Fix {Opus,Vpx}DecoderWrapper flush() buffer handling.

Currently, input/output buffers can 'leak' if they are dequeued then the decoder
is flush()ed. This happens if an input buffer is dequeued then a discontinuity
is read, or an output buffer is dequeued and is early. If this happens several
times, no more buffers are available.

This change makes flush() work like MediaCodec: it returns all dequeued
input/output buffers to the codec. Keeping the behavior in line with MediaCodec
might make it easier to factor out a common decoder interface in the future.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=109054178

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

@@ -263,7 +263,7 @@ public final class LibopusAudioTrackRenderer extends SampleSourceTrackRenderer
     }
     }
 
 
     if (inputBuffer == null) {
     if (inputBuffer == null) {
-      inputBuffer = decoder.getInputBuffer();
+      inputBuffer = decoder.dequeueInputBuffer();
       if (inputBuffer == null) {
       if (inputBuffer == null) {
         return false;
         return false;
       }
       }

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

@@ -36,8 +36,10 @@ import java.util.LinkedList;
   private final Object lock;
   private final Object lock;
   private final OpusHeader opusHeader;
   private final OpusHeader opusHeader;
 
 
+  private final LinkedList<InputBuffer> dequeuedInputBuffers;
   private final LinkedList<InputBuffer> queuedInputBuffers;
   private final LinkedList<InputBuffer> queuedInputBuffers;
   private final LinkedList<OutputBuffer> queuedOutputBuffers;
   private final LinkedList<OutputBuffer> queuedOutputBuffers;
+  private final LinkedList<OutputBuffer> dequeuedOutputBuffers;
   private final InputBuffer[] availableInputBuffers;
   private final InputBuffer[] availableInputBuffers;
   private final OutputBuffer[] availableOutputBuffers;
   private final OutputBuffer[] availableOutputBuffers;
   private int availableInputBufferCount;
   private int availableInputBufferCount;
@@ -66,10 +68,14 @@ import java.util.LinkedList;
       long seekPreRollNs) throws OpusDecoderException {
       long seekPreRollNs) throws OpusDecoderException {
     lock = new Object();
     lock = new Object();
     opusHeader = parseOpusHeader(headerBytes);
     opusHeader = parseOpusHeader(headerBytes);
-    skipSamples = (codecDelayNs == -1) ? opusHeader.skipSamples : nsToSamples(codecDelayNs);
-    seekPreRoll = (seekPreRoll == -1) ? DEFAULT_SEEK_PRE_ROLL : nsToSamples(seekPreRollNs);
+    skipSamples = (codecDelayNs == -1) ? opusHeader.skipSamples
+        : nsToSamples(opusHeader, codecDelayNs);
+    seekPreRoll = (seekPreRoll == -1) ? DEFAULT_SEEK_PRE_ROLL
+        : nsToSamples(opusHeader, seekPreRollNs);
+    dequeuedInputBuffers = new LinkedList<>();
     queuedInputBuffers = new LinkedList<>();
     queuedInputBuffers = new LinkedList<>();
     queuedOutputBuffers = new LinkedList<>();
     queuedOutputBuffers = new LinkedList<>();
+    dequeuedOutputBuffers = new LinkedList<>();
     availableInputBuffers = new InputBuffer[NUM_BUFFERS];
     availableInputBuffers = new InputBuffer[NUM_BUFFERS];
     availableOutputBuffers = new OutputBuffer[NUM_BUFFERS];
     availableOutputBuffers = new OutputBuffer[NUM_BUFFERS];
     availableInputBufferCount = NUM_BUFFERS;
     availableInputBufferCount = NUM_BUFFERS;
@@ -80,7 +86,7 @@ import java.util.LinkedList;
     }
     }
   }
   }
 
 
-  public InputBuffer getInputBuffer() throws OpusDecoderException {
+  public InputBuffer dequeueInputBuffer() throws OpusDecoderException {
     synchronized (lock) {
     synchronized (lock) {
       maybeThrowDecoderError();
       maybeThrowDecoderError();
       if (availableInputBufferCount == 0) {
       if (availableInputBufferCount == 0) {
@@ -88,6 +94,7 @@ import java.util.LinkedList;
       }
       }
       InputBuffer inputBuffer = availableInputBuffers[--availableInputBufferCount];
       InputBuffer inputBuffer = availableInputBuffers[--availableInputBufferCount];
       inputBuffer.reset();
       inputBuffer.reset();
+      dequeuedInputBuffers.addLast(inputBuffer);
       return inputBuffer;
       return inputBuffer;
     }
     }
   }
   }
@@ -95,6 +102,7 @@ import java.util.LinkedList;
   public void queueInputBuffer(InputBuffer inputBuffer) throws OpusDecoderException {
   public void queueInputBuffer(InputBuffer inputBuffer) throws OpusDecoderException {
     synchronized (lock) {
     synchronized (lock) {
       maybeThrowDecoderError();
       maybeThrowDecoderError();
+      dequeuedInputBuffers.remove(inputBuffer);
       queuedInputBuffers.addLast(inputBuffer);
       queuedInputBuffers.addLast(inputBuffer);
       maybeNotifyDecodeLoop();
       maybeNotifyDecodeLoop();
     }
     }
@@ -106,7 +114,9 @@ import java.util.LinkedList;
       if (queuedOutputBuffers.isEmpty()) {
       if (queuedOutputBuffers.isEmpty()) {
         return null;
         return null;
       }
       }
-      return queuedOutputBuffers.removeFirst();
+      OutputBuffer outputBuffer = queuedOutputBuffers.removeFirst();
+      dequeuedOutputBuffers.add(outputBuffer);
+      return outputBuffer;
     }
     }
   }
   }
 
 
@@ -114,6 +124,7 @@ import java.util.LinkedList;
     synchronized (lock) {
     synchronized (lock) {
       maybeThrowDecoderError();
       maybeThrowDecoderError();
       outputBuffer.reset();
       outputBuffer.reset();
+      dequeuedOutputBuffers.remove(outputBuffer);
       availableOutputBuffers[availableOutputBufferCount++] = outputBuffer;
       availableOutputBuffers[availableOutputBufferCount++] = outputBuffer;
       maybeNotifyDecodeLoop();
       maybeNotifyDecodeLoop();
     }
     }
@@ -122,12 +133,18 @@ import java.util.LinkedList;
   public void flush() {
   public void flush() {
     synchronized (lock) {
     synchronized (lock) {
       flushDecodedOutputBuffer = true;
       flushDecodedOutputBuffer = true;
+      while (!dequeuedInputBuffers.isEmpty()) {
+        availableInputBuffers[availableInputBufferCount++] = dequeuedInputBuffers.removeFirst();
+      }
       while (!queuedInputBuffers.isEmpty()) {
       while (!queuedInputBuffers.isEmpty()) {
         availableInputBuffers[availableInputBufferCount++] = queuedInputBuffers.removeFirst();
         availableInputBuffers[availableInputBufferCount++] = queuedInputBuffers.removeFirst();
       }
       }
       while (!queuedOutputBuffers.isEmpty()) {
       while (!queuedOutputBuffers.isEmpty()) {
         availableOutputBuffers[availableOutputBufferCount++] = queuedOutputBuffers.removeFirst();
         availableOutputBuffers[availableOutputBufferCount++] = queuedOutputBuffers.removeFirst();
       }
       }
+      while (!dequeuedOutputBuffers.isEmpty()) {
+        availableOutputBuffers[availableOutputBufferCount++] = dequeuedOutputBuffers.removeFirst();
+      }
     }
     }
   }
   }
 
 
@@ -254,7 +271,7 @@ import java.util.LinkedList;
     return true;
     return true;
   }
   }
 
 
-  private OpusHeader parseOpusHeader(byte[] headerBytes) throws OpusDecoderException {
+  private static OpusHeader parseOpusHeader(byte[] headerBytes) throws OpusDecoderException {
     final int maxChannelCount = 8;
     final int maxChannelCount = 8;
     final int maxChannelCountWithDefaultLayout = 2;
     final int maxChannelCountWithDefaultLayout = 2;
     final int headerSize = 19;
     final int headerSize = 19;
@@ -300,13 +317,13 @@ import java.util.LinkedList;
     }
     }
   }
   }
 
 
-  private int readLittleEndian16(byte[] input, int offset) {
+  private static int readLittleEndian16(byte[] input, int offset) {
     int value = input[offset];
     int value = input[offset];
     value |= input[offset + 1] << 8;
     value |= input[offset + 1] << 8;
     return value;
     return value;
   }
   }
 
 
-  private int nsToSamples(long ns) {
+  private static int nsToSamples(OpusHeader opusHeader, long ns) {
     return (int) (ns * opusHeader.sampleRate / 1000000000);
     return (int) (ns * opusHeader.sampleRate / 1000000000);
   }
   }
 
 

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

@@ -298,7 +298,7 @@ public final class LibvpxVideoTrackRenderer extends SampleSourceTrackRenderer {
     }
     }
 
 
     if (inputBuffer == null) {
     if (inputBuffer == null) {
-      inputBuffer = decoder.getInputBuffer();
+      inputBuffer = decoder.dequeueInputBuffer();
       if (inputBuffer == null) {
       if (inputBuffer == null) {
         return false;
         return false;
       }
       }

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

@@ -32,8 +32,10 @@ import java.util.LinkedList;
 
 
   private final Object lock;
   private final Object lock;
 
 
+  private final LinkedList<InputBuffer> dequeuedInputBuffers;
   private final LinkedList<InputBuffer> queuedInputBuffers;
   private final LinkedList<InputBuffer> queuedInputBuffers;
   private final LinkedList<OutputBuffer> queuedOutputBuffers;
   private final LinkedList<OutputBuffer> queuedOutputBuffers;
+  private final LinkedList<OutputBuffer> dequeuedOutputBuffers;
   private final InputBuffer[] availableInputBuffers;
   private final InputBuffer[] availableInputBuffers;
   private final OutputBuffer[] availableOutputBuffers;
   private final OutputBuffer[] availableOutputBuffers;
   private int availableInputBufferCount;
   private int availableInputBufferCount;
@@ -52,8 +54,10 @@ import java.util.LinkedList;
   public VpxDecoderWrapper(int outputMode) {
   public VpxDecoderWrapper(int outputMode) {
     lock = new Object();
     lock = new Object();
     this.outputMode = outputMode;
     this.outputMode = outputMode;
+    dequeuedInputBuffers = new LinkedList<>();
     queuedInputBuffers = new LinkedList<>();
     queuedInputBuffers = new LinkedList<>();
     queuedOutputBuffers = new LinkedList<>();
     queuedOutputBuffers = new LinkedList<>();
+    dequeuedOutputBuffers = new LinkedList<>();
     availableInputBuffers = new InputBuffer[NUM_BUFFERS];
     availableInputBuffers = new InputBuffer[NUM_BUFFERS];
     availableOutputBuffers = new OutputBuffer[NUM_BUFFERS];
     availableOutputBuffers = new OutputBuffer[NUM_BUFFERS];
     availableInputBufferCount = NUM_BUFFERS;
     availableInputBufferCount = NUM_BUFFERS;
@@ -68,7 +72,7 @@ import java.util.LinkedList;
     this.outputMode = outputMode;
     this.outputMode = outputMode;
   }
   }
 
 
-  public InputBuffer getInputBuffer() throws VpxDecoderException {
+  public InputBuffer dequeueInputBuffer() throws VpxDecoderException {
     synchronized (lock) {
     synchronized (lock) {
       maybeThrowDecoderError();
       maybeThrowDecoderError();
       if (availableInputBufferCount == 0) {
       if (availableInputBufferCount == 0) {
@@ -77,6 +81,7 @@ import java.util.LinkedList;
       InputBuffer inputBuffer = availableInputBuffers[--availableInputBufferCount];
       InputBuffer inputBuffer = availableInputBuffers[--availableInputBufferCount];
       inputBuffer.flags = 0;
       inputBuffer.flags = 0;
       inputBuffer.sampleHolder.clearData();
       inputBuffer.sampleHolder.clearData();
+      dequeuedInputBuffers.addLast(inputBuffer);
       return inputBuffer;
       return inputBuffer;
     }
     }
   }
   }
@@ -84,6 +89,7 @@ import java.util.LinkedList;
   public void queueInputBuffer(InputBuffer inputBuffer) throws VpxDecoderException {
   public void queueInputBuffer(InputBuffer inputBuffer) throws VpxDecoderException {
     synchronized (lock) {
     synchronized (lock) {
       maybeThrowDecoderError();
       maybeThrowDecoderError();
+      dequeuedInputBuffers.remove(inputBuffer);
       queuedInputBuffers.addLast(inputBuffer);
       queuedInputBuffers.addLast(inputBuffer);
       maybeNotifyDecodeLoop();
       maybeNotifyDecodeLoop();
     }
     }
@@ -95,13 +101,16 @@ import java.util.LinkedList;
       if (queuedOutputBuffers.isEmpty()) {
       if (queuedOutputBuffers.isEmpty()) {
         return null;
         return null;
       }
       }
-      return queuedOutputBuffers.removeFirst();
+      OutputBuffer outputBuffer = queuedOutputBuffers.removeFirst();
+      dequeuedOutputBuffers.add(outputBuffer);
+      return outputBuffer;
     }
     }
   }
   }
 
 
   public void releaseOutputBuffer(OutputBuffer outputBuffer) throws VpxDecoderException {
   public void releaseOutputBuffer(OutputBuffer outputBuffer) throws VpxDecoderException {
     synchronized (lock) {
     synchronized (lock) {
       maybeThrowDecoderError();
       maybeThrowDecoderError();
+      dequeuedOutputBuffers.remove(outputBuffer);
       availableOutputBuffers[availableOutputBufferCount++] = outputBuffer;
       availableOutputBuffers[availableOutputBufferCount++] = outputBuffer;
       maybeNotifyDecodeLoop();
       maybeNotifyDecodeLoop();
     }
     }
@@ -110,12 +119,18 @@ import java.util.LinkedList;
   public void flush() {
   public void flush() {
     synchronized (lock) {
     synchronized (lock) {
       flushDecodedOutputBuffer = true;
       flushDecodedOutputBuffer = true;
+      while (!dequeuedInputBuffers.isEmpty()) {
+        availableInputBuffers[availableInputBufferCount++] = dequeuedInputBuffers.removeFirst();
+      }
       while (!queuedInputBuffers.isEmpty()) {
       while (!queuedInputBuffers.isEmpty()) {
         availableInputBuffers[availableInputBufferCount++] = queuedInputBuffers.removeFirst();
         availableInputBuffers[availableInputBufferCount++] = queuedInputBuffers.removeFirst();
       }
       }
       while (!queuedOutputBuffers.isEmpty()) {
       while (!queuedOutputBuffers.isEmpty()) {
         availableOutputBuffers[availableOutputBufferCount++] = queuedOutputBuffers.removeFirst();
         availableOutputBuffers[availableOutputBufferCount++] = queuedOutputBuffers.removeFirst();
       }
       }
+      while (!dequeuedOutputBuffers.isEmpty()) {
+        availableOutputBuffers[availableOutputBufferCount++] = dequeuedOutputBuffers.removeFirst();
+      }
     }
     }
   }
   }