From 4455554e9eb6bf4d1527b24e7d4ecd72afbbef03 Mon Sep 17 00:00:00 2001
From: krocard <krocard@google.com>
Date: Thu, 16 Sep 2021 14:54:19 +0100
Subject: [PATCH] Use Android 12's AudioManager.getPlaybackOffloadSupport

Previously gapless offload support was hardcoded to Pixel
only.

PiperOrigin-RevId: 397070378
---
 .../java/com/google/android/exoplayer2/C.java | 20 ++++++++
 .../exoplayer2/audio/DefaultAudioSink.java    | 46 +++++++++++--------
 2 files changed, 47 insertions(+), 19 deletions(-)

diff --git a/library/common/src/main/java/com/google/android/exoplayer2/C.java b/library/common/src/main/java/com/google/android/exoplayer2/C.java
index 6a2755fe6c..ac7c5d8e04 100644
--- a/library/common/src/main/java/com/google/android/exoplayer2/C.java
+++ b/library/common/src/main/java/com/google/android/exoplayer2/C.java
@@ -459,6 +459,26 @@ public final class C {
   public static final int AUDIOFOCUS_GAIN_TRANSIENT_EXCLUSIVE =
       AudioManager.AUDIOFOCUS_GAIN_TRANSIENT_EXCLUSIVE;
 
+  /**
+   * Playback offload mode. One of {@link #PLAYBACK_OFFLOAD_NOT_SUPPORTED},{@link
+   * PLAYBACK_OFFLOAD_SUPPORTED} or {@link PLAYBACK_OFFLOAD_GAPLESS_SUPPORTED}.
+   */
+  @IntDef({
+    PLAYBACK_OFFLOAD_NOT_SUPPORTED,
+    PLAYBACK_OFFLOAD_SUPPORTED,
+    PLAYBACK_OFFLOAD_GAPLESS_SUPPORTED
+  })
+  @Retention(RetentionPolicy.SOURCE)
+  public @interface AudioManagerOffloadMode {}
+  /** See AudioManager#PLAYBACK_OFFLOAD_NOT_SUPPORTED */
+  public static final int PLAYBACK_OFFLOAD_NOT_SUPPORTED =
+      AudioManager.PLAYBACK_OFFLOAD_NOT_SUPPORTED;
+  /** See AudioManager#PLAYBACK_OFFLOAD_SUPPORTED */
+  public static final int PLAYBACK_OFFLOAD_SUPPORTED = AudioManager.PLAYBACK_OFFLOAD_SUPPORTED;
+  /** See AudioManager#PLAYBACK_OFFLOAD_GAPLESS_SUPPORTED */
+  public static final int PLAYBACK_OFFLOAD_GAPLESS_SUPPORTED =
+      AudioManager.PLAYBACK_OFFLOAD_GAPLESS_SUPPORTED;
+
   /**
    * Flags which can apply to a buffer containing a media sample. Possible flag values are {@link
    * #BUFFER_FLAG_KEY_FRAME}, {@link #BUFFER_FLAG_END_OF_STREAM}, {@link #BUFFER_FLAG_LAST_SAMPLE},
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/audio/DefaultAudioSink.java b/library/core/src/main/java/com/google/android/exoplayer2/audio/DefaultAudioSink.java
index 376776575b..3592aef8bb 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/audio/DefaultAudioSink.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/audio/DefaultAudioSink.java
@@ -1619,33 +1619,41 @@ public final class DefaultAudioSink implements AudioSink {
       return false;
     }
     AudioFormat audioFormat = getAudioFormat(format.sampleRate, channelConfig, encoding);
-    if (!AudioManager.isOffloadedPlaybackSupported(
-        audioFormat, audioAttributes.getAudioAttributesV21())) {
-      return false;
+
+    switch (getOffloadedPlaybackSupport(audioFormat, audioAttributes.getAudioAttributesV21())) {
+      case C.PLAYBACK_OFFLOAD_NOT_SUPPORTED:
+        return false;
+      case C.PLAYBACK_OFFLOAD_SUPPORTED:
+        boolean isGapless = format.encoderDelay != 0 || format.encoderPadding != 0;
+        boolean gaplessSupportRequired = offloadMode == OFFLOAD_MODE_ENABLED_GAPLESS_REQUIRED;
+        return !isGapless || !gaplessSupportRequired;
+      case C.PLAYBACK_OFFLOAD_GAPLESS_SUPPORTED:
+        return true;
+      default:
+        throw new IllegalStateException();
     }
-    boolean isGapless = format.encoderDelay != 0 || format.encoderPadding != 0;
-    boolean offloadRequiresGaplessSupport = offloadMode == OFFLOAD_MODE_ENABLED_GAPLESS_REQUIRED;
-    if (isGapless && offloadRequiresGaplessSupport && !isOffloadedGaplessPlaybackSupported()) {
-      return false;
+  }
+
+  @C.AudioManagerOffloadMode
+  private int getOffloadedPlaybackSupport(
+      AudioFormat audioFormat, android.media.AudioAttributes audioAttributes) {
+    if (Util.SDK_INT >= 31) {
+      return AudioManager.getPlaybackOffloadSupport(audioFormat, audioAttributes);
     }
-    return true;
+    if (!AudioManager.isOffloadedPlaybackSupported(audioFormat, audioAttributes)) {
+      return C.PLAYBACK_OFFLOAD_NOT_SUPPORTED;
+    }
+    // Manual testing has shown that Pixels on Android 11 support gapless offload.
+    if (Util.SDK_INT == 30 && Util.MODEL.startsWith("Pixel")) {
+      return C.PLAYBACK_OFFLOAD_GAPLESS_SUPPORTED;
+    }
+    return C.PLAYBACK_OFFLOAD_SUPPORTED;
   }
 
   private static boolean isOffloadedPlayback(AudioTrack audioTrack) {
     return Util.SDK_INT >= 29 && audioTrack.isOffloadedPlayback();
   }
 
-  /**
-   * Returns whether the device supports gapless in offload playback.
-   *
-   * <p>Gapless offload is not supported by all devices and there is no API to query its support. As
-   * a result this detection is currently based on manual testing.
-   */
-  // TODO(internal b/158191844): Add an SDK API to query offload gapless support.
-  private static boolean isOffloadedGaplessPlaybackSupported() {
-    return Util.SDK_INT >= 30 && Util.MODEL.startsWith("Pixel");
-  }
-
   private static int getMaximumEncodedRateBytesPerSecond(@C.Encoding int encoding) {
     switch (encoding) {
       case C.ENCODING_MP3: