Fix edge case: no frame between trim position and the next sync sample

PiperOrigin-RevId: 664841893

libraries/extractor/src/main/java/androidx/media3/extractor/mp4/Mp4Extractor.java

@@ -484,6 +484,19 @@ public final class Mp4Extractor implements Extractor, SeekMap {
     }
   }
 
+  /**
+   * Returns the list of sample timestamps of a {@code trackId}, in microseconds.
+   *
+   * @param trackId The id of the track to get the sample timestamps.
+   * @return The corresponding sample timestmaps of the track.
+   */
+  public long[] getSampleTimestampsUs(int trackId) {
+    if (tracks.length <= trackId) {
+      return new long[0];
+    }
+    return tracks[trackId].sampleTable.timestampsUs;
+  }
+
   // Private methods.
 
   private void enterReadingAtomHeaderState() {

libraries/transformer/src/androidTest/java/androidx/media3/transformer/AndroidTestUtil.java

@@ -581,6 +581,19 @@ public final class AndroidTestUtil {
                   .build())
           .build();
 
+  // From b/357743907.
+  public static final AssetInfo MP4_ASSET_PHOTOS_TRIM_OPTIMIZATION_VIDEO =
+      new AssetInfo.Builder("asset:///media/mp4/trim_optimization_failure.mp4")
+          .setVideoFormat(
+              new Format.Builder()
+                  .setSampleMimeType(VIDEO_H264)
+                  .setWidth(518)
+                  .setHeight(488)
+                  .setFrameRate(29.882f)
+                  .setCodecs("avc1.640034")
+                  .build())
+          .build();
+
   // The 7 HIGHMOTION files are H264 and AAC.
 
   public static final AssetInfo MP4_REMOTE_1280W_720H_5_SECOND_HIGHMOTION =

libraries/transformer/src/androidTest/java/androidx/media3/transformer/TransformerEndToEndTest.java

@@ -21,6 +21,7 @@ import static androidx.media3.test.utils.TestUtil.retrieveTrackFormat;
 import static androidx.media3.transformer.AndroidTestUtil.JPG_ASSET;
 import static androidx.media3.transformer.AndroidTestUtil.MP3_ASSET;
 import static androidx.media3.transformer.AndroidTestUtil.MP4_ASSET;
+import static androidx.media3.transformer.AndroidTestUtil.MP4_ASSET_PHOTOS_TRIM_OPTIMIZATION_VIDEO;
 import static androidx.media3.transformer.AndroidTestUtil.MP4_ASSET_WITH_INCREASING_TIMESTAMPS;
 import static androidx.media3.transformer.AndroidTestUtil.MP4_ASSET_WITH_INCREASING_TIMESTAMPS_320W_240H_15S;
 import static androidx.media3.transformer.AndroidTestUtil.MP4_ASSET_WITH_SHORTER_AUDIO;
@@ -664,6 +665,47 @@ public class TransformerEndToEndTest {
     assertThat(format.rotationDegrees).isEqualTo(90);
   }
 
+  @Test
+  public void clippedMedia_trimOptimizationEnabledAndTrimFromCloseToKeyFrame_succeeds()
+      throws Exception {
+    // This test covers the case where there's no frame between the trim point and the next sync
+    // sample. The frame has to be further than roughly 25ms apart.
+    assumeFormatsSupported(
+        context,
+        testId,
+        /* inputFormat= */ MP4_ASSET_PHOTOS_TRIM_OPTIMIZATION_VIDEO.videoFormat,
+        /* outputFormat= */ MP4_ASSET_PHOTOS_TRIM_OPTIMIZATION_VIDEO.videoFormat);
+
+    Transformer transformer =
+        new Transformer.Builder(context).experimentalSetTrimOptimizationEnabled(true).build();
+
+    // The previous sample is at 1137 and the next sample (which is a sync sample) is at 1171.
+    long clippingStartMs = 1138;
+    long clippingEndMs = 5601;
+
+    MediaItem mediaItem =
+        new MediaItem.Builder()
+            .setUri(Uri.parse(MP4_ASSET_PHOTOS_TRIM_OPTIMIZATION_VIDEO.uri))
+            .setClippingConfiguration(
+                new MediaItem.ClippingConfiguration.Builder()
+                    .setStartPositionMs(1138)
+                    .setEndPositionMs(5601)
+                    .build())
+            .build();
+
+    ExportTestResult result =
+        new TransformerAndroidTestRunner.Builder(context, transformer)
+            .build()
+            .run(testId, mediaItem);
+
+    assertThat(result.exportResult.optimizationResult)
+        .isEqualTo(OPTIMIZATION_ABANDONED_KEYFRAME_PLACEMENT_OPTIMAL_FOR_TRIM);
+    assertThat(result.exportResult.durationMs).isAtMost(clippingEndMs - clippingStartMs);
+    assertThat(result.exportResult.videoConversionProcess).isEqualTo(CONVERSION_PROCESS_TRANSMUXED);
+    assertThat(result.exportResult.audioConversionProcess).isEqualTo(CONVERSION_PROCESS_TRANSMUXED);
+    assertThat(new File(result.filePath).length()).isGreaterThan(0);
+  }
+
   @Test
   public void clippedMedia_trimOptimizationEnabled_fallbackToNormalExportUponFormatMismatch()
       throws Exception {

libraries/transformer/src/main/java/androidx/media3/transformer/Mp4Info.java

@@ -24,6 +24,7 @@ import androidx.media3.common.C;
 import androidx.media3.common.DataReader;
 import androidx.media3.common.Format;
 import androidx.media3.common.util.ParsableByteArray;
+import androidx.media3.common.util.Util;
 import androidx.media3.datasource.DataSourceUtil;
 import androidx.media3.datasource.DataSpec;
 import androidx.media3.datasource.DefaultDataSource;
@@ -65,6 +66,9 @@ import org.checkerframework.checker.nullness.qual.Nullable;
    */
   public final long firstSyncSampleTimestampUsAfterTimeUs;
 
+  /** Whether the first sample at or after {@code timeUs} is a sync sample. */
+  public final boolean isFirstVideoSampleAfterTimeUsSyncSample;
+
   /** The video {@link Format} or {@code null} if there is no video track. */
   public final @Nullable Format videoFormat;
 
@@ -75,11 +79,13 @@ import org.checkerframework.checker.nullness.qual.Nullable;
       long durationUs,
       long lastSyncSampleTimestampUs,
       long firstSyncSampleTimestampUsAfterTimeUs,
+      boolean isFirstVideoSampleAfterTimeUsSyncSample,
       @Nullable Format videoFormat,
       @Nullable Format audioFormat) {
     this.durationUs = durationUs;
     this.lastSyncSampleTimestampUs = lastSyncSampleTimestampUs;
     this.firstSyncSampleTimestampUsAfterTimeUs = firstSyncSampleTimestampUsAfterTimeUs;
+    this.isFirstVideoSampleAfterTimeUsSyncSample = isFirstVideoSampleAfterTimeUsSyncSample;
     this.videoFormat = videoFormat;
     this.audioFormat = audioFormat;
   }
@@ -143,6 +149,7 @@ import org.checkerframework.checker.nullness.qual.Nullable;
       long durationUs = mp4Extractor.getDurationUs();
       long lastSyncSampleTimestampUs = C.TIME_UNSET;
       long firstSyncSampleTimestampUsAfterTimeUs = C.TIME_UNSET;
+      boolean isFirstSampleAfterTimeUsSyncSample = false;
       @Nullable Format videoFormat = null;
       if (extractorOutput.videoTrackId != C.INDEX_UNSET) {
         ExtractorOutputImpl.TrackOutputImpl videoTrackOutput =
@@ -164,6 +171,21 @@ import org.checkerframework.checker.nullness.qual.Nullable;
           } else { // There is no sync sample after timeUs
             firstSyncSampleTimestampUsAfterTimeUs = C.TIME_END_OF_SOURCE;
           }
+
+          long[] trackTimestampsUs =
+              mp4Extractor.getSampleTimestampsUs(extractorOutput.videoTrackId);
+
+          int indexOfTrackTimestampUsAfterTimeUs =
+              Util.binarySearchCeil(
+                  trackTimestampsUs, timeUs, /* inclusive= */ true, /* stayInBounds= */ false);
+          if (indexOfTrackTimestampUsAfterTimeUs < trackTimestampsUs.length) {
+            // Has found an element that is greater or equal to timeUs.
+            long firstTrackTimestampUsAfterTimeUs =
+                trackTimestampsUs[indexOfTrackTimestampUsAfterTimeUs];
+            if (firstTrackTimestampUsAfterTimeUs == firstSyncSampleTimestampUsAfterTimeUs) {
+              isFirstSampleAfterTimeUsSyncSample = true;
+            }
+          }
         }
       }
 
@@ -178,6 +200,7 @@ import org.checkerframework.checker.nullness.qual.Nullable;
           durationUs,
           lastSyncSampleTimestampUs,
           firstSyncSampleTimestampUsAfterTimeUs,
+          isFirstSampleAfterTimeUsSyncSample,
           videoFormat,
           audioFormat);
     } finally {

libraries/transformer/src/main/java/androidx/media3/transformer/Transformer.java

@@ -1502,7 +1502,8 @@ public final class Transformer {
                       AAC_LC_AUDIO_SAMPLE_COUNT, mp4Info.audioFormat.sampleRate);
             }
             if (mp4Info.firstSyncSampleTimestampUsAfterTimeUs - trimStartTimeUs
-                <= maxEncodedAudioBufferDurationUs) {
+                    <= maxEncodedAudioBufferDurationUs
+                || mp4Info.isFirstVideoSampleAfterTimeUsSyncSample) {
               Transformer.this.composition =
                   buildUponCompositionForTrimOptimization(
                       composition,