Change MediaMetadata update priority to favour MediaItem values.

The static and dynamic metadata now build up in a list, such that when
the MediaMetadata is built, they are applied in an event order. This
means that newer/fresher values will overwrite older ones. The MediaItem
values are then applied at the end, as they take priority over any other.

#minor-release

PiperOrigin-RevId: 405383177

RELEASENOTES.md

@@ -25,6 +25,9 @@
     *   Fix `mediaMetadata` being reset when media is repeated
         ([#9458](https://github.com/google/ExoPlayer/issues/9458)).
     *   Remove final dependency on `jcenter()`.
+    *   Adjust `ExoPlayer` `MediaMetadata` update priority, such that values
+        input through the `MediaItem.MediaMetadata` are used above media
+        derived values.
 *   Video:
     *   Fix bug in `MediaCodecVideoRenderer` that resulted in re-using a
         released `Surface` when playing without an app-provided `Surface`

library/common/src/main/java/com/google/android/exoplayer2/MediaMetadata.java

@@ -383,6 +383,108 @@ public final class MediaMetadata implements Bundleable {
       return this;
     }
 
+    /** Populates all the fields from {@code mediaMetadata}, provided they are non-null. */
+    public Builder populate(@Nullable MediaMetadata mediaMetadata) {
+      if (mediaMetadata == null) {
+        return this;
+      }
+      if (mediaMetadata.title != null) {
+        setTitle(mediaMetadata.title);
+      }
+      if (mediaMetadata.artist != null) {
+        setArtist(mediaMetadata.artist);
+      }
+      if (mediaMetadata.albumTitle != null) {
+        setAlbumTitle(mediaMetadata.albumTitle);
+      }
+      if (mediaMetadata.albumArtist != null) {
+        setAlbumArtist(mediaMetadata.albumArtist);
+      }
+      if (mediaMetadata.displayTitle != null) {
+        setDisplayTitle(mediaMetadata.displayTitle);
+      }
+      if (mediaMetadata.subtitle != null) {
+        setSubtitle(mediaMetadata.subtitle);
+      }
+      if (mediaMetadata.description != null) {
+        setDescription(mediaMetadata.description);
+      }
+      if (mediaMetadata.mediaUri != null) {
+        setMediaUri(mediaMetadata.mediaUri);
+      }
+      if (mediaMetadata.userRating != null) {
+        setUserRating(mediaMetadata.userRating);
+      }
+      if (mediaMetadata.overallRating != null) {
+        setOverallRating(mediaMetadata.overallRating);
+      }
+      if (mediaMetadata.artworkData != null) {
+        setArtworkData(mediaMetadata.artworkData, mediaMetadata.artworkDataType);
+      }
+      if (mediaMetadata.artworkUri != null) {
+        setArtworkUri(mediaMetadata.artworkUri);
+      }
+      if (mediaMetadata.trackNumber != null) {
+        setTrackNumber(mediaMetadata.trackNumber);
+      }
+      if (mediaMetadata.totalTrackCount != null) {
+        setTotalTrackCount(mediaMetadata.totalTrackCount);
+      }
+      if (mediaMetadata.folderType != null) {
+        setFolderType(mediaMetadata.folderType);
+      }
+      if (mediaMetadata.isPlayable != null) {
+        setIsPlayable(mediaMetadata.isPlayable);
+      }
+      if (mediaMetadata.year != null) {
+        setRecordingYear(mediaMetadata.year);
+      }
+      if (mediaMetadata.recordingYear != null) {
+        setRecordingYear(mediaMetadata.recordingYear);
+      }
+      if (mediaMetadata.recordingMonth != null) {
+        setRecordingMonth(mediaMetadata.recordingMonth);
+      }
+      if (mediaMetadata.recordingDay != null) {
+        setRecordingDay(mediaMetadata.recordingDay);
+      }
+      if (mediaMetadata.releaseYear != null) {
+        setReleaseYear(mediaMetadata.releaseYear);
+      }
+      if (mediaMetadata.releaseMonth != null) {
+        setReleaseMonth(mediaMetadata.releaseMonth);
+      }
+      if (mediaMetadata.releaseDay != null) {
+        setReleaseDay(mediaMetadata.releaseDay);
+      }
+      if (mediaMetadata.writer != null) {
+        setWriter(mediaMetadata.writer);
+      }
+      if (mediaMetadata.composer != null) {
+        setComposer(mediaMetadata.composer);
+      }
+      if (mediaMetadata.conductor != null) {
+        setConductor(mediaMetadata.conductor);
+      }
+      if (mediaMetadata.discNumber != null) {
+        setDiscNumber(mediaMetadata.discNumber);
+      }
+      if (mediaMetadata.totalDiscCount != null) {
+        setTotalDiscCount(mediaMetadata.totalDiscCount);
+      }
+      if (mediaMetadata.genre != null) {
+        setGenre(mediaMetadata.genre);
+      }
+      if (mediaMetadata.compilation != null) {
+        setCompilation(mediaMetadata.compilation);
+      }
+      if (mediaMetadata.extras != null) {
+        setExtras(mediaMetadata.extras);
+      }
+
+      return this;
+    }
+
     /** Returns a new {@link MediaMetadata} instance with the current builder values. */
     public MediaMetadata build() {
       return new MediaMetadata(/* builder= */ this);

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

@@ -2065,7 +2065,9 @@ public interface Player {
    *
    * <p>This {@link MediaMetadata} is a combination of the {@link MediaItem#mediaMetadata} and the
    * static and dynamic metadata from the {@link TrackSelection#getFormat(int) track selections'
-   * formats} and {@link Listener#onMetadata(Metadata)}.
+   * formats} and {@link Listener#onMetadata(Metadata)}. If a field is populated in the {@link
+   * MediaItem#mediaMetadata}, it will be prioritised above the same field coming from static or
+   * dynamic metadata.
    */
   MediaMetadata getMediaMetadata();
 

library/common/src/test/java/com/google/android/exoplayer2/MediaMetadataTest.java

@@ -27,6 +27,9 @@ import org.junit.runner.RunWith;
 @RunWith(AndroidJUnit4.class)
 public class MediaMetadataTest {
 
+  private static final String EXTRAS_KEY = "exampleKey";
+  private static final String EXTRAS_VALUE = "exampleValue";
+
   @Test
   public void builder_minimal_correctDefaults() {
     MediaMetadata mediaMetadata = new MediaMetadata.Builder().build();
@@ -91,41 +94,62 @@ public class MediaMetadataTest {
   }
 
   @Test
-  public void roundTripViaBundle_yieldsEqualInstance() {
+  public void populate_populatesEveryField() {
-    Bundle extras = new Bundle();
+    MediaMetadata mediaMetadata = getFullyPopulatedMediaMetadata();
-    extras.putString("exampleKey", "exampleValue");
+    MediaMetadata populated = new MediaMetadata.Builder().populate(mediaMetadata).build();
 
-    MediaMetadata mediaMetadata =
+    // If this assertion fails, it's likely that a field is not being updated in
-        new MediaMetadata.Builder()
+    // MediaMetadata.Builder#populate(MediaMetadata).
-            .setTitle("title")
+    assertThat(populated).isEqualTo(mediaMetadata);
-            .setAlbumArtist("the artist")
+    assertThat(populated.extras.getString(EXTRAS_KEY)).isEqualTo(EXTRAS_VALUE);
-            .setMediaUri(Uri.parse("https://www.google.com"))
+  }
-            .setUserRating(new HeartRating(false))
+
-            .setOverallRating(new PercentageRating(87.4f))
+  @Test
-            .setArtworkData(
+  public void roundTripViaBundle_yieldsEqualInstance() {
-                new byte[] {-88, 12, 3, 2, 124, -54, -33, 69}, MediaMetadata.PICTURE_TYPE_MEDIA)
+    MediaMetadata mediaMetadata = getFullyPopulatedMediaMetadata();
-            .setTrackNumber(4)
-            .setTotalTrackCount(12)
-            .setFolderType(MediaMetadata.FOLDER_TYPE_PLAYLISTS)
-            .setIsPlayable(true)
-            .setRecordingYear(2000)
-            .setRecordingMonth(11)
-            .setRecordingDay(23)
-            .setReleaseYear(2001)
-            .setReleaseMonth(1)
-            .setReleaseDay(2)
-            .setComposer("Composer")
-            .setConductor("Conductor")
-            .setWriter("Writer")
-            .setDiscNumber(1)
-            .setTotalDiscCount(3)
-            .setGenre("Pop")
-            .setCompilation("Amazing songs.")
-            .setExtras(extras) // Extras is not implemented in MediaMetadata.equals(Object o).
-            .build();
 
     MediaMetadata fromBundle = MediaMetadata.CREATOR.fromBundle(mediaMetadata.toBundle());
     assertThat(fromBundle).isEqualTo(mediaMetadata);
-    assertThat(fromBundle.extras.getString("exampleKey")).isEqualTo("exampleValue");
+    // Extras is not implemented in MediaMetadata.equals(Object o).
+    assertThat(fromBundle.extras.getString(EXTRAS_KEY)).isEqualTo(EXTRAS_VALUE);
+  }
+
+  private static MediaMetadata getFullyPopulatedMediaMetadata() {
+    Bundle extras = new Bundle();
+    extras.putString(EXTRAS_KEY, EXTRAS_VALUE);
+
+    return new MediaMetadata.Builder()
+        .setTitle("title")
+        .setArtist("artist")
+        .setAlbumTitle("album title")
+        .setAlbumArtist("album artist")
+        .setDisplayTitle("display title")
+        .setSubtitle("subtitle")
+        .setDescription("description")
+        .setMediaUri(Uri.parse("https://www.google.com"))
+        .setUserRating(new HeartRating(false))
+        .setOverallRating(new PercentageRating(87.4f))
+        .setArtworkData(
+            new byte[] {-88, 12, 3, 2, 124, -54, -33, 69}, MediaMetadata.PICTURE_TYPE_MEDIA)
+        .setArtworkUri(Uri.parse("https://www.google.com"))
+        .setTrackNumber(4)
+        .setTotalTrackCount(12)
+        .setFolderType(MediaMetadata.FOLDER_TYPE_PLAYLISTS)
+        .setIsPlayable(true)
+        .setRecordingYear(2000)
+        .setRecordingMonth(11)
+        .setRecordingDay(23)
+        .setReleaseYear(2001)
+        .setReleaseMonth(1)
+        .setReleaseDay(2)
+        .setComposer("Composer")
+        .setConductor("Conductor")
+        .setWriter("Writer")
+        .setDiscNumber(1)
+        .setTotalDiscCount(3)
+        .setGenre("Pop")
+        .setCompilation("Amazing songs.")
+        .setExtras(extras)
+        .build();
   }
 }

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

@@ -39,6 +39,7 @@ import com.google.android.exoplayer2.source.MediaSource;
 import com.google.android.exoplayer2.source.MediaSource.MediaPeriodId;
 import com.google.android.exoplayer2.source.MediaSourceFactory;
 import com.google.android.exoplayer2.source.ShuffleOrder;
+import com.google.android.exoplayer2.source.TrackGroup;
 import com.google.android.exoplayer2.source.TrackGroupArray;
 import com.google.android.exoplayer2.text.Cue;
 import com.google.android.exoplayer2.trackselection.ExoTrackSelection;
@@ -111,6 +112,10 @@ import java.util.concurrent.CopyOnWriteArraySet;
   private MediaMetadata mediaMetadata;
   private MediaMetadata playlistMetadata;
 
+  // MediaMetadata built from static (TrackGroup Format) and dynamic (onMetadata(Metadata)) metadata
+  // sources.
+  private MediaMetadata staticAndDynamicMediaMetadata;
+
   // Playback information when there is no pending seek/set source operation.
   private PlaybackInfo playbackInfo;
 
@@ -229,6 +234,7 @@ import java.util.concurrent.CopyOnWriteArraySet;
             .build();
     mediaMetadata = MediaMetadata.EMPTY;
     playlistMetadata = MediaMetadata.EMPTY;
+    staticAndDynamicMediaMetadata = MediaMetadata.EMPTY;
     maskingWindowIndex = C.INDEX_UNSET;
     playbackInfoUpdateHandler = clock.createHandler(applicationLooper, /* callback= */ null);
     playbackInfoUpdateListener =
@@ -986,8 +992,11 @@ import java.util.concurrent.CopyOnWriteArraySet;
   }
 
   public void onMetadata(Metadata metadata) {
-    MediaMetadata newMediaMetadata =
+    staticAndDynamicMediaMetadata =
-        mediaMetadata.buildUpon().populateFromMetadata(metadata).build();
+        staticAndDynamicMediaMetadata.buildUpon().populateFromMetadata(metadata).build();
+
+    MediaMetadata newMediaMetadata = buildUpdatedMediaMetadata();
+
     if (newMediaMetadata.equals(mediaMetadata)) {
       return;
     }
@@ -1235,12 +1244,17 @@ import java.util.concurrent.CopyOnWriteArraySet;
                 .windowIndex;
         mediaItem = newPlaybackInfo.timeline.getWindow(windowIndex, window).mediaItem;
       }
-      newMediaMetadata = mediaItem != null ? mediaItem.mediaMetadata : MediaMetadata.EMPTY;
+      staticAndDynamicMediaMetadata = MediaMetadata.EMPTY;
     }
     if (mediaItemTransitioned
         || !previousPlaybackInfo.staticMetadata.equals(newPlaybackInfo.staticMetadata)) {
-      newMediaMetadata =
+      staticAndDynamicMediaMetadata =
-          newMediaMetadata.buildUpon().populateFromMetadata(newPlaybackInfo.staticMetadata).build();
+          staticAndDynamicMediaMetadata
+              .buildUpon()
+              .populateFromMetadata(newPlaybackInfo.staticMetadata)
+              .build();
+
+      newMediaMetadata = buildUpdatedMediaMetadata();
     }
     boolean metadataChanged = !newMediaMetadata.equals(mediaMetadata);
     mediaMetadata = newMediaMetadata;
@@ -1794,6 +1808,24 @@ import java.util.concurrent.CopyOnWriteArraySet;
     return positionUs;
   }
 
+  /**
+   * Builds a {@link MediaMetadata} from the main sources.
+   *
+   * <p>{@link MediaItem} {@link MediaMetadata} is prioritized, with any gaps/missing fields
+   * populated by metadata from static ({@link TrackGroup} {@link Format}) and dynamic ({@link
+   * #onMetadata(Metadata)}) sources.
+   */
+  private MediaMetadata buildUpdatedMediaMetadata() {
+    @Nullable MediaItem mediaItem = getCurrentMediaItem();
+
+    if (mediaItem == null) {
+      return staticAndDynamicMediaMetadata;
+    }
+
+    // MediaItem metadata is prioritized over metadata within the media.
+    return staticAndDynamicMediaMetadata.buildUpon().populate(mediaItem.mediaMetadata).build();
+  }
+
   private static boolean isPlaying(PlaybackInfo playbackInfo) {
     return playbackInfo.playbackState == Player.STATE_READY
         && playbackInfo.playWhenReady

library/core/src/test/java/com/google/android/exoplayer2/ExoPlayerTest.java

@@ -11181,6 +11181,46 @@ public final class ExoPlayerTest {
     assertThat(videoRenderer.get().positionResetCount).isEqualTo(1);
   }
 
+  @Test
+  public void setMediaItem_withMediaMetadata_updatesMediaMetadata() {
+    MediaMetadata mediaMetadata = new MediaMetadata.Builder().setTitle("the title").build();
+
+    ExoPlayer player = new TestExoPlayerBuilder(context).build();
+    player.setMediaItem(
+        new MediaItem.Builder()
+            .setMediaId("id")
+            .setUri(Uri.EMPTY)
+            .setMediaMetadata(mediaMetadata)
+            .build());
+
+    assertThat(player.getMediaMetadata()).isEqualTo(mediaMetadata);
+  }
+
+  @Test
+  public void playingMedia_withNoMetadata_doesNotUpdateMediaMetadata() throws Exception {
+    MediaMetadata mediaMetadata = new MediaMetadata.Builder().setTitle("the title").build();
+
+    ExoPlayer player = new TestExoPlayerBuilder(context).build();
+    MediaItem mediaItem =
+        new MediaItem.Builder()
+            .setMediaId("id")
+            .setUri(Uri.parse("asset://android_asset/media/mp4/sample.mp4"))
+            .setMediaMetadata(mediaMetadata)
+            .build();
+    player.setMediaItem(mediaItem);
+
+    assertThat(player.getMediaMetadata()).isEqualTo(mediaMetadata);
+
+    player.prepare();
+    TestPlayerRunHelper.playUntilPosition(
+        player, /* windowIndex= */ 0, /* positionMs= */ 5 * C.MILLIS_PER_SECOND);
+    player.stop();
+
+    shadowOf(Looper.getMainLooper()).idle();
+
+    assertThat(player.getMediaMetadata()).isEqualTo(mediaMetadata);
+  }
+
   // Internal methods.
 
   private static ActionSchedule.Builder addSurfaceSwitch(ActionSchedule.Builder builder) {