* Before starting playback, specify the input format by calling - * {@link #configure(String, int, int, int, int)}. Next call {@link #initialize(int)}, optionally - * specifying an audio session. + * {@link #configure(String, int, int, int, int)}. Next call {@link #initialize(int)} or + * {@link #initializeV21(int, boolean)}, optionally specifying an audio session and whether the + * track is to be used with tunneling video playback. *
* Call {@link #handleBuffer(ByteBuffer, long)} to write data, and {@link #handleDiscontinuity()} * when the data being fed is discontinuous. Call {@link #play()} to start playing the written data. *
* Call {@link #configure(String, int, int, int, int)} whenever the input format changes. If * {@link #isInitialized()} returns {@code false} after the call, it is necessary to call - * {@link #initialize(int)} before writing more data. + * {@link #initialize(int)} or {@link #initializeV21(int, boolean)} before writing more data. *
* The underlying {@link android.media.AudioTrack} is created by {@link #initialize(int)} and * released by {@link #reset()} (and {@link #configure(String, int, int, int, int)} unless the input - * format is unchanged). It is safe to call {@link #initialize(int)} after calling {@link #reset()} - * without reconfiguration. + * format is unchanged). It is safe to call {@link #initialize(int)} or + * {@link #initializeV21(int, boolean)} after calling {@link #reset()} without reconfiguration. *
* Call {@link #release()} when the instance is no longer required. */ @@ -144,9 +148,11 @@ public final class AudioTrack { public static final int RESULT_BUFFER_CONSUMED = 2; /** - * Represents an unset {@link android.media.AudioTrack} session identifier. + * Represents an unset {@link android.media.AudioTrack} session identifier. Equal to + * {@link AudioManager#AUDIO_SESSION_ID_GENERATE}. */ - public static final int SESSION_ID_NOT_SET = 0; + @SuppressWarnings("InlinedApi") + public static final int SESSION_ID_NOT_SET = AudioManager.AUDIO_SESSION_ID_GENERATE; /** * Returned by {@link #getCurrentPositionUs} when the position is not set. @@ -273,6 +279,10 @@ public final class AudioTrack { private int bufferSize; private long bufferSizeUs; + private boolean useHwAvSync; + private ByteBuffer avSyncHeader; + private int bytesUntilNextAvSync; + private int nextPlayheadOffsetIndex; private int playheadOffsetCount; private long smoothedPlayheadOffsetUs; @@ -341,8 +351,8 @@ public final class AudioTrack { } /** - * Returns whether the audio track has been successfully initialized via {@link #initialize} and - * not yet {@link #reset}. + * Returns whether the audio track has been successfully initialized via {@link #initialize} or + * {@link #initializeV21(int, boolean)}, and has not yet been {@link #reset}. */ public boolean isInitialized() { return audioTrack != null; @@ -498,11 +508,26 @@ public final class AudioTrack { /** * Initializes the audio track for writing new buffers using {@link #handleBuffer}. * - * @param sessionId Audio track session identifier to re-use, or {@link #SESSION_ID_NOT_SET} to - * create a new one. - * @return The new (or re-used) session identifier. + * @param sessionId Audio track session identifier, or {@link #SESSION_ID_NOT_SET} to create one. + * @return The audio track session identifier. */ public int initialize(int sessionId) throws InitializationException { + return initializeInternal(sessionId, false); + } + + /** + * Initializes the audio track for writing new buffers using {@link #handleBuffer}. + * + * @param sessionId Audio track session identifier, or {@link #SESSION_ID_NOT_SET} to create one. + * @param tunneling Whether the audio track is to be used with tunneling video playback. + * @return The audio track session identifier. + */ + public int initializeV21(int sessionId, boolean tunneling) throws InitializationException { + Assertions.checkState(Util.SDK_INT >= 21); + return initializeInternal(sessionId, tunneling); + } + + private int initializeInternal(int sessionId, boolean tunneling) throws InitializationException { // If we're asynchronously releasing a previous audio track then we block until it has been // released. This guarantees that we cannot end up in a state where we have multiple audio // track instances. Without this guarantee it would be possible, in extreme cases, to exhaust @@ -510,7 +535,11 @@ public final class AudioTrack { // initialization of the audio track to fail. releasingConditionVariable.block(); - if (sessionId == SESSION_ID_NOT_SET) { + useHwAvSync = tunneling; + if (useHwAvSync) { + audioTrack = createHwAvSyncAudioTrackV21(sampleRate, channelConfig, targetEncoding, + bufferSize, sessionId); + } else if (sessionId == SESSION_ID_NOT_SET) { audioTrack = new android.media.AudioTrack(streamType, sampleRate, channelConfig, targetEncoding, bufferSize, MODE_STREAM); } else { @@ -692,7 +721,9 @@ public final class AudioTrack { buffer.position(buffer.position() + bytesWritten); } } else { - bytesWritten = writeNonBlockingV21(audioTrack, buffer, bytesRemaining); + bytesWritten = useHwAvSync + ? writeNonBlockingWithAvSyncV21(audioTrack, buffer, bytesRemaining, presentationTimeUs) + : writeNonBlockingV21(audioTrack, buffer, bytesRemaining); } if (bytesWritten < 0) { @@ -718,6 +749,7 @@ public final class AudioTrack { public void handleEndOfStream() { if (isInitialized()) { audioTrackUtil.handleEndOfStream(getSubmittedFrames()); + bytesUntilNextAvSync = 0; } } @@ -743,19 +775,27 @@ public final class AudioTrack { } /** - * Sets the stream type for audio track. If the stream type has changed, {@link #isInitialized()} - * will return {@code false} and the caller must re-{@link #initialize(int)} the audio track - * before writing more data. The caller must not reuse the audio session identifier when - * re-initializing with a new stream type. + * Sets the stream type for audio track. If the stream type has changed and if the audio track + * is not configured for use with video tunneling, then the audio track is reset and the caller + * must re-initialize the audio track before writing more data. The caller must not reuse the + * audio session identifier when re-initializing with a new stream type. + *
+ * If the audio track is configured for use with video tunneling then the stream type is ignored + * and the audio track is not reset. The passed stream type will be used if the audio track is + * later re-configured into non-tunneled mode. * * @param streamType The {@link C.StreamType} to use for audio output. - * @return Whether the stream type changed. + * @return Whether the audio track was reset as a result of this call. */ public boolean setStreamType(@C.StreamType int streamType) { if (this.streamType == streamType) { return false; } this.streamType = streamType; + if (useHwAvSync) { + // The stream type is ignored in tunneling mode, so no need to reset. + return false; + } reset(); return true; } @@ -795,9 +835,9 @@ public final class AudioTrack { /** * Releases the underlying audio track asynchronously. *
- * Calling {@link #initialize(int)} will block until the audio track has been released, so it is - * safe to initialize immediately after a reset. The audio session may remain active until - * {@link #release()} is called. + * Calling {@link #initialize(int)} or {@link #initializeV21(int, boolean)} will block until the + * audio track has been released, so it is safe to initialize immediately after a reset. The audio + * session may remain active until {@link #release()} is called. */ public void reset() { if (isInitialized()) { @@ -805,6 +845,7 @@ public final class AudioTrack { submittedEncodedFrames = 0; framesPerEncodedSample = 0; currentSourceBuffer = null; + avSyncHeader = null; startMediaTimeState = START_NOT_SET; latencyUs = 0; resetSyncParams(); @@ -1020,6 +1061,26 @@ public final class AudioTrack { && audioTrack.getPlaybackHeadPosition() == 0; } + /** + * Instantiates an {@link android.media.AudioTrack} to be used with tunneling video playback. + */ + @TargetApi(21) + private static android.media.AudioTrack createHwAvSyncAudioTrackV21(int sampleRate, + int channelConfig, int encoding, int bufferSize, int sessionId) { + AudioAttributes attributesBuilder = new AudioAttributes.Builder() + .setUsage(AudioAttributes.USAGE_MEDIA) + .setContentType(AudioAttributes.CONTENT_TYPE_MOVIE) + .setFlags(AudioAttributes.FLAG_HW_AV_SYNC) + .build(); + AudioFormat format = new AudioFormat.Builder() + .setChannelMask(channelConfig) + .setEncoding(encoding) + .setSampleRate(sampleRate) + .build(); + return new android.media.AudioTrack(attributesBuilder, format, bufferSize, MODE_STREAM, + sessionId); + } + /** * Converts the provided buffer into 16-bit PCM. * @@ -1125,11 +1186,50 @@ public final class AudioTrack { } @TargetApi(21) - private static int writeNonBlockingV21( - android.media.AudioTrack audioTrack, ByteBuffer buffer, int size) { + private static int writeNonBlockingV21(android.media.AudioTrack audioTrack, ByteBuffer buffer, + int size) { return audioTrack.write(buffer, size, WRITE_NON_BLOCKING); } + @TargetApi(21) + private int writeNonBlockingWithAvSyncV21(android.media.AudioTrack audioTrack, + ByteBuffer buffer, int size, long presentationTimeUs) { + // TODO: Uncomment this when [Internal ref b/33627517] is clarified or fixed. + // if (Util.SDK_INT >= 23) { + // // The underlying platform AudioTrack writes AV sync headers directly. + // return audioTrack.write(buffer, size, WRITE_NON_BLOCKING, presentationTimeUs * 1000); + // } + if (avSyncHeader == null) { + avSyncHeader = ByteBuffer.allocate(16); + avSyncHeader.order(ByteOrder.BIG_ENDIAN); + avSyncHeader.putInt(0x55550001); + } + if (bytesUntilNextAvSync == 0) { + avSyncHeader.putInt(4, size); + avSyncHeader.putLong(8, presentationTimeUs * 1000); + avSyncHeader.position(0); + bytesUntilNextAvSync = size; + } + int avSyncHeaderBytesRemaining = avSyncHeader.remaining(); + if (avSyncHeaderBytesRemaining > 0) { + int result = audioTrack.write(avSyncHeader, avSyncHeaderBytesRemaining, WRITE_NON_BLOCKING); + if (result < 0) { + bytesUntilNextAvSync = 0; + return result; + } + if (result < avSyncHeaderBytesRemaining) { + return 0; + } + } + int result = writeNonBlockingV21(audioTrack, buffer, size); + if (result < 0) { + bytesUntilNextAvSync = 0; + return result; + } + bytesUntilNextAvSync -= result; + return result; + } + @TargetApi(21) private static void setAudioTrackVolumeV21(android.media.AudioTrack audioTrack, float volume) { audioTrack.setVolume(volume);