Allow specifying the AudioTrack's stream type.

Issue: #755

library/src/main/java/com/google/android/exoplayer/MediaCodecAudioTrackRenderer.java

@@ -22,6 +22,7 @@ import com.google.android.exoplayer.drm.DrmSessionManager;
 import com.google.android.exoplayer.util.MimeTypes;
 
 import android.annotation.TargetApi;
+import android.media.AudioManager;
 import android.media.MediaCodec;
 import android.media.audiofx.Virtualizer;
 import android.os.Handler;
@@ -89,7 +90,7 @@ public class MediaCodecAudioTrackRenderer extends MediaCodecTrackRenderer implem
    *     content is not required.
    * @param playClearSamplesWithoutKeys Encrypted media may contain clear (un-encrypted) regions.
    *     For example a media file may start with a short clear region so as to allow playback to
-   *     begin in parallel with key acquisision. This parameter specifies whether the renderer is
+   *     begin in parallel with key acquisition. This parameter specifies whether the renderer is
    *     permitted to play clear regions of encrypted media files before {@code drmSessionManager}
    *     has obtained the keys necessary to decrypt encrypted regions of the media.
    */
@@ -115,7 +116,7 @@ public class MediaCodecAudioTrackRenderer extends MediaCodecTrackRenderer implem
    *     content is not required.
    * @param playClearSamplesWithoutKeys Encrypted media may contain clear (un-encrypted) regions.
    *     For example a media file may start with a short clear region so as to allow playback to
-   *     begin in parallel with key acquisision. This parameter specifies whether the renderer is
+   *     begin in parallel with key acquisition. This parameter specifies whether the renderer is
    *     permitted to play clear regions of encrypted media files before {@code drmSessionManager}
    *     has obtained the keys necessary to decrypt encrypted regions of the media.
    * @param eventHandler A handler to use when delivering events to {@code eventListener}. May be
@@ -134,7 +135,7 @@ public class MediaCodecAudioTrackRenderer extends MediaCodecTrackRenderer implem
    *     content is not required.
    * @param playClearSamplesWithoutKeys Encrypted media may contain clear (un-encrypted) regions.
    *     For example a media file may start with a short clear region so as to allow playback to
-   *     begin in parallel with key acquisision. This parameter specifies whether the renderer is
+   *     begin in parallel with key acquisition. This parameter specifies whether the renderer is
    *     permitted to play clear regions of encrypted media files before {@code drmSessionManager}
    *     has obtained the keys necessary to decrypt encrypted regions of the media.
    * @param eventHandler A handler to use when delivering events to {@code eventListener}. May be
@@ -146,10 +147,33 @@ public class MediaCodecAudioTrackRenderer extends MediaCodecTrackRenderer implem
   public MediaCodecAudioTrackRenderer(SampleSource source, DrmSessionManager drmSessionManager,
       boolean playClearSamplesWithoutKeys, Handler eventHandler, EventListener eventListener,
       AudioCapabilities audioCapabilities) {
+    this(source, drmSessionManager, playClearSamplesWithoutKeys, eventHandler, eventListener,
+        audioCapabilities, AudioManager.STREAM_MUSIC);
+  }
+
+  /**
+   * @param source The upstream source from which the renderer obtains samples.
+   * @param drmSessionManager For use with encrypted content. May be null if support for encrypted
+   *     content is not required.
+   * @param playClearSamplesWithoutKeys Encrypted media may contain clear (un-encrypted) regions.
+   *     For example a media file may start with a short clear region so as to allow playback to
+   *     begin in parallel with key acquisition. This parameter specifies whether the renderer is
+   *     permitted to play clear regions of encrypted media files before {@code drmSessionManager}
+   *     has obtained the keys necessary to decrypt encrypted regions of the media.
+   * @param eventHandler A handler to use when delivering events to {@code eventListener}. May be
+   *     null if delivery of events is not required.
+   * @param eventListener A listener of events. May be null if delivery of events is not required.
+   * @param audioCapabilities The audio capabilities for playback on this device. May be null if the
+   *     default capabilities (no encoded audio passthrough support) should be assumed.
+   * @param streamType The type of audio stream for the {@link AudioTrack}.
+   */
+  public MediaCodecAudioTrackRenderer(SampleSource source, DrmSessionManager drmSessionManager,
+      boolean playClearSamplesWithoutKeys, Handler eventHandler, EventListener eventListener,
+      AudioCapabilities audioCapabilities, int streamType) {
     super(source, drmSessionManager, playClearSamplesWithoutKeys, eventHandler, eventListener);
     this.eventListener = eventListener;
     this.audioSessionId = AudioTrack.SESSION_ID_NOT_SET;
-    this.audioTrack = new AudioTrack(audioCapabilities);
+    this.audioTrack = new AudioTrack(audioCapabilities, streamType);
   }
 
   @Override

library/src/main/java/com/google/android/exoplayer/audio/AudioTrack.java

@@ -165,6 +165,7 @@ public final class AudioTrack {
   public static boolean failOnSpuriousAudioTimestamp = false;
 
   private final AudioCapabilities audioCapabilities;
+  private final int streamType;
   private final ConditionVariable releasingConditionVariable;
   private final long[] playheadOffsets;
   private final AudioTrackUtil audioTrackUtil;
@@ -208,16 +209,18 @@ public final class AudioTrack {
    * Creates an audio track with default audio capabilities (no encoded audio passthrough support).
    */
   public AudioTrack() {
-    this(null);
+    this(null, AudioManager.STREAM_MUSIC);
   }
 
   /**
-   * Creates an audio track using the specified audio capabilities.
+   * Creates an audio track using the specified audio capabilities and stream type.
    *
    * @param audioCapabilities The current audio playback capabilities.
+   * @param streamType The type of audio stream for the underlying {@link android.media.AudioTrack}.
    */
-  public AudioTrack(AudioCapabilities audioCapabilities) {
+  public AudioTrack(AudioCapabilities audioCapabilities, int streamType) {
     this.audioCapabilities = audioCapabilities;
+    this.streamType = streamType;
     releasingConditionVariable = new ConditionVariable(true);
     if (Util.SDK_INT >= 18) {
       try {
@@ -326,19 +329,19 @@ public final class AudioTrack {
     releasingConditionVariable.block();
 
     if (sessionId == SESSION_ID_NOT_SET) {
-      audioTrack = new android.media.AudioTrack(AudioManager.STREAM_MUSIC, sampleRate,
-          channelConfig, encoding, bufferSize, android.media.AudioTrack.MODE_STREAM);
+      audioTrack = new android.media.AudioTrack(streamType, sampleRate, channelConfig, encoding,
+          bufferSize, android.media.AudioTrack.MODE_STREAM);
     } else {
       // Re-attach to the same audio session.
-      audioTrack = new android.media.AudioTrack(AudioManager.STREAM_MUSIC, sampleRate,
-          channelConfig, encoding, bufferSize, android.media.AudioTrack.MODE_STREAM, sessionId);
+      audioTrack = new android.media.AudioTrack(streamType, sampleRate, channelConfig, encoding,
+          bufferSize, android.media.AudioTrack.MODE_STREAM, sessionId);
     }
     checkAudioTrackInitialized();
 
     sessionId = audioTrack.getAudioSessionId();
     if (enablePreV21AudioSessionWorkaround) {
       if (Util.SDK_INT < 21) {
-        // The workaround creates an audio track with a one byte buffer on the same session, and
+        // The workaround creates an audio track with a two byte buffer on the same session, and
         // does not release it until this object is released, which keeps the session active.
         if (keepSessionIdAudioTrack != null
             && sessionId != keepSessionIdAudioTrack.getAudioSessionId()) {
@@ -349,9 +352,8 @@ public final class AudioTrack {
           int channelConfig = AudioFormat.CHANNEL_OUT_MONO;
           int encoding = AudioFormat.ENCODING_PCM_16BIT;
           int bufferSize = 2; // Use a two byte buffer, as it is not actually used for playback.
-          keepSessionIdAudioTrack = new android.media.AudioTrack(AudioManager.STREAM_MUSIC,
-              sampleRate, channelConfig, encoding, bufferSize, android.media.AudioTrack.MODE_STATIC,
-              sessionId);
+          keepSessionIdAudioTrack = new android.media.AudioTrack(streamType, sampleRate,
+              channelConfig, encoding, bufferSize, android.media.AudioTrack.MODE_STATIC, sessionId);
         }
       }
     }