Add vorbis comment support for track/disc numbering fields, and genre

Only `TRACKNUMBER` and `GENRE` are listed here:
https://xiph.org/vorbis/doc/v-comment.html

The rest are derived from the example in Issue: androidx/media#1958.

It's possible that other formats exist in the wild:
https://hydrogenaud.io/index.php/topic,69292.msg613808.html#msg613808

Issue: androidx/media#1958
PiperOrigin-RevId: 704308788

RELEASENOTES.md

@@ -49,6 +49,9 @@
         active at `timeUs` (started before but not yet ended) was incorrectly
         discarded ([#1939](https://github.com/androidx/media/issues/1939)).
 *   Metadata:
+    *   Extract disc/track numbering and genre from Vorbis comments into
+        `MediaMetadata`
+        ([#1958](https://github.com/androidx/media/issues/1958)).
 *   Image:
 *   DRM:
 *   Effect:

libraries/extractor/src/main/java/androidx/media3/extractor/metadata/flac/VorbisComment.java

@@ -24,6 +24,7 @@ import androidx.media3.common.MediaMetadata;
 import androidx.media3.common.Metadata;
 import androidx.media3.common.util.UnstableApi;
 import com.google.common.base.Ascii;
+import com.google.common.primitives.Ints;
 
 /**
  * @deprecated Use {@link androidx.media3.extractor.metadata.vorbis.VorbisComment} instead.
@@ -58,6 +59,9 @@ public class VorbisComment implements Metadata.Entry {
 
   @Override
   public void populateMediaMetadata(MediaMetadata.Builder builder) {
+    // Vorbis comments can have duplicate keys, but all these fields are singular on MediaMetadata,
+    // so we naively overwrite whatever any previously set value (which results in 'keep last'
+    // semantics).
     switch (key) {
       case "TITLE":
         builder.setTitle(value);
@@ -71,6 +75,33 @@ public class VorbisComment implements Metadata.Entry {
       case "ALBUMARTIST":
         builder.setAlbumArtist(value);
         break;
+      case "TRACKNUMBER":
+        @Nullable Integer trackNumber = Ints.tryParse(value);
+        if (trackNumber != null) {
+          builder.setTrackNumber(trackNumber);
+        }
+        break;
+      case "TOTALTRACKS":
+        @Nullable Integer totalTracks = Ints.tryParse(value);
+        if (totalTracks != null) {
+          builder.setTotalTrackCount(totalTracks);
+        }
+        break;
+      case "DISCNUMBER":
+        @Nullable Integer discNumber = Ints.tryParse(value);
+        if (discNumber != null) {
+          builder.setDiscNumber(discNumber);
+        }
+        break;
+      case "TOTALDISCS":
+        @Nullable Integer totalDiscs = Ints.tryParse(value);
+        if (totalDiscs != null) {
+          builder.setTotalDiscCount(totalDiscs);
+        }
+        break;
+      case "GENRE":
+        builder.setGenre(value);
+        break;
       case "DESCRIPTION":
         builder.setDescription(value);
         break;

libraries/extractor/src/test/java/androidx/media3/extractor/metadata/vorbis/VorbisCommentTest.java

@@ -50,6 +50,11 @@ public final class VorbisCommentTest {
     String artist = "artist";
     String albumTitle = "album title";
     String albumArtist = "album Artist";
+    int trackNumber = 3;
+    int totalTracks = 12;
+    int discNumber = 1;
+    int totalDiscs = 3;
+    String genre = "Metal";
     String description = "a description about the audio.";
     List<Metadata.Entry> entries =
         ImmutableList.of(
@@ -57,6 +62,11 @@ public final class VorbisCommentTest {
             new VorbisComment("ArTisT", artist),
             new VorbisComment("ALBUM", albumTitle),
             new VorbisComment("albumartist", albumArtist),
+            new VorbisComment("TRACKNUMBER", String.valueOf(trackNumber)),
+            new VorbisComment("TOTALTRACKS", String.valueOf(totalTracks)),
+            new VorbisComment("DISCNUMBER", String.valueOf(discNumber)),
+            new VorbisComment("TOTALDISCS", String.valueOf(totalDiscs)),
+            new VorbisComment("GENRE", genre),
             new VorbisComment("DESCRIPTION", description));
     MediaMetadata.Builder builder = MediaMetadata.EMPTY.buildUpon();
 
@@ -69,6 +79,11 @@ public final class VorbisCommentTest {
     assertThat(mediaMetadata.artist.toString()).isEqualTo(artist);
     assertThat(mediaMetadata.albumTitle.toString()).isEqualTo(albumTitle);
     assertThat(mediaMetadata.albumArtist.toString()).isEqualTo(albumArtist);
+    assertThat(mediaMetadata.trackNumber).isEqualTo(trackNumber);
+    assertThat(mediaMetadata.totalTrackCount).isEqualTo(totalTracks);
+    assertThat(mediaMetadata.discNumber).isEqualTo(discNumber);
+    assertThat(mediaMetadata.totalDiscCount).isEqualTo(totalDiscs);
+    assertThat(mediaMetadata.genre.toString()).isEqualTo(genre);
     assertThat(mediaMetadata.description.toString()).isEqualTo(description);
   }
 }