameraview.gesture;
 
 
 import com.otaliastudios.cameraview.CameraView;
+import com.otaliastudios.cameraview.filter.Filter;
 import com.otaliastudios.cameraview.markers.AutoFocusMarker;
 
 import androidx.annotation.NonNull;
@@ -63,7 +64,7 @@ public enum GestureAction {
     EXPOSURE_CORRECTION(4, GestureType.CONTINUOUS),
 
     /**
-     * Controls the first parameter of a real-time {@link com.otaliastudios.cameraview.filter.Filter},
+     * Controls the first parameter of a real-time {@link Filter},
      * if it accepts one. This action can be mapped to continuous gestures:
      *
      * - {@link Gesture#PINCH}
@@ -73,7 +74,7 @@ public enum GestureAction {
     FILTER_CONTROL_1(5, GestureType.CONTINUOUS),
 
     /**
-     * Controls the second parameter of a real-time {@link com.otaliastudios.cameraview.filter.Filter},
+     * Controls the second parameter of a real-time {@link Filter},
      * if it accepts one. This action can be mapped to continuous gestures:
      *
      * - {@link Gesture#PINCH}

cameraview/src/main/java/com/otaliastudios/cameraview/gesture/GestureParser.java

@@ -18,11 +18,17 @@ public class GestureParser {
     private int verticalScrollAction;
 
     public GestureParser(@NonNull TypedArray array) {
-        this.tapAction = array.getInteger(R.styleable.CameraView_cameraGestureTap, GestureAction.DEFAULT_TAP.value());
-        this.longTapAction = array.getInteger(R.styleable.CameraView_cameraGestureLongTap, GestureAction.DEFAULT_LONG_TAP.value());
-        this.pinchAction = array.getInteger(R.styleable.CameraView_cameraGesturePinch, GestureAction.DEFAULT_PINCH.value());
-        this.horizontalScrollAction = array.getInteger(R.styleable.CameraView_cameraGestureScrollHorizontal, GestureAction.DEFAULT_SCROLL_HORIZONTAL.value());
-        this.verticalScrollAction = array.getInteger(R.styleable.CameraView_cameraGestureScrollVertical, GestureAction.DEFAULT_SCROLL_VERTICAL.value());
+        tapAction = array.getInteger(R.styleable.CameraView_cameraGestureTap,
+                GestureAction.DEFAULT_TAP.value());
+        longTapAction = array.getInteger(R.styleable.CameraView_cameraGestureLongTap,
+                GestureAction.DEFAULT_LONG_TAP.value());
+        pinchAction = array.getInteger(R.styleable.CameraView_cameraGesturePinch,
+                GestureAction.DEFAULT_PINCH.value());
+        horizontalScrollAction = array.getInteger(
+                R.styleable.CameraView_cameraGestureScrollHorizontal,
+                GestureAction.DEFAULT_SCROLL_HORIZONTAL.value());
+        verticalScrollAction = array.getInteger(R.styleable.CameraView_cameraGestureScrollVertical,
+                GestureAction.DEFAULT_SCROLL_VERTICAL.value());
     }
 
     private GestureAction get(int which) {

cameraview/src/main/java/com/otaliastudios/cameraview/gesture/PinchGestureFinder.java

@@ -19,7 +19,8 @@ public class PinchGestureFinder extends GestureFinder {
     public PinchGestureFinder(@NonNull Controller controller) {
         super(controller, 2);
         setGesture(Gesture.PINCH);
-        mDetector = new ScaleGestureDetector(controller.getContext(), new ScaleGestureDetector.SimpleOnScaleGestureListener() {
+        mDetector = new ScaleGestureDetector(controller.getContext(),
+                new ScaleGestureDetector.SimpleOnScaleGestureListener() {
             @Override
             public boolean onScale(ScaleGestureDetector detector) {
                 mNotify = true;

cameraview/src/main/java/com/otaliastudios/cameraview/gesture/ScrollGestureFinder.java

@@ -21,10 +21,14 @@ public class ScrollGestureFinder extends GestureFinder {
 
     public ScrollGestureFinder(final @NonNull Controller controller) {
         super(controller, 2);
-        mDetector = new GestureDetector(controller.getContext(), new GestureDetector.SimpleOnGestureListener() {
+        mDetector = new GestureDetector(controller.getContext(),
+                new GestureDetector.SimpleOnGestureListener() {
 
             @Override
-            public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
+            public boolean onScroll(MotionEvent e1,
+                                    MotionEvent e2,
+                                    float distanceX,
+                                    float distanceY) {
                 boolean horizontal;
                 LOG.i("onScroll:", "distanceX="+distanceX, "distanceY="+distanceY);
                 if (e1 == null || e2 == null) return false; // Got some crashes about this.
@@ -39,7 +43,8 @@ public class ScrollGestureFinder extends GestureFinder {
                     horizontal = getGesture() == Gesture.SCROLL_HORIZONTAL;
                 }
                 getPoint(1).set(e2.getX(), e2.getY());
-                mFactor = horizontal ? (distanceX / controller.getWidth()) : (distanceY / controller.getHeight());
+                mFactor = horizontal ? (distanceX / controller.getWidth())
+                        : (distanceY / controller.getHeight());
                 mFactor = horizontal ? -mFactor : mFactor; // When vertical, up = positive
                 mNotify = true;
                 return true;

cameraview/src/main/java/com/otaliastudios/cameraview/gesture/TapGestureFinder.java

@@ -16,7 +16,8 @@ public class TapGestureFinder extends GestureFinder {
 
     public TapGestureFinder(@NonNull Controller controller) {
         super(controller, 1);
-        mDetector = new GestureDetector(controller.getContext(), new GestureDetector.SimpleOnGestureListener() {
+        mDetector = new GestureDetector(controller.getContext(),
+                new GestureDetector.SimpleOnGestureListener() {
 
             @Override
             public boolean onSingleTapUp(MotionEvent e) {

cameraview/src/main/java/com/otaliastudios/cameraview/internal/DeviceEncoders.java

@@ -20,9 +20,18 @@ import java.util.List;
 /**
  * Checks the capabilities of device encoders and adjust parameters to ensure
  * that they'll be supported by the final encoder.
- * This can choose the encoder in two ways, based on the mode flag:
  *
- * 1. {@link #MODE_TAKE_FIRST}
+ * Methods in this class might throw either a {@link VideoException} or a {@link AudioException}.
+ * Throwing this exception means that the given parameters will not be supported by the encoder
+ * for that type, and cannot be tweaked to be.
+ *
+ * When this happens, users should retry with a new {@link DeviceEncoders} instance, but with
+ * the audio or video encoder offset incremented. This offset is the position in the encoder list
+ * from which we'll choose the potential encoder.
+ *
+ * This class will inspect the encoders list in two ways, based on the mode flag:
+ *
+ * 1. {@link #MODE_RESPECT_ORDER}
  *
  * Chooses the encoder as the first one that matches the given mime type.
  * This is what {@link android.media.MediaCodec#createEncoderByType(String)} does,
@@ -40,11 +49,12 @@ import java.util.List;
  * - MediaCodecList (https://android.googlesource.com/platform/frameworks/av/+/master/media/libstagefright/MediaCodecList.cpp#322)
  *
  * To be fair, what {@link android.media.MediaRecorder} does is actually choose the first one
- * that configures itself without errors. We currently do not offer this option here. TODO
+ * that configures itself without errors. We currently do not offer this option here.
+ * TODO add a tryConfigure() step, that throws AudioException/VideoException ?
  *
  * 2. {@link #MODE_PREFER_HARDWARE}
  *
- * This takes the list - as ordered by the vendor - and just sorts it such that hardware encoders
+ * This takes the list - as ordered by the vendor - and just sorts it so that hardware encoders
  * are preferred over software ones. It's questionable whether this is good or not. Some vendors
  * might forget to put hardware encoders first in the list, some others might put poor hardware
  * encoders on the bottom of the list on purpose.
@@ -56,9 +66,29 @@ public class DeviceEncoders {
 
     @VisibleForTesting static boolean ENABLED = Build.VERSION.SDK_INT >= 21;
 
-    public final static int MODE_TAKE_FIRST = 0;
+    public final static int MODE_RESPECT_ORDER = 0;
     public final static int MODE_PREFER_HARDWARE = 1;
 
+    /**
+     * Exception thrown when trying to find appropriate values
+     * for a video encoder.
+     */
+    public class VideoException extends RuntimeException {
+        private VideoException(@NonNull String message) {
+            super(message);
+        }
+    }
+
+    /**
+     * Exception thrown when trying to find appropriate values
+     * for an audio encoder. Currently never thrown.
+     */
+    public class AudioException extends RuntimeException {
+        private AudioException(@NonNull String message) {
+            super(message);
+        }
+    }
+
     @SuppressWarnings("FieldCanBeLocal")
     private final MediaCodecInfo mVideoEncoder;
     @SuppressWarnings("FieldCanBeLocal")
@@ -67,17 +97,23 @@ public class DeviceEncoders {
     private final MediaCodecInfo.AudioCapabilities mAudioCapabilities;
 
     @SuppressLint("NewApi")
-    public DeviceEncoders(@NonNull String videoType, @NonNull String audioType, int mode) {
+    public DeviceEncoders(int mode,
+                          @NonNull String videoType,
+                          @NonNull String audioType,
+                          int videoOffset,
+                          int audioOffset) {
         // We could still get a list of MediaCodecInfo for API >= 16, but it seems that the APIs
         // for querying the availability of a specified MediaFormat were only added in 21 anyway.
         if (ENABLED) {
             List<MediaCodecInfo> encoders = getDeviceEncoders();
-            mVideoEncoder = findDeviceEncoder(encoders, videoType, mode);
+            mVideoEncoder = findDeviceEncoder(encoders, videoType, mode, videoOffset);
             LOG.i("Enabled. Found video encoder:", mVideoEncoder.getName());
-            mAudioEncoder = findDeviceEncoder(encoders, audioType, mode);
+            mAudioEncoder = findDeviceEncoder(encoders, audioType, mode, audioOffset);
             LOG.i("Enabled. Found audio encoder:", mAudioEncoder.getName());
-            mVideoCapabilities = mVideoEncoder.getCapabilitiesForType(videoType).getVideoCapabilities();
-            mAudioCapabilities = mAudioEncoder.getCapabilitiesForType(audioType).getAudioCapabilities();
+            mVideoCapabilities = mVideoEncoder.getCapabilitiesForType(videoType)
+                    .getVideoCapabilities();
+            mAudioCapabilities = mAudioEncoder.getCapabilitiesForType(audioType)
+                    .getAudioCapabilities();
         } else {
             mVideoEncoder = null;
             mAudioEncoder = null;
@@ -123,7 +159,7 @@ public class DeviceEncoders {
 
     /**
      * Finds the encoder we'll be using, depending on the given mode flag:
-     * - {@link #MODE_TAKE_FIRST} will just take the first of the list
+     * - {@link #MODE_RESPECT_ORDER} will just take the first of the list
      * - {@link #MODE_PREFER_HARDWARE} will prefer hardware encoders
      * Throws if we find no encoder for this type.
      *
@@ -135,7 +171,10 @@ public class DeviceEncoders {
     @SuppressLint("NewApi")
     @NonNull
     @VisibleForTesting
-    MediaCodecInfo findDeviceEncoder(@NonNull List<MediaCodecInfo> encoders, @NonNull String mimeType, int mode) {
+    MediaCodecInfo findDeviceEncoder(@NonNull List<MediaCodecInfo> encoders,
+                                     @NonNull String mimeType,
+                                     int mode,
+                                     int offset) {
         ArrayList<MediaCodecInfo> results = new ArrayList<>();
         for (MediaCodecInfo encoder : encoders) {
             String[] types = encoder.getSupportedTypes();
@@ -160,10 +199,12 @@ public class DeviceEncoders {
                 }
             });
         }
-        if (results.isEmpty()) {
+        if (results.size() < offset + 1) {
+            // This should not be a VideoException or AudioException - we want the process
+            // to crash here.
             throw new RuntimeException("No encoders for type:" + mimeType);
         }
-        return results.get(0);
+        return results.get(offset);
     }
 
     /**
@@ -199,19 +240,19 @@ public class DeviceEncoders {
 
         // It's still possible that we're BELOW the lower.
         if (!mVideoCapabilities.getSupportedWidths().contains(width)) {
-            throw new RuntimeException("Width not supported after adjustment." +
+            throw new VideoException("Width not supported after adjustment." +
                     " Desired:" + width +
                     " Range:" + mVideoCapabilities.getSupportedWidths());
         }
         if (!mVideoCapabilities.getSupportedHeights().contains(height)) {
-            throw new RuntimeException("Height not supported after adjustment." +
+            throw new VideoException("Height not supported after adjustment." +
                     " Desired:" + height +
                     " Range:" + mVideoCapabilities.getSupportedHeights());
         }
 
         // It's still possible that we're unsupported for other reasons.
         if (!mVideoCapabilities.isSizeSupported(width, height)) {
-            throw new RuntimeException("Size not supported for unknown reason." +
+            throw new VideoException("Size not supported for unknown reason." +
                     " Might be an aspect ratio issue." +
                     " Desired size:" + new Size(width, height));
         }
@@ -231,7 +272,9 @@ public class DeviceEncoders {
     public int getSupportedVideoBitRate(int bitRate) {
         if (!ENABLED) return bitRate;
         int newBitRate = mVideoCapabilities.getBitrateRange().clamp(bitRate);
-        LOG.i("getSupportedVideoBitRate -", "inputRate:", bitRate, "adjustedRate:", newBitRate);
+        LOG.i("getSupportedVideoBitRate -",
+                "inputRate:", bitRate,
+                "adjustedRate:", newBitRate);
         return newBitRate;
     }
 
@@ -248,7 +291,9 @@ public class DeviceEncoders {
         int newFrameRate = (int) (double) mVideoCapabilities
                 .getSupportedFrameRatesFor(size.getWidth(), size.getHeight())
                 .clamp((double) frameRate);
-        LOG.i("getSupportedVideoFrameRate -", "inputRate:", frameRate, "adjustedRate:", newFrameRate);
+        LOG.i("getSupportedVideoFrameRate -",
+                "inputRate:", frameRate,
+                "adjustedRate:", newFrameRate);
         return newFrameRate;
     }
 
@@ -263,7 +308,9 @@ public class DeviceEncoders {
     public int getSupportedAudioBitRate(int bitRate) {
         if (!ENABLED) return bitRate;
         int newBitRate = mAudioCapabilities.getBitrateRange().clamp(bitRate);
-        LOG.i("getSupportedAudioBitRate -", "inputRate:", bitRate, "adjustedRate:", newBitRate);
+        LOG.i("getSupportedAudioBitRate -",
+                "inputRate:", bitRate,
+                "adjustedRate:", newBitRate);
         return newBitRate;
     }
 

cameraview/src/main/java/com/otaliastudios/cameraview/internal/GlUtils.java

@@ -26,7 +26,8 @@ public class GlUtils {
     public static void checkError(@NonNull String opName) {
         int error = GLES20.glGetError();
         if (error != GLES20.GL_NO_ERROR) {
-            String message = LOG.e("Error during", opName, "glError 0x", Integer.toHexString(error));
+            String message = LOG.e("Error during", opName, "glError 0x",
+                    Integer.toHexString(error));
             throw new RuntimeException(message);
         }
     }
@@ -47,7 +48,8 @@ public class GlUtils {
         int[] compiled = new int[1];
         GLES20.glGetShaderiv(shader, GLES20.GL_COMPILE_STATUS, compiled, 0);
         if (compiled[0] == 0) {
-            LOG.e("Could not compile shader", shaderType, ":", GLES20.glGetShaderInfoLog(shader));
+            LOG.e("Could not compile shader", shaderType, ":",
+                    GLES20.glGetShaderInfoLog(shader));
             GLES20.glDeleteShader(shader);
             shader = 0;
         }

cameraview/src/main/java/com/otaliastudios/cameraview/internal/GridLinesLayout.java

@@ -43,7 +43,8 @@ public class GridLinesLayout extends View {
         super(context, attrs);
         horiz = new ColorDrawable(gridColor);
         vert = new ColorDrawable(gridColor);
-        width = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 0.9f, context.getResources().getDisplayMetrics());
+        width = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 0.9f,
+                context.getResources().getDisplayMetrics());
     }
 
     @Override

cameraview/src/main/java/com/otaliastudios/cameraview/internal/Issue514Workaround.java

@@ -36,8 +36,9 @@ import com.otaliastudios.cameraview.preview.RendererThread;
  *    9B. Publish overlays to GL texture using overlaySurfaceTexture.updateTexImage()
  *    9C. GLES - draw textureId
  *    9D. GLES - draw overlayTextureId
- * Both textures are drawn on the same EGLWindow and we manage to overlay them with {@link GLES20#GL_BLEND}.
- * This is the whole procedure and it works for the majority of devices and situations.
+ * Both textures are drawn on the same EGLWindow and we manage to overlay them with
+ * {@link GLES20#GL_BLEND}. This is the whole procedure and it works for the majority of
+ * devices and situations.
  *
  * ISSUE DESCRIPTION
  * The #514 issue can be described as follows:
@@ -66,7 +67,8 @@ import com.otaliastudios.cameraview.preview.RendererThread;
  *
  * So a pixel format conversion takes place, when it shouldn't happen. We can't solve this:
  * - It is done at a lower level, there's no real way for us to specify the surface format, but
- *   it seems that these devices will prefer a YUV format and misunderstand our {@link Canvas} pixels.
+ *   it seems that these devices will prefer a YUV format and misunderstand our {@link Canvas}
+ *   pixels.
  * - There is also no way to identify which devices will present this issue, it's a bug somewhere
  *   and it is implementation specific.
  *
@@ -74,16 +76,18 @@ import com.otaliastudios.cameraview.preview.RendererThread;
  * Hard to say why, but using this class fixes the described issue.
  * It seems that when the {@link SurfaceTexture#updateTexImage()} method for the overlay surface
  * is called - the one that updates the overlayTextureId - we must ensure that the CURRENTLY
- * BOUND TEXTURE ID IS NOT 0. The id we choose to apply might be cameraTextureId, or overlayTextureId,
- * or probably whatever other valid id, and should be passed to {@link #Issue514Workaround(int)}.
+ * BOUND TEXTURE ID IS NOT 0. The id we choose to apply might be cameraTextureId, or
+ * overlayTextureId, or probably whatever other valid id, and should be passed to
+ * {@link #Issue514Workaround(int)}.
  * [Tested with cameraTextureId and overlayTextureId: both do work.]
  * [Tested with invalid id like 9999. This won't work.]
  *
- * This makes no sense, since overlaySurfaceTexture.updateTexImage() is setting it to overlayTextureId
- * anyway, but it fixes the issue. Specifically, after any draw operation with {@link EglViewport},
- * the bound texture is reset to 0 so this must be undone here. We offer:
+ * This makes no sense, since overlaySurfaceTexture.updateTexImage() is setting it to
+ * overlayTextureId anyway, but it fixes the issue. Specifically, after any draw operation with
+ * {@link EglViewport}, the bound texture is reset to 0 so this must be undone here. We offer:
  *
- * - {@link #beforeOverlayUpdateTexImage()} to be called before the {@link SurfaceTexture#updateTexImage()} call
+ * - {@link #beforeOverlayUpdateTexImage()} to be called before the
+ *   {@link SurfaceTexture#updateTexImage()} call
  * - {@link #end()} to release and bring things back to normal state
  *
  * Since updating and rendering can happen on different threads with a shared EGL context,
@@ -93,9 +97,9 @@ import com.otaliastudios.cameraview.preview.RendererThread;
  * REFERENCES
  * https://github.com/natario1/CameraView/issues/514
  * https://android.googlesource.com/platform/frameworks/native/+/5c1139f/libs/gui/SurfaceTexture.cpp
- * I can see here that SurfaceTexture does indeed call glBindTexture with the same parameters whenever
- * updateTexImage is called, but it also does other gl stuff first. This other gl stuff might be
- * breaking when we don't have a bound texture on some specific hardware implementation.
+ * I can see here that SurfaceTexture does indeed call glBindTexture with the same parameters
+ * whenever updateTexImage is called, but it also does other gl stuff first. This other gl stuff
+ * might be breaking when we don't have a bound texture on some specific hardware implementation.
  */
 public class Issue514Workaround {
 

cameraview/src/main/java/com/otaliastudios/cameraview/internal/egl/EglBaseSurface.java

@@ -229,7 +229,8 @@ public class EglBaseSurface {
         int height = getHeight();
         ByteBuffer buf = ByteBuffer.allocateDirect(width * height * 4);
         buf.order(ByteOrder.LITTLE_ENDIAN);
-        GLES20.glReadPixels(0, 0, width, height, GLES20.GL_RGBA, GLES20.GL_UNSIGNED_BYTE, buf);
+        GLES20.glReadPixels(0, 0, width, height, GLES20.GL_RGBA, GLES20.GL_UNSIGNED_BYTE,
+                buf);
         GlUtils.checkError("glReadPixels");
         buf.rewind();
 

cameraview/src/main/java/com/otaliastudios/cameraview/internal/egl/EglCore.java

@@ -172,8 +172,8 @@ public final class EglCore {
         }
         EGLConfig[] configs = new EGLConfig[1];
         int[] numConfigs = new int[1];
-        if (!EGL14.eglChooseConfig(mEGLDisplay, attribList, 0, configs, 0, configs.length,
-                numConfigs, 0)) {
+        if (!EGL14.eglChooseConfig(mEGLDisplay, attribList, 0, configs, 0,
+                configs.length, numConfigs, 0)) {
             Log.w(TAG, "unable to find RGB8888 / " + version + " EGLConfig");
             return null;
         }
@@ -210,7 +210,8 @@ public final class EglCore {
                 // the EGL state, so if a surface or context is still current on another
                 // thread we can't fully release it here.  Exceptions thrown from here
                 // are quietly discarded.  Complain in the log file.
-                Log.w(TAG, "WARNING: EglCore was not explicitly released -- state may be leaked");
+                Log.w(TAG, "WARNING: EglCore was not explicitly released! " +
+                        "State may be leaked");
                 release();
             }
         } finally {

cameraview/src/main/java/com/otaliastudios/cameraview/internal/egl/EglViewport.java

@@ -35,7 +35,8 @@ public class EglViewport {
     }
 
     private void createProgram() {
-        mProgramHandle = GlUtils.createProgram(mFilter.getVertexShader(), mFilter.getFragmentShader());
+        mProgramHandle = GlUtils.createProgram(mFilter.getVertexShader(),
+                mFilter.getFragmentShader());
         mFilter.onCreate(mProgramHandle);
     }
 
@@ -57,10 +58,14 @@ public class EglViewport {
         GLES20.glBindTexture(mTextureTarget, texId);
         GlUtils.checkError("glBindTexture " + texId);
 
-        GLES20.glTexParameterf(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_NEAREST);
-        GLES20.glTexParameterf(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_LINEAR);
-        GLES20.glTexParameteri(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_WRAP_S, GLES20.GL_CLAMP_TO_EDGE);
-        GLES20.glTexParameteri(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_WRAP_T, GLES20.GL_CLAMP_TO_EDGE);
+        GLES20.glTexParameterf(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_MIN_FILTER,
+                GLES20.GL_NEAREST);
+        GLES20.glTexParameterf(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_MAG_FILTER,
+                GLES20.GL_LINEAR);
+        GLES20.glTexParameteri(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_WRAP_S,
+                GLES20.GL_CLAMP_TO_EDGE);
+        GLES20.glTexParameteri(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_WRAP_T,
+                GLES20.GL_CLAMP_TO_EDGE);
         GlUtils.checkError("glTexParameter");
 
         return texId;
@@ -72,7 +77,7 @@ public class EglViewport {
         mPendingFilter = filter;
     }
 
-    public void drawFrame(int textureId, float[] textureMatrix) {
+    public void drawFrame(long timestampUs, int textureId, float[] textureMatrix) {
         if (mPendingFilter != null) {
             release();
             mFilter = mPendingFilter;
@@ -89,7 +94,7 @@ public class EglViewport {
         GLES20.glBindTexture(mTextureTarget, textureId);
 
         // Draw.
-        mFilter.draw(textureMatrix);
+        mFilter.draw(timestampUs, textureMatrix);
 
         // Release.
         GLES20.glBindTexture(mTextureTarget, 0);

cameraview/src/main/java/com/otaliastudios/cameraview/internal/egl/EglWindowSurface.java

@@ -77,25 +77,4 @@ public class EglWindowSurface extends EglBaseSurface {
             mSurface = null;
         }
     }
-
-    /**
-     * Recreate the EGLSurface, using the new EglBase.  The caller should have already
-     * freed the old EGLSurface with releaseEglSurface().
-     * <p>
-     * This is useful when we want to update the EGLSurface associated with a Surface.
-     * For example, if we want to share with a different EGLContext, which can only
-     * be done by tearing down and recreating the context.  (That's handled by the caller;
-     * this just creates a new EGLSurface for the Surface we were handed earlier.)
-     * <p>
-     * If the previous EGLSurface isn't fully destroyed, e.g. it's still current on a
-     * context somewhere, the create call will fail with complaints from the Surface
-     * about already being connected.
-     */
-    public void recreate(EglCore newEglCore) {
-        if (mSurface == null) {
-            throw new RuntimeException("not yet implemented for SurfaceTexture");
-        }
-        mEglCore = newEglCore;          // switch to new context
-        createWindowSurface(mSurface);  // create new surface
-    }
 }

cameraview/src/main/java/com/otaliastudios/cameraview/internal/utils/CamcorderProfiles.java

@@ -31,14 +31,16 @@ public class CamcorderProfiles {
         sizeToProfileMap.put(new Size(1280, 720), CamcorderProfile.QUALITY_720P);
         sizeToProfileMap.put(new Size(1920, 1080), CamcorderProfile.QUALITY_1080P);
         if (Build.VERSION.SDK_INT >= 21) {
-            sizeToProfileMap.put(new Size(3840, 2160), CamcorderProfile.QUALITY_2160P);
+            sizeToProfileMap.put(new Size(3840, 2160),
+                    CamcorderProfile.QUALITY_2160P);
         }
     }
 
 
     /**
      * Returns a CamcorderProfile that's somewhat coherent with the target size,
-     * to ensure we get acceptable video/audio parameters for MediaRecorders (most notably the bitrate).
+     * to ensure we get acceptable video/audio parameters for MediaRecorders
+     * (most notably the bitrate).
      *
      * @param cameraId the camera2 id
      * @param targetSize the target video size
@@ -57,7 +59,8 @@ public class CamcorderProfiles {
 
     /**
      * Returns a CamcorderProfile that's somewhat coherent with the target size,
-     * to ensure we get acceptable video/audio parameters for MediaRecorders (most notably the bitrate).
+     * to ensure we get acceptable video/audio parameters for MediaRecorders
+     * (most notably the bitrate).
      *
      * @param cameraId the camera id
      * @param targetSize the target video size

cameraview/src/main/java/com/otaliastudios/cameraview/internal/utils/ImageHelper.java

@@ -67,7 +67,8 @@ public class ImageHelper {
         }
 
         if (pixelStride == 2 && rowStride == width && uBuffer.get(0) == vBuffer.get(1)) {
-            // maybe V an U planes overlap as per NV21, which means vBuffer[1] is alias of uBuffer[0]
+            // maybe V an U planes overlap as per NV21, which means vBuffer[1]
+            // is alias of uBuffer[0]
             byte savePixel = vBuffer.get(1);
             vBuffer.put(1, (byte)0);
             if (uBuffer.get(0) == 0) {

cameraview/src/main/java/com/otaliastudios/cameraview/internal/utils/OrientationHelper.java

@@ -12,7 +12,8 @@ import android.view.WindowManager;
 
 /**
  * Helps with keeping track of both device orientation (which changes when device is rotated)
- * and the display offset (which depends on the activity orientation wrt the device default orientation).
+ * and the display offset (which depends on the activity orientation
+ * wrt the device default orientation).
  */
 public class OrientationHelper {
 
@@ -35,7 +36,8 @@ public class OrientationHelper {
      */
     public OrientationHelper(@NonNull Context context, @NonNull Callback callback) {
         mCallback = callback;
-        mListener = new OrientationEventListener(context.getApplicationContext(), SensorManager.SENSOR_DELAY_NORMAL) {
+        mListener = new OrientationEventListener(context.getApplicationContext(),
+                SensorManager.SENSOR_DELAY_NORMAL) {
 
             @SuppressWarnings("ConstantConditions")
             @Override
@@ -66,7 +68,9 @@ public class OrientationHelper {
      * @param context a context
      */
     public void enable(@NonNull Context context) {
-        Display display = ((WindowManager) context.getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
+        Display display = ((WindowManager) context
+                .getSystemService(Context.WINDOW_SERVICE))
+                .getDefaultDisplay();
         switch (display.getRotation()) {
             case Surface.ROTATION_0: mDisplayOffset = 0; break;
             case Surface.ROTATION_90: mDisplayOffset = 90; break;

cameraview/src/main/java/com/otaliastudios/cameraview/internal/utils/Pool.java

@@ -92,14 +92,16 @@ public class Pool<T> {
         synchronized (lock) {
             LOG.v("RECYCLE - Recycling item.", this);
             if (--activeCount < 0) {
-                throw new IllegalStateException("Trying to recycle an item which makes activeCount < 0." +
-                        "This means that this or some previous items being recycled were not coming from " +
-                        "this pool, or some item was recycled more than once. " + this);
+                throw new IllegalStateException("Trying to recycle an item which makes " +
+                        "activeCount < 0. This means that this or some previous items being " +
+                        "recycled were not coming from this pool, or some item was recycled " +
+                        "more than once. " + this);
             }
             if (!queue.offer(item)) {
-                throw new IllegalStateException("Trying to recycle an item while the queue is full. " +
-                        "This means that this or some previous items being recycled were not coming from " +
-                        "this pool, or some item was recycled more than once. " + this);
+                throw new IllegalStateException("Trying to recycle an item while the queue " +
+                        "is full. This means that this or some previous items being recycled " +
+                        "were not coming from this pool, or some item was recycled " +
+                        "more than once. " + this);
             }
         }
     }
@@ -121,7 +123,6 @@ public class Pool<T> {
      *
      * @return count
      */
-    @SuppressWarnings("WeakerAccess")
     public final int count() {
         synchronized (lock) {
             return activeCount() + recycledCount();

cameraview/src/main/java/com/otaliastudios/cameraview/internal/utils/RotationHelper.java

@@ -19,7 +19,9 @@ public class RotationHelper {
      * @param rotation desired angle
      * @return a new yuv array
      */
-    public static byte[] rotate(@NonNull final byte[] yuv, @NonNull final Size size, final int rotation) {
+    public static byte[] rotate(@NonNull final byte[] yuv,
+                                @NonNull final Size size,
+                                final int rotation) {
         if (rotation == 0) return yuv;
         if (rotation % 90 != 0 || rotation < 0 || rotation > 270) {
             throw new IllegalArgumentException("0 <= rotation < 360, rotation % 90 == 0");

cameraview/src/main/java/com/otaliastudios/cameraview/internal/utils/WorkerHandler.java

@@ -23,8 +23,10 @@ import java.util.concurrent.Executor;
  */
 public class WorkerHandler {
 
-    private final static CameraLogger LOG = CameraLogger.create(WorkerHandler.class.getSimpleName());
-    private final static ConcurrentHashMap<String, WeakReference<WorkerHandler>> sCache = new ConcurrentHashMap<>(4);
+    private final static CameraLogger LOG
+            = CameraLogger.create(WorkerHandler.class.getSimpleName());
+    private final static ConcurrentHashMap<String, WeakReference<WorkerHandler>> sCache
+            = new ConcurrentHashMap<>(4);
 
     private final static String FALLBACK_NAME = "FallbackCameraThread";
 
@@ -50,7 +52,8 @@ public class WorkerHandler {
                 } else {
                     // Cleanup the old thread before creating a new one
                     cached.destroy();
-                    LOG.w("get:", "Thread reference found, but not alive or interrupted. Removing.", name);
+                    LOG.w("get:", "Thread reference found, but not alive or interrupted.",
+                            "Removing.", name);
                     sCache.remove(name);
                 }
             } else {

cameraview/src/main/java/com/otaliastudios/cameraview/markers/AutoFocusMarker.java

@@ -32,7 +32,9 @@ public interface AutoFocusMarker extends Marker {
      * @param successful whether the operation succeeded
      * @param point coordinates
      */
-    void onAutoFocusEnd(@NonNull AutoFocusTrigger trigger, boolean successful, @NonNull PointF point);
+    void onAutoFocusEnd(@NonNull AutoFocusTrigger trigger,
+                        boolean successful,
+                        @NonNull PointF point);
 
 
 }

cameraview/src/main/java/com/otaliastudios/cameraview/markers/DefaultAutoFocusMarker.java

@@ -27,7 +27,8 @@ public class DefaultAutoFocusMarker implements AutoFocusMarker {
     @Nullable
     @Override
     public View onAttach(@NonNull Context context, @NonNull ViewGroup container) {
-        View view = LayoutInflater.from(context).inflate(R.layout.cameraview_layout_focus_marker, container, false);
+        View view = LayoutInflater.from(context).inflate(R.layout.cameraview_layout_focus_marker,
+                container, false);
         mContainer = view.findViewById(R.id.focusMarkerContainer);
         mFill = view.findViewById(R.id.focusMarkerFill);
         return view;
@@ -49,18 +50,22 @@ public class DefaultAutoFocusMarker implements AutoFocusMarker {
     }
 
     @Override
-    public void onAutoFocusEnd(@NonNull AutoFocusTrigger trigger, boolean successful, @NonNull PointF point) {
+    public void onAutoFocusEnd(@NonNull AutoFocusTrigger trigger,
+                               boolean successful,
+                               @NonNull PointF point) {
         if (trigger == AutoFocusTrigger.METHOD) return;
         if (successful) {
             animate(mContainer, 1, 0, 500, 0, null);
             animate(mFill, 1, 0, 500, 0, null);
         } else {
             animate(mFill, 0, 0, 500, 0, null);
-            animate(mContainer, 1.36f, 1, 500, 0, new AnimatorListenerAdapter() {
+            animate(mContainer, 1.36f, 1, 500, 0,
+                    new AnimatorListenerAdapter() {
                 @Override
                 public void onAnimationEnd(Animator animation) {
                     super.onAnimationEnd(animation);
-                    animate(mContainer, 1.36f, 0, 200, 1000, null);
+                    animate(mContainer, 1.36f, 0, 200, 1000,
+                            null);
                 }
             });
         }

cameraview/src/main/java/com/otaliastudios/cameraview/overlay/OverlayDrawer.java

@@ -24,7 +24,7 @@ import java.nio.Buffer;
  *
  * - Provides a {@link Canvas} to be passed to the Overlay
  * - Lets the overlay draw there: {@link #draw(Overlay.Target)}
- * - Renders this into the current EGL window: {@link #render()}
+ * - Renders this into the current EGL window: {@link #render(long)}
  * - Applies the {@link Issue514Workaround} the correct way
  *
  * In the future we might want to use a different approach than {@link EglViewport},
@@ -93,8 +93,10 @@ public class OverlayDrawer {
      * Renders the drawn content in the current EGL surface, assuming there is one.
      * Should be called after {@link #draw(Overlay.Target)} and any {@link #getTransform()}
      * modification.
+     *
+     * @param timestampUs frame timestamp
      */
-    public void render() {
+    public void render(long timestampUs) {
         // Enable blending
         // Reference http://www.learnopengles.com/android-lesson-five-an-introduction-to-blending/
         GLES20.glDisable(GLES20.GL_CULL_FACE);
@@ -103,7 +105,7 @@ public class OverlayDrawer {
         GLES20.glBlendFunc(GLES20.GL_SRC_ALPHA, GLES20.GL_ONE_MINUS_SRC_ALPHA);
 
         synchronized (mIssue514WorkaroundLock) {
-            mViewport.drawFrame(mTextureId, mTransform);
+            mViewport.drawFrame(timestampUs, mTextureId, mTransform);
         }
     }
 

cameraview/src/main/java/com/otaliastudios/cameraview/overlay/OverlayLayout.java

@@ -183,9 +183,12 @@ public class OverlayLayout extends FrameLayout implements Overlay {
             super(context, attrs);
             TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.CameraView_Layout);
             try {
-                drawOnPreview = a.getBoolean(R.styleable.CameraView_Layout_layout_drawOnPreview, false);
-                drawOnPictureSnapshot = a.getBoolean(R.styleable.CameraView_Layout_layout_drawOnPictureSnapshot, false);
-                drawOnVideoSnapshot = a.getBoolean(R.styleable.CameraView_Layout_layout_drawOnVideoSnapshot, false);
+                drawOnPreview = a.getBoolean(R.styleable.CameraView_Layout_layout_drawOnPreview,
+                        false);
+                drawOnPictureSnapshot = a.getBoolean(
+                        R.styleable.CameraView_Layout_layout_drawOnPictureSnapshot, false);
+                drawOnVideoSnapshot = a.getBoolean(
+                        R.styleable.CameraView_Layout_layout_drawOnVideoSnapshot, false);
             } finally {
                 a.recycle();
             }

cameraview/src/main/java/com/otaliastudios/cameraview/picture/Full1PictureRecorder.java

@@ -54,7 +54,9 @@ public class Full1PictureRecorder extends PictureRecorder {
                         int exifRotation;
                         try {
                             ExifInterface exif = new ExifInterface(new ByteArrayInputStream(data));
-                            int exifOrientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL);
+                            int exifOrientation = exif.getAttributeInt(
+                                    ExifInterface.TAG_ORIENTATION,
+                                    ExifInterface.ORIENTATION_NORMAL);
                             exifRotation = ExifHelper.readExifOrientation(exifOrientation);
                         } catch (IOException e) {
                             exifRotation = 0;

cameraview/src/main/java/com/otaliastudios/cameraview/picture/Full2PictureRecorder.java

@@ -28,7 +28,8 @@ import androidx.exifinterface.media.ExifInterface;
  * A {@link PictureResult} that uses standard APIs.
  */
 @RequiresApi(Build.VERSION_CODES.LOLLIPOP)
-public class Full2PictureRecorder extends PictureRecorder implements ImageReader.OnImageAvailableListener {
+public class Full2PictureRecorder extends PictureRecorder
+        implements ImageReader.OnImageAvailableListener {
 
     private static final String TAG = Full2PictureRecorder.class.getSimpleName();
     private static final CameraLogger LOG = CameraLogger.create(TAG);
@@ -65,7 +66,8 @@ public class Full2PictureRecorder extends PictureRecorder implements ImageReader
             }
 
             @Override
-            public void onCaptureStarted(@NonNull ActionHolder holder, @NonNull CaptureRequest request) {
+            public void onCaptureStarted(@NonNull ActionHolder holder,
+                                         @NonNull CaptureRequest request) {
                 super.onCaptureStarted(holder, request);
                 if (request.getTag() == (Integer) CameraDevice.TEMPLATE_STILL_CAPTURE) {
                     LOG.i("onCaptureStarted:", "Dispatching picture shutter.");

cameraview/src/main/java/com/otaliastudios/cameraview/picture/PictureRecorder.java

@@ -44,7 +44,8 @@ public abstract class PictureRecorder {
      * @param listener a listener
      */
     @SuppressWarnings("WeakerAccess")
-    public PictureRecorder(@NonNull PictureResult.Stub stub, @Nullable PictureResultListener listener) {
+    public PictureRecorder(@NonNull PictureResult.Stub stub,
+                           @Nullable PictureResultListener listener) {
         mResult = stub;
         mListener = listener;
     }

cameraview/src/main/java/com/otaliastudios/cameraview/picture/Snapshot1PictureRecorder.java

@@ -60,7 +60,8 @@ public class Snapshot1PictureRecorder extends PictureRecorder {
                 final Size outputSize = mResult.size;
                 final Size previewStreamSize = mEngine1.getPreviewStreamSize(Reference.SENSOR);
                 if (previewStreamSize == null) {
-                    throw new IllegalStateException("Preview stream size should never be null here.");
+                    throw new IllegalStateException("Preview stream size " +
+                            "should never be null here.");
                 }
                 WorkerHandler.execute(new Runnable() {
                     @Override
@@ -69,7 +70,8 @@ public class Snapshot1PictureRecorder extends PictureRecorder {
                         // then crop if needed. In both cases, transform yuv to jpeg.
                         //noinspection deprecation
                         byte[] data = RotationHelper.rotate(yuv, previewStreamSize, sensorToOutput);
-                        YuvImage yuv = new YuvImage(data, mFormat, outputSize.getWidth(), outputSize.getHeight(), null);
+                        YuvImage yuv = new YuvImage(data, mFormat, outputSize.getWidth(),
+                                outputSize.getHeight(), null);
 
                         ByteArrayOutputStream stream = new ByteArrayOutputStream();
                         Rect outputRect = CropHelper.computeCrop(outputSize, mOutputRatio);

cameraview/src/main/java/com/otaliastudios/cameraview/picture/Snapshot2PictureRecorder.java

@@ -26,18 +26,20 @@ import com.otaliastudios.cameraview.size.AspectRatio;
  * Wraps {@link SnapshotGlPictureRecorder} for Camera2.
  *
  * Camera2 engine supports metering for snapshots and we expect for them to correctly fire flash as well.
- * The first idea, and in theory, the most correct one, was to set {@link CaptureRequest#CONTROL_CAPTURE_INTENT}
- * to {@link CaptureRequest#CONTROL_CAPTURE_INTENT_STILL_CAPTURE}.
+ * The first idea, and in theory, the most correct one, was to set
+ * {@link CaptureRequest#CONTROL_CAPTURE_INTENT} to
+ * {@link CaptureRequest#CONTROL_CAPTURE_INTENT_STILL_CAPTURE}.
  *
  * According to documentation, this will automatically trigger the flash if parameters says so.
  * In fact this is what happens, but it is a very fast flash that only lasts for 1 or 2 frames.
  * It's not easy to call super.take() at the exact time so that we capture the frame that was lit.
- * I have tried by comparing {@link SurfaceTexture#getTimestamp()} and {@link CaptureResult#SENSOR_TIMESTAMP}
- * to identify the correct frame. These timestamps match, but the frame is not the correct one.
+ * I have tried by comparing {@link SurfaceTexture#getTimestamp()} and
+ * {@link CaptureResult#SENSOR_TIMESTAMP} to identify the correct frame. These timestamps match,
+ * but the frame is not the correct one.
  *
- * So what we do here is ignore the {@link CaptureRequest#CONTROL_CAPTURE_INTENT} and instead open the
- * torch, if requested to do so. Then wait for exposure to settle again and finally take a snapshot.
- * I'd still love to use the capture intent instead of this, but was not able yet.
+ * So what we do here is ignore the {@link CaptureRequest#CONTROL_CAPTURE_INTENT} and instead
+ * open the torch, if requested to do so. Then wait for exposure to settle again and finally
+ * take a snapshot. I'd still love to use the capture intent instead of this, but was not able yet.
  */
 @RequiresApi(Build.VERSION_CODES.LOLLIPOP)
 public class Snapshot2PictureRecorder extends SnapshotGlPictureRecorder {
@@ -52,8 +54,10 @@ public class Snapshot2PictureRecorder extends SnapshotGlPictureRecorder {
         protected void onStart(@NonNull ActionHolder holder) {
             super.onStart(holder);
             LOG.i("FlashAction:", "Parameters locked, opening torch.");
-            holder.getBuilder(this).set(CaptureRequest.FLASH_MODE, CaptureRequest.FLASH_MODE_TORCH);
-            holder.getBuilder(this).set(CaptureRequest.CONTROL_AE_MODE, CaptureRequest.CONTROL_AE_MODE_ON);
+            holder.getBuilder(this).set(CaptureRequest.FLASH_MODE,
+                    CaptureRequest.FLASH_MODE_TORCH);
+            holder.getBuilder(this).set(CaptureRequest.CONTROL_AE_MODE,
+                    CaptureRequest.CONTROL_AE_MODE_ON);
             holder.applyBuilder(this);
         }
 
@@ -64,10 +68,12 @@ public class Snapshot2PictureRecorder extends SnapshotGlPictureRecorder {
             super.onCaptureCompleted(holder, request, result);
             Integer flashState = result.get(CaptureResult.FLASH_STATE);
             if (flashState == null) {
-                LOG.w("FlashAction:", "Waiting flash, but flashState is null! Taking snapshot.");
+                LOG.w("FlashAction:", "Waiting flash, but flashState is null!",
+                        "Taking snapshot.");
                 setState(STATE_COMPLETED);
             } else if (flashState == CaptureResult.FLASH_STATE_FIRED) {
-                LOG.i("FlashAction:", "Waiting flash and we have FIRED state! Taking snapshot.");
+                LOG.i("FlashAction:", "Waiting flash and we have FIRED state!",
+                        "Taking snapshot.");
                 setState(STATE_COMPLETED);
             } else {
                 LOG.i("FlashAction:", "Waiting flash but flashState is",
@@ -111,7 +117,8 @@ public class Snapshot2PictureRecorder extends SnapshotGlPictureRecorder {
     @Override
     public void take() {
         if (!mActionNeeded) {
-            LOG.i("take:", "Engine does no metering or needs no flash, taking fast snapshot.");
+            LOG.i("take:", "Engine does no metering or needs no flash.",
+                    "Taking fast snapshot.");
             super.take();
         } else {
             LOG.i("take:", "Engine needs flash. Starting action");

cameraview/src/main/java/com/otaliastudios/cameraview/picture/SnapshotGlPictureRecorder.java

@@ -46,11 +46,13 @@ import android.view.Surface;
  * - We move to another thread, and create a new EGL surface for that EGL context.
  * - We make this new surface current, and re-draw the textureId on it
  * - [Optional: fill the overlayTextureId and draw it on the same surface]
- * - We use glReadPixels (through {@link EglBaseSurface#saveFrameTo(Bitmap.CompressFormat)}) and save to file.
+ * - We use glReadPixels (through {@link EglBaseSurface#saveFrameTo(Bitmap.CompressFormat)})
+ *   and save to file.
  *
  * We create a new EGL surface and redraw the frame because:
  * 1. We want to go off the renderer thread as soon as possible
- * 2. We have overlays to be drawn - we don't want to draw them on the preview surface, not even for a frame.
+ * 2. We have overlays to be drawn - we don't want to draw them on the preview surface,
+ *    not even for a frame.
  */
 public class SnapshotGlPictureRecorder extends PictureRecorder {
 
@@ -102,7 +104,9 @@ public class SnapshotGlPictureRecorder extends PictureRecorder {
 
             @RendererThread
             @Override
-            public void onRendererFrame(@NonNull SurfaceTexture surfaceTexture, final float scaleX, final float scaleY) {
+            public void onRendererFrame(@NonNull SurfaceTexture surfaceTexture,
+                                        final float scaleX,
+                                        final float scaleY) {
                 mPreview.removeRendererFrameCallback(this);
                 SnapshotGlPictureRecorder.this.onRendererFrame(surfaceTexture, scaleX, scaleY);
             }
@@ -110,6 +114,7 @@ public class SnapshotGlPictureRecorder extends PictureRecorder {
         });
     }
 
+    @SuppressWarnings("WeakerAccess")
     @RendererThread
     @TargetApi(Build.VERSION_CODES.KITKAT)
     protected void onRendererTextureCreated(int textureId) {
@@ -126,12 +131,14 @@ public class SnapshotGlPictureRecorder extends PictureRecorder {
         }
     }
 
+    @SuppressWarnings("WeakerAccess")
     @RendererThread
     @TargetApi(Build.VERSION_CODES.KITKAT)
     protected void onRendererFilterChanged(@NonNull Filter filter) {
         mViewport.setFilter(filter.copy());
     }
 
+    @SuppressWarnings("WeakerAccess")
     @RendererThread
     @TargetApi(Build.VERSION_CODES.KITKAT)
     protected void onRendererFrame(@SuppressWarnings("unused") @NonNull final SurfaceTexture surfaceTexture,
@@ -175,9 +182,13 @@ public class SnapshotGlPictureRecorder extends PictureRecorder {
      * @param scaleX frame scale x in {@link Reference#VIEW}
      * @param scaleY frame scale y in {@link Reference#VIEW}
      */
+    @SuppressWarnings("WeakerAccess")
     @WorkerThread
     @TargetApi(Build.VERSION_CODES.KITKAT)
-    protected void takeFrame(@NonNull SurfaceTexture surfaceTexture, float scaleX, float scaleY, @NonNull EGLContext eglContext) {
+    protected void takeFrame(@NonNull SurfaceTexture surfaceTexture,
+                             float scaleX,
+                             float scaleY,
+                             @NonNull EGLContext eglContext) {
 
         // 0. EGL window will need an output.
         // We create a fake one as explained in javadocs.
@@ -223,9 +234,10 @@ public class SnapshotGlPictureRecorder extends PictureRecorder {
         }
 
         // 5. Draw and save
-        LOG.i("takeFrame:", "timestamp:", surfaceTexture.getTimestamp());
-        mViewport.drawFrame(mTextureId, mTransform);
-        if (mHasOverlay) mOverlayDrawer.render();
+        long timestampUs = surfaceTexture.getTimestamp() / 1000L;
+        LOG.i("takeFrame:", "timestampUs:", timestampUs);
+        mViewport.drawFrame(timestampUs, mTextureId, mTransform);
+        if (mHasOverlay) mOverlayDrawer.render(timestampUs);
         mResult.format = PictureResult.FORMAT_JPEG;
         mResult.data = eglSurface.saveFrameTo(Bitmap.CompressFormat.JPEG);
 

cameraview/src/main/java/com/otaliastudios/cameraview/preview/CameraPreview.java

@@ -26,11 +26,13 @@ import com.otaliastudios.cameraview.size.Size;
  * into an output surface that belongs to the view hierarchy.
  *
  * @param <T> the type of view which hosts the content surface
- * @param <Output> the type of output, either {@link android.view.SurfaceHolder} or {@link android.graphics.SurfaceTexture}
+ * @param <Output> the type of output, either {@link android.view.SurfaceHolder}
+ *                 or {@link android.graphics.SurfaceTexture}
  */
 public abstract class CameraPreview<T extends View, Output> {
 
-    protected final static CameraLogger LOG = CameraLogger.create(CameraPreview.class.getSimpleName());
+    protected final static CameraLogger LOG
+            = CameraLogger.create(CameraPreview.class.getSimpleName());
 
     /**
      * This is used to notify CameraEngine to recompute its camera Preview size.
@@ -267,8 +269,9 @@ public abstract class CameraPreview<T extends View, Output> {
     }
 
     /**
-     * At this point we undo the work that was done during {@link #onCreateView(Context, ViewGroup)},
-     * which basically means removing the root view from the hierarchy.
+     * At this point we undo the work that was done during
+     * {@link #onCreateView(Context, ViewGroup)}, which basically means removing the root view
+     * from the hierarchy.
      */
     @SuppressWarnings("WeakerAccess")
     @UiThread

cameraview/src/main/java/com/otaliastudios/cameraview/preview/GlCameraPreview.java

@@ -32,9 +32,10 @@ import javax.microedition.khronos.opengles.GL10;
  *
  * - in the SurfaceTexture constructor we pass the GL texture handle that we have created.
  *
- * - The SurfaceTexture is linked to the Camera1Engine object. The camera will pass down buffers of data with
- *   a specified size (that is, the Camera1Engine preview size). For this reason we don't have to specify
- *   surfaceTexture.setDefaultBufferSize() (like we do, for example, in Snapshot1PictureRecorder).
+ * - The SurfaceTexture is linked to the Camera1Engine object. The camera will pass down
+ *   buffers of data with a specified size (that is, the Camera1Engine preview size).
+ *   For this reason we don't have to specify surfaceTexture.setDefaultBufferSize()
+ *   (like we do, for example, in Snapshot1PictureRecorder).
  *
  * - When SurfaceTexture.updateTexImage() is called, it will fetch the latest texture image from the
  *   camera stream and assign it to the GL texture that was passed.
@@ -42,12 +43,13 @@ import javax.microedition.khronos.opengles.GL10;
  *   the transformation matrix to be applied.
  *
  * - The easy way to render an OpenGL texture is using the {@link GLSurfaceView} class.
- *   It manages the GL context, hosts a surface and runs a separated rendering thread that will perform
- *   the rendering.
+ *   It manages the GL context, hosts a surface and runs a separated rendering thread that will
+ *   perform the rendering.
  *
  * - As per docs, we ask the GLSurfaceView to delegate rendering to us, using
- *   {@link GLSurfaceView#setRenderer(GLSurfaceView.Renderer)}. We request a render on the SurfaceView
- *   anytime the SurfaceTexture notifies that it has new data available (see OnFrameAvailableListener below).
+ *   {@link GLSurfaceView#setRenderer(GLSurfaceView.Renderer)}. We request a render on the
+ *   SurfaceView anytime the SurfaceTexture notifies that it has new data available
+ *   (see OnFrameAvailableListener below).
  *
  * - So in short:
  *   - The SurfaceTexture has buffers of data of mInputStreamSize
@@ -55,9 +57,10 @@ import javax.microedition.khronos.opengles.GL10;
  *     These are determined by the CameraView.onMeasure method.
  *   - We have a GL rich texture to be drawn (in the given method and thread).
  *
- * This class will provide rendering callbacks to anyone who registers a {@link RendererFrameCallback}.
- * Callbacks are guaranteed to be called on the renderer thread, which means that we can fetch
- * the GL context that was created and is managed by the {@link GLSurfaceView}.
+ * This class will provide rendering callbacks to anyone who registers a
+ * {@link RendererFrameCallback}. Callbacks are guaranteed to be called on the renderer thread,
+ * which means that we can fetch the GL context that was created and is managed
+ * by the {@link GLSurfaceView}.
  */
 public class GlCameraPreview extends FilterCameraPreview<GLSurfaceView, SurfaceTexture> {
 
@@ -66,7 +69,8 @@ public class GlCameraPreview extends FilterCameraPreview<GLSurfaceView, SurfaceT
     private int mOutputTextureId = 0;
     private SurfaceTexture mInputSurfaceTexture;
     private EglViewport mOutputViewport;
-    private final Set<RendererFrameCallback> mRendererFrameCallbacks = Collections.synchronizedSet(new HashSet<RendererFrameCallback>());
+    private final Set<RendererFrameCallback> mRendererFrameCallbacks
+            = Collections.synchronizedSet(new HashSet<RendererFrameCallback>());
     @VisibleForTesting float mCropScaleX = 1F;
     @VisibleForTesting float mCropScaleY = 1F;
     private View mRootView;
@@ -79,7 +83,8 @@ public class GlCameraPreview extends FilterCameraPreview<GLSurfaceView, SurfaceT
     @NonNull
     @Override
     protected GLSurfaceView onCreateView(@NonNull Context context, @NonNull ViewGroup parent) {
-        ViewGroup root = (ViewGroup) LayoutInflater.from(context).inflate(R.layout.cameraview_gl_view, parent, false);
+        ViewGroup root = (ViewGroup) LayoutInflater.from(context)
+                .inflate(R.layout.cameraview_gl_view, parent, false);
         GLSurfaceView glView = root.findViewById(R.id.gl_surface_view);
         glView.setEGLContextClientVersion(2);
         glView.setRenderer(instantiateRenderer());
@@ -160,8 +165,8 @@ public class GlCameraPreview extends FilterCameraPreview<GLSurfaceView, SurfaceT
                 }
             });
 
-            // Since we are using GLSurfaceView.RENDERMODE_WHEN_DIRTY, we must notify the SurfaceView
-            // of dirtyness, so that it draws again. This is how it's done.
+            // Since we are using GLSurfaceView.RENDERMODE_WHEN_DIRTY, we must notify
+            // the SurfaceView of dirtyness, so that it draws again. This is how it's done.
             mInputSurfaceTexture.setOnFrameAvailableListener(new SurfaceTexture.OnFrameAvailableListener() {
                 @Override
                 public void onFrameAvailable(SurfaceTexture surfaceTexture) {
@@ -209,14 +214,17 @@ public class GlCameraPreview extends FilterCameraPreview<GLSurfaceView, SurfaceT
 
             if (isCropping()) {
                 // Scaling is easy, but we must also translate before:
-                // If the view is 10x1000 (very tall), it will show only the left strip of the preview (not the center one).
-                // If the view is 1000x10 (very large), it will show only the bottom strip of the preview (not the center one).
+                // If the view is 10x1000 (very tall), it will show only the left strip
+                // of the preview (not the center one).
+                // If the view is 1000x10 (very large), it will show only the bottom strip
+                // of the preview (not the center one).
                 float translX = (1F - mCropScaleX) / 2F;
                 float translY = (1F - mCropScaleY) / 2F;
                 Matrix.translateM(mTransformMatrix, 0, translX, translY, 0);
                 Matrix.scaleM(mTransformMatrix, 0, mCropScaleX, mCropScaleY, 1);
             }
-            mOutputViewport.drawFrame(mOutputTextureId, mTransformMatrix);
+            mOutputViewport.drawFrame(mInputSurfaceTexture.getTimestamp() / 1000L,
+                    mOutputTextureId, mTransformMatrix);
             synchronized (mRendererFrameCallbacks) {
                 // Need to synchronize when iterating the Collections.synchronizedSet
                 for (RendererFrameCallback callback : mRendererFrameCallbacks) {
@@ -244,21 +252,23 @@ public class GlCameraPreview extends FilterCameraPreview<GLSurfaceView, SurfaceT
     }
 
     /**
-     * To crop in GL, we could actually use view.setScaleX and setScaleY, but only from Android N onward.
-     * See documentation: https://developer.android.com/reference/android/view/SurfaceView
+     * To crop in GL, we could actually use view.setScaleX and setScaleY, but only from Android N
+     * onward. See documentation: https://developer.android.com/reference/android/view/SurfaceView
      *
-     *   Note: Starting in platform version Build.VERSION_CODES.N, SurfaceView's window position is updated
-     *   synchronously with other View rendering. This means that translating and scaling a SurfaceView on
-     *   screen will not cause rendering artifacts. Such artifacts may occur on previous versions of the
-     *   platform when its window is positioned asynchronously.
+     *   Note: Starting in platform version Build.VERSION_CODES.N, SurfaceView's window position
+     *   is updated synchronously with other View rendering. This means that translating and scaling
+     *   a SurfaceView on screen will not cause rendering artifacts. Such artifacts may occur on
+     *   previous versions of the platform when its window is positioned asynchronously.
      *
-     * But to support older platforms, this seem to work - computing scale values and requesting a new frame,
-     * then drawing it with a scaled transformation matrix. See {@link Renderer#onDrawFrame(GL10)}.
+     * But to support older platforms, this seem to work - computing scale values and requesting
+     * a new frame, then drawing it with a scaled transformation matrix.
+     * See {@link Renderer#onDrawFrame(GL10)}.
      */
     @Override
     protected void crop(@NonNull Op<Void> op) {
         op.start();
-        if (mInputStreamWidth > 0 && mInputStreamHeight > 0 && mOutputSurfaceWidth > 0 && mOutputSurfaceHeight > 0) {
+        if (mInputStreamWidth > 0 && mInputStreamHeight > 0 && mOutputSurfaceWidth > 0
+                && mOutputSurfaceHeight > 0) {
             float scaleX = 1f, scaleY = 1f;
             AspectRatio current = AspectRatio.of(mOutputSurfaceWidth, mOutputSurfaceHeight);
             AspectRatio target = AspectRatio.of(mInputStreamWidth, mInputStreamHeight);

cameraview/src/main/java/com/otaliastudios/cameraview/preview/SurfaceCameraPreview.java

@@ -14,14 +14,15 @@ import com.otaliastudios.cameraview.R;
 
 /**
  * This is the fallback preview when hardware acceleration is off, and is the last resort.
- * Currently does not support cropping, which means that {@link com.otaliastudios.cameraview.CameraView}
- * is forced to be wrap_content.
+ * Currently does not support cropping, which means that
+ * {@link com.otaliastudios.cameraview.CameraView} is forced to be wrap_content.
  *
  * Do not use.
  */
 public class SurfaceCameraPreview extends CameraPreview<SurfaceView, SurfaceHolder> {
 
-    private final static CameraLogger LOG = CameraLogger.create(SurfaceCameraPreview.class.getSimpleName());
+    private final static CameraLogger LOG
+            = CameraLogger.create(SurfaceCameraPreview.class.getSimpleName());
 
     private boolean mDispatched;
     private View mRootView;
@@ -33,7 +34,8 @@ public class SurfaceCameraPreview extends CameraPreview<SurfaceView, SurfaceHold
     @NonNull
     @Override
     protected SurfaceView onCreateView(@NonNull Context context, @NonNull ViewGroup parent) {
-        View root = LayoutInflater.from(context).inflate(R.layout.cameraview_surface_view, parent, false);
+        View root = LayoutInflater.from(context).inflate(R.layout.cameraview_surface_view, parent,
+                false);
         parent.addView(root, 0);
         SurfaceView surfaceView = root.findViewById(R.id.surface_view);
         final SurfaceHolder holder = surfaceView.getHolder();
@@ -48,7 +50,10 @@ public class SurfaceCameraPreview extends CameraPreview<SurfaceView, SurfaceHold
 
             @Override
             public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
-                LOG.i("callback:", "surfaceChanged", "w:", width, "h:", height, "dispatched:", mDispatched);
+                LOG.i("callback:", "surfaceChanged",
+                        "w:", width,
+                        "h:", height,
+                        "dispatched:", mDispatched);
                 if (!mDispatched) {
                     dispatchOnSurfaceAvailable(width, height);
                     mDispatched = true;