Small fixes (#524)

* Add picture snapshot comments

* Release temp viewport

* Add ImageReader version of picture recorder

* Fix default camera

* Increase I frame interval, add comments

* Improve demo app

* Use surface size instead of view size for snapshot ratio

* Avoid weird sizes in snapshot output

* Review snapshot picture recorder again

* Fix auto focus callback

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

@@ -128,7 +128,7 @@ public class MockCameraEngine extends CameraEngine {
     }
 
     @Override
-    protected void onTakePictureSnapshot(@NonNull PictureResult.Stub stub, @NonNull AspectRatio viewAspectRatio) {
+    protected void onTakePictureSnapshot(@NonNull PictureResult.Stub stub, @NonNull AspectRatio outputRatio) {
 
     }
 
@@ -138,7 +138,7 @@ public class MockCameraEngine extends CameraEngine {
     }
 
     @Override
-    protected void onTakeVideoSnapshot(@NonNull VideoResult.Stub stub, @NonNull AspectRatio viewAspectRatio) {
+    protected void onTakeVideoSnapshot(@NonNull VideoResult.Stub stub, @NonNull AspectRatio outputRatio) {
 
     }
 

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

@@ -425,10 +425,10 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
             int height, width;
             if (freeWidth) {
                 height = heightValue;
-                width = (int) (height / ratio);
+                width = Math.round(height / ratio);
             } else {
                 width = widthValue;
-                height = (int) (width * ratio);
+                height = Math.round(width * ratio);
             }
             LOG.i("onMeasure:", "one dimension was free, we adapted it to fit the aspect ratio.",
                     "(" + width + "x" + height + ")");
@@ -445,10 +445,10 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
             int height, width;
             if (freeWidth) {
                 height = heightValue;
-                width = Math.min((int) (height / ratio), widthValue);
+                width = Math.min(Math.round(height / ratio), widthValue);
             } else {
                 width = widthValue;
-                height = Math.min((int) (width * ratio), heightValue);
+                height = Math.min(Math.round(width * ratio), heightValue);
             }
             LOG.i("onMeasure:", "one dimension was EXACTLY, another AT_MOST.",
                     "We have TRIED to fit the aspect ratio, but it's not guaranteed.",
@@ -465,10 +465,10 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
         if (atMostRatio >= ratio) {
             // We must reduce height.
             width = widthValue;
-            height = (int) (width * ratio);
+            height = Math.round(width * ratio);
         } else {
             height = heightValue;
-            width = (int) (height / ratio);
+            width = Math.round(height / ratio);
         }
         LOG.i("onMeasure:", "both dimension were AT_MOST.",
                 "We fit the preview aspect ratio.",
@@ -1465,9 +1465,8 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
      * @see #takePicture()
      */
     public void takePictureSnapshot() {
-        if (getWidth() == 0 || getHeight() == 0) return;
         PictureResult.Stub stub = new PictureResult.Stub();
-        mCameraEngine.takePictureSnapshot(stub, AspectRatio.of(getWidth(), getHeight()));
+        mCameraEngine.takePictureSnapshot(stub);
     }
 
 
@@ -1499,9 +1498,8 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
      * @param file a file where the video will be saved
      */
     public void takeVideoSnapshot(@NonNull File file) {
-        if (getWidth() == 0 || getHeight() == 0) return;
         VideoResult.Stub stub = new VideoResult.Stub();
-        mCameraEngine.takeVideoSnapshot(stub, file, AspectRatio.of(getWidth(), getHeight()));
+        mCameraEngine.takeVideoSnapshot(stub, file);
         mUiHandler.post(new Runnable() {
             @Override
             public void run() {

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

@@ -306,10 +306,9 @@ public class Camera1Engine extends CameraEngine implements
 
     @WorkerThread
     @Override
-    protected void onTakePictureSnapshot(@NonNull PictureResult.Stub stub, @NonNull AspectRatio viewAspectRatio) {
+    protected void onTakePictureSnapshot(@NonNull PictureResult.Stub stub, @NonNull AspectRatio outputRatio) {
         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.
-        AspectRatio outputRatio = getAngles().flip(Reference.OUTPUT, Reference.VIEW) ? viewAspectRatio.flip() : viewAspectRatio;
 
         if (mPreview instanceof GlCameraPreview && Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
             mPictureRecorder = new SnapshotGlPictureRecorder(stub, this, (GlCameraPreview) mPreview, outputRatio, getOverlay());
@@ -343,7 +342,7 @@ public class Camera1Engine extends CameraEngine implements
     @SuppressLint("NewApi")
     @WorkerThread
     @Override
-    protected void onTakeVideoSnapshot(@NonNull VideoResult.Stub stub, @NonNull AspectRatio viewAspectRatio) {
+    protected void onTakeVideoSnapshot(@NonNull VideoResult.Stub stub, @NonNull AspectRatio outputRatio) {
         if (!(mPreview instanceof GlCameraPreview)) {
             throw new IllegalStateException("Video snapshots are only supported with GlCameraPreview.");
         }
@@ -355,7 +354,6 @@ public class Camera1Engine extends CameraEngine implements
         if (outputSize == null) {
             throw new IllegalStateException("outputSize should not be null.");
         }
-        AspectRatio outputRatio = getAngles().flip(Reference.VIEW, Reference.OUTPUT) ? viewAspectRatio.flip() : viewAspectRatio;
         Rect outputCrop = CropHelper.computeCrop(outputSize, outputRatio);
         outputSize = new Size(outputCrop.width(), outputCrop.height());
         stub.size = outputSize;

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

@@ -610,10 +610,9 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
 
     @WorkerThread
     @Override
-    protected void onTakePictureSnapshot(@NonNull PictureResult.Stub stub, @NonNull AspectRatio viewAspectRatio) {
+    protected void onTakePictureSnapshot(@NonNull PictureResult.Stub stub, @NonNull AspectRatio outputRatio) {
         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.
-        AspectRatio outputRatio = getAngles().flip(Reference.OUTPUT, Reference.VIEW) ? viewAspectRatio.flip() : viewAspectRatio;
         if (mPreview instanceof GlCameraPreview) {
             mPictureRecorder = new SnapshotGlPictureRecorder(stub, this, (GlCameraPreview) mPreview, outputRatio, getOverlay());
         } else {
@@ -695,7 +694,7 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
 
     @WorkerThread
     @Override
-    protected void onTakeVideoSnapshot(@NonNull VideoResult.Stub stub, @NonNull AspectRatio viewAspectRatio) {
+    protected void onTakeVideoSnapshot(@NonNull VideoResult.Stub stub, @NonNull AspectRatio outputRatio) {
         if (!(mPreview instanceof GlCameraPreview)) {
             throw new IllegalStateException("Video snapshots are only supported with GlCameraPreview.");
         }
@@ -704,7 +703,6 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
         if (outputSize == null) {
             throw new IllegalStateException("outputSize should not be null.");
         }
-        AspectRatio outputRatio = getAngles().flip(Reference.VIEW, Reference.OUTPUT) ? viewAspectRatio.flip() : viewAspectRatio;
         Rect outputCrop = CropHelper.computeCrop(outputSize, outputRatio);
         outputSize = new Size(outputCrop.width(), outputCrop.height());
         stub.size = outputSize;
@@ -1257,8 +1255,8 @@ public class Camera2Engine extends CameraEngine implements ImageReader.OnImageAv
     private void onAutoFocusCapture(@NonNull CaptureResult result) {
         Integer afState = result.get(CaptureResult.CONTROL_AF_STATE);
         if (afState == null) {
-            LOG.e("onAutoFocusCapture", "afState is null! Assuming AF failed.");
+            LOG.i("onAutoFocusCapture", "afState is null! This can happen for partial results. Waiting.");
-            afState = CaptureResult.CONTROL_AF_STATE_NOT_FOCUSED_LOCKED;
+            return;
         }
         switch (afState) {
             case CaptureRequest.CONTROL_AF_STATE_FOCUSED_LOCKED: {

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

@@ -1087,9 +1087,8 @@ public abstract class CameraEngine implements
      * The snapshot size is the {@link #getPreviewStreamSize(Reference)}, but cropped based on the
      * view/surface aspect ratio.
      * @param stub a picture stub
-     * @param viewAspectRatio the view aspect ratio
      */
-    public final void takePictureSnapshot(final @NonNull PictureResult.Stub stub, @NonNull final AspectRatio viewAspectRatio) {
+    public final void takePictureSnapshot(final @NonNull PictureResult.Stub stub) {
         LOG.v("takePictureSnapshot", "scheduling");
         mHandler.run(new Runnable() {
             @Override
@@ -1101,7 +1100,9 @@ public abstract class CameraEngine implements
                 stub.isSnapshot = true;
                 stub.facing = mFacing;
                 // Leave the other parameters to subclasses.
-                onTakePictureSnapshot(stub, viewAspectRatio);
+                //noinspection ConstantConditions
+                AspectRatio ratio = AspectRatio.of(getPreviewSurfaceSize(Reference.OUTPUT));
+                onTakePictureSnapshot(stub, ratio);
             }
         });
     }
@@ -1155,9 +1156,8 @@ public abstract class CameraEngine implements
     /**
      * @param stub a video stub
      * @param file the output file
-     * @param viewAspectRatio the view aspect ratio
      */
-    public final void takeVideoSnapshot(final @NonNull VideoResult.Stub stub, @NonNull final File file, @NonNull final AspectRatio viewAspectRatio) {
+    public final void takeVideoSnapshot(final @NonNull VideoResult.Stub stub, @NonNull final File file) {
         LOG.v("takeVideoSnapshot", "scheduling");
         mHandler.run(new Runnable() {
             @Override
@@ -1175,7 +1175,9 @@ public abstract class CameraEngine implements
                 stub.audio = mAudio;
                 stub.maxSize = mVideoMaxSize;
                 stub.maxDuration = mVideoMaxDuration;
-                onTakeVideoSnapshot(stub, viewAspectRatio);
+                //noinspection ConstantConditions
+                AspectRatio ratio = AspectRatio.of(getPreviewSurfaceSize(Reference.OUTPUT));
+                onTakeVideoSnapshot(stub, ratio);
             }
         });
     }
@@ -1220,10 +1222,10 @@ public abstract class CameraEngine implements
     protected abstract void onTakePicture(@NonNull PictureResult.Stub stub);
 
     @WorkerThread
-    protected abstract void onTakePictureSnapshot(@NonNull PictureResult.Stub stub, @NonNull AspectRatio viewAspectRatio);
+    protected abstract void onTakePictureSnapshot(@NonNull PictureResult.Stub stub, @NonNull AspectRatio outputRatio);
 
     @WorkerThread
-    protected abstract void onTakeVideoSnapshot(@NonNull VideoResult.Stub stub, @NonNull AspectRatio viewAspectRatio);
+    protected abstract void onTakeVideoSnapshot(@NonNull VideoResult.Stub stub, @NonNull AspectRatio outputRatio);
 
     @WorkerThread
     protected abstract void onTakeVideo(@NonNull VideoResult.Stub stub);

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

@@ -51,7 +51,7 @@ public class EglBaseSurface extends EglElement {
     private int mWidth = -1;
     private int mHeight = -1;
 
-    protected EglBaseSurface(EglCore eglCore) {
+    public EglBaseSurface(EglCore eglCore) {
         mEglCore = eglCore;
     }
 

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

@@ -17,7 +17,7 @@ public class CropHelper {
     public static Rect computeCrop(@NonNull Size currentSize, @NonNull AspectRatio targetRatio) {
         int currentWidth = currentSize.getWidth();
         int currentHeight = currentSize.getHeight();
-        if (targetRatio.matches(currentSize)) {
+        if (targetRatio.matches(currentSize, 0.0005F)) {
             return new Rect(0, 0, currentWidth, currentHeight);
         }
 
@@ -26,13 +26,13 @@ public class CropHelper {
         int x, y, width, height;
         if (currentRatio.toFloat() > targetRatio.toFloat()) {
             height = currentHeight;
-            width = (int) (height * targetRatio.toFloat());
+            width = Math.round(height * targetRatio.toFloat());
             y = 0;
-            x = (currentWidth - width) / 2;
+            x = Math.round((currentWidth - width) / 2F);
         } else {
             width = currentWidth;
-            height = (int) (width / targetRatio.toFloat());
+            height = Math.round(width / targetRatio.toFloat());
-            y = (currentHeight - height) / 2;
+            y = Math.round((currentHeight - height) / 2F);
             x = 0;
         }
         return new Rect(x, y, x + width, y + height);

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

@@ -14,6 +14,7 @@ import android.os.Build;
 
 import com.otaliastudios.cameraview.CameraLogger;
 import com.otaliastudios.cameraview.PictureResult;
+import com.otaliastudios.cameraview.internal.egl.EglBaseSurface;
 import com.otaliastudios.cameraview.overlay.Overlay;
 import com.otaliastudios.cameraview.controls.Facing;
 import com.otaliastudios.cameraview.engine.CameraEngine;
@@ -35,6 +36,23 @@ import androidx.annotation.Nullable;
 
 import android.view.Surface;
 
+/**
+ * API 19.
+ * Records a picture snapshots from the {@link GlCameraPreview}. It works as follows:
+ *
+ * - We register a one time {@link RendererFrameCallback} on the preview
+ * - We get the textureId and the frame callback on the {@link RendererThread}
+ * - [Optional: we construct another textureId for overlays]
+ * - We take a handle of the EGL context from the {@link RendererThread}
+ * - 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 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.
+ */
 public class SnapshotGlPictureRecorder extends PictureRecorder {
 
     private static final String TAG = SnapshotGlPictureRecorder.class.getSimpleName();
@@ -47,6 +65,17 @@ public class SnapshotGlPictureRecorder extends PictureRecorder {
     private Overlay mOverlay;
     private boolean mHasOverlay;
 
+    private int mTextureId;
+    private SurfaceTexture mSurfaceTexture;
+    private float[] mTransform;
+
+    private int mOverlayTextureId = 0;
+    private SurfaceTexture mOverlaySurfaceTexture;
+    private Surface mOverlaySurface;
+    private float[] mOverlayTransform;
+
+    private EglViewport mViewport;
+
     public SnapshotGlPictureRecorder(
             @NonNull PictureResult.Stub stub,
             @NonNull CameraEngine engine,
@@ -66,142 +95,148 @@ public class SnapshotGlPictureRecorder extends PictureRecorder {
     public void take() {
         mPreview.addRendererFrameCallback(new RendererFrameCallback() {
 
-            int mTextureId;
-            SurfaceTexture mSurfaceTexture;
-            float[] mTransform;
-
-            int mOverlayTextureId = 0;
-            SurfaceTexture mOverlaySurfaceTexture;
-            Surface mOverlaySurface;
-            float[] mOverlayTransform;
-
-            EglViewport mViewport;
-
             @RendererThread
             public void onRendererTextureCreated(int textureId) {
-                mTextureId = textureId;
+                SnapshotGlPictureRecorder.this.onRendererTextureCreated(textureId);
-                mViewport = new EglViewport();
-                mSurfaceTexture = new SurfaceTexture(mTextureId, true);
-                // Need to crop the size.
-                Rect crop = CropHelper.computeCrop(mResult.size, mOutputRatio);
-                mResult.size = new Size(crop.width(), crop.height());
-                mSurfaceTexture.setDefaultBufferSize(mResult.size.getWidth(), mResult.size.getHeight());
-                mTransform = new float[16];
-
-                if (mHasOverlay) {
-                    mOverlayTextureId = mViewport.createTexture();
-                    mOverlaySurfaceTexture = new SurfaceTexture(mOverlayTextureId, true);
-                    mOverlaySurfaceTexture.setDefaultBufferSize(mResult.size.getWidth(), mResult.size.getHeight());
-                    mOverlaySurface = new Surface(mOverlaySurfaceTexture);
-                    mOverlayTransform = new float[16];
-                }
             }
 
             @RendererThread
             @Override
             public void onRendererFrame(@NonNull SurfaceTexture surfaceTexture, final float scaleX, final float scaleY) {
                 mPreview.removeRendererFrameCallback(this);
+                SnapshotGlPictureRecorder.this.onRendererFrame(scaleX, scaleY);
+            }
+        });
+    }
 
-                // This kinda work but has drawbacks:
+    @RendererThread
-                // - output is upside down due to coordinates in GL: need to flip the byte[] someway
+    @TargetApi(Build.VERSION_CODES.KITKAT)
-                // - output is not rotated as we would like to: need to create a bitmap copy...
+    private void onRendererTextureCreated(int textureId) {
-                // - works only in the renderer thread, where it allocates the buffer and reads pixels. Bad!
+        mTextureId = textureId;
-                /*
+        mViewport = new EglViewport();
-                ByteBuffer buffer = ByteBuffer.allocateDirect(width * height * 4);
+        mSurfaceTexture = new SurfaceTexture(mTextureId, true);
-                buffer.order(ByteOrder.LITTLE_ENDIAN);
+        // Need to crop the size.
-                GLES20.glReadPixels(0, 0, width, height, GLES20.GL_RGBA, GLES20.GL_UNSIGNED_BYTE, buffer);
+        Rect crop = CropHelper.computeCrop(mResult.size, mOutputRatio);
-                buffer.rewind();
+        mResult.size = new Size(crop.width(), crop.height());
-                ByteArrayOutputStream bos = new ByteArrayOutputStream(buffer.array().length);
+        mSurfaceTexture.setDefaultBufferSize(mResult.size.getWidth(), mResult.size.getHeight());
-                Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
+        mTransform = new float[16];
-                bitmap.copyPixelsFromBuffer(buffer);
+
-                bitmap.compress(Bitmap.CompressFormat.JPEG, 90, bos);
+        if (mHasOverlay) {
-                bitmap.recycle(); */
+            mOverlayTextureId = mViewport.createTexture();
-
+            mOverlaySurfaceTexture = new SurfaceTexture(mOverlayTextureId, true);
-                // For this reason it is better to create a new surface,
+            mOverlaySurfaceTexture.setDefaultBufferSize(mResult.size.getWidth(), mResult.size.getHeight());
-                // and draw the last frame again there.
+            mOverlaySurface = new Surface(mOverlaySurfaceTexture);
-                final EGLContext eglContext = EGL14.eglGetCurrentContext();
+            mOverlayTransform = new float[16];
-                final EglCore core = new EglCore(eglContext, EglCore.FLAG_RECORDABLE);
+        }
-                // final EGLSurface oldSurface = EGL14.eglGetCurrentSurface(EGL14.EGL_DRAW);
+    }
-                // final EGLDisplay oldDisplay = EGL14.eglGetCurrentDisplay();
+
-                WorkerHandler.execute(new Runnable() {
+    /**
-                    @Override
+     * The tricky part here is the EGL surface creation.
-                    public void run() {
+     *
-                        // 1. Get latest texture
+     * We don't have a real output window for the EGL surface - we will use glReadPixels()
-                        EglWindowSurface surface = new EglWindowSurface(core, mSurfaceTexture);
+     * and never call swapBuffers(), so what we draw is never published.
-                        surface.makeCurrent();
+     *
-                        mSurfaceTexture.updateTexImage();
+     * 1. One option is to use a pbuffer EGL surface. This works, we just have to pass
-                        mSurfaceTexture.getTransformMatrix(mTransform);
+     *    the correct width and height. However, it is significantly slower than the current
-
+     *    solution.
-                        // 2. Apply scale and crop:
+     *
-                        // scaleX and scaleY are in REF_VIEW, while our input appears to be in REF_SENSOR.
+     * 2. Another option is to create the EGL surface out of a ImageReader.getSurface()
-                        boolean flip = mEngine.getAngles().flip(Reference.VIEW, Reference.SENSOR);
+     *    and use the reader to create a JPEG. In this case, we would have to publish
-                        float realScaleX = flip ? scaleY : scaleX;
+     *    the frame with swapBuffers(). However, currently ImageReader does not support
-                        float realScaleY = flip ? scaleX : scaleY;
+     *    all formats, it's risky. This is an example error that we get:
-                        float scaleTranslX = (1F - realScaleX) / 2F;
+     *    "RGBA override BLOB format buffer should have height == width"
-                        float scaleTranslY = (1F - realScaleY) / 2F;
+     *
-                        Matrix.translateM(mTransform, 0, scaleTranslX, scaleTranslY, 0);
+     * The third option, which we are using, is to create the EGL surface using whatever
-                        Matrix.scaleM(mTransform, 0, realScaleX, realScaleY, 1);
+     * {@link Surface} or {@link SurfaceTexture} we have at hand. Since we never call
-
+     * swapBuffers(), the frame will not actually be rendered. This is the fastest.
-                        // 3. Go back to 0,0 so that rotate and flip work well.
+     *
-                        Matrix.translateM(mTransform, 0, 0.5F, 0.5F, 0);
+     * @param scaleX frame scale x in {@link Reference#VIEW}
-
+     * @param scaleY frame scale y in {@link Reference#VIEW}
-                        // 4. Apply rotation:
+     */
-                        // Not sure why we need the minus here.
+    @RendererThread
-                        Matrix.rotateM(mTransform, 0, -mResult.rotation, 0, 0, 1);
+    @TargetApi(Build.VERSION_CODES.KITKAT)
-                        mResult.rotation = 0;
+    private void onRendererFrame(final float scaleX, final float scaleY) {
-
+        // Get egl context from the RendererThread, which is the one in which we have created
-                        // 5. Flip horizontally for front camera:
+        // the textureId and the overlayTextureId, managed by the GlSurfaceView.
-                        if (mResult.facing == Facing.FRONT) {
+        // Next operations can then be performed on different threads using this handle.
-                            Matrix.scaleM(mTransform, 0, -1, 1, 1);
+        final EGLContext eglContext = EGL14.eglGetCurrentContext();
-                        }
+        final EglCore core = new EglCore(eglContext, EglCore.FLAG_RECORDABLE);
-
+        WorkerHandler.execute(new Runnable() {
-                        // 6. Go back to old position.
+            @Override
-                        Matrix.translateM(mTransform, 0, -0.5F, -0.5F, 0);
+            public void run() {
-
+                // 0. Create an EGL surface
-                        // 7. Do pretty much the same for overlays, though with
+                EglBaseSurface eglSurface = new EglWindowSurface(core, mSurfaceTexture);
-                        // some differences.
+                eglSurface.makeCurrent();
-                        if (mHasOverlay) {
+
-                            // 1. First we must draw on the texture and get latest image.
+                // 1. Get latest texture
-                            try {
+                mSurfaceTexture.updateTexImage();
-                                final Canvas surfaceCanvas = mOverlaySurface.lockCanvas(null);
+                mSurfaceTexture.getTransformMatrix(mTransform);
-                                surfaceCanvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR);
+
-                                mOverlay.drawOn(Overlay.Target.PICTURE_SNAPSHOT, surfaceCanvas);
+                // 2. Apply scale and crop
-                                mOverlaySurface.unlockCanvasAndPost(surfaceCanvas);
+                boolean flip = mEngine.getAngles().flip(Reference.VIEW, Reference.SENSOR);
-                            } catch (Surface.OutOfResourcesException e) {
+                float realScaleX = flip ? scaleY : scaleX;
-                                LOG.w("Got Surface.OutOfResourcesException while drawing picture overlays", e);
+                float realScaleY = flip ? scaleX : scaleY;
-                            }
+                float scaleTranslX = (1F - realScaleX) / 2F;
-                            mOverlaySurfaceTexture.updateTexImage();
+                float scaleTranslY = (1F - realScaleY) / 2F;
-                            mOverlaySurfaceTexture.getTransformMatrix(mOverlayTransform);
+                Matrix.translateM(mTransform, 0, scaleTranslX, scaleTranslY, 0);
-
+                Matrix.scaleM(mTransform, 0, realScaleX, realScaleY, 1);
-                            // 2. Then we can apply the transformations.
+
-                            int rotation = mEngine.getAngles().offset(Reference.VIEW, Reference.OUTPUT, Axis.ABSOLUTE);
+                // 3. Go back to 0,0 so that rotate and flip work well
-                            Matrix.translateM(mOverlayTransform, 0, 0.5F, 0.5F, 0);
+                Matrix.translateM(mTransform, 0, 0.5F, 0.5F, 0);
-                            Matrix.rotateM(mOverlayTransform, 0, rotation, 0, 0, 1);
+
-                            // No need to flip the x axis for front camera, but need to flip the y axis always.
+                // 4. Apply rotation (not sure why we need the minus here)
-                            Matrix.scaleM(mOverlayTransform, 0, 1, -1, 1);
+                Matrix.rotateM(mTransform, 0, -mResult.rotation, 0, 0, 1);
-                            Matrix.translateM(mOverlayTransform, 0, -0.5F, -0.5F, 0);
+                mResult.rotation = 0;
-                        }
+
-
+                // 5. Flip horizontally for front camera
-                        // 8. Draw and save
+                if (mResult.facing == Facing.FRONT) {
-                        mViewport.drawFrame(mTextureId, mTransform);
+                    Matrix.scaleM(mTransform, 0, -1, 1, 1);
-                        if (mHasOverlay) mViewport.drawFrame(mOverlayTextureId, mOverlayTransform);
+                }
-                        // don't - surface.swapBuffers();
+
-                        mResult.data = surface.saveFrameTo(Bitmap.CompressFormat.JPEG);
+                // 6. Go back to old position
-                        mResult.format = PictureResult.FORMAT_JPEG;
+                Matrix.translateM(mTransform, 0, -0.5F, -0.5F, 0);
-
+
-                        // 9. Cleanup
+                // 7. Do pretty much the same for overlays
-                        mSurfaceTexture.releaseTexImage();
+                if (mHasOverlay) {
-                        surface.release();
+                    // 1. First we must draw on the texture and get latest image
-                        mViewport.release();
+                    try {
-                        mSurfaceTexture.release();
+                        final Canvas surfaceCanvas = mOverlaySurface.lockCanvas(null);
-                        if (mHasOverlay) {
+                        surfaceCanvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR);
-                            mOverlaySurface.release();
+                        mOverlay.drawOn(Overlay.Target.PICTURE_SNAPSHOT, surfaceCanvas);
-                            mOverlaySurfaceTexture.release();
+                        mOverlaySurface.unlockCanvasAndPost(surfaceCanvas);
-                        }
+                    } catch (Surface.OutOfResourcesException e) {
-                        core.release();
+                        LOG.w("Got Surface.OutOfResourcesException while drawing picture overlays", e);
-                        dispatchResult();
                     }
-                });
+                    mOverlaySurfaceTexture.updateTexImage();
+                    mOverlaySurfaceTexture.getTransformMatrix(mOverlayTransform);
+
+                    // 2. Then we can apply the transformations
+                    int rotation = mEngine.getAngles().offset(Reference.VIEW, Reference.OUTPUT, Axis.ABSOLUTE);
+                    Matrix.translateM(mOverlayTransform, 0, 0.5F, 0.5F, 0);
+                    Matrix.rotateM(mOverlayTransform, 0, rotation, 0, 0, 1);
+                    // No need to flip the x axis for front camera, but need to flip the y axis always.
+                    Matrix.scaleM(mOverlayTransform, 0, 1, -1, 1);
+                    Matrix.translateM(mOverlayTransform, 0, -0.5F, -0.5F, 0);
+                }
+
+                // 8. Draw and save
+                mViewport.drawFrame(mTextureId, mTransform);
+                if (mHasOverlay) mViewport.drawFrame(mOverlayTextureId, mOverlayTransform);
+                mResult.format = PictureResult.FORMAT_JPEG;
+                mResult.data = eglSurface.saveFrameTo(Bitmap.CompressFormat.JPEG);
+
+                // 9. Cleanup
+                mSurfaceTexture.releaseTexImage();
+                eglSurface.releaseEglSurface();
+                mViewport.release();
+                mSurfaceTexture.release();
+                if (mHasOverlay) {
+                    mOverlaySurfaceTexture.releaseTexImage();
+                    mOverlaySurface.release();
+                    mOverlaySurfaceTexture.release();
+                }
+                core.release();
+                dispatchResult();
             }
         });
     }

cameraview/src/main/java/com/otaliastudios/cameraview/size/AspectRatio.java

@@ -19,7 +19,7 @@ public class AspectRatio implements Comparable<AspectRatio> {
      * @return a (possibly cached) aspect ratio
      */
     @NonNull
-    public static AspectRatio of(Size size) {
+    public static AspectRatio of(@NonNull Size size) {
         return AspectRatio.of(size.getWidth(), size.getHeight());
     }
 
@@ -78,7 +78,6 @@ public class AspectRatio implements Comparable<AspectRatio> {
         return mY;
     }
 
-    @SuppressWarnings("WeakerAccess")
     public boolean matches(@NonNull Size size) {
         int gcd = gcd(size.getWidth(), size.getHeight());
         int x = size.getWidth() / gcd;
@@ -86,6 +85,10 @@ public class AspectRatio implements Comparable<AspectRatio> {
         return mX == x && mY == y;
     }
 
+    public boolean matches(@NonNull Size size, float tolerance) {
+        return Math.abs(toFloat() - (float) size.getWidth() / size.getHeight()) <= tolerance;
+    }
+
     @Override
     public boolean equals(Object o) {
         if (o == null) {
@@ -107,7 +110,6 @@ public class AspectRatio implements Comparable<AspectRatio> {
         return mX + ":" + mY;
     }
 
-    @SuppressWarnings("WeakerAccess")
     public float toFloat() {
         return (float) mX / mY;
     }

cameraview/src/main/java/com/otaliastudios/cameraview/video/SnapshotVideoRecorder.java

@@ -98,6 +98,7 @@ public class SnapshotVideoRecorder extends VideoRecorder implements RendererFram
             mOverlaySurfaceTexture = new SurfaceTexture(mOverlayTextureId);
             mOverlaySurfaceTexture.setDefaultBufferSize(mResult.size.getWidth(), mResult.size.getHeight());
             mOverlaySurface = new Surface(mOverlaySurfaceTexture);
+            temp.release(true);
         }
     }
 
@@ -135,6 +136,9 @@ public class SnapshotVideoRecorder extends VideoRecorder implements RendererFram
             videoConfig.textureId = mTextureId;
             videoConfig.scaleX = scaleX;
             videoConfig.scaleY = scaleY;
+            // Get egl context from the RendererThread, which is the one in which we have created
+            // the textureId and the overlayTextureId, managed by the GlSurfaceView.
+            // Next operations can then be performed on different threads using this handle.
             videoConfig.eglContext = EGL14.eglGetCurrentContext();
             if (mHasOverlay) {
                 videoConfig.overlayTextureId = mOverlayTextureId;

cameraview/src/main/java/com/otaliastudios/cameraview/video/encoding/TextureMediaEncoder.java

@@ -1,6 +1,7 @@
 package com.otaliastudios.cameraview.video.encoding;
 
 import android.graphics.SurfaceTexture;
+import android.media.ImageReader;
 import android.opengl.Matrix;
 import android.os.Build;
 
@@ -94,8 +95,7 @@ public class TextureMediaEncoder extends VideoMediaEncoder<TextureConfig> {
         super.onPrepare(controller, maxLengthMillis);
         mEglCore = new EglCore(mConfig.eglContext, EglCore.FLAG_RECORDABLE);
         mWindow = new EglWindowSurface(mEglCore, mSurface, true);
-        mWindow.makeCurrent(); // drawing will happen on the InputWindowSurface, which
+        mWindow.makeCurrent();
-        // is backed by mVideoEncoder.getInputSurface()
         mViewport = new EglViewport();
     }
 

cameraview/src/main/java/com/otaliastudios/cameraview/video/encoding/VideoMediaEncoder.java

@@ -53,16 +53,16 @@ abstract class VideoMediaEncoder<C extends VideoConfig> extends MediaEncoder {
     protected void onPrepare(@NonNull MediaEncoderEngine.Controller controller, long maxLengthMillis) {
         MediaFormat format = MediaFormat.createVideoFormat(mConfig.mimeType, mConfig.width, mConfig.height);
 
-        // Set some properties.  Failing to specify some of these can cause the MediaCodec
+        // Failing to specify some of these can cause the MediaCodec configure() call to throw an unhelpful exception.
-        // configure() call to throw an unhelpful exception.
+        // About COLOR_FormatSurface, see https://stackoverflow.com/q/28027858/4288782
+        // This just means it is an opaque, implementation-specific format that the device GPU prefers.
+        // So as long as we use the GPU to draw, the format will match what the encoder expects.
         format.setInteger(MediaFormat.KEY_COLOR_FORMAT, MediaCodecInfo.CodecCapabilities.COLOR_FormatSurface);
         format.setInteger(MediaFormat.KEY_BIT_RATE, mConfig.bitRate);
         format.setInteger(MediaFormat.KEY_FRAME_RATE, mConfig.frameRate);
-        format.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, 2);
+        format.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, 5);
         format.setInteger("rotation-degrees", mConfig.rotation);
 
-        // Create a MediaCodec encoder, and configure it with our format.  Get a Surface
-        // we can use for input and wrap it with a class that handles the EGL work.
         try {
             mMediaCodec = MediaCodec.createEncoderByType(mConfig.mimeType);
         } catch (IOException e) {

demo/src/main/AndroidManifest.xml

@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
     package="com.otaliastudios.cameraview.demo">
 
     <uses-permission android:name="android.permission.RECORD_AUDIO"/>
@@ -8,9 +9,9 @@
         android:allowBackup="false"
         android:icon="@mipmap/cameraview"
         android:label="@string/app_name"
-        android:roundIcon="@mipmap/cameraview"
         android:supportsRtl="true"
-        android:theme="@style/AppTheme">
+        android:theme="@style/AppTheme"
+        tools:ignore="GoogleAppIndexingWarning">
 
         <activity
             android:name=".CameraActivity"

demo/src/main/java/com/otaliastudios/cameraview/demo/PicturePreviewActivity.java

@@ -13,30 +13,30 @@ import com.otaliastudios.cameraview.size.AspectRatio;
 import com.otaliastudios.cameraview.BitmapCallback;
 import com.otaliastudios.cameraview.PictureResult;
 
-import java.lang.ref.WeakReference;
-
 
 public class PicturePreviewActivity extends Activity {
 
-    private static WeakReference<PictureResult> image;
+    private static PictureResult picture;
 
-    public static void setPictureResult(@Nullable PictureResult im) {
+    public static void setPictureResult(@Nullable PictureResult pictureResult) {
-        image = im != null ? new WeakReference<>(im) : null;
+        picture = pictureResult;
     }
 
     @Override
     protected void onCreate(@Nullable Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_picture_preview);
-        final ImageView imageView = findViewById(R.id.image);
+        final PictureResult result = picture;
-        final MessageView captureResolution = findViewById(R.id.nativeCaptureResolution);
-        final MessageView captureLatency = findViewById(R.id.captureLatency);
-        final MessageView exifRotation = findViewById(R.id.exifRotation);
-        PictureResult result = image == null ? null : image.get();
         if (result == null) {
             finish();
             return;
         }
+
+        final ImageView imageView = findViewById(R.id.image);
+        final MessageView captureResolution = findViewById(R.id.nativeCaptureResolution);
+        final MessageView captureLatency = findViewById(R.id.captureLatency);
+        final MessageView exifRotation = findViewById(R.id.exifRotation);
+
         final long delay = getIntent().getLongExtra("delay", 0);
         AspectRatio ratio = AspectRatio.of(result.getSize());
         captureLatency.setTitleAndMessage("Approx. latency", delay + " milliseconds");

demo/src/main/java/com/otaliastudios/cameraview/demo/VideoPreviewActivity.java

@@ -13,23 +13,28 @@ import android.widget.MediaController;
 import android.widget.VideoView;
 
 import com.otaliastudios.cameraview.VideoResult;
-
+import com.otaliastudios.cameraview.size.AspectRatio;
-import java.lang.ref.WeakReference;
 
 
 public class VideoPreviewActivity extends Activity {
 
     private VideoView videoView;
 
-    private static WeakReference<VideoResult> videoResult;
+    private static VideoResult videoResult;
 
     public static void setVideoResult(@Nullable VideoResult result) {
-        videoResult = result != null ? new WeakReference<>(result) : null;
+        videoResult = result;
     }
     @Override
     protected void onCreate(@Nullable Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_video_preview);
+        final VideoResult result = videoResult;
+        if (result == null) {
+            finish();
+            return;
+        }
+
         videoView = findViewById(R.id.video);
         videoView.setOnClickListener(new View.OnClickListener() {
             @Override
@@ -46,13 +51,8 @@ public class VideoPreviewActivity extends Activity {
         final MessageView videoBitRate = findViewById(R.id.videoBitRate);
         final MessageView videoFrameRate = findViewById(R.id.videoFrameRate);
 
-        final VideoResult result = videoResult == null ? null : videoResult.get();
+        AspectRatio ratio = AspectRatio.of(result.getSize());
-        if (result == null) {
+        actualResolution.setTitleAndMessage("Size", result.getSize() + " (" + ratio + ")");
-            finish();
-            return;
-        }
-
-        actualResolution.setTitleAndMessage("Size", result.getSize() + "");
         isSnapshot.setTitleAndMessage("Snapshot", result.isSnapshot() + "");
         rotation.setTitleAndMessage("Rotation", result.getRotation() + "");
         audio.setTitleAndMessage("Audio", result.getAudio().name());
@@ -85,8 +85,9 @@ public class VideoPreviewActivity extends Activity {
     }
 
     void playVideo() {
-        if (videoView.isPlaying()) return;
+        if (!videoView.isPlaying()) {
-        videoView.start();
+            videoView.start();
+        }
     }
 
     @Override

demo/src/main/res/layout/activity_camera.xml

@@ -23,7 +23,7 @@
         app:cameraGrid="off"
         app:cameraFlash="off"
         app:cameraAudio="on"
-        app:cameraFacing="front"
+        app:cameraFacing="back"
         app:cameraGestureTap="autoFocus"
         app:cameraGestureLongTap="none"
         app:cameraGesturePinch="zoom"