Flesh out ExoPlayer extensions.

1. AudioDecoderTrackRenderer now reports decoder initialization
   and AudioTrack underruns.
2. AudioDecoderTrackRenderer can now render more than one output
   buffer per call to doSomeWork, to be consistent with
   MediaCodecAudioTrackRenderer. This may also prevent audio
   underruns in the case that audio is fragmented into many small
   buffers.
3. AudioDecoderTrackRenderer now has an overridable method that
   receives the audio session id, to be consistent with
   MediaCodecAudioTrackRenderer.
4. Fix unsafe event notification in LibvpxVideoTrackRenderer.
5. Vpx and AudioDecoder extensions now increment the CodecCounter
   inputBufferCount field correctly.
6. Decoders now have names :).
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=122250009

extensions/flac/src/main/java/com/google/android/exoplayer/ext/flac/FlacDecoder.java

@@ -61,6 +61,11 @@ import java.util.List;
     maxOutputBufferSize = streamInfo.maxDecodedFrameSize();
   }
 
+  @Override
+  public String getName() {
+    return "libflac";
+  }
+
   @Override
   public DecoderInputBuffer createInputBuffer() {
     return new DecoderInputBuffer(DecoderInputBuffer.BUFFER_REPLACEMENT_MODE_NORMAL);

extensions/opus/src/main/java/com/google/android/exoplayer/ext/opus/OpusDecoder.java

@@ -132,6 +132,11 @@ import java.util.List;
     setInitialInputBufferSize(initialInputBufferSize);
   }
 
+  @Override
+  public String getName() {
+    return "libopus" + getLibopusVersion();
+  }
+
   @Override
   public DecoderInputBuffer createInputBuffer() {
     return new DecoderInputBuffer(DecoderInputBuffer.BUFFER_REPLACEMENT_MODE_DIRECT);

extensions/vp9/src/main/java/com/google/android/exoplayer/ext/vp9/LibvpxVideoTrackRenderer.java

@@ -151,13 +151,15 @@ public final class LibvpxVideoTrackRenderer extends TrackRenderer {
     try {
       if (decoder == null) {
         // If we don't have a decoder yet, we need to instantiate one.
-        long startElapsedRealtimeMs = SystemClock.elapsedRealtime();
+        long codecInitializingTimestamp = SystemClock.elapsedRealtime();
         decoder = new VpxDecoder(NUM_BUFFERS, NUM_BUFFERS, INITIAL_INPUT_BUFFER_SIZE);
         decoder.setOutputMode(outputMode);
-        notifyDecoderInitialized(startElapsedRealtimeMs, SystemClock.elapsedRealtime());
+        long codecInitializedTimestamp = SystemClock.elapsedRealtime();
+        notifyDecoderInitialized(decoder.getName(), codecInitializedTimestamp,
+            codecInitializedTimestamp - codecInitializingTimestamp);
         codecCounters.codecInitCount++;
       }
-      while (processOutputBuffer(positionUs)) {}
+      while (drainOutputBuffer(positionUs)) {}
       while (feedInputBuffer()) {}
     } catch (VpxDecoderException e) {
       throw ExoPlaybackException.createForRenderer(e, getIndex());
@@ -165,8 +167,7 @@ public final class LibvpxVideoTrackRenderer extends TrackRenderer {
     codecCounters.ensureUpdated();
   }
 
-  private boolean processOutputBuffer(long positionUs)
+  private boolean drainOutputBuffer(long positionUs) throws VpxDecoderException {
-      throws VpxDecoderException {
     if (outputStreamEnded) {
       return false;
     }
@@ -226,7 +227,7 @@ public final class LibvpxVideoTrackRenderer extends TrackRenderer {
 
   private void renderBuffer() {
     codecCounters.renderedOutputBufferCount++;
-    notifyIfVideoSizeChanged(outputBuffer);
+    notifyIfVideoSizeChanged(outputBuffer.width, outputBuffer.height);
     if (outputBuffer.mode == VpxDecoder.OUTPUT_MODE_RGB && surface != null) {
       renderRgbFrame(outputBuffer, scaleToFit);
       if (!drawnToSurface) {
@@ -280,9 +281,13 @@ public final class LibvpxVideoTrackRenderer extends TrackRenderer {
     }
     if (inputBuffer.isEndOfStream()) {
       inputStreamEnded = true;
+      decoder.queueInputBuffer(inputBuffer);
+      inputBuffer = null;
+      return false;
     }
     inputBuffer.flip();
     decoder.queueInputBuffer(inputBuffer);
+    codecCounters.inputBufferCount++;
     inputBuffer = null;
     return true;
   }
@@ -398,16 +403,16 @@ public final class LibvpxVideoTrackRenderer extends TrackRenderer {
     }
   }
 
-  private void notifyIfVideoSizeChanged(final VpxOutputBuffer outputBuffer) {
+  private void notifyIfVideoSizeChanged(final int width, final int height) {
-    if (previousWidth == -1 || previousHeight == -1
+    if (previousWidth == -1 || previousHeight == -1 || previousWidth != width
-        || previousWidth != outputBuffer.width || previousHeight != outputBuffer.height) {
+        || previousHeight != height) {
-      previousWidth = outputBuffer.width;
+      previousWidth = width;
-      previousHeight = outputBuffer.height;
+      previousHeight = height;
       if (eventHandler != null && eventListener != null) {
         eventHandler.post(new Runnable()  {
           @Override
           public void run() {
-            eventListener.onVideoSizeChanged(outputBuffer.width, outputBuffer.height, 0, 1);
+            eventListener.onVideoSizeChanged(width, height, 0, 1);
           }
         });
       }
@@ -441,14 +446,14 @@ public final class LibvpxVideoTrackRenderer extends TrackRenderer {
     }
   }
 
-  private void notifyDecoderInitialized(
+  private void notifyDecoderInitialized(final String decoderName,
-      final long startElapsedRealtimeMs, final long finishElapsedRealtimeMs) {
+      final long initializedTimestamp, final long initializationDuration) {
     if (eventHandler != null && eventListener != null) {
       eventHandler.post(new Runnable() {
         @Override
         public void run() {
-          eventListener.onDecoderInitialized("libvpx" + getLibvpxVersion(),
+          eventListener.onDecoderInitialized(decoderName, initializedTimestamp,
-              finishElapsedRealtimeMs, finishElapsedRealtimeMs - startElapsedRealtimeMs);
+              initializationDuration);
         }
       });
     }

extensions/vp9/src/main/java/com/google/android/exoplayer/ext/vp9/VpxDecoder.java

@@ -74,6 +74,11 @@ import java.nio.ByteBuffer;
     setInitialInputBufferSize(initialInputBufferSize);
   }
 
+  @Override
+  public String getName() {
+    return "libvpx" + getLibvpxVersion();
+  }
+
   /**
    * Sets the output mode for frames rendered by the decoder.
    *

library/src/main/java/com/google/android/exoplayer/extensions/AudioDecoderTrackRenderer.java

@@ -30,6 +30,7 @@ import com.google.android.exoplayer.audio.AudioTrack;
 import com.google.android.exoplayer.util.MimeTypes;
 
 import android.os.Handler;
+import android.os.SystemClock;
 
 /**
  * Decodes and renders audio using a {@link SimpleDecoder}.
@@ -63,6 +64,9 @@ public abstract class AudioDecoderTrackRenderer extends TrackRenderer implements
   private final AudioTrack audioTrack;
   private int audioSessionId;
 
+  private boolean audioTrackHasData;
+  private long lastFeedElapsedRealtimeMs;
+
   public AudioDecoderTrackRenderer() {
     this(null, null);
   }
@@ -101,16 +105,20 @@ public abstract class AudioDecoderTrackRenderer extends TrackRenderer implements
     // If we don't have a decoder yet, we need to instantiate one.
     if (decoder == null) {
       try {
+        long codecInitializingTimestamp = SystemClock.elapsedRealtime();
         decoder = createDecoder(inputFormat);
+        long codecInitializedTimestamp = SystemClock.elapsedRealtime();
+        notifyDecoderInitialized(decoder.getName(), codecInitializedTimestamp,
+            codecInitializedTimestamp - codecInitializingTimestamp);
+        codecCounters.codecInitCount++;
       } catch (AudioDecoderException e) {
         throw ExoPlaybackException.createForRenderer(e, getIndex());
       }
-      codecCounters.codecInitCount++;
     }
 
     // Rendering loop.
     try {
-      renderBuffer();
+      while (drainOutputBuffer()) {}
       while (feedInputBuffer()) {}
     } catch (AudioTrack.InitializationException e) {
       notifyAudioTrackInitializationError(e);
@@ -145,16 +153,16 @@ public abstract class AudioDecoderTrackRenderer extends TrackRenderer implements
         null, null, null);
   }
 
-  private void renderBuffer() throws AudioDecoderException, AudioTrack.InitializationException,
+  private boolean drainOutputBuffer() throws AudioDecoderException,
-      AudioTrack.WriteException {
+      AudioTrack.InitializationException, AudioTrack.WriteException {
     if (outputStreamEnded) {
-      return;
+      return false;
     }
 
     if (outputBuffer == null) {
       outputBuffer = decoder.dequeueOutputBuffer();
       if (outputBuffer == null) {
-        return;
+        return false;
       }
     }
 
@@ -163,7 +171,7 @@ public abstract class AudioDecoderTrackRenderer extends TrackRenderer implements
       audioTrack.handleEndOfStream();
       outputBuffer.release();
       outputBuffer = null;
-      return;
+      return false;
     }
 
     if (!audioTrack.isInitialized()) {
@@ -174,14 +182,26 @@ public abstract class AudioDecoderTrackRenderer extends TrackRenderer implements
         audioTrack.initialize(audioSessionId);
       } else {
         audioSessionId = audioTrack.initialize();
+        onAudioSessionId(audioSessionId);
       }
+      audioTrackHasData = false;
       if (getState() == TrackRenderer.STATE_STARTED) {
         audioTrack.play();
       }
+    } else {
+      // Check for AudioTrack underrun.
+      boolean audioTrackHadData = audioTrackHasData;
+      audioTrackHasData = audioTrack.hasPendingData();
+      if (audioTrackHadData && !audioTrackHasData && getState() == TrackRenderer.STATE_STARTED) {
+        long elapsedSinceLastFeedMs = SystemClock.elapsedRealtime() - lastFeedElapsedRealtimeMs;
+        long bufferSizeUs = audioTrack.getBufferSizeUs();
+        long bufferSizeMs = bufferSizeUs == C.UNSET_TIME_US ? -1 : bufferSizeUs / 1000;
+        notifyAudioTrackUnderrun(audioTrack.getBufferSize(), bufferSizeMs, elapsedSinceLastFeedMs);
+      }
     }
 
-    int handleBufferResult;
+    int handleBufferResult = audioTrack.handleBuffer(outputBuffer.data, outputBuffer.timestampUs);
-    handleBufferResult = audioTrack.handleBuffer(outputBuffer.data, outputBuffer.timestampUs);
+    lastFeedElapsedRealtimeMs = SystemClock.elapsedRealtime();
 
     // If we are out of sync, allow currentPositionUs to jump backwards.
     if ((handleBufferResult & AudioTrack.RESULT_POSITION_DISCONTINUITY) != 0) {
@@ -193,7 +213,10 @@ public abstract class AudioDecoderTrackRenderer extends TrackRenderer implements
       codecCounters.renderedOutputBufferCount++;
       outputBuffer.release();
       outputBuffer = null;
+      return true;
     }
+
+    return false;
   }
 
   private boolean feedInputBuffer() throws AudioDecoderException {
@@ -218,10 +241,13 @@ public abstract class AudioDecoderTrackRenderer extends TrackRenderer implements
     }
     if (inputBuffer.isEndOfStream()) {
       inputStreamEnded = true;
+      decoder.queueInputBuffer(inputBuffer);
+      inputBuffer = null;
+      return false;
     }
-
     inputBuffer.flip();
     decoder.queueInputBuffer(inputBuffer);
+    codecCounters.inputBufferCount++;
     inputBuffer = null;
     return true;
   }
@@ -269,6 +295,19 @@ public abstract class AudioDecoderTrackRenderer extends TrackRenderer implements
     }
   }
 
+  /**
+   * Invoked when the audio session id becomes known. Once the id is known it will not change
+   * (and hence this method will not be invoked again) unless the renderer is disabled and then
+   * subsequently re-enabled.
+   * <p>
+   * The default implementation is a no-op.
+   *
+   * @param audioSessionId The audio session id.
+   */
+  protected void onAudioSessionId(int audioSessionId) {
+    // Do nothing.
+  }
+
   @Override
   protected void onEnabled(Format[] formats, boolean joining) throws ExoPlaybackException {
     notifyAudioCodecCounters();
@@ -320,6 +359,19 @@ public abstract class AudioDecoderTrackRenderer extends TrackRenderer implements
     }
   }
 
+  private void notifyDecoderInitialized(final String decoderName,
+      final long initializedTimestamp, final long initializationDuration) {
+    if (eventHandler != null && eventListener != null) {
+      eventHandler.post(new Runnable() {
+        @Override
+        public void run() {
+          eventListener.onDecoderInitialized(decoderName, initializedTimestamp,
+              initializationDuration);
+        }
+      });
+    }
+  }
+
   private void notifyAudioTrackInitializationError(final AudioTrack.InitializationException e) {
     if (eventHandler != null && eventListener != null) {
       eventHandler.post(new Runnable() {
@@ -342,6 +394,18 @@ public abstract class AudioDecoderTrackRenderer extends TrackRenderer implements
     }
   }
 
+  private void notifyAudioTrackUnderrun(final int bufferSize, final long bufferSizeMs,
+      final long elapsedSinceLastFeedMs) {
+    if (eventHandler != null && eventListener != null) {
+      eventHandler.post(new Runnable()  {
+        @Override
+        public void run() {
+          eventListener.onAudioTrackUnderrun(bufferSize, bufferSizeMs, elapsedSinceLastFeedMs);
+        }
+      });
+    }
+  }
+
   private void notifyAudioCodecCounters() {
     if (eventHandler != null && eventListener != null) {
       eventHandler.post(new Runnable() {

library/src/main/java/com/google/android/exoplayer/extensions/Decoder.java

@@ -24,6 +24,13 @@ package com.google.android.exoplayer.extensions;
  */
 public interface Decoder<I, O, E extends Exception> {
 
+  /**
+   * Returns the name of the decoder.
+   *
+   * @return The name of the decoder.
+   */
+  String getName();
+
   /**
    * Dequeues the next input buffer to be filled and queued to the decoder.
    *

library/src/main/java/com/google/android/exoplayer/text/SimpleSubtitleParser.java

@@ -27,11 +27,19 @@ public abstract class SimpleSubtitleParser extends
     SimpleDecoder<SubtitleInputBuffer, SubtitleOutputBuffer, ParserException> implements
     SubtitleParser {
 
-  protected SimpleSubtitleParser() {
+  private final String name;
+
+  protected SimpleSubtitleParser(String name) {
     super(new SubtitleInputBuffer[2], new SubtitleOutputBuffer[2]);
+    this.name = name;
     setInitialInputBufferSize(1024);
   }
 
+  @Override
+  public final String getName() {
+    return name;
+  }
+
   @Override
   public void setPositionUs(long timeUs) {
     // Do nothing

library/src/main/java/com/google/android/exoplayer/text/eia608/Eia608Parser.java

@@ -205,6 +205,11 @@ public final class Eia608Parser implements SubtitleParser {
     captionRowCount = DEFAULT_CAPTIONS_ROW_COUNT;
   }
 
+  @Override
+  public String getName() {
+    return "Eia608Parser";
+  }
+
   @Override
   public void setPositionUs(long positionUs) {
     playbackPositionUs = positionUs;

library/src/main/java/com/google/android/exoplayer/text/subrip/SubripParser.java

@@ -43,6 +43,7 @@ public final class SubripParser extends SimpleSubtitleParser {
   private final StringBuilder textBuilder;
 
   public SubripParser() {
+    super("SubripParser");
     textBuilder = new StringBuilder();
   }
 

library/src/main/java/com/google/android/exoplayer/text/ttml/TtmlParser.java

@@ -87,6 +87,7 @@ public final class TtmlParser extends SimpleSubtitleParser {
   private final XmlPullParserFactory xmlParserFactory;
 
   public TtmlParser() {
+    super("TtmlParser");
     try {
       xmlParserFactory = XmlPullParserFactory.newInstance();
       xmlParserFactory.setNamespaceAware(true);

library/src/main/java/com/google/android/exoplayer/text/tx3g/Tx3gParser.java

@@ -26,6 +26,10 @@ import com.google.android.exoplayer.text.Subtitle;
  */
 public final class Tx3gParser extends SimpleSubtitleParser {
 
+  public Tx3gParser() {
+    super("Tx3gParser");
+  }
+
   @Override
   protected Subtitle decode(byte[] bytes, int length) {
     String cueText = new String(bytes, 0, length);

library/src/main/java/com/google/android/exoplayer/text/webvtt/Mp4WebvttParser.java

@@ -40,6 +40,7 @@ public final class Mp4WebvttParser extends SimpleSubtitleParser {
   private final WebvttCue.Builder builder;
 
   public Mp4WebvttParser() {
+    super("Mp4WebvttParser");
     sampleData = new ParsableByteArray();
     builder = new WebvttCue.Builder();
   }

library/src/main/java/com/google/android/exoplayer/text/webvtt/WebvttParser.java

@@ -46,6 +46,7 @@ public final class WebvttParser extends SimpleSubtitleParser {
   private final List<WebvttCssStyle> definedStyles;
 
   public WebvttParser() {
+    super("WebvttParser");
     cueParser = new WebvttCueParser();
     parsableWebvttData = new ParsableByteArray();
     webvttCueBuilder = new WebvttCue.Builder();