Encoders improvements (#545)

* Create DeviceEncoders

* Prefer hardware encoders, adjust size and bitrate

* Do the same for video frame rate

* Fix docs

* Rename CameraView method

* Fix DeviceEncoders comparator

* Add tests

* Fix tests

* Fix tests again

* Scale down based on encoder requirements

* Add DeviceEncoders MODE_ values

* Use DeviceEncoders for full videos as well

* Fix small bug

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

@@ -0,0 +1,224 @@
+package com.otaliastudios.cameraview.internal;
+
+
+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;
+
+import java.util.Arrays;
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
+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
+public class DeviceEncodersTest extends BaseTest {
+
+    // This is guaranteed to work, see
+    // https://developer.android.com/guide/topics/media/media-formats
+    private final static Size GUARANTEED_SIZE = new Size(176, 144);
+
+    private boolean enabled;
+
+    @Before
+    public void setUp() {
+        enabled = DeviceEncoders.ENABLED;
+    }
+
+    @After
+    public void tearDown() {
+        DeviceEncoders.ENABLED = enabled;
+    }
+
+    @NonNull
+    private DeviceEncoders create() {
+        return new DeviceEncoders(
+                "video/avc",
+                "audio/mp4a-latm",
+                DeviceEncoders.MODE_TAKE_FIRST);
+    }
+
+    @Test
+    public void testGetDeviceEncoders() {
+        DeviceEncoders deviceEncoders = create();
+        if (DeviceEncoders.ENABLED) {
+            List<MediaCodecInfo> infos = deviceEncoders.getDeviceEncoders();
+            for (MediaCodecInfo info : infos) {
+                assertTrue(info.isEncoder());
+            }
+        }
+    }
+
+    @Test
+    public void testIsHardwareEncoder() {
+        DeviceEncoders deviceEncoders = create();
+        if (DeviceEncoders.ENABLED) {
+            assertFalse(deviceEncoders.isHardwareEncoder("OMX.google.encoder"));
+            assertTrue(deviceEncoders.isHardwareEncoder("OMX.other.encoder"));
+        }
+    }
+
+    @Test
+    public void testFindDeviceEncoder() {
+        DeviceEncoders deviceEncoders = create();
+        if (DeviceEncoders.ENABLED) {
+            List<MediaCodecInfo> allEncoders = deviceEncoders.getDeviceEncoders();
+            MediaCodecInfo encoder = deviceEncoders.findDeviceEncoder(allEncoders,
+                    "video/avc", DeviceEncoders.MODE_TAKE_FIRST);
+            assertNotNull(encoder);
+            List<String> encoderTypes = Arrays.asList(encoder.getSupportedTypes());
+            assertTrue(encoderTypes.contains("video/avc"));
+        }
+    }
+
+    @Test
+    public void testGetVideoEncoder() {
+        if (DeviceEncoders.ENABLED) {
+            DeviceEncoders deviceEncoders = create();
+            assertNotNull(deviceEncoders.getVideoEncoder());
+        }
+
+        DeviceEncoders.ENABLED = false;
+        DeviceEncoders deviceEncoders = create();
+        assertNull(deviceEncoders.getVideoEncoder());
+    }
+
+    @Test
+    public void testGetAudioEncoder() {
+        if (DeviceEncoders.ENABLED) {
+            DeviceEncoders deviceEncoders = create();
+            assertNotNull(deviceEncoders.getAudioEncoder());
+        }
+
+        DeviceEncoders.ENABLED = false;
+        DeviceEncoders deviceEncoders = create();
+        assertNull(deviceEncoders.getAudioEncoder());
+    }
+
+    @Test
+    public void testGetSupportedVideoSize_disabled() {
+        DeviceEncoders.ENABLED = false;
+        DeviceEncoders deviceEncoders = create();
+        Size input = new Size(GUARANTEED_SIZE.getWidth(), GUARANTEED_SIZE.getHeight());
+        Size output = deviceEncoders.getSupportedVideoSize(input);
+        assertSame(input, output);
+    }
+
+    @Test
+    public void testGetSupportedVideoSize_scalesDown() {
+        DeviceEncoders deviceEncoders = create();
+        if (DeviceEncoders.ENABLED) {
+            Size input = new Size(
+                    GUARANTEED_SIZE.getWidth() * 1000,
+                    GUARANTEED_SIZE.getHeight() * 1000);
+            try {
+                Size output = deviceEncoders.getSupportedVideoSize(input);
+                assertTrue(AspectRatio.of(input).matches(output, 0.01F));
+            } catch (RuntimeException e) {
+                // The scaled down size happens to be not supported.
+                // I see no way of testing this easily if we're not sure of supported ranges.
+                // This depends highly on the alignment since scaling down, while keeping AR,
+                // can change the alignment and require width / height changes.
+            }
+        }
+    }
+
+    @Test
+    public void testGetSupportedVideoSize_aligns() {
+        DeviceEncoders deviceEncoders = create();
+        if (DeviceEncoders.ENABLED) {
+            Size input = new Size(GUARANTEED_SIZE.getWidth() + 1,
+                    GUARANTEED_SIZE.getHeight() + 1);
+            Size output = deviceEncoders.getSupportedVideoSize(input);
+            assertTrue(output.getWidth() <= input.getWidth());
+            assertTrue(output.getHeight() <= input.getHeight());
+        }
+    }
+
+    @Test
+    public void testGetSupportedVideoBitRate_disabled() {
+        DeviceEncoders.ENABLED = false;
+        DeviceEncoders deviceEncoders = create();
+        int input = 1000;
+        int output = deviceEncoders.getSupportedVideoBitRate(input);
+        assertEquals(input, output);
+    }
+
+    @Test
+    public void testGetSupportedVideoBitRate_enabled() {
+        DeviceEncoders deviceEncoders = create();
+        if (DeviceEncoders.ENABLED) {
+            // Ensure it's clamped: we can pass a negative value and check it's >= 0.
+            int input = -1000;
+            int output = deviceEncoders.getSupportedVideoBitRate(input);
+            assertNotEquals(input, output);
+            assertTrue(output >= 0);
+        }
+    }
+
+    @Test
+    public void testGetSupportedAudioBitRate_disabled() {
+        DeviceEncoders.ENABLED = false;
+        DeviceEncoders deviceEncoders = create();
+        int input = 1000;
+        int output = deviceEncoders.getSupportedAudioBitRate(input);
+        assertEquals(input, output);
+    }
+
+    @Test
+    public void testGetSupportedAudioBitRate_enabled() {
+        DeviceEncoders deviceEncoders = create();
+        if (DeviceEncoders.ENABLED) {
+            // Ensure it's clamped: we can pass a negative value and check it's >= 0.
+            int input = -1000;
+            int output = deviceEncoders.getSupportedAudioBitRate(input);
+            assertNotEquals(input, output);
+            assertTrue(output >= 0);
+        }
+    }
+
+    @Test
+    public void testGetSupportedFrameRate_disabled() {
+        DeviceEncoders.ENABLED = false;
+        DeviceEncoders deviceEncoders = create();
+        int input = 1000;
+        int output = deviceEncoders.getSupportedVideoFrameRate(GUARANTEED_SIZE, input);
+        assertEquals(input, output);
+    }
+
+    @Test
+    public void testGetSupportedFrameRate_enabled() {
+        DeviceEncoders deviceEncoders = create();
+        if (DeviceEncoders.ENABLED) {
+            // Ensure it's clamped: we can pass a negative value and check it's >= 0.
+            int input = -10;
+            Size inputSize = deviceEncoders.getSupportedVideoSize(GUARANTEED_SIZE);
+            int output = deviceEncoders.getSupportedVideoFrameRate(inputSize, input);
+            assertNotEquals(input, output);
+            assertTrue(output >= 0);
+        }
+    }
+}

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

@@ -148,18 +148,18 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
 
     public CameraView(@NonNull Context context) {
         super(context, null);
-        init(context, null);
+        initialize(context, null);
     }
 
     public CameraView(@NonNull Context context, @Nullable AttributeSet attrs) {
         super(context, attrs);
-        init(context, attrs);
+        initialize(context, attrs);
     }
 
     //region Init
 
     @SuppressWarnings("WrongConstant")
-    private void init(@NonNull Context context, @Nullable AttributeSet attrs) {
+    private void initialize(@NonNull Context context, @Nullable AttributeSet attrs) {
         setWillNotDraw(false);
         TypedArray a = context.getTheme().obtainStyledAttributes(attrs, R.styleable.CameraView, 0, 0);
         ControlParser controls = new ControlParser(context, a);
@@ -1664,6 +1664,12 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
      * (for example if the surface is not ready). This is the preview size, rotated to match
      * the output orientation, and cropped to the visible part.
      *
+     * This also includes the {@link #setSnapshotMaxWidth(int)} and
+     * {@link #setSnapshotMaxHeight(int)} constraints.
+     *
+     * This does NOT include any constraints specific to video encoding, which are
+     * device specific and depend on the capabilities of the device codec.
+     *
      * @return the size of snapshots
      */
     @Nullable

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

@@ -19,7 +19,7 @@ import java.nio.FloatBuffer;
  * to be changed. Most effects can be rendered by simply changing the fragment shader, thus
  * by overriding {@link #getFragmentShader()}.
  *
- * All {@link BaseFilter}s should have a no-op public constructor.
+ * All {@link BaseFilter}s should have a no-arguments public constructor.
  * This class will try to automatically implement {@link #copy()} thanks to this.
  * If your filter implements public parameters, please implement {@link OneParameterFilter}
  * and {@link TwoParameterFilter} to handle them and have them passed automatically to copies.
@@ -226,9 +226,9 @@ public abstract class BaseFilter implements Filter {
         try {
             return getClass().newInstance();
         } catch (IllegalAccessException e) {
-            throw new RuntimeException("Filters should have a public no-op constructor.", e);
+            throw new RuntimeException("Filters should have a public no-arguments constructor.", e);
         } catch (InstantiationException e) {
-            throw new RuntimeException("Filters should have a public no-op constructor.", e);
+            throw new RuntimeException("Filters should have a public no-arguments constructor.", e);
         }
     }
 }

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

@@ -19,7 +19,7 @@ import java.io.File;
  * Advanced users can create custom filters using GLES.
  * It is recommended to extend {@link BaseFilter} instead of this class.
  *
- * All {@link Filter}s should have a no-op public constructor.
+ * All {@link Filter}s should have a no-arguments public constructor.
  * This ensures that you can pass the filter class to XML attribute {@code app:cameraFilter},
  * and also helps {@link BaseFilter} automatically make a copy of the filter.
  *

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

@@ -0,0 +1,302 @@
+package com.otaliastudios.cameraview.internal;
+
+import android.annotation.SuppressLint;
+import android.media.MediaCodecInfo;
+import android.media.MediaCodecList;
+import android.os.Build;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.annotation.VisibleForTesting;
+
+import com.otaliastudios.cameraview.CameraLogger;
+import com.otaliastudios.cameraview.size.Size;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+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}
+ *
+ * Chooses the encoder as the first one that matches the given mime type.
+ * This is what {@link android.media.MediaCodec#createEncoderByType(String)} does,
+ * and what {@link android.media.MediaRecorder} also does when recording.
+ *
+ * The list is ordered based on the encoder definitions in system/etc/media_codecs.xml,
+ * as explained here: https://source.android.com/devices/media , for example.
+ * So taking the first means respecting the vendor priorities and should generally be
+ * a good idea.
+ *
+ * About {@link android.media.MediaRecorder}, we know it uses this option from here:
+ * https://stackoverflow.com/q/57479564/4288782 where all links to source code are shown.
+ * - StagefrightRecorder (https://android.googlesource.com/platform/frameworks/av/+/master/media/libmediaplayerservice/StagefrightRecorder.cpp#1782)
+ * - MediaCodecSource (https://android.googlesource.com/platform/frameworks/av/+/master/media/libstagefright/MediaCodecSource.cpp#515)
+ * - 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
+ *
+ * 2. {@link #MODE_PREFER_HARDWARE}
+ *
+ * This takes the list - as ordered by the vendor - and just sorts it such 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.
+ */
+public class DeviceEncoders {
+
+    private final static String TAG = DeviceEncoders.class.getSimpleName();
+    private final static CameraLogger LOG = CameraLogger.create(TAG);
+
+    @VisibleForTesting static boolean ENABLED = Build.VERSION.SDK_INT >= 21;
+
+    public final static int MODE_TAKE_FIRST = 0;
+    public final static int MODE_PREFER_HARDWARE = 1;
+
+    @SuppressWarnings("FieldCanBeLocal")
+    private final MediaCodecInfo mVideoEncoder;
+    @SuppressWarnings("FieldCanBeLocal")
+    private final MediaCodecInfo mAudioEncoder;
+    private final MediaCodecInfo.VideoCapabilities mVideoCapabilities;
+    private final MediaCodecInfo.AudioCapabilities mAudioCapabilities;
+
+    @SuppressLint("NewApi")
+    public DeviceEncoders(@NonNull String videoType, @NonNull String audioType, int mode) {
+        // 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);
+            LOG.i("Enabled. Found video encoder:", mVideoEncoder.getName());
+            mAudioEncoder = findDeviceEncoder(encoders, audioType, mode);
+            LOG.i("Enabled. Found audio encoder:", mAudioEncoder.getName());
+            mVideoCapabilities = mVideoEncoder.getCapabilitiesForType(videoType).getVideoCapabilities();
+            mAudioCapabilities = mAudioEncoder.getCapabilitiesForType(audioType).getAudioCapabilities();
+        } else {
+            mVideoEncoder = null;
+            mAudioEncoder = null;
+            mVideoCapabilities = null;
+            mAudioCapabilities = null;
+            LOG.i("Disabled.");
+        }
+    }
+
+    /**
+     * Collects all the device encoders, which means excluding decoders.
+     * @return encoders
+     */
+    @NonNull
+    @SuppressLint("NewApi")
+    @VisibleForTesting
+    List<MediaCodecInfo> getDeviceEncoders() {
+        ArrayList<MediaCodecInfo> results = new ArrayList<>();
+        MediaCodecInfo[] array = new MediaCodecList(MediaCodecList.REGULAR_CODECS).getCodecInfos();
+        for (MediaCodecInfo info : array) {
+            if (info.isEncoder()) results.add(info);
+        }
+        return results;
+    }
+
+    /**
+     * Whether an encoder is a hardware encoder or not. We don't have an API to check this,
+     * but we can follow what libstagefright does:
+     * https://android.googlesource.com/platform/frameworks/av/+/master/media/libstagefright/MediaCodecList.cpp#293
+     *
+     * @param encoder encoder
+     * @return true if hardware
+     */
+    @SuppressLint("NewApi")
+    @VisibleForTesting
+    boolean isHardwareEncoder(@NonNull String encoder) {
+        encoder = encoder.toLowerCase();
+        boolean isSoftwareEncoder = encoder.startsWith("omx.google.")
+                || encoder.startsWith("c2.android.")
+                || (!encoder.startsWith("omx.") && !encoder.startsWith("c2."));
+        return !isSoftwareEncoder;
+    }
+
+    /**
+     * 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_PREFER_HARDWARE} will prefer hardware encoders
+     * Throws if we find no encoder for this type.
+     *
+     * @param encoders encoders
+     * @param mimeType mime type
+     * @param mode mode
+     * @return encoder
+     */
+    @SuppressLint("NewApi")
+    @NonNull
+    @VisibleForTesting
+    MediaCodecInfo findDeviceEncoder(@NonNull List<MediaCodecInfo> encoders, @NonNull String mimeType, int mode) {
+        ArrayList<MediaCodecInfo> results = new ArrayList<>();
+        for (MediaCodecInfo encoder : encoders) {
+            String[] types = encoder.getSupportedTypes();
+            for (String type : types) {
+                if (type.equalsIgnoreCase(mimeType)) {
+                    results.add(encoder);
+                    break;
+                }
+            }
+        }
+        LOG.i("findDeviceEncoder -", "type:", mimeType, "encoders:", results.size());
+        if (mode == MODE_PREFER_HARDWARE) {
+            Collections.sort(results, new Comparator<MediaCodecInfo>() {
+                @Override
+                public int compare(MediaCodecInfo o1, MediaCodecInfo o2) {
+                    boolean hw1 = isHardwareEncoder(o1.getName());
+                    boolean hw2 = isHardwareEncoder(o2.getName());
+                    if (hw1 && hw2) return 0;
+                    if (hw1) return -1;
+                    if (hw2) return 1;
+                    return 0;
+                }
+            });
+        }
+        if (results.isEmpty()) {
+            throw new RuntimeException("No encoders for type:" + mimeType);
+        }
+        return results.get(0);
+    }
+
+    /**
+     * Returns a video size supported by the device encoders.
+     * Throws if input width or height are out of the supported boundaries.
+     *
+     * @param size input size
+     * @return adjusted size
+     */
+    @SuppressLint("NewApi")
+    @NonNull
+    public Size getSupportedVideoSize(@NonNull Size size) {
+        if (!ENABLED) return size;
+        int width = size.getWidth();
+        int height = size.getHeight();
+        double aspect = (double) width / height;
+
+        // If width is too large, scale down, but keep aspect ratio.
+        if (mVideoCapabilities.getSupportedWidths().getUpper() < width) {
+            width = mVideoCapabilities.getSupportedWidths().getUpper();
+            height = (int) Math.round(width / aspect);
+        }
+
+        // If height is too large, scale down, but keep aspect ratio.
+        if (mVideoCapabilities.getSupportedHeights().getUpper() < height) {
+            height = mVideoCapabilities.getSupportedHeights().getUpper();
+            width = (int) Math.round(aspect * height);
+        }
+
+        // Adjust the alignment.
+        while (width % mVideoCapabilities.getWidthAlignment() != 0) width--;
+        while (height % mVideoCapabilities.getHeightAlignment() != 0) height--;
+
+        // It's still possible that we're BELOW the lower.
+        if (!mVideoCapabilities.getSupportedWidths().contains(width)) {
+            throw new RuntimeException("Width not supported after adjustment." +
+                    " Desired:" + width +
+                    " Range:" + mVideoCapabilities.getSupportedWidths());
+        }
+        if (!mVideoCapabilities.getSupportedHeights().contains(height)) {
+            throw new RuntimeException("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." +
+                    " Might be an aspect ratio issue." +
+                    " Desired size:" + new Size(width, height));
+        }
+        Size adjusted = new Size(width, height);
+        LOG.i("getSupportedVideoSize -", "inputSize:", size, "adjustedSize:", adjusted);
+        return adjusted;
+    }
+
+    /**
+     * Returns a video bit rate supported by the device encoders.
+     * This means adjusting the input bit rate if needed, to match encoder constraints.
+     *
+     * @param bitRate input rate
+     * @return adjusted rate
+     */
+    @SuppressLint("NewApi")
+    public int getSupportedVideoBitRate(int bitRate) {
+        if (!ENABLED) return bitRate;
+        int newBitRate = mVideoCapabilities.getBitrateRange().clamp(bitRate);
+        LOG.i("getSupportedVideoBitRate -", "inputRate:", bitRate, "adjustedRate:", newBitRate);
+        return newBitRate;
+    }
+
+    /**
+     * Returns a video frame rate supported by the device encoders.
+     * This means adjusting the input frame rate if needed, to match encoder constraints.
+     *
+     * @param frameRate input rate
+     * @return adjusted rate
+     */
+    @SuppressLint("NewApi")
+    public int getSupportedVideoFrameRate(@NonNull Size size, int frameRate) {
+        if (!ENABLED) return frameRate;
+        int newFrameRate = (int) (double) mVideoCapabilities
+                .getSupportedFrameRatesFor(size.getWidth(), size.getHeight())
+                .clamp((double) frameRate);
+        LOG.i("getSupportedVideoFrameRate -", "inputRate:", frameRate, "adjustedRate:", newFrameRate);
+        return newFrameRate;
+    }
+
+    /**
+     * Returns an audio bit rate supported by the device encoders.
+     * This means adjusting the input bit rate if needed, to match encoder constraints.
+     *
+     * @param bitRate input rate
+     * @return adjusted rate
+     */
+    @SuppressLint("NewApi")
+    public int getSupportedAudioBitRate(int bitRate) {
+        if (!ENABLED) return bitRate;
+        int newBitRate = mAudioCapabilities.getBitrateRange().clamp(bitRate);
+        LOG.i("getSupportedAudioBitRate -", "inputRate:", bitRate, "adjustedRate:", newBitRate);
+        return newBitRate;
+    }
+
+
+    // Won't do this for audio sample rate. As far as I remember, the value we're using,
+    // 44.1kHz, is guaranteed to be available, and it's not configurable.
+
+    /**
+     * Returns the name of the video encoder if we were able to determine one.
+     * @return encoder name
+     */
+    @SuppressLint("NewApi")
+    @Nullable
+    public String getVideoEncoder() {
+        if (mVideoEncoder != null) {
+            return mVideoEncoder.getName();
+        } else {
+            return null;
+        }
+    }
+
+    /**
+     * Returns the name of the audio encoder if we were able to determine one.
+     * @return encoder name
+     */
+    @SuppressLint("NewApi")
+    @Nullable
+    public String getAudioEncoder() {
+        if (mAudioEncoder != null) {
+            return mAudioEncoder.getName();
+        } else {
+            return null;
+        }
+    }
+
+}

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

@@ -6,6 +6,8 @@ import android.media.MediaRecorder;
 import com.otaliastudios.cameraview.CameraLogger;
 import com.otaliastudios.cameraview.VideoResult;
 import com.otaliastudios.cameraview.controls.Audio;
+import com.otaliastudios.cameraview.controls.VideoCodec;
+import com.otaliastudios.cameraview.internal.DeviceEncoders;
 import com.otaliastudios.cameraview.size.Size;
 
 import androidx.annotation.NonNull;
@@ -45,49 +47,85 @@ public abstract class FullVideoRecorder extends VideoRecorder {
 
     protected boolean onPrepareMediaRecorder(@NonNull VideoResult.Stub stub, @NonNull MediaRecorder mediaRecorder) {
         mMediaRecorder = mediaRecorder;
-        Size size = stub.rotation % 180 != 0 ? stub.size.flip() : stub.size;
+        boolean hasAudio = stub.audio == Audio.ON
-        if (stub.audio == Audio.ON || stub.audio == Audio.MONO || stub.audio == Audio.STEREO) {
+                || stub.audio == Audio.MONO
-            // Must be called before setOutputFormat.
+                || stub.audio == Audio.STEREO;
+        if (hasAudio) {
             mMediaRecorder.setAudioSource(MediaRecorder.AudioSource.DEFAULT);
         }
-
         mMediaRecorder.setOutputFormat(mProfile.fileFormat);
-        if (stub.videoFrameRate <= 0) {
+
-            mMediaRecorder.setVideoFrameRate(mProfile.videoFrameRate);
+        // Get the audio mime type
-            stub.videoFrameRate = mProfile.videoFrameRate;
+        // https://android.googlesource.com/platform/frameworks/av/+/master/media/libmediaplayerservice/StagefrightRecorder.cpp#1096
-        } else {
+        // https://github.com/MrAlex94/Waterfox-Old/blob/master/media/libstagefright/frameworks/av/media/libstagefright/MediaDefs.cpp
-            mMediaRecorder.setVideoFrameRate(stub.videoFrameRate);
+        String audioType;
+        switch (mProfile.audioCodec) {
+            case MediaRecorder.AudioEncoder.AMR_NB: audioType = "audio/3gpp"; break;
+            case MediaRecorder.AudioEncoder.AMR_WB: audioType = "audio/amr-wb"; break;
+            case MediaRecorder.AudioEncoder.AAC:
+            case MediaRecorder.AudioEncoder.HE_AAC:
+            case MediaRecorder.AudioEncoder.AAC_ELD: audioType = "audio/mp4a-latm"; break;
+            case MediaRecorder.AudioEncoder.VORBIS: audioType = "audio/vorbis"; break;
+            case MediaRecorder.AudioEncoder.DEFAULT:
+            default: audioType = "audio/3gpp";
         }
-        mMediaRecorder.setVideoSize(size.getWidth(), size.getHeight());
+
-        switch (stub.videoCodec) {
+        // Get the video mime type
-            case H_263: mMediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H263); break;
+        // https://android.googlesource.com/platform/frameworks/av/+/master/media/libmediaplayerservice/StagefrightRecorder.cpp#1650
-            case H_264: mMediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H264); break;
+        // https://github.com/MrAlex94/Waterfox-Old/blob/master/media/libstagefright/frameworks/av/media/libstagefright/MediaDefs.cpp
-            case DEVICE_DEFAULT: mMediaRecorder.setVideoEncoder(mProfile.videoCodec); break;
+        String videoType;
+        if (stub.videoCodec == VideoCodec.H_264) mProfile.videoCodec = MediaRecorder.VideoEncoder.H264;
+        if (stub.videoCodec == VideoCodec.H_263) mProfile.videoCodec = MediaRecorder.VideoEncoder.H263;
+        switch (mProfile.videoCodec) {
+            case MediaRecorder.VideoEncoder.H263: videoType = "video/3gpp"; break;
+            case MediaRecorder.VideoEncoder.H264: videoType = "video/avc"; break;
+            case MediaRecorder.VideoEncoder.MPEG_4_SP: videoType = "video/mp4v-es"; break;
+            case MediaRecorder.VideoEncoder.VP8: videoType = "video/x-vnd.on2.vp8"; break;
+            case MediaRecorder.VideoEncoder.HEVC: videoType = "video/hevc"; break;
+            case MediaRecorder.VideoEncoder.DEFAULT:
+            default: videoType = "video/avc";
         }
-        if (stub.videoBitRate <= 0) {
+
-            mMediaRecorder.setVideoEncodingBitRate(mProfile.videoBitRate);
+        // Merge stub and profile
-            stub.videoBitRate = mProfile.videoBitRate;
+        stub.videoFrameRate = stub.videoFrameRate > 0 ? stub.videoFrameRate : mProfile.videoFrameRate;
-        } else {
+        stub.videoBitRate = stub.videoBitRate > 0 ? stub.videoBitRate : mProfile.videoBitRate;
-            mMediaRecorder.setVideoEncodingBitRate(stub.videoBitRate);
+        if (hasAudio) {
+            stub.audioBitRate = stub.audioBitRate > 0 ? stub.audioBitRate : mProfile.audioBitRate;
         }
-        if (stub.audio == Audio.ON || stub.audio == Audio.MONO || stub.audio == Audio.STEREO) {
+
+        // Check DeviceEncoders support
+        DeviceEncoders encoders = new DeviceEncoders(videoType, audioType, DeviceEncoders.MODE_TAKE_FIRST);
+        boolean flip = stub.rotation % 180 != 0;
+        if (flip) stub.size = stub.size.flip();
+        stub.size = encoders.getSupportedVideoSize(stub.size);
+        stub.videoBitRate = encoders.getSupportedVideoBitRate(stub.videoBitRate);
+        stub.audioBitRate = encoders.getSupportedAudioBitRate(stub.audioBitRate);
+        stub.videoFrameRate = encoders.getSupportedVideoFrameRate(stub.size, stub.videoFrameRate);
+        if (flip) stub.size = stub.size.flip();
+
+        // Set video params
+        mMediaRecorder.setVideoSize(
+                flip ? stub.size.getHeight() : stub.size.getWidth(),
+                flip ? stub.size.getWidth() : stub.size.getHeight());
+        mMediaRecorder.setVideoFrameRate(stub.videoFrameRate);
+        mMediaRecorder.setVideoEncoder(mProfile.videoCodec);
+        mMediaRecorder.setVideoEncodingBitRate(stub.videoBitRate);
+
+        // Set audio params
+        if (hasAudio) {
             if (stub.audio == Audio.ON) {
                 mMediaRecorder.setAudioChannels(mProfile.audioChannels);
             } else if (stub.audio == Audio.MONO) {
                 mMediaRecorder.setAudioChannels(1);
-            } else //noinspection ConstantConditions
+            } else if (stub.audio == Audio.STEREO) {
-                if (stub.audio == Audio.STEREO) {
                 mMediaRecorder.setAudioChannels(2);
             }
             mMediaRecorder.setAudioSamplingRate(mProfile.audioSampleRate);
             mMediaRecorder.setAudioEncoder(mProfile.audioCodec);
-            if (stub.audioBitRate <= 0) {
+            mMediaRecorder.setAudioEncodingBitRate(stub.audioBitRate);
-                mMediaRecorder.setAudioEncodingBitRate(mProfile.audioBitRate);
-                stub.audioBitRate = mProfile.audioBitRate;
-            } else {
-                mMediaRecorder.setAudioEncodingBitRate(stub.audioBitRate);
-            }
         }
+
+        // Set other params
         if (stub.location != null) {
             mMediaRecorder.setLocation(
                     (float) stub.location.getLatitude(),
@@ -113,6 +151,7 @@ public abstract class FullVideoRecorder extends VideoRecorder {
             }
         });
 
+        // Prepare the Recorder
         try {
             mMediaRecorder.prepare();
             mMediaRecorderPrepared = true;

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

@@ -5,6 +5,7 @@ import android.opengl.EGL14;
 import android.os.Build;
 
 import com.otaliastudios.cameraview.CameraLogger;
+import com.otaliastudios.cameraview.internal.DeviceEncoders;
 import com.otaliastudios.cameraview.overlay.Overlay;
 import com.otaliastudios.cameraview.VideoResult;
 import com.otaliastudios.cameraview.controls.Audio;
@@ -121,26 +122,31 @@ public class SnapshotVideoRecorder extends VideoRecorder implements RendererFram
             if (mResult.videoBitRate <= 0) mResult.videoBitRate = estimateVideoBitRate(mResult.size, mResult.videoFrameRate);
             if (mResult.audioBitRate <= 0) mResult.audioBitRate = DEFAULT_AUDIO_BITRATE;
 
-            // Video. Ensure width and height are divisible by 2, as I have read somewhere.
+            // Define mime types
-            Size size = mResult.size;
+            String videoType = "";
-            int width = size.getWidth();
-            int height = size.getHeight();
-            width = width % 2 == 0 ? width : width + 1;
-            height = height % 2 == 0 ? height : height + 1;
-            String type = "";
             switch (mResult.videoCodec) {
-                case H_263: type = "video/3gpp"; break; // MediaFormat.MIMETYPE_VIDEO_H263;
+                case H_263: videoType = "video/3gpp"; break; // MediaFormat.MIMETYPE_VIDEO_H263;
-                case H_264: type = "video/avc"; break; // MediaFormat.MIMETYPE_VIDEO_AVC:
+                case H_264: videoType = "video/avc"; break; // MediaFormat.MIMETYPE_VIDEO_AVC:
-                case DEVICE_DEFAULT: type = "video/avc"; break;
+                case DEVICE_DEFAULT: videoType = "video/avc"; break;
             }
-            LOG.w("Creating frame encoder. Rotation:", mResult.rotation);
+            String audioType = "audio/mp4a-latm";
+
+            // Check the availability of values
+            DeviceEncoders deviceEncoders = new DeviceEncoders(videoType, audioType, DeviceEncoders.MODE_PREFER_HARDWARE);
+            mResult.size = deviceEncoders.getSupportedVideoSize(mResult.size);
+            mResult.videoBitRate = deviceEncoders.getSupportedVideoBitRate(mResult.videoBitRate);
+            mResult.audioBitRate = deviceEncoders.getSupportedAudioBitRate(mResult.audioBitRate);
+            mResult.videoFrameRate = deviceEncoders.getSupportedVideoFrameRate(mResult.size, mResult.videoFrameRate);
+
+            // Video
             TextureConfig videoConfig = new TextureConfig();
-            videoConfig.width = width;
+            videoConfig.width = mResult.size.getWidth();
-            videoConfig.height = height;
+            videoConfig.height = mResult.size.getHeight();
             videoConfig.bitRate = mResult.videoBitRate;
             videoConfig.frameRate = mResult.videoFrameRate;
             videoConfig.rotation = mResult.rotation;
-            videoConfig.mimeType = type;
+            videoConfig.mimeType = videoType;
+            videoConfig.encoder = deviceEncoders.getVideoEncoder();
             videoConfig.textureId = mTextureId;
             videoConfig.scaleX = scaleX;
             videoConfig.scaleY = scaleY;
@@ -162,12 +168,17 @@ public class SnapshotVideoRecorder extends VideoRecorder implements RendererFram
                 audioConfig.bitRate = mResult.audioBitRate;
                 if (mResult.audio == Audio.MONO) audioConfig.channels = 1;
                 if (mResult.audio == Audio.STEREO) audioConfig.channels = 2;
+                audioConfig.encoder = deviceEncoders.getAudioEncoder();
                 audioEncoder = new AudioMediaEncoder(audioConfig);
             }
 
             // Engine
-            mEncoderEngine = new MediaEncoderEngine(mResult.file, videoEncoder, audioEncoder,
+            mEncoderEngine = new MediaEncoderEngine(mResult.file,
-                    mResult.maxDuration, mResult.maxSize, SnapshotVideoRecorder.this);
+                    videoEncoder,
+                    audioEncoder,
+                    mResult.maxDuration,
+                    mResult.maxSize,
+                    SnapshotVideoRecorder.this);
             mEncoderEngine.notify(TextureMediaEncoder.FILTER_EVENT, mCurrentFilter);
             mEncoderEngine.start();
             mResult.rotation = 0; // We will rotate the result instead.

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

@@ -14,9 +14,10 @@ public class AudioConfig {
     // Configurable options
     public int bitRate; // ENCODED bit rate
     public int channels = 1;
+    public String encoder;
+    public String mimeType = "audio/mp4a-latm";
 
     // Not configurable options (for now)
-    final String mimeType = "audio/mp4a-latm";
     final int encoding = AudioFormat.ENCODING_PCM_16BIT; // Determines the sampleSizePerChannel
     // The 44.1KHz frequency is the only setting guaranteed to be available on all devices.
     final int samplingFrequency = 44100; // samples/sec
@@ -28,6 +29,8 @@ public class AudioConfig {
         AudioConfig config = new AudioConfig();
         config.bitRate = this.bitRate;
         config.channels = this.channels;
+        config.encoder = this.encoder;
+        config.mimeType = mimeType;
         return config;
     }
 

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

@@ -71,7 +71,11 @@ public class AudioMediaEncoder extends MediaEncoder {
         audioFormat.setInteger(MediaFormat.KEY_CHANNEL_MASK, mConfig.audioFormatChannels());
         audioFormat.setInteger(MediaFormat.KEY_BIT_RATE, mConfig.bitRate);
         try {
-            mMediaCodec = MediaCodec.createEncoderByType(mConfig.mimeType);
+            if (mConfig.encoder != null) {
+                mMediaCodec = MediaCodec.createByCodecName(mConfig.encoder);
+            } else {
+                mMediaCodec = MediaCodec.createEncoderByType(mConfig.mimeType);
+            }
         } catch (IOException e) {
             throw new RuntimeException(e);
         }

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

@@ -13,6 +13,7 @@ public class VideoConfig {
     public int frameRate;
     public int rotation;
     public String mimeType;
+    public String encoder;
 
     protected <C extends VideoConfig> void copy(@NonNull C output) {
         output.width = this.width;
@@ -21,5 +22,6 @@ public class VideoConfig {
         output.frameRate = this.frameRate;
         output.rotation = this.rotation;
         output.mimeType = this.mimeType;
+        output.encoder = this.encoder;
     }
 }

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

@@ -67,7 +67,11 @@ abstract class VideoMediaEncoder<C extends VideoConfig> extends MediaEncoder {
         format.setInteger("rotation-degrees", mConfig.rotation);
 
         try {
-            mMediaCodec = MediaCodec.createEncoderByType(mConfig.mimeType);
+            if (mConfig.encoder != null) {
+                mMediaCodec = MediaCodec.createByCodecName(mConfig.encoder);
+            } else {
+                mMediaCodec = MediaCodec.createEncoderByType(mConfig.mimeType);
+            }
         } catch (IOException e) {
             throw new RuntimeException(e);
         }

docs/_posts/2019-02-24-snapshot-size.md

@@ -42,6 +42,17 @@ This is very useful as it decouples the snapshot size logic from the preview. By
 you can have a pleasant, good looking preview stream, while still capturing fast, low-res snapshots
 with no issues.
 
+### Video Codec requirements
+
+When taking video snapshots, the video codec that the device provides might require extra constraints,
+like
+
+- width / height alignment
+- maximum width or height 
+
+CameraView will try to read these requirements and apply them, which can result in video snapshots
+that are smaller than you would expect, or with a **very slightly** different aspect ratio.
+
 ### XML Attributes
 
 ```xml