Merge pull request #1265 from DolbyLaboratories:dlb/ac4-level4/dev_new2

PiperOrigin-RevId: 696157037
(cherry picked from commit 74611bb)

Author: copybara-github

RELEASENOTES.md

@@ -2,6 +2,9 @@
 
 ### Unreleased changes
 
+*   Extractors:
+    *   Add AC-4 Level-4 ISO base media file format support
+        ([#1265](https://github.com/androidx/media/pull/1265)).
 *   Text:
     *   Fix garbled CEA-608 subtitles in content with more than one SEI message
         per sample.

libraries/common/src/main/java/androidx/media3/common/util/Util.java

@@ -2250,6 +2250,24 @@ public static int getAudioTrackChannelConfig(int channelCount) {
         }
       case 12:
         return AudioFormat.CHANNEL_OUT_7POINT1POINT4;
+      case 24:
+        if (Util.SDK_INT >= 32) {
+          return AudioFormat.CHANNEL_OUT_7POINT1POINT4
+              | AudioFormat.CHANNEL_OUT_FRONT_LEFT_OF_CENTER
+              | AudioFormat.CHANNEL_OUT_FRONT_RIGHT_OF_CENTER
+              | AudioFormat.CHANNEL_OUT_BACK_CENTER
+              | AudioFormat.CHANNEL_OUT_TOP_CENTER
+              | AudioFormat.CHANNEL_OUT_TOP_FRONT_CENTER
+              | AudioFormat.CHANNEL_OUT_TOP_BACK_CENTER
+              | AudioFormat.CHANNEL_OUT_TOP_SIDE_LEFT
+              | AudioFormat.CHANNEL_OUT_TOP_SIDE_RIGHT
+              | AudioFormat.CHANNEL_OUT_BOTTOM_FRONT_LEFT
+              | AudioFormat.CHANNEL_OUT_BOTTOM_FRONT_RIGHT
+              | AudioFormat.CHANNEL_OUT_BOTTOM_FRONT_CENTER
+              | AudioFormat.CHANNEL_OUT_LOW_FREQUENCY_2;
+        } else {
+          return AudioFormat.CHANNEL_INVALID;
+        }
       default:
         return AudioFormat.CHANNEL_INVALID;
     }

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/trackselection/DefaultTrackSelector.java

@@ -4224,18 +4224,22 @@ public boolean isEnabled() {
 
     public boolean canBeSpatialized(AudioAttributes audioAttributes, Format format) {
       int linearChannelCount;
-      if (Objects.equals(format.sampleMimeType, MimeTypes.AUDIO_E_AC3_JOC)
-          && format.channelCount == 16) {
+      if (Objects.equals(format.sampleMimeType, MimeTypes.AUDIO_E_AC3_JOC)) {
         // For E-AC3 JOC, the format is object based. When the channel count is 16, this maps to 12
         // linear channels and the rest are used for objects. See
         // https://github.com/google/ExoPlayer/pull/10322#discussion_r895265881
-        linearChannelCount = 12;
-      } else if (Objects.equals(format.sampleMimeType, MimeTypes.AUDIO_IAMF)
-          && format.channelCount == Format.NO_VALUE) {
+        linearChannelCount = format.channelCount == 16 ? 12 : format.channelCount;
+      } else if (Objects.equals(format.sampleMimeType, MimeTypes.AUDIO_IAMF)) {
         // IAMF with no channel count specified, assume 5.1 channels. This depends on
         // IamfDecoder.SPATIALIZED_OUTPUT_LAYOUT being set to AudioFormat.CHANNEL_OUT_5POINT1. Any
         // changes to that constant will require updates to this logic.
-        linearChannelCount = 6;
+        linearChannelCount = format.channelCount == Format.NO_VALUE ? 6 : format.channelCount;
+      } else if (Objects.equals(format.sampleMimeType, MimeTypes.AUDIO_AC4)) {
+        // For AC-4 level 3 or level 4, the format may be object based. When the channel count is
+        // 18 (level 3 17.1 OBI) or 21 (level 4 20.1 OBI), it is mapped to 24 linear channels (some
+        // channels are used for metadata transfer).
+        linearChannelCount =
+            (format.channelCount == 18 || format.channelCount == 21) ? 24 : format.channelCount;
       } else {
         linearChannelCount = format.channelCount;
       }