More steps towards unified extractors.

library/src/main/java/com/google/android/exoplayer/extractor/DefaultTrackOutput.java

@@ -24,9 +24,8 @@ import com.google.android.exoplayer.util.ParsableByteArray;
 import java.io.IOException;
 
 /**
- * Wraps a {@link RollingSampleBuffer}, adding higher level functionality such as enforcing that
- * the first sample returned from the queue is a keyframe, allowing splicing to another queue, and
- * so on.
+ * A {@link TrackOutput} that buffers extracted samples in a queue, and allows for consumption from
+ * that queue.
  */
 public final class DefaultTrackOutput implements TrackOutput {
 
@@ -51,27 +50,60 @@ public final class DefaultTrackOutput implements TrackOutput {
     largestParsedTimestampUs = Long.MIN_VALUE;
   }
 
-  public void release() {
-    rollingBuffer.release();
+  // Called by the consuming thread, but only when there is no loading thread.
+
+  /**
+   * Clears the queue, returning all allocations to the allocator.
+   */
+  public void clear() {
+    rollingBuffer.clear();
+    needKeyframe = true;
+    lastReadTimeUs = Long.MIN_VALUE;
+    spliceOutTimeUs = Long.MIN_VALUE;
+    largestParsedTimestampUs = Long.MIN_VALUE;
+  }
+
+  /**
+   * Returns the current absolute write index.
+   */
+  public int getWriteIndex() {
+    return rollingBuffer.getWriteIndex();
   }
 
   // Called by the consuming thread.
 
   /**
+   * Returns the current absolute read index.
+   */
+  public int getReadIndex() {
+    return rollingBuffer.getReadIndex();
+  }
+
+  /**
    * True if the output has received a format. False otherwise.
    */
   public boolean hasFormat() {
     return format != null;
   }
 
+  /**
+   * The format most recently received by the output, or null if a format has yet to be received.
+   */
   public MediaFormat getFormat() {
     return format;
   }
 
+  /**
+   * The largest timestamp of any sample received by the output, or {@link Long#MIN_VALUE} if a
+   * sample has yet to be received.
+   */
   public long getLargestParsedTimestampUs() {
     return largestParsedTimestampUs;
   }
 
+  /**
+   * True if at least one sample can be read from the queue. False otherwise.
+   */
   public boolean isEmpty() {
     return !advanceToEligibleSample();
   }

library/src/main/java/com/google/android/exoplayer/hls/HlsExtractorWrapper.java

@@ -125,13 +125,11 @@ public final class HlsExtractorWrapper implements ExtractorOutput {
   }
 
   /**
-   * Releases the extractor, recycling any pending or incomplete samples to the sample pool.
-   * <p>
-   * This method should not be called whilst {@link #read(ExtractorInput)} is also being invoked.
+   * Clears queues for all tracks, returning all allocations to the buffer pool.
    */
-  public void release() {
+  public void clear() {
     for (int i = 0; i < sampleQueues.size(); i++) {
-      sampleQueues.valueAt(i).release();
+      sampleQueues.valueAt(i).clear();
     }
   }
 
@@ -140,7 +138,7 @@ public final class HlsExtractorWrapper implements ExtractorOutput {
    *
    * @return The largest timestamp, or {@link Long#MIN_VALUE} if no samples have been parsed.
    */
-  public long getLargestSampleTimestamp() {
+  public long getLargestParsedTimestampUs() {
     long largestParsedTimestampUs = Long.MIN_VALUE;
     for (int i = 0; i < sampleQueues.size(); i++) {
       largestParsedTimestampUs = Math.max(largestParsedTimestampUs,

library/src/main/java/com/google/android/exoplayer/hls/HlsSampleSource.java

@@ -261,7 +261,7 @@ public class HlsSampleSource implements SampleSource, Loader.Callback {
     } else if (loadingFinished) {
       return TrackRenderer.END_OF_TRACK_US;
     } else {
-      long largestSampleTimestamp = extractors.getLast().getLargestSampleTimestamp();
+      long largestSampleTimestamp = extractors.getLast().getLargestParsedTimestampUs();
       return largestSampleTimestamp == Long.MIN_VALUE ? downstreamPositionUs
           : largestSampleTimestamp;
     }
@@ -333,7 +333,7 @@ public class HlsSampleSource implements SampleSource, Loader.Callback {
     HlsExtractorWrapper extractor = extractors.getFirst();
     while (extractors.size() > 1 && !haveSamplesForEnabledTracks(extractor)) {
       // We're finished reading from the extractor for all tracks, and so can discard it.
-      extractors.removeFirst().release();
+      extractors.removeFirst().clear();
       extractor = extractors.getFirst();
     }
     return extractor;
@@ -382,7 +382,7 @@ public class HlsSampleSource implements SampleSource, Loader.Callback {
 
   private void clearState() {
     for (int i = 0; i < extractors.size(); i++) {
-      extractors.get(i).release();
+      extractors.get(i).clear();
     }
     extractors.clear();
     clearCurrentLoadable();