Fix failure to write negative PTS sample

Fixes an issue caused by no support for negative audio PTS and edit lists
in FrameworkMuxer, Android versions before 11

PiperOrigin-RevId: 607690507
(cherry picked from commit e43f96687c3c6d13907da1a5c53e90ffa57d624c)

RELEASENOTES.md

@@ -4,6 +4,9 @@
 
 *   Effect:
     *   Improved PQ to SDR tone-mapping by converting color spaces.
+*   Transformer:
+    *   Add workaround for exception thrown due to `MediaMuxer` not supporting
+        negative presentation timestamps before API 30.
 *   UI:
     *   Fallback to include audio track language name if `Locale` cannot
         identify a display name

libraries/test_data/src/test/assets/transformerdumps/mp4/iibbibb_editlist_videoonly.mp4/transmuxed.dump

@@ -0,0 +1,95 @@
+format video:
+  id = 1
+  sampleMimeType = video/avc
+  codecs = avc1.F40016
+  maxInputSize = 7838
+  width = 704
+  height = 576
+  frameRate = 1.04
+  colorInfo:
+    lumaBitdepth = 8
+    chromaBitdepth = 8
+  metadata = entries=[TSSE: description=null: values=[Lavf60.3.100], Mp4Timestamp: creation time=0, modification time=0, timescale=1000]
+  initializationData:
+    data = length 30, hash 9DFD8D5
+    data = length 9, hash FBADD682
+container metadata = entries=[TSSE: description=null: values=[Lavf60.3.100], Mp4Timestamp: creation time=0, modification time=0, timescale=1000]
+sample:
+  trackType = video
+  dataHashCode = 1491581480
+  size = 7804
+  isKeyFrame = true
+  presentationTimeUs = 0
+sample:
+  trackType = video
+  dataHashCode = -1689048121
+  size = 7808
+  isKeyFrame = true
+  presentationTimeUs = 2500000
+sample:
+  trackType = video
+  dataHashCode = 1018268785
+  size = 1301
+  isKeyFrame = false
+  presentationTimeUs = 1500000
+sample:
+  trackType = video
+  dataHashCode = -1625273408
+  size = 1114
+  isKeyFrame = false
+  presentationTimeUs = 500000
+sample:
+  trackType = video
+  dataHashCode = -374381878
+  size = 7730
+  isKeyFrame = true
+  presentationTimeUs = 5500000
+sample:
+  trackType = video
+  dataHashCode = -2004918573
+  size = 1247
+  isKeyFrame = false
+  presentationTimeUs = 4500000
+sample:
+  trackType = video
+  dataHashCode = 1940057858
+  size = 1110
+  isKeyFrame = false
+  presentationTimeUs = 3500000
+sample:
+  trackType = video
+  dataHashCode = 472148756
+  size = 7595
+  isKeyFrame = true
+  presentationTimeUs = 8500000
+sample:
+  trackType = video
+  dataHashCode = 911200371
+  size = 1273
+  isKeyFrame = false
+  presentationTimeUs = 7500000
+sample:
+  trackType = video
+  dataHashCode = -954114383
+  size = 1130
+  isKeyFrame = false
+  presentationTimeUs = 6500000
+sample:
+  trackType = video
+  dataHashCode = 77841273
+  size = 6734
+  isKeyFrame = true
+  presentationTimeUs = 11500000
+sample:
+  trackType = video
+  dataHashCode = 1932832421
+  size = 1437
+  isKeyFrame = false
+  presentationTimeUs = 10500000
+sample:
+  trackType = video
+  dataHashCode = -2133964046
+  size = 1186
+  isKeyFrame = false
+  presentationTimeUs = 9500000
+released = true

libraries/test_data/src/test/assets/transformerdumps/mp4/long_edit_list_audioonly.mp4/transmuxed.dump

@@ -0,0 +1,423 @@
+format audio:
+  averageBitrate = 140021
+  peakBitrate = 140781
+  id = 1
+  sampleMimeType = audio/mp4a-latm
+  codecs = mp4a.40.2
+  maxInputSize = 476
+  channelCount = 2
+  sampleRate = 44100
+  language = und
+  metadata = entries=[TSSE: description=null: values=[Lavf60.3.100], Mp4Timestamp: creation time=0, modification time=0, timescale=1000]
+  initializationData:
+    data = length 2, hash 5FF
+container metadata = entries=[TSSE: description=null: values=[Lavf60.3.100], Mp4Timestamp: creation time=0, modification time=0, timescale=1000]
+sample:
+  trackType = audio
+  dataHashCode = -620111888
+  size = 423
+  isKeyFrame = true
+  presentationTimeUs = -16826
+sample:
+  trackType = audio
+  dataHashCode = -1530182437
+  size = 411
+  isKeyFrame = true
+  presentationTimeUs = 6394
+sample:
+  trackType = audio
+  dataHashCode = 1230616627
+  size = 404
+  isKeyFrame = true
+  presentationTimeUs = 29614
+sample:
+  trackType = audio
+  dataHashCode = -1245126751
+  size = 403
+  isKeyFrame = true
+  presentationTimeUs = 52834
+sample:
+  trackType = audio
+  dataHashCode = -1410779761
+  size = 422
+  isKeyFrame = true
+  presentationTimeUs = 76054
+sample:
+  trackType = audio
+  dataHashCode = -1047441584
+  size = 418
+  isKeyFrame = true
+  presentationTimeUs = 99274
+sample:
+  trackType = audio
+  dataHashCode = 1146337558
+  size = 421
+  isKeyFrame = true
+  presentationTimeUs = 122494
+sample:
+  trackType = audio
+  dataHashCode = 1933912787
+  size = 400
+  isKeyFrame = true
+  presentationTimeUs = 145714
+sample:
+  trackType = audio
+  dataHashCode = 252268411
+  size = 400
+  isKeyFrame = true
+  presentationTimeUs = 168934
+sample:
+  trackType = audio
+  dataHashCode = -329438270
+  size = 410
+  isKeyFrame = true
+  presentationTimeUs = 192154
+sample:
+  trackType = audio
+  dataHashCode = 165440818
+  size = 391
+  isKeyFrame = true
+  presentationTimeUs = 215374
+sample:
+  trackType = audio
+  dataHashCode = 1712500598
+  size = 361
+  isKeyFrame = true
+  presentationTimeUs = 238594
+sample:
+  trackType = audio
+  dataHashCode = 1264185277
+  size = 391
+  isKeyFrame = true
+  presentationTimeUs = 261814
+sample:
+  trackType = audio
+  dataHashCode = -1934387857
+  size = 390
+  isKeyFrame = true
+  presentationTimeUs = 285034
+sample:
+  trackType = audio
+  dataHashCode = -105475655
+  size = 388
+  isKeyFrame = true
+  presentationTimeUs = 308253
+sample:
+  trackType = audio
+  dataHashCode = 671697059
+  size = 399
+  isKeyFrame = true
+  presentationTimeUs = 331473
+sample:
+  trackType = audio
+  dataHashCode = -1835652942
+  size = 390
+  isKeyFrame = true
+  presentationTimeUs = 354693
+sample:
+  trackType = audio
+  dataHashCode = 1445535733
+  size = 387
+  isKeyFrame = true
+  presentationTimeUs = 377913
+sample:
+  trackType = audio
+  dataHashCode = 713025022
+  size = 446
+  isKeyFrame = true
+  presentationTimeUs = 401133
+sample:
+  trackType = audio
+  dataHashCode = 226962058
+  size = 436
+  isKeyFrame = true
+  presentationTimeUs = 424353
+sample:
+  trackType = audio
+  dataHashCode = -361162400
+  size = 394
+  isKeyFrame = true
+  presentationTimeUs = 447573
+sample:
+  trackType = audio
+  dataHashCode = -1091817776
+  size = 417
+  isKeyFrame = true
+  presentationTimeUs = 470793
+sample:
+  trackType = audio
+  dataHashCode = -33570145
+  size = 442
+  isKeyFrame = true
+  presentationTimeUs = 494013
+sample:
+  trackType = audio
+  dataHashCode = 791597935
+  size = 416
+  isKeyFrame = true
+  presentationTimeUs = 517233
+sample:
+  trackType = audio
+  dataHashCode = 486177154
+  size = 396
+  isKeyFrame = true
+  presentationTimeUs = 540453
+sample:
+  trackType = audio
+  dataHashCode = 697876210
+  size = 395
+  isKeyFrame = true
+  presentationTimeUs = 563673
+sample:
+  trackType = audio
+  dataHashCode = -1416713338
+  size = 389
+  isKeyFrame = true
+  presentationTimeUs = 586893
+sample:
+  trackType = audio
+  dataHashCode = 180955111
+  size = 404
+  isKeyFrame = true
+  presentationTimeUs = 610113
+sample:
+  trackType = audio
+  dataHashCode = 1614220208
+  size = 418
+  isKeyFrame = true
+  presentationTimeUs = 633333
+sample:
+  trackType = audio
+  dataHashCode = 1619215866
+  size = 393
+  isKeyFrame = true
+  presentationTimeUs = 656553
+sample:
+  trackType = audio
+  dataHashCode = -730291234
+  size = 402
+  isKeyFrame = true
+  presentationTimeUs = 679773
+sample:
+  trackType = audio
+  dataHashCode = -1734250280
+  size = 404
+  isKeyFrame = true
+  presentationTimeUs = 702993
+sample:
+  trackType = audio
+  dataHashCode = -24161892
+  size = 397
+  isKeyFrame = true
+  presentationTimeUs = 726213
+sample:
+  trackType = audio
+  dataHashCode = 1339131070
+  size = 386
+  isKeyFrame = true
+  presentationTimeUs = 749433
+sample:
+  trackType = audio
+  dataHashCode = 1996219279
+  size = 377
+  isKeyFrame = true
+  presentationTimeUs = 772653
+sample:
+  trackType = audio
+  dataHashCode = -1832486999
+  size = 409
+  isKeyFrame = true
+  presentationTimeUs = 795873
+sample:
+  trackType = audio
+  dataHashCode = 1120922082
+  size = 402
+  isKeyFrame = true
+  presentationTimeUs = 819092
+sample:
+  trackType = audio
+  dataHashCode = -1514208718
+  size = 390
+  isKeyFrame = true
+  presentationTimeUs = 842312
+sample:
+  trackType = audio
+  dataHashCode = 1442267846
+  size = 388
+  isKeyFrame = true
+  presentationTimeUs = 865532
+sample:
+  trackType = audio
+  dataHashCode = -2064065315
+  size = 377
+  isKeyFrame = true
+  presentationTimeUs = 888752
+sample:
+  trackType = audio
+  dataHashCode = -502416917
+  size = 391
+  isKeyFrame = true
+  presentationTimeUs = 911972
+sample:
+  trackType = audio
+  dataHashCode = 730491655
+  size = 398
+  isKeyFrame = true
+  presentationTimeUs = 935192
+sample:
+  trackType = audio
+  dataHashCode = -1910342128
+  size = 381
+  isKeyFrame = true
+  presentationTimeUs = 958412
+sample:
+  trackType = audio
+  dataHashCode = 475981018
+  size = 393
+  isKeyFrame = true
+  presentationTimeUs = 981632
+sample:
+  trackType = audio
+  dataHashCode = -746607724
+  size = 393
+  isKeyFrame = true
+  presentationTimeUs = 1004852
+sample:
+  trackType = audio
+  dataHashCode = 1641658609
+  size = 380
+  isKeyFrame = true
+  presentationTimeUs = 1028072
+sample:
+  trackType = audio
+  dataHashCode = -1148163632
+  size = 395
+  isKeyFrame = true
+  presentationTimeUs = 1051292
+sample:
+  trackType = audio
+  dataHashCode = 665110699
+  size = 379
+  isKeyFrame = true
+  presentationTimeUs = 1074512
+sample:
+  trackType = audio
+  dataHashCode = 798207150
+  size = 403
+  isKeyFrame = true
+  presentationTimeUs = 1097732
+sample:
+  trackType = audio
+  dataHashCode = 1359581525
+  size = 415
+  isKeyFrame = true
+  presentationTimeUs = 1120952
+sample:
+  trackType = audio
+  dataHashCode = -335439207
+  size = 400
+  isKeyFrame = true
+  presentationTimeUs = 1144172
+sample:
+  trackType = audio
+  dataHashCode = -198311225
+  size = 401
+  isKeyFrame = true
+  presentationTimeUs = 1167392
+sample:
+  trackType = audio
+  dataHashCode = -924672246
+  size = 400
+  isKeyFrame = true
+  presentationTimeUs = 1190612
+sample:
+  trackType = audio
+  dataHashCode = -1282928372
+  size = 408
+  isKeyFrame = true
+  presentationTimeUs = 1213832
+sample:
+  trackType = audio
+  dataHashCode = -50597927
+  size = 406
+  isKeyFrame = true
+  presentationTimeUs = 1237052
+sample:
+  trackType = audio
+  dataHashCode = -1671375815
+  size = 411
+  isKeyFrame = true
+  presentationTimeUs = 1260272
+sample:
+  trackType = audio
+  dataHashCode = -1897083943
+  size = 414
+  isKeyFrame = true
+  presentationTimeUs = 1283492
+sample:
+  trackType = audio
+  dataHashCode = -1693247556
+  size = 393
+  isKeyFrame = true
+  presentationTimeUs = 1306712
+sample:
+  trackType = audio
+  dataHashCode = 1287376831
+  size = 405
+  isKeyFrame = true
+  presentationTimeUs = 1329931
+sample:
+  trackType = audio
+  dataHashCode = -1463566839
+  size = 412
+  isKeyFrame = true
+  presentationTimeUs = 1353151
+sample:
+  trackType = audio
+  dataHashCode = -841250803
+  size = 409
+  isKeyFrame = true
+  presentationTimeUs = 1376371
+sample:
+  trackType = audio
+  dataHashCode = 167279197
+  size = 423
+  isKeyFrame = true
+  presentationTimeUs = 1399591
+sample:
+  trackType = audio
+  dataHashCode = 1819296695
+  size = 399
+  isKeyFrame = true
+  presentationTimeUs = 1422811
+sample:
+  trackType = audio
+  dataHashCode = 696153948
+  size = 400
+  isKeyFrame = true
+  presentationTimeUs = 1446031
+sample:
+  trackType = audio
+  dataHashCode = 1462953378
+  size = 397
+  isKeyFrame = true
+  presentationTimeUs = 1469251
+sample:
+  trackType = audio
+  dataHashCode = 310189811
+  size = 398
+  isKeyFrame = true
+  presentationTimeUs = 1492471
+sample:
+  trackType = audio
+  dataHashCode = -1082736404
+  size = 424
+  isKeyFrame = true
+  presentationTimeUs = 1515691
+sample:
+  trackType = audio
+  dataHashCode = 1980862648
+  size = 417
+  isKeyFrame = true
+  presentationTimeUs = 1538911
+released = true

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

@@ -68,6 +68,11 @@ import androidx.media3.effect.RgbFilter;
 import androidx.media3.effect.ScaleAndRotateTransformation;
 import androidx.media3.effect.TimestampWrapper;
 import androidx.media3.exoplayer.audio.TeeAudioProcessor;
+import androidx.media3.extractor.mp4.Mp4Extractor;
+import androidx.media3.extractor.text.DefaultSubtitleParserFactory;
+import androidx.media3.test.utils.FakeExtractorOutput;
+import androidx.media3.test.utils.FakeTrackOutput;
+import androidx.media3.test.utils.TestUtil;
 import androidx.test.core.app.ApplicationProvider;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 import com.google.common.collect.ImmutableList;
@@ -923,6 +928,118 @@ public class TransformerEndToEndTest {
     assertThat(result.exportResult.channelCount).isEqualTo(2);
   }
 
+  @Test
+  public void transmux_audioWithEditList_preservesDuration() throws Exception {
+    String testId = "transmux_audioWithEditList_preservesDuration";
+    Context context = ApplicationProvider.getApplicationContext();
+    Transformer transformer = new Transformer.Builder(context).build();
+    MediaItem mediaItem =
+        MediaItem.fromUri(Uri.parse("asset:///media/mp4/long_edit_list_audioonly.mp4"));
+
+    ExportTestResult exportTestResult =
+        new TransformerAndroidTestRunner.Builder(context, transformer)
+            .build()
+            .run(testId, mediaItem);
+
+    Mp4Extractor mp4Extractor = new Mp4Extractor(new DefaultSubtitleParserFactory());
+    FakeExtractorOutput fakeExtractorOutput =
+        TestUtil.extractAllSamplesFromFilePath(mp4Extractor, exportTestResult.filePath);
+    // TODO: b/324842222 - Mp4Extractor reports incorrect duration, without considering edit lists.
+    assertThat(fakeExtractorOutput.seekMap.getDurationUs()).isEqualTo(1_579_000);
+    assertThat(fakeExtractorOutput.numberOfTracks).isEqualTo(1);
+    FakeTrackOutput audioTrack = fakeExtractorOutput.trackOutputs.get(0);
+    int expectedSampleCount = 68;
+    audioTrack.assertSampleCount(expectedSampleCount);
+    if (Util.SDK_INT >= 30) {
+      // TODO: b/324842222 - Mp4Extractor doesn't interpret Transformer's generated output as
+      //  "gapless" audio. The generated file should have encoderDelay = 742 and first
+      //  sample PTS of 0.
+      assertThat(audioTrack.lastFormat.encoderDelay).isEqualTo(0);
+      assertThat(audioTrack.getSampleTimeUs(/* index= */ 0)).isEqualTo(-16_826);
+      assertThat(audioTrack.getSampleTimeUs(/* index= */ expectedSampleCount - 1))
+          .isEqualTo(1_538_911);
+    } else {
+      // Edit lists are not supported b/142580952 : sample times start from zero,
+      // and output duration will be longer than input duration by encoder delay.
+      assertThat(audioTrack.lastFormat.encoderDelay).isEqualTo(0);
+      assertThat(audioTrack.getSampleTimeUs(/* index= */ 0)).isEqualTo(0);
+      assertThat(audioTrack.getSampleTimeUs(/* index= */ expectedSampleCount - 1))
+          .isEqualTo(1_555_736);
+    }
+  }
+
+  @Test
+  public void transmux_audioWithEditListUsingInAppMuxer_preservesDuration() throws Exception {
+    String testId = "transmux_AudioWithEditListUsingInAppMuxer_preservesDuration";
+    Context context = ApplicationProvider.getApplicationContext();
+    Transformer transformer =
+        new Transformer.Builder(context)
+            .setMuxerFactory(new InAppMuxer.Factory.Builder().build())
+            .build();
+    MediaItem mediaItem =
+        MediaItem.fromUri(Uri.parse("asset:///media/mp4/long_edit_list_audioonly.mp4"));
+
+    ExportTestResult exportTestResult =
+        new TransformerAndroidTestRunner.Builder(context, transformer)
+            .build()
+            .run(testId, mediaItem);
+
+    Mp4Extractor mp4Extractor = new Mp4Extractor(new DefaultSubtitleParserFactory());
+    FakeExtractorOutput fakeExtractorOutput =
+        TestUtil.extractAllSamplesFromFilePath(mp4Extractor, exportTestResult.filePath);
+    // TODO: b/324903070 - The generated output file has incorrect duration.
+    assertThat(fakeExtractorOutput.seekMap.getDurationUs()).isEqualTo(1_555_700);
+    assertThat(fakeExtractorOutput.numberOfTracks).isEqualTo(1);
+    FakeTrackOutput audioTrack = fakeExtractorOutput.trackOutputs.get(0);
+    int expectedSampleCount = 68;
+    audioTrack.assertSampleCount(expectedSampleCount);
+    // TODO: b/324903070 - InAppMuxer doesn't write edit lists to support gapless audio muxing.
+    //  Output incorrectly starts at encoderDelay 0, PTS 0
+    assertThat(audioTrack.lastFormat.encoderDelay).isEqualTo(0);
+    assertThat(audioTrack.getSampleTimeUs(/* index= */ 0)).isEqualTo(0);
+    // TODO: b/270583563 - InAppMuxer always uses 1 / 48_000 timebase for audio.
+    //  The audio file in this test is 44_100 Hz, with timebase for audio of 1 / 44_100 and
+    //  each sample duration is exactly 1024 / 44_100, with no rounding errors.
+    //  Since InAppMuxer uses a different timebase for audio, some rounding errors are introduced
+    //  and MP4 sample durations are off.
+    // TODO: b/324903070 - expectedLastSampleTimeUs & expectedDurationUs are incorrect.
+    //  Last sample time cannot be greater than total duration.
+    assertThat(audioTrack.getSampleTimeUs(/* index= */ expectedSampleCount - 1))
+        .isEqualTo(1_555_708);
+  }
+
+  @Test
+  public void transmux_videoWithEditList_trimsFirstIDRFrameDuration() throws Exception {
+    String testId = "transmux_videoWithEditList_trimsFirstIDRFrameDuration";
+    Context context = ApplicationProvider.getApplicationContext();
+    assumeTrue(
+        "MediaMuxer doesn't support B frames reliably on older SDK versions", Util.SDK_INT >= 29);
+    Transformer transformer = new Transformer.Builder(context).build();
+    MediaItem mediaItem =
+        MediaItem.fromUri(Uri.parse("asset:///media/mp4/iibbibb_editlist_videoonly.mp4"));
+
+    ExportTestResult exportTestResult =
+        new TransformerAndroidTestRunner.Builder(context, transformer)
+            .build()
+            .run(testId, mediaItem);
+
+    Mp4Extractor mp4Extractor = new Mp4Extractor(new DefaultSubtitleParserFactory());
+    FakeExtractorOutput fakeExtractorOutput =
+        TestUtil.extractAllSamplesFromFilePath(mp4Extractor, exportTestResult.filePath);
+    assertThat(fakeExtractorOutput.numberOfTracks).isEqualTo(1);
+
+    // TODO: b/324842222 - Duration isn't written correctly when transmuxing, and differs
+    //  between SDK versions. Do not assert for duration yet.
+    FakeTrackOutput videoTrack = fakeExtractorOutput.trackOutputs.get(0);
+    int expectedSampleCount = 13;
+    videoTrack.assertSampleCount(expectedSampleCount);
+    assertThat(videoTrack.getSampleTimeUs(/* index= */ 0)).isEqualTo(0);
+    int sampleIndexWithLargestSampleTime = 10;
+    assertThat(videoTrack.getSampleTimeUs(sampleIndexWithLargestSampleTime)).isEqualTo(11_500_000);
+    assertThat(videoTrack.getSampleTimeUs(/* index= */ expectedSampleCount - 1))
+        .isEqualTo(9_500_000);
+  }
+
   private static AudioProcessor createSonic(float pitch) {
     SonicAudioProcessor sonic = new SonicAudioProcessor();
     sonic.setPitch(pitch);

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

@@ -91,6 +91,7 @@ import java.nio.ByteBuffer;
   private final long videoDurationUs;
   private final MediaCodec.BufferInfo bufferInfo;
   private final SparseLongArray trackIndexToLastPresentationTimeUs;
+  private final SparseLongArray trackIndexToPresentationTimeOffsetUs;
 
   private int videoTrackIndex;
 
@@ -103,6 +104,7 @@ import java.nio.ByteBuffer;
     this.videoDurationUs = Util.msToUs(videoDurationMs);
     bufferInfo = new MediaCodec.BufferInfo();
     trackIndexToLastPresentationTimeUs = new SparseLongArray();
+    trackIndexToPresentationTimeOffsetUs = new SparseLongArray();
     videoTrackIndex = C.INDEX_UNSET;
   }
 
@@ -153,6 +155,9 @@ import java.nio.ByteBuffer;
 
     if (!isStarted) {
       isStarted = true;
+      if (Util.SDK_INT < 30 && presentationTimeUs < 0) {
+        trackIndexToPresentationTimeOffsetUs.put(trackIndex, -presentationTimeUs);
+      }
       try {
         mediaMuxer.start();
       } catch (RuntimeException e) {
@@ -163,6 +168,9 @@ import java.nio.ByteBuffer;
     int offset = data.position();
     int size = data.limit() - offset;
 
+    long presentationTimeOffsetUs = trackIndexToPresentationTimeOffsetUs.get(trackIndex);
+    presentationTimeUs += presentationTimeOffsetUs;
+
     bufferInfo.set(offset, size, presentationTimeUs, TransformerUtil.getMediaCodecFlags(flags));
     long lastSamplePresentationTimeUs = trackIndexToLastPresentationTimeUs.get(trackIndex);
     // writeSampleData blocks on old API versions, so check here to avoid calling the method.
@@ -174,6 +182,15 @@ import java.nio.ByteBuffer;
             + lastSamplePresentationTimeUs
             + ") unsupported on this API version");
     trackIndexToLastPresentationTimeUs.put(trackIndex, presentationTimeUs);
+
+    checkState(
+        presentationTimeOffsetUs == 0 || presentationTimeUs >= lastSamplePresentationTimeUs,
+        "Samples not in presentation order ("
+            + presentationTimeUs
+            + " < "
+            + lastSamplePresentationTimeUs
+            + ") unsupported when using negative PTS workaround");
+
     try {
       mediaMuxer.writeSampleData(trackIndex, data, bufferInfo);
     } catch (RuntimeException e) {

libraries/transformer/src/test/java/androidx/media3/transformer/MediaItemExportTest.java

@@ -19,15 +19,18 @@ package androidx.media3.transformer;
 import static androidx.media3.test.utils.robolectric.RobolectricUtil.runLooperUntil;
 import static androidx.media3.transformer.AssetLoader.SUPPORTED_OUTPUT_TYPE_DECODED;
 import static androidx.media3.transformer.AssetLoader.SUPPORTED_OUTPUT_TYPE_ENCODED;
+import static androidx.media3.transformer.DefaultMuxer.Factory.DEFAULT_MAX_DELAY_BETWEEN_SAMPLES_MS;
 import static androidx.media3.transformer.ExportResult.OPTIMIZATION_ABANDONED_KEYFRAME_PLACEMENT_OPTIMAL_FOR_TRIM;
 import static androidx.media3.transformer.ExportResult.OPTIMIZATION_FAILED_EXTRACTION_FAILED;
 import static androidx.media3.transformer.TestUtil.ASSET_URI_PREFIX;
 import static androidx.media3.transformer.TestUtil.FILE_AUDIO_AMR_NB;
 import static androidx.media3.transformer.TestUtil.FILE_AUDIO_AMR_WB;
+import static androidx.media3.transformer.TestUtil.FILE_AUDIO_ELST_SKIP_500MS;
 import static androidx.media3.transformer.TestUtil.FILE_AUDIO_RAW;
 import static androidx.media3.transformer.TestUtil.FILE_AUDIO_VIDEO;
 import static androidx.media3.transformer.TestUtil.FILE_AUDIO_VIDEO_INCREASING_TIMESTAMPS_15S;
 import static androidx.media3.transformer.TestUtil.FILE_UNKNOWN_DURATION;
+import static androidx.media3.transformer.TestUtil.FILE_VIDEO_ELST_TRIM_IDR_DURATION;
 import static androidx.media3.transformer.TestUtil.FILE_VIDEO_ONLY;
 import static androidx.media3.transformer.TestUtil.FILE_WITH_SEF_SLOW_MOTION;
 import static androidx.media3.transformer.TestUtil.FILE_WITH_SUBTITLES;
@@ -66,6 +69,7 @@ import androidx.media3.common.Format;
 import androidx.media3.common.MediaItem;
 import androidx.media3.common.MimeTypes;
 import androidx.media3.common.audio.SonicAudioProcessor;
+import androidx.media3.effect.Contrast;
 import androidx.media3.effect.Presentation;
 import androidx.media3.effect.ScaleAndRotateTransformation;
 import androidx.media3.exoplayer.source.DefaultMediaSourceFactory;
@@ -101,6 +105,7 @@ import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
 import org.junit.runner.RunWith;
 import org.mockito.ArgumentCaptor;
+import org.robolectric.annotation.Config;
 import org.robolectric.shadows.ShadowMediaCodec;
 
 /**
@@ -1381,6 +1386,79 @@ public final class MediaItemExportTest {
     assertThat(illegalStateException.get()).isNotNull();
   }
 
+  @Test
+  @Config(minSdk = 30)
+  // This test requires Android SDK >= 30 for MediaMuxer negative PTS support.
+  public void transmux_audioWithEditList_api30_correctDuration() throws Exception {
+    Transformer transformer =
+        createTransformerBuilder(muxerFactory, /* enableFallback= */ false).build();
+    MediaItem mediaItem = MediaItem.fromUri(ASSET_URI_PREFIX + FILE_AUDIO_ELST_SKIP_500MS);
+
+    transformer.start(mediaItem, outputDir.newFile().getPath());
+    ExportResult result = TransformerTestRunner.runLooper(transformer);
+
+    // TODO: b/324245196 - Update this test when bugs are fixed.
+    //  Duration is actually 68267 / 44100 = 1548ms.
+    //  Last frame PTS is 67866 / 44100 = 1.53891 which rounds down to 1538ms.
+    assertThat(result.durationMs).isEqualTo(1538);
+    // TODO: b/325020444 - Update this test when bugs are fixed.
+    //  Dump incorrectly includes the last clipped audio sample from input file.
+    DumpFileAsserts.assertOutput(
+        context,
+        muxerFactory.getCreatedMuxer(),
+        getDumpFileName(
+            /* originalFileName= */ FILE_AUDIO_ELST_SKIP_500MS,
+            /* modifications...= */ "transmuxed"));
+  }
+
+  @Test
+  @Config(minSdk = 21, maxSdk = 29)
+  // This test requires Android SDK < 30 with no MediaMuxer negative PTS support.
+  public void transmux_audioWithEditList_api29_frameworkMuxerDoesNotThrow() throws Exception {
+    // Do not use CapturingMuxer.Factory(), as this test checks for a workaround in
+    // FrameworkMuxer.
+    Transformer transformer =
+        createTransformerBuilder(
+                new FrameworkMuxer.Factory(DEFAULT_MAX_DELAY_BETWEEN_SAMPLES_MS, C.TIME_UNSET),
+                /* enableFallback= */ false)
+            .build();
+    MediaItem mediaItem = MediaItem.fromUri(ASSET_URI_PREFIX + FILE_AUDIO_ELST_SKIP_500MS);
+
+    transformer.start(mediaItem, outputDir.newFile().getPath());
+    ExportResult result = TransformerTestRunner.runLooper(transformer);
+
+    // TODO: b/324842222 - Update this test when bugs are fixed.
+    //  The result.durationMs is incorrect in this test because
+    //  FrameworkMuxer workaround doesn't propagate changed timestamps to MuxerWrapper.
+    assertThat(result.durationMs).isEqualTo(1538);
+    assertThat(result.exportException).isNull();
+  }
+
+  @Test
+  @Config(minSdk = 25)
+  // This test requires Android SDK < 30 for lack of MediaMuxer negative PTS support
+  // and SDK >= 25 for B-frame support.
+  public void transmux_trimsFirstIDRDuration() throws Exception {
+    Transformer transformer =
+        createTransformerBuilder(muxerFactory, /* enableFallback= */ false).build();
+    MediaItem mediaItem = MediaItem.fromUri(ASSET_URI_PREFIX + FILE_VIDEO_ELST_TRIM_IDR_DURATION);
+
+    transformer.start(mediaItem, outputDir.newFile().getPath());
+    ExportResult result = TransformerTestRunner.runLooper(transformer);
+
+    // TODO: b/324245196 - Update this test when bugs are fixed.
+    //  Duration is actually 12_500. Last frame PTS is 11_500.
+    assertThat(result.durationMs).isEqualTo(11_500);
+    int inputFrameCount = 13;
+    assertThat(result.videoFrameCount).isEqualTo(inputFrameCount);
+    DumpFileAsserts.assertOutput(
+        context,
+        muxerFactory.getCreatedMuxer(),
+        getDumpFileName(
+            /* originalFileName= */ FILE_VIDEO_ELST_TRIM_IDR_DURATION,
+            /* modifications...= */ "transmuxed"));
+  }
+
   private static final class SlowExtractorsFactory implements ExtractorsFactory {
 
     private final long delayBetweenReadsMs;

libraries/transformer/src/test/java/androidx/media3/transformer/TestUtil.java

@@ -53,6 +53,9 @@ public final class TestUtil {
   public static final String FILE_AUDIO_AMR_NB = "amr/sample_nb.amr";
   public static final String FILE_AUDIO_AC3_UNSUPPORTED_BY_MUXER = "mp4/sample_ac3.mp4";
   public static final String FILE_UNKNOWN_DURATION = "mp4/sample_fragmented.mp4";
+  public static final String FILE_AUDIO_ELST_SKIP_500MS = "mp4/long_edit_list_audioonly.mp4";
+  public static final String FILE_VIDEO_ELST_TRIM_IDR_DURATION =
+      "mp4/iibbibb_editlist_videoonly.mp4";
 
   private static final String DUMP_FILE_OUTPUT_DIRECTORY = "transformerdumps";
   private static final String DUMP_FILE_EXTENSION = "dump";
@@ -60,7 +63,7 @@ public final class TestUtil {
   private TestUtil() {}
 
   public static Transformer.Builder createTransformerBuilder(
-      CapturingMuxer.Factory muxerFactory, boolean enableFallback) {
+      Muxer.Factory muxerFactory, boolean enableFallback) {
     Context context = ApplicationProvider.getApplicationContext();
     return new Transformer.Builder(context)
         .setClock(new FakeClock(/* isAutoAdvancing= */ true))