Add SVC layer count to MP4 metadata

This is necessary to implement SEF video flattening.

PiperOrigin-RevId: 337048264

library/extractor/src/main/java/com/google/android/exoplayer2/extractor/mp4/MdtaMetadataEntry.java

@@ -28,6 +28,12 @@ import java.util.Arrays;
  */
  */
 public final class MdtaMetadataEntry implements Metadata.Entry {
 public final class MdtaMetadataEntry implements Metadata.Entry {
 
 
+  /** Key for the capture frame rate (in frames per second). */
+  public static final String KEY_ANDROID_CAPTURE_FPS = "com.android.capture.fps";
+  /** Key for the temporal SVC layer count. */
+  public static final String KEY_ANDROID_TEMPORAL_LAYER_COUNT =
+      "com.android.video.temporal_layers_count";
+
   /** The metadata key name. */
   /** The metadata key name. */
   public final String key;
   public final String key;
   /** The payload. The interpretation of the value depends on {@link #typeIndicator}. */
   /** The payload. The interpretation of the value depends on {@link #typeIndicator}. */

library/extractor/src/main/java/com/google/android/exoplayer2/extractor/mp4/MetadataUtil.java

@@ -30,6 +30,8 @@ import com.google.android.exoplayer2.metadata.id3.InternalFrame;
 import com.google.android.exoplayer2.metadata.id3.TextInformationFrame;
 import com.google.android.exoplayer2.metadata.id3.TextInformationFrame;
 import com.google.android.exoplayer2.util.Log;
 import com.google.android.exoplayer2.util.Log;
 import com.google.android.exoplayer2.util.ParsableByteArray;
 import com.google.android.exoplayer2.util.ParsableByteArray;
+import java.util.ArrayList;
+import java.util.List;
 
 
 /** Utilities for handling metadata in MP4. */
 /** Utilities for handling metadata in MP4. */
 /* package */ final class MetadataUtil {
 /* package */ final class MetadataUtil {
@@ -282,8 +284,6 @@ import com.google.android.exoplayer2.util.ParsableByteArray;
   private static final int TYPE_TOP_BYTE_COPYRIGHT = 0xA9;
   private static final int TYPE_TOP_BYTE_COPYRIGHT = 0xA9;
   private static final int TYPE_TOP_BYTE_REPLACEMENT = 0xFD; // Truncated value of \uFFFD.
   private static final int TYPE_TOP_BYTE_REPLACEMENT = 0xFD; // Truncated value of \uFFFD.
 
 
-  private static final String MDTA_KEY_ANDROID_CAPTURE_FPS = "com.android.capture.fps";
-
   private MetadataUtil() {}
   private MetadataUtil() {}
 
 
   /** Updates a {@link Format.Builder} to include metadata from the provided sources. */
   /** Updates a {@link Format.Builder} to include metadata from the provided sources. */
@@ -305,15 +305,20 @@ import com.google.android.exoplayer2.util.ParsableByteArray;
       }
       }
     } else if (trackType == C.TRACK_TYPE_VIDEO && mdtaMetadata != null) {
     } else if (trackType == C.TRACK_TYPE_VIDEO && mdtaMetadata != null) {
       // Populate only metadata keys that are known to be specific to video.
       // Populate only metadata keys that are known to be specific to video.
+      List<MdtaMetadataEntry> mdtaMetadataEntries = new ArrayList<>();
       for (int i = 0; i < mdtaMetadata.length(); i++) {
       for (int i = 0; i < mdtaMetadata.length(); i++) {
         Metadata.Entry entry = mdtaMetadata.get(i);
         Metadata.Entry entry = mdtaMetadata.get(i);
         if (entry instanceof MdtaMetadataEntry) {
         if (entry instanceof MdtaMetadataEntry) {
           MdtaMetadataEntry mdtaMetadataEntry = (MdtaMetadataEntry) entry;
           MdtaMetadataEntry mdtaMetadataEntry = (MdtaMetadataEntry) entry;
-          if (MDTA_KEY_ANDROID_CAPTURE_FPS.equals(mdtaMetadataEntry.key)) {
-            formatBuilder.setMetadata(new Metadata(mdtaMetadataEntry));
+          if (MdtaMetadataEntry.KEY_ANDROID_CAPTURE_FPS.equals(mdtaMetadataEntry.key)
+              || MdtaMetadataEntry.KEY_ANDROID_TEMPORAL_LAYER_COUNT.equals(mdtaMetadataEntry.key)) {
+            mdtaMetadataEntries.add(mdtaMetadataEntry);
           }
           }
         }
         }
       }
       }
+      if (!mdtaMetadataEntries.isEmpty()) {
+        formatBuilder.setMetadata(new Metadata(mdtaMetadataEntries));
+      }
     }
     }
   }
   }