Fully reset AudioProcessors on releasing AudioTrack

Issue: #2675

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=153445372

extensions/gvr/src/main/java/com/google/android/exoplayer2/ext/gvr/GvrAudioProcessor.java

@@ -152,14 +152,19 @@ public final class GvrAudioProcessor implements AudioProcessor {
 
   @Override
   public void flush() {
-    gvrAudioSurround.flush();
+    if (gvrAudioSurround != null) {
+      gvrAudioSurround.flush();
+    }
     inputEnded = false;
   }
 
   @Override
-  public synchronized void release() {
-    buffer = null;
+  public synchronized void reset() {
     maybeReleaseGvrAudioSurround();
+    inputEnded = false;
+    buffer = null;
+    sampleRateHz = Format.NO_VALUE;
+    channelCount = Format.NO_VALUE;
   }
 
   private void maybeReleaseGvrAudioSurround() {

library/core/src/main/java/com/google/android/exoplayer2/audio/AudioProcessor.java

@@ -116,8 +116,8 @@ public interface AudioProcessor {
   void flush();
 
   /**
-   * Releases any resources associated with this instance.
+   * Resets the processor to its initial state.
    */
-  void release();
+  void reset();
 
 }

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

@@ -1187,7 +1187,7 @@ public final class AudioTrack {
     reset();
     releaseKeepSessionIdAudioTrack();
     for (AudioProcessor audioProcessor : availableAudioProcessors) {
-      audioProcessor.release();
+      audioProcessor.reset();
     }
     audioSessionId = C.AUDIO_SESSION_ID_UNSET;
     playing = false;

library/core/src/main/java/com/google/android/exoplayer2/audio/ChannelMappingAudioProcessor.java

@@ -17,6 +17,7 @@ package com.google.android.exoplayer2.audio;
 
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.C.Encoding;
+import com.google.android.exoplayer2.Format;
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
 import java.util.Arrays;
@@ -43,6 +44,8 @@ import java.util.Arrays;
   public ChannelMappingAudioProcessor() {
     buffer = EMPTY_BUFFER;
     outputBuffer = EMPTY_BUFFER;
+    channelCount = Format.NO_VALUE;
+    sampleRateHz = Format.NO_VALUE;
   }
 
   /**
@@ -147,9 +150,13 @@ import java.util.Arrays;
   }
 
   @Override
-  public void release() {
+  public void reset() {
     flush();
     buffer = EMPTY_BUFFER;
+    channelCount = Format.NO_VALUE;
+    sampleRateHz = Format.NO_VALUE;
+    outputChannels = null;
+    active = false;
   }
 
 }

library/core/src/main/java/com/google/android/exoplayer2/audio/ResamplingAudioProcessor.java

@@ -168,9 +168,12 @@ import java.nio.ByteOrder;
   }
 
   @Override
-  public void release() {
+  public void reset() {
     flush();
     buffer = EMPTY_BUFFER;
+    sampleRateHz = Format.NO_VALUE;
+    channelCount = Format.NO_VALUE;
+    encoding = C.ENCODING_INVALID;
   }
 
 }

library/core/src/main/java/com/google/android/exoplayer2/audio/SonicAudioProcessor.java

@@ -58,9 +58,8 @@ import java.nio.ShortBuffer;
   private float speed;
   private float pitch;
 
-  private ShortBuffer shortBuffer;
-
   private ByteBuffer buffer;
+  private ShortBuffer shortBuffer;
   private ByteBuffer outputBuffer;
   private long inputBytes;
   private long outputBytes;
@@ -199,13 +198,16 @@ import java.nio.ShortBuffer;
   }
 
   @Override
-  public void release() {
+  public void reset() {
     sonic = null;
-    channelCount = Format.NO_VALUE;
-    sampleRateHz = Format.NO_VALUE;
     buffer = EMPTY_BUFFER;
     shortBuffer = buffer.asShortBuffer();
     outputBuffer = EMPTY_BUFFER;
+    channelCount = Format.NO_VALUE;
+    sampleRateHz = Format.NO_VALUE;
+    inputBytes = 0;
+    outputBytes = 0;
+    inputEnded = false;
   }
 
 }