Add possibility to set the audio session id

Issue: #6975
PiperOrigin-RevId: 299328798

RELEASENOTES.md

@@ -19,6 +19,8 @@
     *   Add `Player.onPlayWhenReadyChanged` with reasons.
     *   Add `Player.onPlaybackStateChanged` and deprecate
         `Player.onPlayerStateChanged`.
+    *   Add `Player.setAudioSessionId` to set the session ID attached to the
+        `AudioTrack`.
     *   Deprecate and rename `getPlaybackError` to `getPlayerError` for
         consistency.
     *   Deprecate and rename `onLoadingChanged` to `onIsLoadingChanged` for

library/core/src/main/java/com/google/android/exoplayer2/Player.java

@@ -15,6 +15,7 @@
  */
 package com.google.android.exoplayer2;
 
+import android.content.Context;
 import android.os.Looper;
 import android.view.Surface;
 import android.view.SurfaceHolder;
@@ -123,6 +124,18 @@ public interface Player {
     /** Returns the attributes for audio playback. */
     AudioAttributes getAudioAttributes();
 
+    /**
+     * Sets the ID of the audio session to attach to the underlying {@link
+     * android.media.AudioTrack}.
+     *
+     * <p>The audio session ID can be generated using {@link C#generateAudioSessionIdV21(Context)}
+     * for API 21+.
+     *
+     * @param audioSessionId The audio session ID, or {@link C#AUDIO_SESSION_ID_UNSET} if it should
+     *     be generated by the framework.
+     */
+    void setAudioSessionId(int audioSessionId);
+
     /** Returns the audio session identifier, or {@link C#AUDIO_SESSION_ID_UNSET} if not set. */
     int getAudioSessionId();
 

library/core/src/main/java/com/google/android/exoplayer2/Renderer.java

@@ -131,6 +131,12 @@ public interface Renderer extends PlayerMessage.Target {
    * telling whether to enable or disable skipping silences in the audio stream.
    */
   int MSG_SET_SKIP_SILENCE_ENABLED = 101;
+  /**
+   * A type of a message that can be passed to an audio renderer via {@link
+   * ExoPlayer#createMessage(Target)}. The message payload should be an {@link Integer} instance
+   * representing the audio session ID that will be attached to the underlying audio track.
+   */
+  int MSG_SET_AUDIO_SESSION_ID = 102;
   /**
    * Applications or extensions may define custom {@code MSG_*} constants that can be passed to
    * renderers. These custom constants must be greater than or equal to this value.

library/core/src/main/java/com/google/android/exoplayer2/SimpleExoPlayer.java

@@ -672,6 +672,21 @@ public class SimpleExoPlayer extends BasePlayer
     return audioAttributes;
   }
 
+  @Override
+  public void setAudioSessionId(int audioSessionId) {
+    verifyApplicationThread();
+    this.audioSessionId = audioSessionId;
+    for (Renderer renderer : renderers) {
+      if (renderer.getTrackType() == C.TRACK_TYPE_AUDIO) {
+        player
+            .createMessage(renderer)
+            .setType(Renderer.MSG_SET_AUDIO_SESSION_ID)
+            .setPayload(audioSessionId)
+            .send();
+      }
+    }
+  }
+
   @Override
   public int getAudioSessionId() {
     return audioSessionId;

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

@@ -673,6 +673,9 @@ public class MediaCodecAudioRenderer extends MediaCodecRenderer implements Media
       case MSG_SET_SKIP_SILENCE_ENABLED:
         audioSink.setSkipSilenceEnabled((Boolean) message);
         break;
+      case MSG_SET_AUDIO_SESSION_ID:
+        audioSink.setAudioSessionId((Integer) message);
+        break;
       default:
         super.handleMessage(messageType, message);
         break;

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

@@ -564,6 +564,9 @@ public abstract class SimpleDecoderAudioRenderer extends BaseRenderer implements
       case MSG_SET_SKIP_SILENCE_ENABLED:
         audioSink.setSkipSilenceEnabled((Boolean) message);
         break;
+      case MSG_SET_AUDIO_SESSION_ID:
+        audioSink.setAudioSessionId((Integer) message);
+        break;
       default:
         super.handleMessage(messageType, message);
         break;