Simplify AudioTrack.handleBuffer's return value.

Position discontinuities are notified via AudioTrack.Listener.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=144202048

library/src/main/java/com/google/android/exoplayer2/audio/AudioTrack.java

@@ -63,6 +63,19 @@ public final class AudioTrack {
    */
   public interface Listener {
 
+    /**
+     * Called when the audio track has been initialized with the specified {@code audioSessionId}.
+     *
+     * @param audioSessionId The audio session id.
+     */
+    void onAudioSessionId(int audioSessionId);
+
+    /**
+     * Called when the audio track handles a buffer whose timestamp is discontinuous with the last
+     * buffer handled since it was reset.
+     */
+    void onPositionDiscontinuity();
+
     /**
      * Called when the audio track underruns.
      *
@@ -74,13 +87,6 @@ public final class AudioTrack {
      */
     void onUnderrun(int bufferSize, long bufferSizeMs, long elapsedSinceLastFeedMs);
 
-    /**
-     * Called when the audio track has been initialized with the specified {@code audioSessionId}.
-     *
-     * @param audioSessionId The audio session id.
-     */
-    void onAudioSessionId(int audioSessionId);
-
   }
 
   /**
@@ -144,15 +150,6 @@ public final class AudioTrack {
 
   }
 
-  /**
-   * Returned in the result of {@link #handleBuffer} if the buffer was discontinuous.
-   */
-  public static final int RESULT_POSITION_DISCONTINUITY = 1;
-  /**
-   * Returned in the result of {@link #handleBuffer} if the buffer can be released.
-   */
-  public static final int RESULT_BUFFER_CONSUMED = 2;
-
   /**
    * Returned by {@link #getCurrentPositionUs} when the position is not set.
    */
@@ -591,24 +588,21 @@ public final class AudioTrack {
    * Attempts to write data from a {@link ByteBuffer} to the audio track, starting from its current
    * position and ending at its limit (exclusive). The position of the {@link ByteBuffer} is
    * advanced by the number of bytes that were successfully written.
+   * {@link Listener#onPositionDiscontinuity()} will be called if {@code presentationTimeUs} is
+   * discontinuous with the last buffer handled since the track was reset.
    * <p>
-   * Returns a bit field containing {@link #RESULT_BUFFER_CONSUMED} if the data was written in full,
+   * Returns whether the data was written in full. If the data was not written in full then the same
-   * and {@link #RESULT_POSITION_DISCONTINUITY} if the buffer was discontinuous with previously
+   * {@link ByteBuffer} must be provided to subsequent calls until it has been fully consumed,
-   * written data.
+   * except in the case of an interleaving call to {@link #reset()} (or an interleaving call to
-   * <p>
+   * {@link #configure(String, int, int, int, int)} that caused the track to be reset).
-   * If the data was not written in full then the same {@link ByteBuffer} must be provided to
-   * subsequent calls until it has been fully consumed, except in the case of an interleaving call
-   * to {@link #configure} or {@link #reset}.
    *
    * @param buffer The buffer containing audio data to play back.
    * @param presentationTimeUs Presentation timestamp of the next buffer in microseconds.
-   * @return A bit field with {@link #RESULT_BUFFER_CONSUMED} if the buffer can be released, and
+   * @return Whether the buffer was consumed fully.
-   *     {@link #RESULT_POSITION_DISCONTINUITY} if the buffer was not contiguous with previously
-   *     written data.
    * @throws InitializationException If an error occurs initializing the track.
    * @throws WriteException If an error occurs writing the audio data.
    */
-  public int handleBuffer(ByteBuffer buffer, long presentationTimeUs)
+  public boolean handleBuffer(ByteBuffer buffer, long presentationTimeUs)
       throws InitializationException, WriteException {
     if (!isInitialized()) {
       initialize();
@@ -623,12 +617,12 @@ public final class AudioTrack {
       long elapsedSinceLastFeedMs = SystemClock.elapsedRealtime() - lastFeedElapsedRealtimeMs;
       listener.onUnderrun(bufferSize, C.usToMs(bufferSizeUs), elapsedSinceLastFeedMs);
     }
-    int result = writeBuffer(buffer, presentationTimeUs);
+    boolean result = writeBuffer(buffer, presentationTimeUs);
     lastFeedElapsedRealtimeMs = SystemClock.elapsedRealtime();
     return result;
   }
 
-  private int writeBuffer(ByteBuffer buffer, long presentationTimeUs) throws WriteException {
+  private boolean writeBuffer(ByteBuffer buffer, long presentationTimeUs) throws WriteException {
     boolean isNewSourceBuffer = currentSourceBuffer == null;
     Assertions.checkState(isNewSourceBuffer || currentSourceBuffer == buffer);
     currentSourceBuffer = buffer;
@@ -637,7 +631,7 @@ public final class AudioTrack {
       // An AC-3 audio track continues to play data written while it is paused. Stop writing so its
       // buffer empties. See [Internal: b/18899620].
       if (audioTrack.getPlayState() == PLAYSTATE_PAUSED) {
-        return 0;
+        return false;
       }
 
       // A new AC-3 audio track's playback position continues to increase from the old track's
@@ -645,7 +639,7 @@ public final class AudioTrack {
       // head position actually returns to zero.
       if (audioTrack.getPlayState() == PLAYSTATE_STOPPED
           && audioTrackUtil.getPlaybackHeadPosition() != 0) {
-        return 0;
+        return false;
       }
     }
 
@@ -656,7 +650,7 @@ public final class AudioTrack {
       if (!currentSourceBuffer.hasRemaining()) {
         // The buffer is empty.
         currentSourceBuffer = null;
-        return RESULT_BUFFER_CONSUMED;
+        return true;
       }
 
       useResampledBuffer = targetEncoding != sourceEncoding;
@@ -689,7 +683,7 @@ public final class AudioTrack {
           // number of bytes submitted.
           startMediaTimeUs += (presentationTimeUs - expectedPresentationTimeUs);
           startMediaTimeState = START_IN_SYNC;
-          result |= RESULT_POSITION_DISCONTINUITY;
+          listener.onPositionDiscontinuity();
         }
       }
       if (Util.SDK_INT < 21) {
@@ -739,9 +733,9 @@ public final class AudioTrack {
         submittedEncodedFrames += framesPerEncodedSample;
       }
       currentSourceBuffer = null;
-      result |= RESULT_BUFFER_CONSUMED;
+      return true;
     }
-    return result;
+    return false;
   }
 
   /**

library/src/main/java/com/google/android/exoplayer2/audio/MediaCodecAudioRenderer.java

@@ -228,29 +228,26 @@ public class MediaCodecAudioRenderer extends MediaCodecRenderer implements Media
   }
 
   /**
-   * Called when the audio session id becomes known. Once the id is known it will not change (and
+   * Called when the audio session id becomes known. The default implementation is a no-op. One
-   * hence this method will not be called again) unless the renderer is disabled and then
+   * reason for overriding this method would be to instantiate and enable a {@link Virtualizer} in
-   * subsequently re-enabled.
+   * order to spatialize the audio channels. For this use case, any {@link Virtualizer} instances
-   * <p>
+   * should be released in {@link #onDisabled()} (if not before).
-   * The default implementation is a no-op. One reason for overriding this method would be to
-   * instantiate and enable a {@link Virtualizer} in order to spatialize the audio channels. For
-   * this use case, any {@link Virtualizer} instances should be released in {@link #onDisabled()}
-   * (if not before).
    *
-   * @param audioSessionId The audio session id.
+   * @see AudioTrack.Listener#onAudioSessionId(int)
    */
   protected void onAudioSessionId(int audioSessionId) {
     // Do nothing.
   }
 
   /**
-   * Called when an {@link AudioTrack} underrun occurs.
+   * @see AudioTrack.Listener#onPositionDiscontinuity()
-   *
+   */
-   * @param bufferSize The size of the {@link AudioTrack}'s buffer, in bytes.
+  protected void onAudioTrackPositionDiscontinuity() {
-   * @param bufferSizeMs The size of the {@link AudioTrack}'s buffer, in milliseconds, if it is
+    // Do nothing.
-   *     configured for PCM output. {@link C#TIME_UNSET} if it is configured for passthrough output,
+  }
-   *     as the buffered media can have a variable bitrate so the duration may be unknown.
+
-   * @param elapsedSinceLastFeedMs The time since the {@link AudioTrack} was last fed data.
+  /**
+   * @see AudioTrack.Listener#onUnderrun(int, long, long)
    */
   protected void onAudioTrackUnderrun(int bufferSize, long bufferSizeMs,
       long elapsedSinceLastFeedMs) {
@@ -335,26 +332,15 @@ public class MediaCodecAudioRenderer extends MediaCodecRenderer implements Media
       return true;
     }
 
-    int handleBufferResult;
     try {
-      handleBufferResult = audioTrack.handleBuffer(buffer, bufferPresentationTimeUs);
+      if (audioTrack.handleBuffer(buffer, bufferPresentationTimeUs)) {
-    } catch (AudioTrack.InitializationException | AudioTrack.WriteException e) {
-      throw ExoPlaybackException.createForRenderer(e, getIndex());
-    }
-
-    // If we are out of sync, allow currentPositionUs to jump backwards.
-    if ((handleBufferResult & AudioTrack.RESULT_POSITION_DISCONTINUITY) != 0) {
-      handleAudioTrackDiscontinuity();
-      allowPositionDiscontinuity = true;
-    }
-
-    // Release the buffer if it was consumed.
-    if ((handleBufferResult & AudioTrack.RESULT_BUFFER_CONSUMED) != 0) {
         codec.releaseOutputBuffer(bufferIndex, false);
         decoderCounters.renderedOutputBufferCount++;
         return true;
       }
-
+    } catch (AudioTrack.InitializationException | AudioTrack.WriteException e) {
+      throw ExoPlaybackException.createForRenderer(e, getIndex());
+    }
     return false;
   }
 
@@ -363,10 +349,6 @@ public class MediaCodecAudioRenderer extends MediaCodecRenderer implements Media
     audioTrack.handleEndOfStream();
   }
 
-  protected void handleAudioTrackDiscontinuity() {
-    // Do nothing
-  }
-
   @Override
   public void handleMessage(int messageType, Object message) throws ExoPlaybackException {
     switch (messageType) {
@@ -388,19 +370,25 @@ public class MediaCodecAudioRenderer extends MediaCodecRenderer implements Media
 
   private final class AudioTrackListener implements AudioTrack.Listener {
 
-    @Override
-    public void onUnderrun(int bufferSize, long bufferSizeMs, long elapsedSinceLastFeedMs) {
-      eventDispatcher.audioTrackUnderrun(bufferSize, bufferSizeMs, elapsedSinceLastFeedMs);
-      MediaCodecAudioRenderer.this.onAudioTrackUnderrun(bufferSize, bufferSizeMs,
-          elapsedSinceLastFeedMs);
-    }
-
     @Override
     public void onAudioSessionId(int audioSessionId) {
       eventDispatcher.audioSessionId(audioSessionId);
       MediaCodecAudioRenderer.this.onAudioSessionId(audioSessionId);
     }
 
+    @Override
+    public void onPositionDiscontinuity() {
+      onAudioTrackPositionDiscontinuity();
+      // We are out of sync so allow currentPositionUs to jump backwards.
+      MediaCodecAudioRenderer.this.allowPositionDiscontinuity = true;
+    }
+
+    @Override
+    public void onUnderrun(int bufferSize, long bufferSizeMs, long elapsedSinceLastFeedMs) {
+      eventDispatcher.audioTrackUnderrun(bufferSize, bufferSizeMs, elapsedSinceLastFeedMs);
+      onAudioTrackUnderrun(bufferSize, bufferSizeMs, elapsedSinceLastFeedMs);
+    }
+
   }
 
 }

library/src/main/java/com/google/android/exoplayer2/audio/SimpleDecoderAudioRenderer.java

@@ -183,29 +183,26 @@ public abstract class SimpleDecoderAudioRenderer extends BaseRenderer implements
   }
 
   /**
-   * Called when the audio session id becomes known. Once the id is known it will not change (and
+   * Called when the audio session id becomes known. The default implementation is a no-op. One
-   * hence this method will not be called again) unless the renderer is disabled and then
+   * reason for overriding this method would be to instantiate and enable a {@link Virtualizer} in
-   * subsequently re-enabled.
+   * order to spatialize the audio channels. For this use case, any {@link Virtualizer} instances
-   * <p>
+   * should be released in {@link #onDisabled()} (if not before).
-   * The default implementation is a no-op. One reason for overriding this method would be to
-   * instantiate and enable a {@link Virtualizer} in order to spatialize the audio channels. For
-   * this use case, any {@link Virtualizer} instances should be released in {@link #onDisabled()}
-   * (if not before).
    *
-   * @param audioSessionId The audio session id.
+   * @see AudioTrack.Listener#onAudioSessionId(int)
    */
   protected void onAudioSessionId(int audioSessionId) {
     // Do nothing.
   }
 
   /**
-   * Called when an {@link AudioTrack} underrun occurs.
+   * @see AudioTrack.Listener#onPositionDiscontinuity()
-   *
+   */
-   * @param bufferSize The size of the {@link AudioTrack}'s buffer, in bytes.
+  protected void onAudioTrackPositionDiscontinuity() {
-   * @param bufferSizeMs The size of the {@link AudioTrack}'s buffer, in milliseconds, if it is
+    // Do nothing.
-   *     configured for PCM output. {@link C#TIME_UNSET} if it is configured for passthrough output,
+  }
-   *     as the buffered media can have a variable bitrate so the duration may be unknown.
+
-   * @param elapsedSinceLastFeedMs The time since the {@link AudioTrack} was last fed data.
+  /**
+   * @see AudioTrack.Listener#onUnderrun(int, long, long)
    */
   protected void onAudioTrackUnderrun(int bufferSize, long bufferSizeMs,
       long elapsedSinceLastFeedMs) {
@@ -271,15 +268,7 @@ public abstract class SimpleDecoderAudioRenderer extends BaseRenderer implements
       audioTrackNeedsConfigure = false;
     }
 
-    int handleBufferResult = audioTrack.handleBuffer(outputBuffer.data, outputBuffer.timeUs);
+    if (audioTrack.handleBuffer(outputBuffer.data, outputBuffer.timeUs)) {
-
-    // If we are out of sync, allow currentPositionUs to jump backwards.
-    if ((handleBufferResult & AudioTrack.RESULT_POSITION_DISCONTINUITY) != 0) {
-      allowPositionDiscontinuity = true;
-    }
-
-    // Release the buffer if it was consumed.
-    if ((handleBufferResult & AudioTrack.RESULT_BUFFER_CONSUMED) != 0) {
       decoderCounters.renderedOutputBufferCount++;
       outputBuffer.release();
       outputBuffer = null;
@@ -563,19 +552,25 @@ public abstract class SimpleDecoderAudioRenderer extends BaseRenderer implements
 
   private final class AudioTrackListener implements AudioTrack.Listener {
 
-    @Override
-    public void onUnderrun(int bufferSize, long bufferSizeMs, long elapsedSinceLastFeedMs) {
-      eventDispatcher.audioTrackUnderrun(bufferSize, bufferSizeMs, elapsedSinceLastFeedMs);
-      SimpleDecoderAudioRenderer.this.onAudioTrackUnderrun(bufferSize, bufferSizeMs,
-          elapsedSinceLastFeedMs);
-    }
-
     @Override
     public void onAudioSessionId(int audioSessionId) {
       eventDispatcher.audioSessionId(audioSessionId);
       SimpleDecoderAudioRenderer.this.onAudioSessionId(audioSessionId);
     }
 
+    @Override
+    public void onPositionDiscontinuity() {
+      onAudioTrackPositionDiscontinuity();
+      // We are out of sync so allow currentPositionUs to jump backwards.
+      SimpleDecoderAudioRenderer.this.allowPositionDiscontinuity = true;
+    }
+
+    @Override
+    public void onUnderrun(int bufferSize, long bufferSizeMs, long elapsedSinceLastFeedMs) {
+      eventDispatcher.audioTrackUnderrun(bufferSize, bufferSizeMs, elapsedSinceLastFeedMs);
+      onAudioTrackUnderrun(bufferSize, bufferSizeMs, elapsedSinceLastFeedMs);
+    }
+
   }
 
 }