Rollback of https://github.com/google/ExoPlayer/commit/01f484cbe965f7858f9621c97fec94d30eef188a

*** Original commit ***

Modify EventMessageDecoder to return null if decoding fails (currently throws exceptions)

This matches the documentation on MetadataDecoder.decode:
"@return The decoded metadata object, or null if the metadata could not be decoded."

***

PiperOrigin-RevId: 272405287

library/core/src/main/java/com/google/android/exoplayer2/metadata/emsg/EventMessageDecoder.java

@@ -15,7 +15,6 @@
  */
 package com.google.android.exoplayer2.metadata.emsg;
 
-import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.metadata.Metadata;
 import com.google.android.exoplayer2.metadata.MetadataDecoder;
 import com.google.android.exoplayer2.metadata.MetadataInputBuffer;
@@ -29,31 +28,20 @@ public final class EventMessageDecoder implements MetadataDecoder {
 
   @SuppressWarnings("ByteBufferBackingArray")
   @Override
-  @Nullable
   public Metadata decode(MetadataInputBuffer inputBuffer) {
     ByteBuffer buffer = Assertions.checkNotNull(inputBuffer.data);
     byte[] data = buffer.array();
     int size = buffer.limit();
-    EventMessage decodedEventMessage = decode(new ParsableByteArray(data, size));
-    if (decodedEventMessage == null) {
-      return null;
-    } else {
-      return new Metadata(decodedEventMessage);
-    }
+    return new Metadata(decode(new ParsableByteArray(data, size)));
   }
 
-  @Nullable
   public EventMessage decode(ParsableByteArray emsgData) {
-    try {
-      String schemeIdUri = Assertions.checkNotNull(emsgData.readNullTerminatedString());
-      String value = Assertions.checkNotNull(emsgData.readNullTerminatedString());
-      long durationMs = emsgData.readUnsignedInt();
-      long id = emsgData.readUnsignedInt();
-      byte[] messageData =
-          Arrays.copyOfRange(emsgData.data, emsgData.getPosition(), emsgData.limit());
-      return new EventMessage(schemeIdUri, value, durationMs, id, messageData);
-    } catch (RuntimeException e) {
-      return null;
-    }
+    String schemeIdUri = Assertions.checkNotNull(emsgData.readNullTerminatedString());
+    String value = Assertions.checkNotNull(emsgData.readNullTerminatedString());
+    long durationMs = emsgData.readUnsignedInt();
+    long id = emsgData.readUnsignedInt();
+    byte[] messageData =
+        Arrays.copyOfRange(emsgData.data, emsgData.getPosition(), emsgData.limit());
+    return new EventMessage(schemeIdUri, value, durationMs, id, messageData);
   }
 }

library/core/src/test/java/com/google/android/exoplayer2/metadata/MetadataRendererTest.java

@@ -78,7 +78,7 @@ public class MetadataRendererTest {
             /* id= */ 0,
             "Test data".getBytes(UTF_8));
 
-    List<Metadata> metadata = runRenderer(EMSG_FORMAT, eventMessageEncoder.encode(emsg));
+    List<Metadata> metadata = runRenderer(eventMessageEncoder.encode(emsg));
 
     assertThat(metadata).hasSize(1);
     assertThat(metadata.get(0).length()).isEqualTo(1);
@@ -86,13 +86,6 @@ public class MetadataRendererTest {
   }
 
   @Test
-  public void decodeMetadata_skipsMalformed() throws Exception {
-    List<Metadata> metadata = runRenderer(EMSG_FORMAT, "not valid emsg bytes".getBytes(UTF_8));
-
-    assertThat(metadata).isEmpty();
-  }
-
-  @Test
   public void decodeMetadata_handlesId3WrappedInEmsg() throws Exception {
     EventMessage emsg =
         new EventMessage(
@@ -102,7 +95,7 @@ public class MetadataRendererTest {
             /* id= */ 0,
             encodeTxxxId3Frame("Test description", "Test value"));
 
-    List<Metadata> metadata = runRenderer(EMSG_FORMAT, eventMessageEncoder.encode(emsg));
+    List<Metadata> metadata = runRenderer(eventMessageEncoder.encode(emsg));
 
     assertThat(metadata).hasSize(1);
     assertThat(metadata.get(0).length()).isEqualTo(1);
@@ -122,7 +115,7 @@ public class MetadataRendererTest {
             /* id= */ 0,
             SCTE35_TIME_SIGNAL_BYTES);
 
-    List<Metadata> metadata = runRenderer(EMSG_FORMAT, eventMessageEncoder.encode(emsg));
+    List<Metadata> metadata = runRenderer(eventMessageEncoder.encode(emsg));
 
     assertThat(metadata).hasSize(1);
     assertThat(metadata.get(0).length()).isEqualTo(1);
@@ -139,18 +132,17 @@ public class MetadataRendererTest {
             /* id= */ 0,
             "Not a real ID3 tag".getBytes(ISO_8859_1));
 
-    List<Metadata> metadata = runRenderer(EMSG_FORMAT, eventMessageEncoder.encode(emsg));
+    List<Metadata> metadata = runRenderer(eventMessageEncoder.encode(emsg));
 
     assertThat(metadata).isEmpty();
   }
 
-  private static List<Metadata> runRenderer(Format format, byte[] input)
-      throws ExoPlaybackException {
+  private static List<Metadata> runRenderer(byte[] input) throws ExoPlaybackException {
     List<Metadata> metadata = new ArrayList<>();
     MetadataRenderer renderer = new MetadataRenderer(metadata::add, /* outputLooper= */ null);
     renderer.replaceStream(
-        new Format[] {format},
-        new FakeSampleStream(format, /* eventDispatcher= */ null, input),
+        new Format[] {EMSG_FORMAT},
+        new FakeSampleStream(EMSG_FORMAT, /* eventDispatcher= */ null, input),
         /* offsetUs= */ 0L);
     renderer.render(/* positionUs= */ 0, /* elapsedRealtimeUs= */ 0); // Read the format
     renderer.render(/* positionUs= */ 0, /* elapsedRealtimeUs= */ 0); // Read the data

library/dash/src/main/java/com/google/android/exoplayer2/source/dash/PlayerEmsgHandler.java

@@ -360,9 +360,6 @@ public final class PlayerEmsgHandler implements Handler.Callback {
         }
         long eventTimeUs = inputBuffer.timeUs;
         Metadata metadata = decoder.decode(inputBuffer);
-        if (metadata == null) {
-          continue;
-        }
         EventMessage eventMessage = (EventMessage) metadata.get(0);
         if (isPlayerEmsgEvent(eventMessage.schemeIdUri, eventMessage.value)) {
           parsePlayerEmsgEvent(eventTimeUs, eventMessage);