Rollback of https://github.com/androidx/media/commit/8a4168271db6402964fa7e969d2adfc0be493fb3

*** Original commit ***

Keep AudioTrack on flush as default

***

PiperOrigin-RevId: 444327724

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/audio/AudioSink.java

@@ -457,6 +457,18 @@ public interface AudioSink {
    */
   void flush();
 
+  /**
+   * Flushes the sink, after which it is ready to receive buffers from a new playback position.
+   *
+   * <p>Does not release the {@link AudioTrack} held by the sink.
+   *
+   * <p>This method is experimental, and will be renamed or removed in a future release.
+   *
+   * <p>Only for experimental use as part of {@link
+   * MediaCodecAudioRenderer#experimentalSetEnableKeepAudioTrackOnSeek(boolean)}.
+   */
+  void experimentalFlushWithoutAudioTrackRelease();
+
   /** Resets the sink, releasing any resources that it currently holds. */
   void reset();
 }

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/audio/DecoderAudioRenderer.java

@@ -129,6 +129,7 @@ public abstract class DecoderAudioRenderer<
   private int encoderDelay;
   private int encoderPadding;
 
+  private boolean experimentalKeepAudioTrackOnSeek;
   private boolean firstStreamSampleRead;
 
   @Nullable private T decoder;
@@ -208,6 +209,19 @@ public abstract class DecoderAudioRenderer<
     audioSinkNeedsConfigure = true;
   }
 
+  /**
+   * Sets whether to enable the experimental feature that keeps and flushes the {@link
+   * android.media.AudioTrack} when a seek occurs, as opposed to releasing and reinitialising. Off
+   * by default.
+   *
+   * <p>This method is experimental, and will be renamed or removed in a future release.
+   *
+   * @param enableKeepAudioTrackOnSeek Whether to keep the {@link android.media.AudioTrack} on seek.
+   */
+  public void experimentalSetEnableKeepAudioTrackOnSeek(boolean enableKeepAudioTrackOnSeek) {
+    this.experimentalKeepAudioTrackOnSeek = enableKeepAudioTrackOnSeek;
+  }
+
   @Override
   @Nullable
   public MediaClock getMediaClock() {
@@ -541,7 +555,12 @@ public abstract class DecoderAudioRenderer<
 
   @Override
   protected void onPositionReset(long positionUs, boolean joining) throws ExoPlaybackException {
+    if (experimentalKeepAudioTrackOnSeek) {
+      audioSink.experimentalFlushWithoutAudioTrackRelease();
+    } else {
       audioSink.flush();
+    }
+
     currentPositionUs = positionUs;
     allowFirstBufferPositionDiscontinuity = true;
     allowPositionDiscontinuity = true;

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/audio/DefaultAudioSink.java

@@ -907,7 +907,7 @@ public final class DefaultAudioSink implements AudioSink {
           // We're waiting for playout on the current audio track to finish.
           return false;
         }
-        flushAndReleaseAudioTrack();
+        flush();
       } else {
         // The current audio track can be reused for the new configuration.
         configuration = pendingConfiguration;
@@ -1034,7 +1034,7 @@ public final class DefaultAudioSink implements AudioSink {
 
     if (audioTrackPositionTracker.isStalled(getWrittenFrames())) {
       Log.w(TAG, "Resetting stalled audio track");
-      flushAndReleaseAudioTrack();
+      flush();
       return true;
     }
 
@@ -1324,8 +1324,7 @@ public final class DefaultAudioSink implements AudioSink {
       // The audio attributes are ignored in tunneling mode, so no need to reset.
       return;
     }
-    // audioAttributes change requires the audioTrack to be recreated.
-    flushAndReleaseAudioTrack();
+    flush();
   }
 
   @Override
@@ -1338,8 +1337,7 @@ public final class DefaultAudioSink implements AudioSink {
     if (this.audioSessionId != audioSessionId) {
       this.audioSessionId = audioSessionId;
       externalAudioSessionIdProvided = audioSessionId != C.AUDIO_SESSION_ID_UNSET;
-      // audioSessionId change requires the audioTrack to be recreated.
-      flushAndReleaseAudioTrack();
+      flush();
     }
   }
 
@@ -1367,7 +1365,7 @@ public final class DefaultAudioSink implements AudioSink {
     Assertions.checkState(externalAudioSessionIdProvided);
     if (!tunneling) {
       tunneling = true;
-      flushAndReleaseAudioTrack();
+      flush();
     }
   }
 
@@ -1375,7 +1373,7 @@ public final class DefaultAudioSink implements AudioSink {
   public void disableTunneling() {
     if (tunneling) {
       tunneling = false;
-      flushAndReleaseAudioTrack();
+      flush();
     }
   }
 
@@ -1407,60 +1405,9 @@ public final class DefaultAudioSink implements AudioSink {
 
   @Override
   public void flush() {
-    if (!isAudioTrackInitialized()) {
-      return;
-    }
-
-    // Prior to SDK 25, AudioTrack flush does not work as intended, so it must be released and
-    // reinitialized. (Internal reference: b/143500232)
-    if (Util.SDK_INT < 25) {
-      flushAndReleaseAudioTrack();
-      return;
-    }
-
-    writeExceptionPendingExceptionHolder.clear();
-    initializationExceptionPendingExceptionHolder.clear();
-
+    if (isAudioTrackInitialized()) {
       resetSinkStateForFlush();
-    if (audioTrackPositionTracker.isPlaying()) {
-      audioTrack.pause();
-    }
-
-    audioTrack.flush();
-    audioTrackPositionTracker.reset();
-    audioTrackPositionTracker.setAudioTrack(
-        audioTrack,
-        /* isPassthrough= */ configuration.outputMode == OUTPUT_MODE_PASSTHROUGH,
-        configuration.outputEncoding,
-        configuration.outputPcmFrameSize,
-        configuration.bufferSize);
-    startMediaTimeUsNeedsInit = true;
-  }
-
-  @Override
-  public void reset() {
-    flushAndReleaseAudioTrack();
-    for (AudioProcessor audioProcessor : toIntPcmAvailableAudioProcessors) {
-      audioProcessor.reset();
-    }
-    for (AudioProcessor audioProcessor : toFloatPcmAvailableAudioProcessors) {
-      audioProcessor.reset();
-    }
-    playing = false;
-    offloadDisabledUntilNextConfiguration = false;
-  }
-
-  // Internal methods.
-
-  private void flushAndReleaseAudioTrack() {
-    if (!isAudioTrackInitialized()) {
-      return;
-    }
-
-    writeExceptionPendingExceptionHolder.clear();
-    initializationExceptionPendingExceptionHolder.clear();
 
-    resetSinkStateForFlush();
       if (audioTrackPositionTracker.isPlaying()) {
         audioTrack.pause();
       }
@@ -1496,6 +1443,57 @@ public final class DefaultAudioSink implements AudioSink {
         }
       }.start();
     }
+    writeExceptionPendingExceptionHolder.clear();
+    initializationExceptionPendingExceptionHolder.clear();
+  }
+
+  @Override
+  public void experimentalFlushWithoutAudioTrackRelease() {
+    // Prior to SDK 25, AudioTrack flush does not work as intended, and therefore it must be
+    // released and reinitialized. (Internal reference: b/143500232)
+    if (Util.SDK_INT < 25) {
+      flush();
+      return;
+    }
+
+    writeExceptionPendingExceptionHolder.clear();
+    initializationExceptionPendingExceptionHolder.clear();
+
+    if (!isAudioTrackInitialized()) {
+      return;
+    }
+
+    resetSinkStateForFlush();
+    if (audioTrackPositionTracker.isPlaying()) {
+      audioTrack.pause();
+    }
+    audioTrack.flush();
+
+    audioTrackPositionTracker.reset();
+    audioTrackPositionTracker.setAudioTrack(
+        audioTrack,
+        /* isPassthrough= */ configuration.outputMode == OUTPUT_MODE_PASSTHROUGH,
+        configuration.outputEncoding,
+        configuration.outputPcmFrameSize,
+        configuration.bufferSize);
+
+    startMediaTimeUsNeedsInit = true;
+  }
+
+  @Override
+  public void reset() {
+    flush();
+    for (AudioProcessor audioProcessor : toIntPcmAvailableAudioProcessors) {
+      audioProcessor.reset();
+    }
+    for (AudioProcessor audioProcessor : toFloatPcmAvailableAudioProcessors) {
+      audioProcessor.reset();
+    }
+    playing = false;
+    offloadDisabledUntilNextConfiguration = false;
+  }
+
+  // Internal methods.
 
   private void resetSinkStateForFlush() {
     submittedPcmBytes = 0;

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/audio/ForwardingAudioSink.java

@@ -164,6 +164,11 @@ public class ForwardingAudioSink implements AudioSink {
   }
 
   @Override
+  public void experimentalFlushWithoutAudioTrackRelease() {
+    sink.experimentalFlushWithoutAudioTrackRelease();
+  }
+
+  @Override
   public void reset() {
     sink.reset();
   }

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/audio/MediaCodecAudioRenderer.java

@@ -109,6 +109,8 @@ public class MediaCodecAudioRenderer extends MediaCodecRenderer implements Media
   private boolean allowPositionDiscontinuity;
   private boolean audioSinkNeedsConfigure;
 
+  private boolean experimentalKeepAudioTrackOnSeek;
+
   @Nullable private WakeupListener wakeupListener;
 
   /**
@@ -264,6 +266,19 @@ public class MediaCodecAudioRenderer extends MediaCodecRenderer implements Media
     return TAG;
   }
 
+  /**
+   * Sets whether to enable the experimental feature that keeps and flushes the {@link
+   * android.media.AudioTrack} when a seek occurs, as opposed to releasing and reinitialising. Off
+   * by default.
+   *
+   * <p>This method is experimental, and will be renamed or removed in a future release.
+   *
+   * @param enableKeepAudioTrackOnSeek Whether to keep the {@link android.media.AudioTrack} on seek.
+   */
+  public void experimentalSetEnableKeepAudioTrackOnSeek(boolean enableKeepAudioTrackOnSeek) {
+    this.experimentalKeepAudioTrackOnSeek = enableKeepAudioTrackOnSeek;
+  }
+
   @Override
   protected @Capabilities int supportsFormat(MediaCodecSelector mediaCodecSelector, Format format)
       throws DecoderQueryException {
@@ -516,7 +531,11 @@ public class MediaCodecAudioRenderer extends MediaCodecRenderer implements Media
   @Override
   protected void onPositionReset(long positionUs, boolean joining) throws ExoPlaybackException {
     super.onPositionReset(positionUs, joining);
+    if (experimentalKeepAudioTrackOnSeek) {
+      audioSink.experimentalFlushWithoutAudioTrackRelease();
+    } else {
       audioSink.flush();
+    }
 
     currentPositionUs = positionUs;
     allowFirstBufferPositionDiscontinuity = true;

libraries/exoplayer/src/test/java/androidx/media3/exoplayer/audio/DefaultAudioSinkTest.java

@@ -265,15 +265,15 @@ public final class DefaultAudioSinkTest {
   }
 
   @Test
-  public void handleBuffer_afterFlush_doesntThrow() throws Exception {
-    // This is demonstrating that no Exceptions are thrown as a result of handling a buffer after a
-    // flush.
+  public void handlesBufferAfterExperimentalFlush() throws Exception {
+    // This is demonstrating that no Exceptions are thrown as a result of handling a buffer after an
+    // experimental flush.
     configureDefaultAudioSink(CHANNEL_COUNT_STEREO);
     defaultAudioSink.handleBuffer(
         createDefaultSilenceBuffer(), /* presentationTimeUs= */ 0, /* encodedAccessUnitCount= */ 1);
 
-    // After the flush we can successfully queue more input.
-    defaultAudioSink.flush();
+    // After the experimental flush we can successfully queue more input.
+    defaultAudioSink.experimentalFlushWithoutAudioTrackRelease();
     defaultAudioSink.handleBuffer(
         createDefaultSilenceBuffer(),
         /* presentationTimeUs= */ 5_000,
@@ -281,13 +281,13 @@ public final class DefaultAudioSinkTest {
   }
 
   @Test
-  public void getCurrentPosition_afterFlush_returnsUnset() throws Exception {
+  public void getCurrentPosition_returnsUnset_afterExperimentalFlush() throws Exception {
     configureDefaultAudioSink(CHANNEL_COUNT_STEREO);
     defaultAudioSink.handleBuffer(
         createDefaultSilenceBuffer(),
         /* presentationTimeUs= */ 5 * C.MICROS_PER_SECOND,
         /* encodedAccessUnitCount= */ 1);
-    defaultAudioSink.flush();
+    defaultAudioSink.experimentalFlushWithoutAudioTrackRelease();
     assertThat(defaultAudioSink.getCurrentPositionUs(/* sourceEnded= */ false))
         .isEqualTo(CURRENT_POSITION_NOT_SET);
   }