Add support for processing 3 byte NAL start code in Mp4Muxer

Issue: androidx/media#725

Ideally the test to transmux a `ts` file (having 3 bytes NAL start code)
should go into `Mp4MuxerEndToEndTest`but `Mp4MuxerEndToEndTest` uses `MediaExtractor` and `MediaExtractor` is returning samples with `4 byte NAL start code` which will not exercise the newly added code path.
Hence the test is added in `TransformerWithInAppMuxerEndToEndTest` which
internally uses `media3 extractor` and feeds samples with `3 bytes NAL start code`
only.

PiperOrigin-RevId: 617985866

libraries/muxer/src/main/java/androidx/media3/muxer/AnnexBToAvccConverter.java

@@ -32,7 +32,7 @@ public interface AnnexBToAvccConverter {
   AnnexBToAvccConverter DEFAULT =
       (ByteBuffer inputBuffer) -> {
         if (!inputBuffer.hasRemaining()) {
-          return;
+          return inputBuffer;
         }
 
         checkArgument(
@@ -40,25 +40,33 @@ public interface AnnexBToAvccConverter {
 
         ImmutableList<ByteBuffer> nalUnitList = AnnexBUtils.findNalUnits(inputBuffer);
 
+        int totalBytesNeeded = 0;
+
         for (int i = 0; i < nalUnitList.size(); i++) {
-          int currentNalUnitLength = nalUnitList.get(i).remaining();
+          // 4 bytes to store NAL unit length.
-
+          totalBytesNeeded += 4 + nalUnitList.get(i).remaining();
-          // Replace the start code with the NAL unit length.
-          inputBuffer.putInt(currentNalUnitLength);
-
-          // Shift the input buffer's position to next start code.
-          int newPosition = inputBuffer.position() + currentNalUnitLength;
-          inputBuffer.position(newPosition);
         }
-        inputBuffer.rewind();
+
+        ByteBuffer outputBuffer = ByteBuffer.allocate(totalBytesNeeded);
+
+        for (int i = 0; i < nalUnitList.size(); i++) {
+          ByteBuffer currentNalUnit = nalUnitList.get(i);
+          int currentNalUnitLength = currentNalUnit.remaining();
+
+          // Rewrite NAL units with NAL unit length in place of start code.
+          outputBuffer.putInt(currentNalUnitLength);
+          outputBuffer.put(currentNalUnit);
+        }
+        outputBuffer.rewind();
+        return outputBuffer;
       };
 
   /**
-   * Processes a buffer in-place.
+   * Returns the processed {@link ByteBuffer}.
    *
    * <p>Expects a {@link ByteBuffer} input with a zero offset.
    *
    * @param inputBuffer The buffer to be converted.
    */
-  void process(ByteBuffer inputBuffer);
+  ByteBuffer process(ByteBuffer inputBuffer);
 }

libraries/muxer/src/main/java/androidx/media3/muxer/AnnexBUtils.java

@@ -15,47 +15,87 @@
  */
 package androidx.media3.muxer;
 
+import androidx.media3.common.C;
 import androidx.media3.common.MimeTypes;
 import com.google.common.collect.ImmutableList;
 import java.nio.ByteBuffer;
 
 /** NAL unit utilities for start codes and emulation prevention. */
 /* package */ final class AnnexBUtils {
+  private static final int THREE_BYTE_NAL_START_CODE_SIZE = 3;
+
   private AnnexBUtils() {}
 
   /**
-   * Splits a {@link ByteBuffer} into individual NAL units (0x00000001 start code).
+   * Splits a {@link ByteBuffer} into individual NAL units (0x000001 or 0x00000001 start code).
    *
-   * <p>An empty list is returned if the input is not NAL units.
+   * <p>An {@link IllegalStateException} is thrown if the NAL units are invalid. The NAL units are
+   * identified as per ITU-T H264 spec:Annex B.2.
    *
-   * <p>The position of the input buffer is unchanged after calling this method.
+   * <p>The input buffer must have position set to 0 and the position remains unchanged after
+   * calling this method.
    */
   public static ImmutableList<ByteBuffer> findNalUnits(ByteBuffer input) {
-    if (input.remaining() < 4 || input.getInt(0) != 1) {
+    if (input.remaining() == 0) {
       return ImmutableList.of();
     }
 
-    ImmutableList.Builder<ByteBuffer> nalUnits = new ImmutableList.Builder<>();
+    int nalStartIndex = C.INDEX_UNSET;
+    int inputLimit = input.limit();
+    boolean readingNalUnit = false;
 
-    int lastStart = 4;
+    // The input must start with a NAL unit.
-    int zerosSeen = 0;
+    for (int i = 0; i < inputLimit; i++) {
-
+      if (isThreeByteNalStartCode(input, i)) {
-    for (int i = 4; i < input.limit(); i++) {
+        nalStartIndex = i + THREE_BYTE_NAL_START_CODE_SIZE;
-      if (input.get(i) == 1 && zerosSeen >= 3) {
+        readingNalUnit = true;
-        // We're just looking at a start code.
+        break;
-        nalUnits.add(getBytes(input, lastStart, i - 3 - lastStart));
+      } else if (input.get(i) == 0) {
-        lastStart = i + 1;
+        // Skip the leading zeroes.
-      }
-
-      // Handle the end of the stream.
-      if (i == input.limit() - 1) {
-        nalUnits.add(getBytes(input, lastStart, input.limit() - lastStart));
-      }
-
-      if (input.get(i) == 0) {
-        zerosSeen++;
       } else {
-        zerosSeen = 0;
+        throw new IllegalStateException("Sample does not start with a NAL unit");
+      }
+    }
+
+    ImmutableList.Builder<ByteBuffer> nalUnits = new ImmutableList.Builder<>();
+    // Look for start code 0x000001. The logic will work for 0x00000001 start code as well because a
+    // NAL unit gets ended even when 0x000000 (which is a prefix of 0x00000001 start code) is found.
+    for (int i = nalStartIndex; i < inputLimit; ) {
+      if (readingNalUnit) {
+        // Found next start code 0x000001.
+        if (isThreeByteNalStartCode(input, i)) {
+          nalUnits.add(getBytes(input, nalStartIndex, i - nalStartIndex));
+          i = i + THREE_BYTE_NAL_START_CODE_SIZE;
+          nalStartIndex = i;
+          continue;
+        } else if (isThreeBytesZeroSequence(input, i)) {
+          // Found code 0x000000; The previous NAL unit should be ended.
+          nalUnits.add(getBytes(input, nalStartIndex, i - nalStartIndex));
+          // Stop reading NAL unit until next start code is found.
+          readingNalUnit = false;
+          i++;
+        } else {
+          // Continue reading NAL unit.
+          i++;
+        }
+      } else {
+        // Found new start code 0x000001.
+        if (isThreeByteNalStartCode(input, i)) {
+          i = i + THREE_BYTE_NAL_START_CODE_SIZE;
+          nalStartIndex = i;
+          readingNalUnit = true;
+        } else if (input.get(i) == 0x00) {
+          // Skip trailing zeroes.
+          i++;
+        } else {
+          // Found garbage data.
+          throw new IllegalStateException("Invalid NAL units");
+        }
+      }
+
+      // Add the last NAL unit.
+      if (i == inputLimit && readingNalUnit) {
+        nalUnits.add(getBytes(input, nalStartIndex, i - nalStartIndex));
       }
     }
     input.rewind();
@@ -97,6 +137,20 @@ import java.nio.ByteBuffer;
         || sampleMimeType.equals(MimeTypes.VIDEO_H265);
   }
 
+  private static boolean isThreeByteNalStartCode(ByteBuffer input, int currentIndex) {
+    return (currentIndex < input.limit() - THREE_BYTE_NAL_START_CODE_SIZE
+        && input.get(currentIndex) == 0x00
+        && input.get(currentIndex + 1) == 0x00
+        && input.get(currentIndex + 2) == 0x01);
+  }
+
+  private static boolean isThreeBytesZeroSequence(ByteBuffer input, int currentIndex) {
+    return (currentIndex < input.limit() - THREE_BYTE_NAL_START_CODE_SIZE
+        && input.get(currentIndex) == 0x00
+        && input.get(currentIndex + 1) == 0x00
+        && input.get(currentIndex + 2) == 0x00);
+  }
+
   private static ByteBuffer getBytes(ByteBuffer buf, int offset, int length) {
     ByteBuffer result = buf.duplicate();
     result.position(offset);

libraries/muxer/src/main/java/androidx/media3/muxer/BasicMp4Writer.java

@@ -264,6 +264,7 @@ import java.util.concurrent.atomic.AtomicBoolean;
 
   /** Writes out any pending samples to the file. */
   private void flushPending(Track track) throws IOException {
+    checkState(track.pendingSamplesByteBuffer.size() == track.pendingSamplesBufferInfo.size());
     if (track.pendingSamplesBufferInfo.isEmpty()) {
       return;
     }
@@ -278,13 +279,7 @@ import java.util.concurrent.atomic.AtomicBoolean;
       bytesNeededInMdat += sample.limit();
     }
 
-    // If the required number of bytes doesn't fit in the gap between the actual data and the moov
+    extendMdatIfRequired(bytesNeededInMdat);
-    // box, extend the file and write out the moov box to the end again.
-    if (mdatDataEnd + bytesNeededInMdat >= mdatEnd) {
-      // Reserve some extra space than required, so that mdat box extension is less frequent.
-      rewriteMoovWithMdatEmptySpace(
-          /* bytesNeeded= */ getMdatExtensionAmount(mdatDataEnd) + bytesNeededInMdat);
-    }
 
     track.writtenChunkOffsets.add(mdatDataEnd);
     track.writtenChunkSampleCounts.add(track.pendingSamplesBufferInfo.size());
@@ -293,22 +288,38 @@ import java.util.concurrent.atomic.AtomicBoolean;
       BufferInfo currentSampleBufferInfo = track.pendingSamplesBufferInfo.removeFirst();
       ByteBuffer currentSampleByteBuffer = track.pendingSamplesByteBuffer.removeFirst();
 
-      track.writtenSamples.add(currentSampleBufferInfo);
-
       // Convert the H.264/H.265 samples from Annex-B format (output by MediaCodec) to
       // Avcc format (required by MP4 container).
       if (doesSampleContainAnnexBNalUnits(checkNotNull(track.format.sampleMimeType))) {
-        annexBToAvccConverter.process(currentSampleByteBuffer);
+        currentSampleByteBuffer = annexBToAvccConverter.process(currentSampleByteBuffer);
+        currentSampleBufferInfo.set(
+            currentSampleByteBuffer.position(),
+            currentSampleByteBuffer.remaining(),
+            currentSampleBufferInfo.presentationTimeUs,
+            currentSampleBufferInfo.flags);
       }
 
-      currentSampleByteBuffer.rewind();
+      // If the original sample had 3 bytes NAL start code instead of 4 bytes, then after AnnexB to
+      // Avcc conversion it will have 1 additional byte.
+      extendMdatIfRequired(currentSampleByteBuffer.remaining());
 
       mdatDataEnd += output.write(currentSampleByteBuffer, mdatDataEnd);
+      track.writtenSamples.add(currentSampleBufferInfo);
     } while (!track.pendingSamplesBufferInfo.isEmpty());
 
     checkState(mdatDataEnd <= mdatEnd);
   }
 
+  private void extendMdatIfRequired(long additionalBytesNeeded) throws IOException {
+    // If the required number of bytes doesn't fit in the gap between the actual data and the moov
+    // box, extend the file and write out the moov box to the end again.
+    if (mdatDataEnd + additionalBytesNeeded >= mdatEnd) {
+      // Reserve some extra space than required, so that mdat box extension is less frequent.
+      rewriteMoovWithMdatEmptySpace(
+          /* bytesNeeded= */ getMdatExtensionAmount(mdatDataEnd) + additionalBytesNeeded);
+    }
+  }
+
   private void updateMdatSize() throws IOException {
     // Assuming that the mdat box has a 64-bit length, skip the box type (4 bytes) and
     // the 32-bit box length field (4 bytes).

libraries/muxer/src/main/java/androidx/media3/muxer/FragmentedMp4Writer.java

@@ -277,23 +277,30 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
 
   private ProcessedTrackInfo processTrack(int trackId, Track track) {
     checkState(track.pendingSamplesByteBuffer.size() == track.pendingSamplesBufferInfo.size());
+
     ImmutableList.Builder<ByteBuffer> pendingSamplesByteBuffer = new ImmutableList.Builder<>();
+    ImmutableList.Builder<BufferInfo> pendingSamplesBufferInfoBuilder =
+        new ImmutableList.Builder<>();
     if (doesSampleContainAnnexBNalUnits(checkNotNull(track.format.sampleMimeType))) {
       while (!track.pendingSamplesByteBuffer.isEmpty()) {
         ByteBuffer currentSampleByteBuffer = track.pendingSamplesByteBuffer.removeFirst();
-        annexBToAvccConverter.process(currentSampleByteBuffer);
+        currentSampleByteBuffer = annexBToAvccConverter.process(currentSampleByteBuffer);
         pendingSamplesByteBuffer.add(currentSampleByteBuffer);
+        BufferInfo currentSampleBufferInfo = track.pendingSamplesBufferInfo.removeFirst();
+        currentSampleBufferInfo.set(
+            currentSampleByteBuffer.position(),
+            currentSampleByteBuffer.remaining(),
+            currentSampleBufferInfo.presentationTimeUs,
+            currentSampleBufferInfo.flags);
+        pendingSamplesBufferInfoBuilder.add(currentSampleBufferInfo);
       }
     } else {
       pendingSamplesByteBuffer.addAll(track.pendingSamplesByteBuffer);
       track.pendingSamplesByteBuffer.clear();
+      pendingSamplesBufferInfoBuilder.addAll(track.pendingSamplesBufferInfo);
+      track.pendingSamplesBufferInfo.clear();
     }
 
-    ImmutableList.Builder<BufferInfo> pendingSamplesBufferInfoBuilder =
-        new ImmutableList.Builder<>();
-    pendingSamplesBufferInfoBuilder.addAll(track.pendingSamplesBufferInfo);
-    track.pendingSamplesBufferInfo.clear();
-
     ImmutableList<BufferInfo> pendingSamplesBufferInfo = pendingSamplesBufferInfoBuilder.build();
     List<Long> sampleDurations =
         Boxes.convertPresentationTimestampsToDurationsVu(

libraries/muxer/src/test/java/androidx/media3/muxer/AnnexBUtilsTest.java

@@ -17,6 +17,7 @@ package androidx.media3.muxer;
 
 import static androidx.media3.common.util.Util.getBytesFromHexString;
 import static com.google.common.truth.Truth.assertThat;
+import static org.junit.Assert.assertThrows;
 
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 import com.google.common.collect.ImmutableList;
@@ -29,76 +30,109 @@ import org.junit.runner.RunWith;
 public class AnnexBUtilsTest {
   @Test
   public void findNalUnits_emptyBuffer_returnsEmptyList() {
-    ByteBuffer buf = ByteBuffer.wrap(getBytesFromHexString(""));
+    ByteBuffer buffer = ByteBuffer.wrap(getBytesFromHexString(""));
 
-    ImmutableList<ByteBuffer> components = AnnexBUtils.findNalUnits(buf);
+    ImmutableList<ByteBuffer> components = AnnexBUtils.findNalUnits(buffer);
 
     assertThat(components).isEmpty();
   }
 
   @Test
-  public void findNalUnits_noNalUnit_returnsEmptyList() {
+  public void findNalUnits_noNalUnit_throws() {
-    ByteBuffer buf = ByteBuffer.wrap(getBytesFromHexString("ABCDEFABC"));
+    ByteBuffer buffer = ByteBuffer.wrap(getBytesFromHexString("ABCDEFABC"));
 
-    ImmutableList<ByteBuffer> components = AnnexBUtils.findNalUnits(buf);
+    assertThrows(IllegalStateException.class, () -> AnnexBUtils.findNalUnits(buffer));
-
-    assertThat(components).isEmpty();
   }
 
   @Test
-  public void findNalUnits_singleNalUnit_returnsSingleElement() {
+  public void findNalUnits_singleNalUnitWithFourByteStartCode_returnsSingleElement() {
-    ByteBuffer buf = ByteBuffer.wrap(getBytesFromHexString("00000001ABCDEF"));
+    ByteBuffer buffer = ByteBuffer.wrap(getBytesFromHexString("00000001ABCDEF"));
 
-    ImmutableList<ByteBuffer> components = AnnexBUtils.findNalUnits(buf);
+    ImmutableList<ByteBuffer> components = AnnexBUtils.findNalUnits(buffer);
 
-    assertThat(components).hasSize(1);
+    assertThat(components).containsExactly(ByteBuffer.wrap(getBytesFromHexString("ABCDEF")));
-    assertThat(components.get(0)).isEqualTo(ByteBuffer.wrap(getBytesFromHexString("ABCDEF")));
   }
 
   @Test
-  public void findNalUnits_multipleNalUnits_allReturned() {
+  public void findNalUnits_singleNalUnitWithThreeByteStartCode_returnsSingleElement() {
-    ByteBuffer buf =
+    ByteBuffer buffer = ByteBuffer.wrap(getBytesFromHexString("000001ABCDEF"));
+
+    ImmutableList<ByteBuffer> components = AnnexBUtils.findNalUnits(buffer);
+
+    assertThat(components).containsExactly(ByteBuffer.wrap(getBytesFromHexString("ABCDEF")));
+  }
+
+  @Test
+  public void findNalUnits_multipleNalUnitsWithFourByteStartCode_allReturned() {
+    ByteBuffer buffer =
         ByteBuffer.wrap(getBytesFromHexString("00000001ABCDEF00000001DDCC00000001BBAA"));
 
-    ImmutableList<ByteBuffer> components = AnnexBUtils.findNalUnits(buf);
+    ImmutableList<ByteBuffer> components = AnnexBUtils.findNalUnits(buffer);
 
-    assertThat(components).hasSize(3);
+    assertThat(components)
-    assertThat(components.get(0)).isEqualTo(ByteBuffer.wrap(getBytesFromHexString("ABCDEF")));
+        .containsExactly(
-    assertThat(components.get(1)).isEqualTo(ByteBuffer.wrap(getBytesFromHexString("DDCC")));
+            ByteBuffer.wrap(getBytesFromHexString("ABCDEF")),
-    assertThat(components.get(2)).isEqualTo(ByteBuffer.wrap(getBytesFromHexString("BBAA")));
+            ByteBuffer.wrap(getBytesFromHexString("DDCC")),
+            ByteBuffer.wrap(getBytesFromHexString("BBAA")))
+        .inOrder();
   }
 
   @Test
-  public void findNalUnits_partialStartCodes_ignored() {
+  public void findNalUnits_multipleNalUnitsWithThreeByteStartCode_allReturned() {
+    ByteBuffer buffer = ByteBuffer.wrap(getBytesFromHexString("000001ABCDEF000001DDCC000001BBAA"));
+
+    ImmutableList<ByteBuffer> components = AnnexBUtils.findNalUnits(buffer);
+
+    assertThat(components)
+        .containsExactly(
+            ByteBuffer.wrap(getBytesFromHexString("ABCDEF")),
+            ByteBuffer.wrap(getBytesFromHexString("DDCC")),
+            ByteBuffer.wrap(getBytesFromHexString("BBAA")))
+        .inOrder();
+  }
+
+  @Test
+  public void findNalUnits_withTrainingZeroesFollowedByGarbageData_throws() {
     // The NAL unit has lots of zeros but no start code.
-    ByteBuffer buf =
+    ByteBuffer buffer =
         ByteBuffer.wrap(getBytesFromHexString("00000001ABCDEF0000AB0000CDEF00000000AB"));
 
-    ImmutableList<ByteBuffer> components = AnnexBUtils.findNalUnits(buf);
+    assertThrows(IllegalStateException.class, () -> AnnexBUtils.findNalUnits(buffer));
-
-    assertThat(components).hasSize(1);
-    assertThat(components.get(0))
-        .isEqualTo(ByteBuffer.wrap(getBytesFromHexString("ABCDEF0000AB0000CDEF00000000AB")));
   }
 
   @Test
-  public void findNalUnits_startCodeWithManyZeros_stillSplits() {
+  public void findNalUnits_withTrailingZeroes_stripsTrailingZeroes() {
-    // The NAL unit has a start code that starts with more than 3 zeros (although too many zeros
+    // The first NAL unit has some training zeroes.
-    // aren't allowed).
+    ByteBuffer buffer = ByteBuffer.wrap(getBytesFromHexString("00000001ABCDEF000000000001AB"));
-    ByteBuffer buf = ByteBuffer.wrap(getBytesFromHexString("00000001ABCDEF000000000001AB"));
 
-    ImmutableList<ByteBuffer> components = AnnexBUtils.findNalUnits(buf);
+    ImmutableList<ByteBuffer> components = AnnexBUtils.findNalUnits(buffer);
 
-    assertThat(components).hasSize(2);
+    assertThat(components)
-    assertThat(components.get(0)).isEqualTo(ByteBuffer.wrap(getBytesFromHexString("ABCDEF0000")));
+        .containsExactly(
-    assertThat(components.get(1)).isEqualTo(ByteBuffer.wrap(getBytesFromHexString("AB")));
+            ByteBuffer.wrap(getBytesFromHexString("ABCDEF")),
+            ByteBuffer.wrap(getBytesFromHexString("AB")))
+        .inOrder();
+  }
+
+  @Test
+  public void findNalUnits_withBothThreeBytesAndFourBytesNalStartCode_returnsAllNalUnits() {
+    ByteBuffer buffer = ByteBuffer.wrap(getBytesFromHexString("00000001ABCDEF000001AB000001CDEF"));
+
+    ImmutableList<ByteBuffer> components = AnnexBUtils.findNalUnits(buffer);
+
+    assertThat(components)
+        .containsExactly(
+            ByteBuffer.wrap(getBytesFromHexString("ABCDEF")),
+            ByteBuffer.wrap(getBytesFromHexString("AB")),
+            ByteBuffer.wrap(getBytesFromHexString("CDEF")))
+        .inOrder();
   }
 
   @Test
   public void stripEmulationPrevention_noEmulationPreventionBytes_copiesInput() {
-    ByteBuffer buf = ByteBuffer.wrap(getBytesFromHexString("00000001ABCDEF000000000001AB"));
+    ByteBuffer buffer = ByteBuffer.wrap(getBytesFromHexString("00000001ABCDEF000000000001AB"));
 
-    ByteBuffer output = AnnexBUtils.stripEmulationPrevention(buf);
+    ByteBuffer output = AnnexBUtils.stripEmulationPrevention(buffer);
 
     assertThat(output)
         .isEqualTo(ByteBuffer.wrap(getBytesFromHexString("00000001ABCDEF000000000001AB")));
@@ -107,9 +141,9 @@ public class AnnexBUtilsTest {
   @Test
   public void stripEmulationPrevention_emulationPreventionPresent_bytesStripped() {
     // The NAL unit has a 00 00 03 * sequence.
-    ByteBuffer buf = ByteBuffer.wrap(getBytesFromHexString("00000001ABCDEF00000300000001AB"));
+    ByteBuffer buffer = ByteBuffer.wrap(getBytesFromHexString("00000001ABCDEF00000300000001AB"));
 
-    ByteBuffer output = AnnexBUtils.stripEmulationPrevention(buf);
+    ByteBuffer output = AnnexBUtils.stripEmulationPrevention(buffer);
 
     assertThat(output)
         .isEqualTo(ByteBuffer.wrap(getBytesFromHexString("00000001ABCDEF000000000001AB")));
@@ -118,9 +152,9 @@ public class AnnexBUtilsTest {
   @Test
   public void stripEmulationPrevention_03WithoutEnoughZeros_notStripped() {
     // The NAL unit has a 03 byte around, but not preceded by enough zeros.
-    ByteBuffer buf = ByteBuffer.wrap(getBytesFromHexString("ABCDEFABCD0003EFABCD03ABCD"));
+    ByteBuffer buffer = ByteBuffer.wrap(getBytesFromHexString("ABCDEFABCD0003EFABCD03ABCD"));
 
-    ByteBuffer output = AnnexBUtils.stripEmulationPrevention(buf);
+    ByteBuffer output = AnnexBUtils.stripEmulationPrevention(buffer);
 
     assertThat(output)
         .isEqualTo(ByteBuffer.wrap(getBytesFromHexString("ABCDEFABCD0003EFABCD03ABCD")));
@@ -129,9 +163,9 @@ public class AnnexBUtilsTest {
   @Test
   public void stripEmulationPrevention_03AtEnd_stripped() {
     // The NAL unit has a 03 byte at the very end of the input.
-    ByteBuffer buf = ByteBuffer.wrap(getBytesFromHexString("ABCDEF000003"));
+    ByteBuffer buffer = ByteBuffer.wrap(getBytesFromHexString("ABCDEF000003"));
 
-    ByteBuffer output = AnnexBUtils.stripEmulationPrevention(buf);
+    ByteBuffer output = AnnexBUtils.stripEmulationPrevention(buffer);
 
     assertThat(output).isEqualTo(ByteBuffer.wrap(getBytesFromHexString("ABCDEF0000")));
   }

libraries/muxer/src/test/java/androidx/media3/muxer/DefaultAnnexBToAvccConverterTest.java

@@ -16,6 +16,7 @@
 package androidx.media3.muxer;
 
 import static com.google.common.truth.Truth.assertThat;
+import static org.junit.Assert.assertThrows;
 
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 import java.nio.ByteBuffer;
@@ -27,55 +28,49 @@ import org.junit.runner.RunWith;
 public final class DefaultAnnexBToAvccConverterTest {
   @Test
   public void convertAnnexBToAvcc_singleNalUnit() {
-    ByteBuffer in = generateFakeNalUnitData(1000);
+    ByteBuffer input = generateFakeNalUnitData(1000);
     // Add start code for the NAL unit.
-    in.put(0, (byte) 0);
+    input.put(0, (byte) 0);
-    in.put(1, (byte) 0);
+    input.put(1, (byte) 0);
-    in.put(2, (byte) 0);
+    input.put(2, (byte) 0);
-    in.put(3, (byte) 1);
+    input.put(3, (byte) 1);
 
     AnnexBToAvccConverter annexBToAvccConverter = AnnexBToAvccConverter.DEFAULT;
-    annexBToAvccConverter.process(in);
+    ByteBuffer output = annexBToAvccConverter.process(input);
 
     // The start code should get replaced with the length of the NAL unit.
-    assertThat(in.getInt(0)).isEqualTo(996);
+    assertThat(output.getInt(0)).isEqualTo(996);
   }
 
   @Test
   public void convertAnnexBToAvcc_twoNalUnits() {
-    ByteBuffer in = generateFakeNalUnitData(1000);
+    ByteBuffer input = generateFakeNalUnitData(1000);
     // Add start code for the first NAL unit.
-    in.put(0, (byte) 0);
+    input.put(0, (byte) 0);
-    in.put(1, (byte) 0);
+    input.put(1, (byte) 0);
-    in.put(2, (byte) 0);
+    input.put(2, (byte) 0);
-    in.put(3, (byte) 1);
+    input.put(3, (byte) 1);
 
     // Add start code for the second NAL unit.
-    in.put(600, (byte) 0);
+    input.put(600, (byte) 0);
-    in.put(601, (byte) 0);
+    input.put(601, (byte) 0);
-    in.put(602, (byte) 0);
+    input.put(602, (byte) 0);
-    in.put(603, (byte) 1);
+    input.put(603, (byte) 1);
 
     AnnexBToAvccConverter annexBToAvccConverter = AnnexBToAvccConverter.DEFAULT;
-    annexBToAvccConverter.process(in);
+    ByteBuffer output = annexBToAvccConverter.process(input);
 
     // Both the NAL units should have length headers.
-    assertThat(in.getInt(0)).isEqualTo(596);
+    assertThat(output.getInt(0)).isEqualTo(596);
-    assertThat(in.getInt(600)).isEqualTo(396);
+    assertThat(output.getInt(600)).isEqualTo(396);
   }
 
   @Test
-  public void convertAnnexBToAvcc_noNalUnit_outputSameAsInput() {
+  public void convertAnnexBToAvcc_noNalUnit_throws() {
     ByteBuffer input = generateFakeNalUnitData(1000);
-    ByteBuffer inputCopy = ByteBuffer.allocate(input.limit());
-    inputCopy.put(input);
-    input.rewind();
-    inputCopy.rewind();
 
     AnnexBToAvccConverter annexBToAvccConverter = AnnexBToAvccConverter.DEFAULT;
-    annexBToAvccConverter.process(input);
+    assertThrows(IllegalStateException.class, () -> annexBToAvccConverter.process(input));
-
-    assertThat(input).isEqualTo(inputCopy);
   }
 
   /** Returns {@link ByteBuffer} filled with random NAL unit data without start code. */

libraries/test_data/src/test/assets/muxerdumps/mp4_with_0_orientation.mp4.dump

@@ -7,13 +7,13 @@ seekMap:
   getPosition(0) = [[timeUs=0, position=44]]
 numberOfTracks = 1
 track 0:
-  total output bytes = 55
+  total output bytes = 56
   sample count = 1
   format 0:
     id = 1
     sampleMimeType = video/avc
     codecs = avc1.F4000A
-    maxInputSize = 85
+    maxInputSize = 86
     width = 12
     height = 10
     colorInfo:
@@ -27,5 +27,5 @@ track 0:
   sample 0:
     time = 0
     flags = 536870913
-    data = length 55, hash A481CEF4
+    data = length 56, hash C4551A2E
 tracksEnded = true

libraries/test_data/src/test/assets/muxerdumps/mp4_with_180_orientation.mp4.dump

@@ -7,13 +7,13 @@ seekMap:
   getPosition(0) = [[timeUs=0, position=44]]
 numberOfTracks = 1
 track 0:
-  total output bytes = 55
+  total output bytes = 56
   sample count = 1
   format 0:
     id = 1
     sampleMimeType = video/avc
     codecs = avc1.F4000A
-    maxInputSize = 85
+    maxInputSize = 86
     width = 12
     height = 10
     rotationDegrees = 180
@@ -28,5 +28,5 @@ track 0:
   sample 0:
     time = 0
     flags = 536870913
-    data = length 55, hash A481CEF4
+    data = length 56, hash C4551A2E
 tracksEnded = true

libraries/test_data/src/test/assets/muxerdumps/mp4_with_270_orientation.mp4.dump

@@ -7,13 +7,13 @@ seekMap:
   getPosition(0) = [[timeUs=0, position=44]]
 numberOfTracks = 1
 track 0:
-  total output bytes = 55
+  total output bytes = 56
   sample count = 1
   format 0:
     id = 1
     sampleMimeType = video/avc
     codecs = avc1.F4000A
-    maxInputSize = 85
+    maxInputSize = 86
     width = 12
     height = 10
     rotationDegrees = 270
@@ -28,5 +28,5 @@ track 0:
   sample 0:
     time = 0
     flags = 536870913
-    data = length 55, hash A481CEF4
+    data = length 56, hash C4551A2E
 tracksEnded = true

libraries/test_data/src/test/assets/muxerdumps/mp4_with_90_orientation.mp4.dump

@@ -7,13 +7,13 @@ seekMap:
   getPosition(0) = [[timeUs=0, position=44]]
 numberOfTracks = 1
 track 0:
-  total output bytes = 55
+  total output bytes = 56
   sample count = 1
   format 0:
     id = 1
     sampleMimeType = video/avc
     codecs = avc1.F4000A
-    maxInputSize = 85
+    maxInputSize = 86
     width = 12
     height = 10
     rotationDegrees = 90
@@ -28,5 +28,5 @@ track 0:
   sample 0:
     time = 0
     flags = 536870913
-    data = length 55, hash A481CEF4
+    data = length 56, hash C4551A2E
 tracksEnded = true

libraries/test_data/src/test/assets/muxerdumps/mp4_with_different_tracks_offset.mp4.dump

@@ -2,18 +2,18 @@ seekMap:
   isSeekable = true
   duration = 200
   getPosition(0) = [[timeUs=0, position=44]]
-  getPosition(1) = [[timeUs=0, position=44], [timeUs=100, position=99]]
+  getPosition(1) = [[timeUs=0, position=44], [timeUs=100, position=100]]
-  getPosition(100) = [[timeUs=100, position=99]]
+  getPosition(100) = [[timeUs=100, position=100]]
-  getPosition(200) = [[timeUs=100, position=99]]
+  getPosition(200) = [[timeUs=100, position=100]]
 numberOfTracks = 2
 track 0:
-  total output bytes = 110
+  total output bytes = 112
   sample count = 2
   format 0:
     id = 1
     sampleMimeType = video/avc
     codecs = avc1.F4000A
-    maxInputSize = 85
+    maxInputSize = 86
     width = 12
     height = 10
     frameRate = 20000.0
@@ -28,19 +28,19 @@ track 0:
   sample 0:
     time = 0
     flags = 1
-    data = length 55, hash A481CEF4
+    data = length 56, hash C4551A2E
   sample 1:
     time = 100
     flags = 536870913
-    data = length 55, hash A481CEF4
+    data = length 56, hash C4551A2E
 track 1:
-  total output bytes = 110
+  total output bytes = 112
   sample count = 2
   format 0:
     id = 2
     sampleMimeType = video/avc
     codecs = avc1.F4000A
-    maxInputSize = 85
+    maxInputSize = 86
     width = 12
     height = 10
     frameRate = 10000.0
@@ -55,9 +55,9 @@ track 1:
   sample 0:
     time = 0
     flags = 1
-    data = length 55, hash A481CEF4
+    data = length 56, hash C4551A2E
   sample 1:
     time = 200
     flags = 536870913
-    data = length 55, hash A481CEF4
+    data = length 56, hash C4551A2E
 tracksEnded = true

libraries/test_data/src/test/assets/muxerdumps/mp4_with_float_metadata.mp4.dump

@@ -7,13 +7,13 @@ seekMap:
   getPosition(0) = [[timeUs=0, position=44]]
 numberOfTracks = 1
 track 0:
-  total output bytes = 55
+  total output bytes = 56
   sample count = 1
   format 0:
     id = 1
     sampleMimeType = video/avc
     codecs = avc1.F4000A
-    maxInputSize = 85
+    maxInputSize = 86
     width = 12
     height = 10
     colorInfo:
@@ -27,5 +27,5 @@ track 0:
   sample 0:
     time = 0
     flags = 536870913
-    data = length 55, hash A481CEF4
+    data = length 56, hash C4551A2E
 tracksEnded = true

libraries/test_data/src/test/assets/muxerdumps/mp4_with_frame_rate.mp4.dump

@@ -7,13 +7,13 @@ seekMap:
   getPosition(0) = [[timeUs=0, position=44]]
 numberOfTracks = 1
 track 0:
-  total output bytes = 55
+  total output bytes = 56
   sample count = 1
   format 0:
     id = 1
     sampleMimeType = video/avc
     codecs = avc1.F4000A
-    maxInputSize = 85
+    maxInputSize = 86
     width = 12
     height = 10
     colorInfo:
@@ -27,5 +27,5 @@ track 0:
   sample 0:
     time = 0
     flags = 536870913
-    data = length 55, hash A481CEF4
+    data = length 56, hash C4551A2E
 tracksEnded = true

libraries/test_data/src/test/assets/muxerdumps/mp4_with_location.mp4.dump

@@ -7,13 +7,13 @@ seekMap:
   getPosition(0) = [[timeUs=0, position=44]]
 numberOfTracks = 1
 track 0:
-  total output bytes = 55
+  total output bytes = 56
   sample count = 1
   format 0:
     id = 1
     sampleMimeType = video/avc
     codecs = avc1.F4000A
-    maxInputSize = 85
+    maxInputSize = 86
     width = 12
     height = 10
     colorInfo:
@@ -27,5 +27,5 @@ track 0:
   sample 0:
     time = 0
     flags = 536870913
-    data = length 55, hash A481CEF4
+    data = length 56, hash C4551A2E
 tracksEnded = true

libraries/test_data/src/test/assets/muxerdumps/mp4_with_null_location.mp4.dump

@@ -7,13 +7,13 @@ seekMap:
   getPosition(0) = [[timeUs=0, position=44]]
 numberOfTracks = 1
 track 0:
-  total output bytes = 55
+  total output bytes = 56
   sample count = 1
   format 0:
     id = 1
     sampleMimeType = video/avc
     codecs = avc1.F4000A
-    maxInputSize = 85
+    maxInputSize = 86
     width = 12
     height = 10
     colorInfo:
@@ -27,5 +27,5 @@ track 0:
   sample 0:
     time = 0
     flags = 536870913
-    data = length 55, hash A481CEF4
+    data = length 56, hash C4551A2E
 tracksEnded = true

libraries/test_data/src/test/assets/muxerdumps/mp4_with_same_tracks_offset.mp4.dump

@@ -2,18 +2,18 @@ seekMap:
   isSeekable = true
   duration = 200
   getPosition(0) = [[timeUs=0, position=44]]
-  getPosition(1) = [[timeUs=0, position=44], [timeUs=100, position=99]]
+  getPosition(1) = [[timeUs=0, position=44], [timeUs=100, position=100]]
-  getPosition(100) = [[timeUs=100, position=99]]
+  getPosition(100) = [[timeUs=100, position=100]]
-  getPosition(200) = [[timeUs=100, position=99]]
+  getPosition(200) = [[timeUs=100, position=100]]
 numberOfTracks = 2
 track 0:
-  total output bytes = 110
+  total output bytes = 112
   sample count = 2
   format 0:
     id = 1
     sampleMimeType = video/avc
     codecs = avc1.F4000A
-    maxInputSize = 85
+    maxInputSize = 86
     width = 12
     height = 10
     frameRate = 20000.0
@@ -28,19 +28,19 @@ track 0:
   sample 0:
     time = 0
     flags = 1
-    data = length 55, hash A481CEF4
+    data = length 56, hash C4551A2E
   sample 1:
     time = 100
     flags = 536870913
-    data = length 55, hash A481CEF4
+    data = length 56, hash C4551A2E
 track 1:
-  total output bytes = 110
+  total output bytes = 112
   sample count = 2
   format 0:
     id = 2
     sampleMimeType = video/avc
     codecs = avc1.F4000A
-    maxInputSize = 85
+    maxInputSize = 86
     width = 12
     height = 10
     frameRate = 10000.0
@@ -55,9 +55,9 @@ track 1:
   sample 0:
     time = 0
     flags = 1
-    data = length 55, hash A481CEF4
+    data = length 56, hash C4551A2E
   sample 1:
     time = 200
     flags = 536870913
-    data = length 55, hash A481CEF4
+    data = length 56, hash C4551A2E
 tracksEnded = true

libraries/test_data/src/test/assets/muxerdumps/mp4_with_samples_and_metadata.mp4.dump

@@ -1,7 +1,7 @@
 ftyp (28 bytes):
   Data = length 20, hash EF896440
-mdat (71 bytes):
+mdat (72 bytes):
-  Data = length 55, hash 6B19F4A7
+  Data = length 56, hash DB5662FB
 moov (873 bytes):
   mvhd (108 bytes):
     Data = length 100, hash 2613A5C
@@ -33,7 +33,7 @@ moov (873 bytes):
           stts (24 bytes):
             Data = length 16, hash E4FC6483
           stsz (24 bytes):
-            Data = length 16, hash 50B7F5B9
+            Data = length 16, hash 50B7F5BA
           stsc (28 bytes):
             Data = length 20, hash 8F6E8285
           co64 (24 bytes):

libraries/test_data/src/test/assets/muxerdumps/mp4_with_string_metadata.mp4.dump

@@ -7,13 +7,13 @@ seekMap:
   getPosition(0) = [[timeUs=0, position=44]]
 numberOfTracks = 1
 track 0:
-  total output bytes = 55
+  total output bytes = 56
   sample count = 1
   format 0:
     id = 1
     sampleMimeType = video/avc
     codecs = avc1.F4000A
-    maxInputSize = 85
+    maxInputSize = 86
     width = 12
     height = 10
     colorInfo:
@@ -27,5 +27,5 @@ track 0:
   sample 0:
     time = 0
     flags = 536870913
-    data = length 55, hash A481CEF4
+    data = length 56, hash C4551A2E
 tracksEnded = true

libraries/test_data/src/test/assets/muxerdumps/mp4_with_xmp.mp4.dump

@@ -1,7 +1,7 @@
 ftyp (28 bytes):
   Data = length 20, hash EF896440
-mdat (71 bytes):
+mdat (72 bytes):
-  Data = length 55, hash 6B19F4A7
+  Data = length 56, hash DB5662FB
 moov (658 bytes):
   mvhd (108 bytes):
     Data = length 100, hash 2613A5C
@@ -24,7 +24,7 @@ moov (658 bytes):
           stts (24 bytes):
             Data = length 16, hash E4FC6483
           stsz (24 bytes):
-            Data = length 16, hash 50B7F5B9
+            Data = length 16, hash 50B7F5BA
           stsc (28 bytes):
             Data = length 20, hash 8F6E8285
           co64 (24 bytes):

libraries/test_data/src/test/assets/muxerdumps/mp4_without_empty_track.mp4.dump

@@ -1,7 +1,7 @@
 ftyp (28 bytes):
   Data = length 20, hash EF896440
-mdat (126 bytes):
+mdat (128 bytes):
-  Data = length 110, hash 48173D41
+  Data = length 112, hash 1AAF8FF5
 moov (674 bytes):
   mvhd (108 bytes):
     Data = length 100, hash 105FA889
@@ -24,7 +24,7 @@ moov (674 bytes):
           stts (32 bytes):
             Data = length 24, hash 4A7D0E0E
           stsz (28 bytes):
-            Data = length 20, hash 3828E071
+            Data = length 20, hash 3836F7F3
           stsc (28 bytes):
             Data = length 20, hash 8F7C9A06
           co64 (24 bytes):

libraries/test_data/src/test/assets/muxerdumps/sample_no_bframes.mp4.dump

@@ -201,13 +201,13 @@ track 0:
     flags = 536870913
     data = length 6, hash 31B22286
 track 1:
-  total output bytes = 301392
+  total output bytes = 301222
   sample count = 30
   format 0:
     id = 2
     sampleMimeType = video/avc
     codecs = avc1.640034
-    maxInputSize = 22910
+    maxInputSize = 22904
     width = 1080
     height = 720
     frameRate = 31.004547
@@ -224,7 +224,7 @@ track 1:
   sample 0:
     time = 0
     flags = 1
-    data = length 7744, hash DDF91733
+    data = length 7735, hash 87BD736D
   sample 1:
     time = 33355
     flags = 0
@@ -232,7 +232,7 @@ track 1:
   sample 2:
     time = 66722
     flags = 0
-    data = length 960, hash D4AD9EF0
+    data = length 955, hash 9626CB10
   sample 3:
     time = 100100
     flags = 0
@@ -248,7 +248,7 @@ track 1:
   sample 6:
     time = 200200
     flags = 0
-    data = length 3856, hash 3D7DCD46
+    data = length 3850, hash 6E1AB9C6
   sample 7:
     time = 233555
     flags = 0
@@ -256,7 +256,7 @@ track 1:
   sample 8:
     time = 266922
     flags = 0
-    data = length 6144, hash 8FD9AD7D
+    data = length 6137, hash AAA5D523
   sample 9:
     time = 300300
     flags = 0
@@ -268,43 +268,43 @@ track 1:
   sample 11:
     time = 367022
     flags = 0
-    data = length 14496, hash E0F2E0BA
+    data = length 14490, hash C5F0743A
   sample 12:
     time = 400400
     flags = 0
-    data = length 17664, hash 3E3189E
+    data = length 17652, hash 63C959E
   sample 13:
     time = 433755
     flags = 0
-    data = length 5712, hash CA808ECF
+    data = length 5703, hash 44AFBC51
   sample 14:
     time = 467122
     flags = 0
-    data = length 9776, hash C875D1AA
+    data = length 9766, hash 77D5FE2A
   sample 15:
     time = 500500
     flags = 0
-    data = length 17712, hash 69AE17D4
+    data = length 17704, hash CF5D2BD4
   sample 16:
     time = 533855
     flags = 0
-    data = length 11440, hash 7370E78C
+    data = length 11436, hash 9DCA8D8C
   sample 17:
     time = 567222
     flags = 0
-    data = length 8544, hash 5A581986
+    data = length 8540, hash BEBDCC86
   sample 18:
     time = 600600
     flags = 0
-    data = length 19904, hash 98AB5C44
+    data = length 19894, hash 6212144
   sample 19:
     time = 633955
     flags = 0
-    data = length 14352, hash 74B754E3
+    data = length 14342, hash EC6E84A3
   sample 20:
     time = 667322
     flags = 0
-    data = length 9568, hash 369746A6
+    data = length 9555, hash 601CE39A
   sample 21:
     time = 700700
     flags = 0
@@ -312,33 +312,33 @@ track 1:
   sample 22:
     time = 734055
     flags = 0
-    data = length 22880, hash 75E833BA
+    data = length 22874, hash 4620073A
   sample 23:
     time = 767422
     flags = 0
-    data = length 16832, hash E8BFCFE3
+    data = length 16821, hash 95A33FFD
   sample 24:
     time = 800800
     flags = 0
-    data = length 5120, hash E04AEF94
+    data = length 5114, hash F0CB2E94
   sample 25:
     time = 834155
     flags = 0
-    data = length 9888, hash 1166103E
+    data = length 9884, hash 103DF3E
   sample 26:
     time = 867522
     flags = 0
-    data = length 17024, hash F9A96740
+    data = length 17011, hash 82DFD0C0
   sample 27:
     time = 900900
     flags = 0
-    data = length 20864, hash DF9E88B8
+    data = length 20860, hash 5DEFA4B8
   sample 28:
     time = 934255
     flags = 0
-    data = length 7216, hash BE22BE2F
+    data = length 7209, hash AFAC48B1
   sample 29:
     time = 967622
     flags = 536870912
-    data = length 14240, hash E190BF31
+    data = length 14234, hash 101837F1
 tracksEnded = true

libraries/test_data/src/test/assets/transformerdumps/mp4/sample_no_bframes.mp4/transmuxed_with_inappmuxer.dump

@@ -7,13 +7,13 @@ seekMap:
   getPosition(1065600) = [[timeUs=0, position=44]]
 numberOfTracks = 2
 track 0:
-  total output bytes = 301392
+  total output bytes = 301222
   sample count = 30
   format 0:
     id = 1
     sampleMimeType = video/avc
     codecs = avc1.640034
-    maxInputSize = 22910
+    maxInputSize = 22904
     width = 1080
     height = 720
     frameRate = 31.004547
@@ -30,7 +30,7 @@ track 0:
   sample 0:
     time = 0
     flags = 1
-    data = length 7744, hash DDF91733
+    data = length 7735, hash 87BD736D
   sample 1:
     time = 33355
     flags = 0
@@ -38,7 +38,7 @@ track 0:
   sample 2:
     time = 66722
     flags = 0
-    data = length 960, hash D4AD9EF0
+    data = length 955, hash 9626CB10
   sample 3:
     time = 100100
     flags = 0
@@ -54,7 +54,7 @@ track 0:
   sample 6:
     time = 200200
     flags = 0
-    data = length 3856, hash 3D7DCD46
+    data = length 3850, hash 6E1AB9C6
   sample 7:
     time = 233555
     flags = 0
@@ -62,7 +62,7 @@ track 0:
   sample 8:
     time = 266922
     flags = 0
-    data = length 6144, hash 8FD9AD7D
+    data = length 6137, hash AAA5D523
   sample 9:
     time = 300300
     flags = 0
@@ -74,43 +74,43 @@ track 0:
   sample 11:
     time = 367022
     flags = 0
-    data = length 14496, hash E0F2E0BA
+    data = length 14490, hash C5F0743A
   sample 12:
     time = 400400
     flags = 0
-    data = length 17664, hash 3E3189E
+    data = length 17652, hash 63C959E
   sample 13:
     time = 433755
     flags = 0
-    data = length 5712, hash CA808ECF
+    data = length 5703, hash 44AFBC51
   sample 14:
     time = 467122
     flags = 0
-    data = length 9776, hash C875D1AA
+    data = length 9766, hash 77D5FE2A
   sample 15:
     time = 500500
     flags = 0
-    data = length 17712, hash 69AE17D4
+    data = length 17704, hash CF5D2BD4
   sample 16:
     time = 533855
     flags = 0
-    data = length 11440, hash 7370E78C
+    data = length 11436, hash 9DCA8D8C
   sample 17:
     time = 567222
     flags = 0
-    data = length 8544, hash 5A581986
+    data = length 8540, hash BEBDCC86
   sample 18:
     time = 600600
     flags = 0
-    data = length 19904, hash 98AB5C44
+    data = length 19894, hash 6212144
   sample 19:
     time = 633955
     flags = 0
-    data = length 14352, hash 74B754E3
+    data = length 14342, hash EC6E84A3
   sample 20:
     time = 667322
     flags = 0
-    data = length 9568, hash 369746A6
+    data = length 9555, hash 601CE39A
   sample 21:
     time = 700700
     flags = 0
@@ -118,35 +118,35 @@ track 0:
   sample 22:
     time = 734055
     flags = 0
-    data = length 22880, hash 75E833BA
+    data = length 22874, hash 4620073A
   sample 23:
     time = 767422
     flags = 0
-    data = length 16832, hash E8BFCFE3
+    data = length 16821, hash 95A33FFD
   sample 24:
     time = 800800
     flags = 0
-    data = length 5120, hash E04AEF94
+    data = length 5114, hash F0CB2E94
   sample 25:
     time = 834155
     flags = 0
-    data = length 9888, hash 1166103E
+    data = length 9884, hash 103DF3E
   sample 26:
     time = 867522
     flags = 0
-    data = length 17024, hash F9A96740
+    data = length 17011, hash 82DFD0C0
   sample 27:
     time = 900900
     flags = 0
-    data = length 20864, hash DF9E88B8
+    data = length 20860, hash 5DEFA4B8
   sample 28:
     time = 934255
     flags = 0
-    data = length 7216, hash BE22BE2F
+    data = length 7209, hash AFAC48B1
   sample 29:
     time = 967622
     flags = 536870912
-    data = length 14240, hash E190BF31
+    data = length 14234, hash 101837F1
 track 1:
   total output bytes = 9529
   sample count = 45

libraries/test_data/src/test/assets/transformerdumps/ts/sample_no_bframes.ts/transmuxed_with_inappmuxer.dump

@@ -0,0 +1,344 @@
+seekMap:
+  isSeekable = true
+  duration = 1065600
+  getPosition(0) = [[timeUs=0, position=44]]
+  getPosition(1) = [[timeUs=0, position=44]]
+  getPosition(532800) = [[timeUs=0, position=44]]
+  getPosition(1065600) = [[timeUs=0, position=44]]
+numberOfTracks = 2
+track 0:
+  total output bytes = 301430
+  sample count = 30
+  format 0:
+    id = 1
+    sampleMimeType = video/avc
+    codecs = avc1.640034
+    maxInputSize = 22910
+    width = 1080
+    height = 720
+    frameRate = 31.004547
+    colorInfo:
+      colorSpace = 1
+      colorRange = 2
+      colorTransfer = 3
+      lumaBitdepth = 8
+      chromaBitdepth = 8
+    metadata = entries=[Mp4Timestamp: creation time=3000000000, modification time=4000000000, timescale=10000]
+    initializationData:
+      data = length 24, hash 489E4AD2
+      data = length 9, hash FBAFBC0C
+  sample 0:
+    time = 0
+    flags = 1
+    data = length 7773, hash 97BEE8E7
+  sample 1:
+    time = 33355
+    flags = 0
+    data = length 1175, hash 875A0AD8
+  sample 2:
+    time = 66722
+    flags = 0
+    data = length 961, hash 39E26608
+  sample 3:
+    time = 100100
+    flags = 0
+    data = length 979, hash 9843943C
+  sample 4:
+    time = 133455
+    flags = 0
+    data = length 1367, hash C795AD6F
+  sample 5:
+    time = 166822
+    flags = 0
+    data = length 2295, hash 90C61830
+  sample 6:
+    time = 200200
+    flags = 0
+    data = length 3856, hash E5178FCE
+  sample 7:
+    time = 233555
+    flags = 0
+    data = length 4055, hash DC2E0B64
+  sample 8:
+    time = 266922
+    flags = 0
+    data = length 6143, hash 6C8C0E1B
+  sample 9:
+    time = 300300
+    flags = 0
+    data = length 7639, hash 40ABA1B0
+  sample 10:
+    time = 333655
+    flags = 0
+    data = length 9795, hash 824B4D8D
+  sample 11:
+    time = 367022
+    flags = 0
+    data = length 14496, hash D3EEBA42
+  sample 12:
+    time = 400400
+    flags = 0
+    data = length 17658, hash 12A7A1A6
+  sample 13:
+    time = 433755
+    flags = 0
+    data = length 5709, hash ACD2349
+  sample 14:
+    time = 467122
+    flags = 0
+    data = length 9772, hash B00DF832
+  sample 15:
+    time = 500500
+    flags = 0
+    data = length 17710, hash 366FC3DC
+  sample 16:
+    time = 533855
+    flags = 0
+    data = length 11442, hash 9B226194
+  sample 17:
+    time = 567222
+    flags = 0
+    data = length 8546, hash D86DF08E
+  sample 18:
+    time = 600600
+    flags = 0
+    data = length 19900, hash C6748B4C
+  sample 19:
+    time = 633955
+    flags = 0
+    data = length 14348, hash D91E9EAB
+  sample 20:
+    time = 667322
+    flags = 0
+    data = length 9561, hash 819E9692
+  sample 21:
+    time = 700700
+    flags = 0
+    data = length 12195, hash 895ADC1E
+  sample 22:
+    time = 734055
+    flags = 0
+    data = length 22880, hash A618D42
+  sample 23:
+    time = 767422
+    flags = 0
+    data = length 16827, hash 4E6A74F5
+  sample 24:
+    time = 800800
+    flags = 0
+    data = length 5120, hash 3EF0149C
+  sample 25:
+    time = 834155
+    flags = 0
+    data = length 9890, hash 32BAC346
+  sample 26:
+    time = 867522
+    flags = 0
+    data = length 17017, hash 2D24A3B8
+  sample 27:
+    time = 900900
+    flags = 0
+    data = length 20866, hash 219DA8C0
+  sample 28:
+    time = 934255
+    flags = 0
+    data = length 7215, hash A853B1A9
+  sample 29:
+    time = 967622
+    flags = 536870912
+    data = length 14240, hash 4EE77DF9
+track 1:
+  total output bytes = 9529
+  sample count = 45
+  format 0:
+    id = 2
+    sampleMimeType = audio/mp4a-latm
+    codecs = mp4a.40.2
+    maxInputSize = 294
+    channelCount = 1
+    sampleRate = 44100
+    language = und
+    metadata = entries=[Mp4Timestamp: creation time=3000000000, modification time=4000000000, timescale=10000]
+    initializationData:
+      data = length 2, hash 5F7
+  sample 0:
+    time = 0
+    flags = 1
+    data = length 23, hash 47DE9131
+  sample 1:
+    time = 67187
+    flags = 1
+    data = length 6, hash 31EC5206
+  sample 2:
+    time = 90416
+    flags = 1
+    data = length 148, hash 894A176B
+  sample 3:
+    time = 113625
+    flags = 1
+    data = length 189, hash CEF235A1
+  sample 4:
+    time = 136854
+    flags = 1
+    data = length 205, hash BBF5F7B0
+  sample 5:
+    time = 160062
+    flags = 1
+    data = length 210, hash F278B193
+  sample 6:
+    time = 183291
+    flags = 1
+    data = length 210, hash 82DA1589
+  sample 7:
+    time = 206520
+    flags = 1
+    data = length 207, hash 5BE231DF
+  sample 8:
+    time = 229729
+    flags = 1
+    data = length 225, hash 18819EE1
+  sample 9:
+    time = 252958
+    flags = 1
+    data = length 215, hash CA7FA67B
+  sample 10:
+    time = 276166
+    flags = 1
+    data = length 211, hash 581A1C18
+  sample 11:
+    time = 299395
+    flags = 1
+    data = length 216, hash ADB88187
+  sample 12:
+    time = 322604
+    flags = 1
+    data = length 229, hash 2E8BA4DC
+  sample 13:
+    time = 345833
+    flags = 1
+    data = length 232, hash 22F0C510
+  sample 14:
+    time = 369041
+    flags = 1
+    data = length 235, hash 867AD0DC
+  sample 15:
+    time = 392270
+    flags = 1
+    data = length 231, hash 84E823A8
+  sample 16:
+    time = 415500
+    flags = 1
+    data = length 226, hash 1BEF3A95
+  sample 17:
+    time = 438708
+    flags = 1
+    data = length 216, hash EAA345AE
+  sample 18:
+    time = 461937
+    flags = 1
+    data = length 229, hash 6957411F
+  sample 19:
+    time = 485145
+    flags = 1
+    data = length 219, hash 41275022
+  sample 20:
+    time = 508375
+    flags = 1
+    data = length 241, hash 6495DF96
+  sample 21:
+    time = 531583
+    flags = 1
+    data = length 228, hash 63D95906
+  sample 22:
+    time = 554812
+    flags = 1
+    data = length 238, hash 34F676F9
+  sample 23:
+    time = 578020
+    flags = 1
+    data = length 234, hash E5CBC045
+  sample 24:
+    time = 601250
+    flags = 1
+    data = length 231, hash 5FC43661
+  sample 25:
+    time = 624458
+    flags = 1
+    data = length 217, hash 682708ED
+  sample 26:
+    time = 647687
+    flags = 1
+    data = length 239, hash D43780FC
+  sample 27:
+    time = 670916
+    flags = 1
+    data = length 243, hash C5E17980
+  sample 28:
+    time = 694145
+    flags = 1
+    data = length 231, hash AC5837BA
+  sample 29:
+    time = 717354
+    flags = 1
+    data = length 230, hash 169EE895
+  sample 30:
+    time = 740583
+    flags = 1
+    data = length 238, hash C48FF3F1
+  sample 31:
+    time = 763791
+    flags = 1
+    data = length 225, hash 531E4599
+  sample 32:
+    time = 787020
+    flags = 1
+    data = length 232, hash CB3C6B8D
+  sample 33:
+    time = 810229
+    flags = 1
+    data = length 243, hash F8C94C7
+  sample 34:
+    time = 833458
+    flags = 1
+    data = length 232, hash A646A7D0
+  sample 35:
+    time = 856666
+    flags = 1
+    data = length 237, hash E8B787A5
+  sample 36:
+    time = 879895
+    flags = 1
+    data = length 228, hash 3FA7A29F
+  sample 37:
+    time = 903104
+    flags = 1
+    data = length 235, hash B9B33B0A
+  sample 38:
+    time = 926333
+    flags = 1
+    data = length 264, hash 71A4869E
+  sample 39:
+    time = 949562
+    flags = 1
+    data = length 257, hash D049B54C
+  sample 40:
+    time = 972770
+    flags = 1
+    data = length 227, hash 66757231
+  sample 41:
+    time = 996000
+    flags = 1
+    data = length 227, hash BD374F1B
+  sample 42:
+    time = 1019208
+    flags = 1
+    data = length 235, hash 999477F6
+  sample 43:
+    time = 1042437
+    flags = 1
+    data = length 229, hash FFF98DF0
+  sample 44:
+    time = 1065645
+    flags = 536870913
+    data = length 6, hash 31B22286
+tracksEnded = true

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

@@ -16,6 +16,7 @@
 package androidx.media3.transformer;
 
 import static androidx.media3.common.util.Assertions.checkState;
+import static androidx.media3.test.utils.TestUtil.extractAllSamplesFromFilePath;
 import static androidx.media3.test.utils.TestUtil.retrieveTrackFormat;
 import static com.google.common.truth.Truth.assertThat;
 
@@ -51,6 +52,7 @@ import org.junit.runner.RunWith;
 public class TransformerWithInAppMuxerEndToEndTest {
   private static final String MP4_FILE_PATH = "asset:///media/mp4/sample_no_bframes.mp4";
   private static final String MP4_FILE_NAME = "mp4/sample_no_bframes.mp4";
+
   @Rule public final TemporaryFolder outputDir = new TemporaryFolder();
 
   private final Context context = ApplicationProvider.getApplicationContext();
@@ -85,7 +87,7 @@ public class TransformerWithInAppMuxerEndToEndTest {
     TransformerTestRunner.runLooper(transformer);
 
     FakeExtractorOutput fakeExtractorOutput =
-        androidx.media3.test.utils.TestUtil.extractAllSamplesFromFilePath(
+        extractAllSamplesFromFilePath(
             new Mp4Extractor(new DefaultSubtitleParserFactory()), outputPath);
     DumpFileAsserts.assertOutput(
         context,
@@ -95,6 +97,46 @@ public class TransformerWithInAppMuxerEndToEndTest {
             /* modifications...= */ "transmuxed_with_inappmuxer"));
   }
 
+  @Test
+  public void transmux_tsFileHavingThreeByteNalStartCode_outputMatchesExpected() throws Exception {
+    String tsFilePath = "asset:///media/ts/sample_no_bframes.ts";
+    String tsFileName = "ts/sample_no_bframes.ts";
+    Muxer.Factory inAppMuxerFactory =
+        new InAppMuxer.Factory.Builder()
+            .setMetadataProvider(
+                metadataEntries ->
+                    // Add timestamp to make output file deterministic.
+                    metadataEntries.add(
+                        new Mp4TimestampData(
+                            /* creationTimestampSeconds= */ 3_000_000_000L,
+                            /* modificationTimestampSeconds= */ 4_000_000_000L)))
+            .build();
+
+    Transformer transformer =
+        new Transformer.Builder(context)
+            .setClock(new FakeClock(/* isAutoAdvancing= */ true))
+            .setMuxerFactory(inAppMuxerFactory)
+            .build();
+    MediaItem mediaItem =
+        new MediaItem.Builder()
+            .setUri(Uri.parse(tsFilePath))
+            .setClippingConfiguration(
+                new MediaItem.ClippingConfiguration.Builder().setEndPositionMs(2_000).build())
+            .build();
+    transformer.start(mediaItem, outputPath);
+    TransformerTestRunner.runLooper(transformer);
+
+    FakeExtractorOutput fakeExtractorOutput =
+        extractAllSamplesFromFilePath(
+            new Mp4Extractor(new DefaultSubtitleParserFactory()), outputPath);
+    DumpFileAsserts.assertOutput(
+        context,
+        fakeExtractorOutput,
+        TestUtil.getDumpFileName(
+            /* originalFileName= */ tsFileName,
+            /* modifications...= */ "transmuxed_with_inappmuxer"));
+  }
+
   @Test
   public void transmux_withLocationMetadata_writesSameLocationMetadata() throws Exception {
     Mp4LocationData expectedLocationData =