Ignore all edit lists if one track's edits can't be applied

Issue: #4348

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=204261718

RELEASENOTES.md

@@ -85,6 +85,8 @@
 * Add workaround for track index mismatches between tfhd and tkhd boxes in
   fragmented MP4 files
   ([#4083](https://github.com/google/ExoPlayer/issues/4083)).
+* Ignore all MP4 edit lists if one edit list couldn't be handled
+  ([#4348](https://github.com/google/ExoPlayer/issues/4348)).
 * Fix issue when switching track selection from an embedded track to a primary
   track in DASH ([#4477](https://github.com/google/ExoPlayer/issues/4477)).
 

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

@@ -43,6 +43,9 @@ import java.util.List;
  */
 /* package */ final class AtomParsers {
 
+  /** Thrown if an edit list couldn't be applied. */
+  public static final class UnhandledEditListException extends ParserException {}
+
   private static final String TAG = "AtomParsers";
 
   private static final int TYPE_vide = Util.getIntegerCodeForString("vide");
@@ -117,10 +120,12 @@ import java.util.List;
    * @param stblAtom stbl (sample table) atom to decode.
    * @param gaplessInfoHolder Holder to populate with gapless playback information.
    * @return Sample table described by the stbl atom.
-   * @throws ParserException If the resulting sample sequence does not contain a sync sample.
+   * @throws UnhandledEditListException Thrown if the edit list can't be applied.
+   * @throws ParserException Thrown if the stbl atom can't be parsed.
    */
-  public static TrackSampleTable parseStbl(Track track, Atom.ContainerAtom stblAtom,
+  public static TrackSampleTable parseStbl(
-      GaplessInfoHolder gaplessInfoHolder) throws ParserException {
+      Track track, Atom.ContainerAtom stblAtom, GaplessInfoHolder gaplessInfoHolder)
+      throws ParserException {
     SampleSizeBox sampleSizeBox;
     Atom.LeafAtom stszAtom = stblAtom.getLeafAtomOfType(Atom.TYPE_stsz);
     if (stszAtom != null) {
@@ -136,7 +141,13 @@ import java.util.List;
     int sampleCount = sampleSizeBox.getSampleCount();
     if (sampleCount == 0) {
       return new TrackSampleTable(
-          new long[0], new int[0], 0, new long[0], new int[0], C.TIME_UNSET);
+          track,
+          /* offsets= */ new long[0],
+          /* sizes= */ new int[0],
+          /* maximumSize= */ 0,
+          /* timestampsUs= */ new long[0],
+          /* flags= */ new int[0],
+          /* durationUs= */ C.TIME_UNSET);
     }
 
     // Entries are byte offsets of chunks.
@@ -315,7 +326,8 @@ import java.util.List;
       // There is no edit list, or we are ignoring it as we already have gapless metadata to apply.
       // This implementation does not support applying both gapless metadata and an edit list.
       Util.scaleLargeTimestampsInPlace(timestamps, C.MICROS_PER_SECOND, track.timescale);
-      return new TrackSampleTable(offsets, sizes, maximumSize, timestamps, flags, durationUs);
+      return new TrackSampleTable(
+          track, offsets, sizes, maximumSize, timestamps, flags, durationUs);
     }
 
     // See the BMFF spec (ISO 14496-12) subsection 8.6.6. Edit lists that require prerolling from a
@@ -342,7 +354,8 @@ import java.util.List;
           gaplessInfoHolder.encoderDelay = (int) encoderDelay;
           gaplessInfoHolder.encoderPadding = (int) encoderPadding;
           Util.scaleLargeTimestampsInPlace(timestamps, C.MICROS_PER_SECOND, track.timescale);
-          return new TrackSampleTable(offsets, sizes, maximumSize, timestamps, flags, durationUs);
+          return new TrackSampleTable(
+              track, offsets, sizes, maximumSize, timestamps, flags, durationUs);
         }
       }
     }
@@ -359,7 +372,8 @@ import java.util.List;
       }
       durationUs =
           Util.scaleLargeTimestamp(duration - editStartTime, C.MICROS_PER_SECOND, track.timescale);
-      return new TrackSampleTable(offsets, sizes, maximumSize, timestamps, flags, durationUs);
+      return new TrackSampleTable(
+          track, offsets, sizes, maximumSize, timestamps, flags, durationUs);
     }
 
     // Omit any sample at the end point of an edit for audio tracks.
@@ -409,6 +423,11 @@ import java.util.List;
           System.arraycopy(sizes, startIndex, editedSizes, sampleIndex, count);
           System.arraycopy(flags, startIndex, editedFlags, sampleIndex, count);
         }
+        if (startIndex < endIndex && (editedFlags[sampleIndex] & C.BUFFER_FLAG_KEY_FRAME) == 0) {
+          // Applying the edit list would require prerolling from a sync sample.
+          Log.w(TAG, "Ignoring edit list: edit does not start with a sync sample.");
+          throw new UnhandledEditListException();
+        }
         for (int j = startIndex; j < endIndex; j++) {
           long ptsUs = Util.scaleLargeTimestamp(pts, C.MICROS_PER_SECOND, track.movieTimescale);
           long timeInSegmentUs =
@@ -424,20 +443,8 @@ import java.util.List;
       pts += editDuration;
     }
     long editedDurationUs = Util.scaleLargeTimestamp(pts, C.MICROS_PER_SECOND, track.timescale);
-
-    boolean hasSyncSample = false;
-    for (int i = 0; i < editedFlags.length && !hasSyncSample; i++) {
-      hasSyncSample |= (editedFlags[i] & C.BUFFER_FLAG_KEY_FRAME) != 0;
-    }
-    if (!hasSyncSample) {
-      // We don't support edit lists where the edited sample sequence doesn't contain a sync sample.
-      // Such edit lists are often (although not always) broken, so we ignore it and continue.
-      Log.w(TAG, "Ignoring edit list: Edited sample sequence does not contain a sync sample.");
-      Util.scaleLargeTimestampsInPlace(timestamps, C.MICROS_PER_SECOND, track.timescale);
-      return new TrackSampleTable(offsets, sizes, maximumSize, timestamps, flags, durationUs);
-    }
-
     return new TrackSampleTable(
+        track,
         editedOffsets,
         editedSizes,
         editedMaximumSize,

library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/Mp4Extractor.java

@@ -391,25 +391,21 @@ public final class Mp4Extractor implements Extractor, SeekMap {
       }
     }
 
-    for (int i = 0; i < moov.containerChildren.size(); i++) {
+    boolean ignoreEditLists = (flags & FLAG_WORKAROUND_IGNORE_EDIT_LISTS) != 0;
-      Atom.ContainerAtom atom = moov.containerChildren.get(i);
+    ArrayList<TrackSampleTable> trackSampleTables;
-      if (atom.type != Atom.TYPE_trak) {
+    try {
-        continue;
+      trackSampleTables = getTrackSampleTables(moov, gaplessInfoHolder, ignoreEditLists);
-      }
+    } catch (AtomParsers.UnhandledEditListException e) {
-
+      // Discard gapless info as we aren't able to handle corresponding edits.
-      Track track = AtomParsers.parseTrak(atom, moov.getLeafAtomOfType(Atom.TYPE_mvhd),
+      gaplessInfoHolder = new GaplessInfoHolder();
-          C.TIME_UNSET, null, (flags & FLAG_WORKAROUND_IGNORE_EDIT_LISTS) != 0, isQuickTime);
+      trackSampleTables =
-      if (track == null) {
+          getTrackSampleTables(moov, gaplessInfoHolder, /* ignoreEditLists= */ true);
-        continue;
+    }
-      }
-
-      Atom.ContainerAtom stblAtom = atom.getContainerAtomOfType(Atom.TYPE_mdia)
-          .getContainerAtomOfType(Atom.TYPE_minf).getContainerAtomOfType(Atom.TYPE_stbl);
-      TrackSampleTable trackSampleTable = AtomParsers.parseStbl(track, stblAtom, gaplessInfoHolder);
-      if (trackSampleTable.sampleCount == 0) {
-        continue;
-      }
 
+    int trackCount = trackSampleTables.size();
+    for (int i = 0; i < trackCount; i++) {
+      TrackSampleTable trackSampleTable = trackSampleTables.get(i);
+      Track track = trackSampleTable.track;
       Mp4Track mp4Track = new Mp4Track(track, trackSampleTable,
           extractorOutput.track(i, track.type));
       // Each sample has up to three bytes of overhead for the start code that replaces its length.
@@ -445,6 +441,39 @@ public final class Mp4Extractor implements Extractor, SeekMap {
     extractorOutput.seekMap(this);
   }
 
+  private ArrayList<TrackSampleTable> getTrackSampleTables(
+      ContainerAtom moov, GaplessInfoHolder gaplessInfoHolder, boolean ignoreEditLists)
+      throws ParserException {
+    ArrayList<TrackSampleTable> trackSampleTables = new ArrayList<>();
+    for (int i = 0; i < moov.containerChildren.size(); i++) {
+      Atom.ContainerAtom atom = moov.containerChildren.get(i);
+      if (atom.type != Atom.TYPE_trak) {
+        continue;
+      }
+      Track track =
+          AtomParsers.parseTrak(
+              atom,
+              moov.getLeafAtomOfType(Atom.TYPE_mvhd),
+              /* duration= */ C.TIME_UNSET,
+              /* drmInitData= */ null,
+              ignoreEditLists,
+              isQuickTime);
+      if (track == null) {
+        continue;
+      }
+      Atom.ContainerAtom stblAtom =
+          atom.getContainerAtomOfType(Atom.TYPE_mdia)
+              .getContainerAtomOfType(Atom.TYPE_minf)
+              .getContainerAtomOfType(Atom.TYPE_stbl);
+      TrackSampleTable trackSampleTable = AtomParsers.parseStbl(track, stblAtom, gaplessInfoHolder);
+      if (trackSampleTable.sampleCount == 0) {
+        continue;
+      }
+      trackSampleTables.add(trackSampleTable);
+    }
+    return trackSampleTables;
+  }
+
   /**
    * Attempts to extract the next sample in the current mdat atom for the specified track.
    * <p>

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

@@ -24,29 +24,19 @@ import com.google.android.exoplayer2.util.Util;
  */
 /* package */ final class TrackSampleTable {
 
-  /**
+  /** The track corresponding to this sample table. */
-   * Number of samples.
+  public final Track track;
-   */
+  /** Number of samples. */
   public final int sampleCount;
-  /**
+  /** Sample offsets in bytes. */
-   * Sample offsets in bytes.
-   */
   public final long[] offsets;
-  /**
+  /** Sample sizes in bytes. */
-   * Sample sizes in bytes.
-   */
   public final int[] sizes;
-  /**
+  /** Maximum sample size in {@link #sizes}. */
-   * Maximum sample size in {@link #sizes}.
-   */
   public final int maximumSize;
-  /**
+  /** Sample timestamps in microseconds. */
-   * Sample timestamps in microseconds.
-   */
   public final long[] timestampsUs;
-  /**
+  /** Sample flags. */
-   * Sample flags.
-   */
   public final int[] flags;
   /**
    * The duration of the track sample table in microseconds, or {@link C#TIME_UNSET} if the sample
@@ -55,6 +45,7 @@ import com.google.android.exoplayer2.util.Util;
   public final long durationUs;
 
   public TrackSampleTable(
+      Track track,
       long[] offsets,
       int[] sizes,
       int maximumSize,
@@ -65,6 +56,7 @@ import com.google.android.exoplayer2.util.Util;
     Assertions.checkArgument(offsets.length == timestampsUs.length);
     Assertions.checkArgument(flags.length == timestampsUs.length);
 
+    this.track = track;
     this.offsets = offsets;
     this.sizes = sizes;
     this.maximumSize = maximumSize;