Derive duration from sample table if missing from track header

Issue: #3926

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=188020756

RELEASENOTES.md

@@ -9,6 +9,8 @@
   `Timeline.Window.windowStartTimeMs` field
   ([#3865](https://github.com/google/ExoPlayer/issues/3865),
   [#3888](https://github.com/google/ExoPlayer/issues/3888)).
+* Enable seeking in MP4 streams where duration is set incorrectly in the track
+  header ([#3926](https://github.com/google/ExoPlayer/issues/3926)).
 
 ### 2.7.0 ###
 

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

@@ -49,7 +49,6 @@ import java.util.List;
   private static final int TYPE_sbtl = Util.getIntegerCodeForString("sbtl");
   private static final int TYPE_subt = Util.getIntegerCodeForString("subt");
   private static final int TYPE_clcp = Util.getIntegerCodeForString("clcp");
-  private static final int TYPE_cenc = Util.getIntegerCodeForString("cenc");
   private static final int TYPE_meta = Util.getIntegerCodeForString("meta");
 
   /**
@@ -128,7 +127,8 @@ 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]);
+      return new TrackSampleTable(
+          new long[0], new int[0], 0, new long[0], new int[0], C.TIME_UNSET);
     }
 
     // Entries are byte offsets of chunks.
@@ -193,6 +193,7 @@ import java.util.List;
     long[] timestamps;
     int[] flags;
     long timestampTimeUnits = 0;
+    long duration;
 
     if (!isRechunkable) {
       offsets = new long[sampleCount];
@@ -260,6 +261,7 @@ import java.util.List;
         offset += sizes[i];
         remainingSamplesInChunk--;
       }
+      duration = timestampTimeUnits + timestampOffset;
 
       Assertions.checkArgument(remainingSamplesAtTimestampOffset == 0);
       // Remove trailing ctts entries with 0-valued sample counts.
@@ -294,13 +296,15 @@ import java.util.List;
       maximumSize = rechunkedResults.maximumSize;
       timestamps = rechunkedResults.timestamps;
       flags = rechunkedResults.flags;
+      duration = rechunkedResults.duration;
     }
+    long durationUs = Util.scaleLargeTimestamp(duration, C.MICROS_PER_SECOND, track.timescale);
 
     if (track.editListDurations == null || gaplessInfoHolder.hasGaplessInfo()) {
       // 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);
+      return new TrackSampleTable(offsets, sizes, maximumSize, timestamps, flags, durationUs);
     }
 
     // See the BMFF spec (ISO 14496-12) subsection 8.6.6. Edit lists that require prerolling from a
@@ -317,10 +321,11 @@ import java.util.List;
       long editStartTime = track.editListMediaTimes[0];
       long editEndTime = editStartTime + Util.scaleLargeTimestamp(track.editListDurations[0],
           track.timescale, track.movieTimescale);
-      long lastSampleEndTime = timestampTimeUnits;
+      if (timestamps[0] <= editStartTime
-      if (timestamps[0] <= editStartTime && editStartTime < timestamps[1]
+          && editStartTime < timestamps[1]
-          && timestamps[timestamps.length - 1] < editEndTime && editEndTime <= lastSampleEndTime) {
+          && timestamps[timestamps.length - 1] < editEndTime
-        long paddingTimeUnits = lastSampleEndTime - editEndTime;
+          && editEndTime <= duration) {
+        long paddingTimeUnits = duration - editEndTime;
         long encoderDelay = Util.scaleLargeTimestamp(editStartTime - timestamps[0],
             track.format.sampleRate, track.timescale);
         long encoderPadding = Util.scaleLargeTimestamp(paddingTimeUnits,
@@ -330,7 +335,7 @@ 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);
+          return new TrackSampleTable(offsets, sizes, maximumSize, timestamps, flags, durationUs);
         }
       }
     }
@@ -339,11 +344,15 @@ import java.util.List;
       // The current version of the spec leaves handling of an edit with zero segment_duration in
       // unfragmented files open to interpretation. We handle this as a special case and include all
       // samples in the edit.
+      long editStartTime = track.editListMediaTimes[0];
       for (int i = 0; i < timestamps.length; i++) {
-        timestamps[i] = Util.scaleLargeTimestamp(timestamps[i] - track.editListMediaTimes[0],
+        timestamps[i] =
-            C.MICROS_PER_SECOND, track.timescale);
+            Util.scaleLargeTimestamp(
+                timestamps[i] - editStartTime, C.MICROS_PER_SECOND, track.timescale);
       }
-      return new TrackSampleTable(offsets, sizes, maximumSize, timestamps, flags);
+      durationUs =
+          Util.scaleLargeTimestamp(duration - editStartTime, C.MICROS_PER_SECOND, track.timescale);
+      return new TrackSampleTable(offsets, sizes, maximumSize, timestamps, flags, durationUs);
     }
 
     // Omit any sample at the end point of an edit for audio tracks.
@@ -354,13 +363,15 @@ import java.util.List;
     int nextSampleIndex = 0;
     boolean copyMetadata = false;
     for (int i = 0; i < track.editListDurations.length; i++) {
-      long mediaTime = track.editListMediaTimes[i];
+      long editMediaTime = track.editListMediaTimes[i];
-      if (mediaTime != -1) {
+      if (editMediaTime != -1) {
-        long duration = Util.scaleLargeTimestamp(track.editListDurations[i], track.timescale,
+        long editDuration =
-            track.movieTimescale);
+            Util.scaleLargeTimestamp(
-        int startIndex = Util.binarySearchCeil(timestamps, mediaTime, true, true);
+                track.editListDurations[i], track.timescale, track.movieTimescale);
-        int endIndex = Util.binarySearchCeil(timestamps, mediaTime + duration, omitClippedSample,
+        int startIndex = Util.binarySearchCeil(timestamps, editMediaTime, true, true);
-            false);
+        int endIndex =
+            Util.binarySearchCeil(
+                timestamps, editMediaTime + editDuration, omitClippedSample, false);
         editedSampleCount += endIndex - startIndex;
         copyMetadata |= nextSampleIndex != startIndex;
         nextSampleIndex = endIndex;
@@ -377,12 +388,13 @@ import java.util.List;
     long pts = 0;
     int sampleIndex = 0;
     for (int i = 0; i < track.editListDurations.length; i++) {
-      long mediaTime = track.editListMediaTimes[i];
+      long editMediaTime = track.editListMediaTimes[i];
-      long duration = track.editListDurations[i];
+      long editDuration = track.editListDurations[i];
-      if (mediaTime != -1) {
+      if (editMediaTime != -1) {
-        long endMediaTime = mediaTime + Util.scaleLargeTimestamp(duration, track.timescale,
+        long endMediaTime =
-            track.movieTimescale);
+            editMediaTime
-        int startIndex = Util.binarySearchCeil(timestamps, mediaTime, true, true);
+                + Util.scaleLargeTimestamp(editDuration, track.timescale, track.movieTimescale);
+        int startIndex = Util.binarySearchCeil(timestamps, editMediaTime, true, true);
         int endIndex = Util.binarySearchCeil(timestamps, endMediaTime, omitClippedSample, false);
         if (copyMetadata) {
           int count = endIndex - startIndex;
@@ -392,8 +404,9 @@ import java.util.List;
         }
         for (int j = startIndex; j < endIndex; j++) {
           long ptsUs = Util.scaleLargeTimestamp(pts, C.MICROS_PER_SECOND, track.movieTimescale);
-          long timeInSegmentUs = Util.scaleLargeTimestamp(timestamps[j] - mediaTime,
+          long timeInSegmentUs =
-              C.MICROS_PER_SECOND, track.timescale);
+              Util.scaleLargeTimestamp(
+                  timestamps[j] - editMediaTime, C.MICROS_PER_SECOND, track.timescale);
           editedTimestamps[sampleIndex] = ptsUs + timeInSegmentUs;
           if (copyMetadata && editedSizes[sampleIndex] > editedMaximumSize) {
             editedMaximumSize = sizes[j];
@@ -401,8 +414,9 @@ import java.util.List;
           sampleIndex++;
         }
       }
-      pts += duration;
+      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++) {
@@ -413,11 +427,16 @@ import java.util.List;
       // 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);
+      return new TrackSampleTable(offsets, sizes, maximumSize, timestamps, flags, durationUs);
     }
 
-    return new TrackSampleTable(editedOffsets, editedSizes, editedMaximumSize, editedTimestamps,
+    return new TrackSampleTable(
-        editedFlags);
+        editedOffsets,
+        editedSizes,
+        editedMaximumSize,
+        editedTimestamps,
+        editedFlags,
+        editedDurationUs);
   }
 
   /**

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

@@ -33,13 +33,21 @@ import com.google.android.exoplayer2.util.Util;
     public final int maximumSize;
     public final long[] timestamps;
     public final int[] flags;
+    public final long duration;
 
-    private Results(long[] offsets, int[] sizes, int maximumSize, long[] timestamps, int[] flags) {
+    private Results(
+        long[] offsets,
+        int[] sizes,
+        int maximumSize,
+        long[] timestamps,
+        int[] flags,
+        long duration) {
       this.offsets = offsets;
       this.sizes = sizes;
       this.maximumSize = maximumSize;
       this.timestamps = timestamps;
       this.flags = flags;
+      this.duration = duration;
     }
 
   }
@@ -95,8 +103,9 @@ import com.google.android.exoplayer2.util.Util;
         newSampleIndex++;
       }
     }
+    long duration = timestampDeltaInTimeUnits * originalSampleIndex;
 
-    return new Results(offsets, sizes, maximumSize, timestamps, flags);
+    return new Results(offsets, sizes, maximumSize, timestamps, flags, duration);
   }
 
 }

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

@@ -427,7 +427,10 @@ public final class Mp4Extractor implements Extractor, SeekMap {
       }
       mp4Track.trackOutput.format(format);
 
-      durationUs = Math.max(durationUs, track.durationUs);
+      durationUs =
+          Math.max(
+              durationUs,
+              track.durationUs != C.TIME_UNSET ? track.durationUs : trackSampleTable.durationUs);
       if (track.type == C.TRACK_TYPE_VIDEO && firstVideoTrackIndex == C.INDEX_UNSET) {
         firstVideoTrackIndex = tracks.size();
       }

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

@@ -48,9 +48,19 @@ import com.google.android.exoplayer2.util.Util;
    * Sample flags.
    */
   public final int[] flags;
+  /**
+   * The duration of the track sample table in microseconds, or {@link C#TIME_UNSET} if the sample
+   * table is empty.
+   */
+  public final long durationUs;
 
-  public TrackSampleTable(long[] offsets, int[] sizes, int maximumSize, long[] timestampsUs,
+  public TrackSampleTable(
-      int[] flags) {
+      long[] offsets,
+      int[] sizes,
+      int maximumSize,
+      long[] timestampsUs,
+      int[] flags,
+      long durationUs) {
     Assertions.checkArgument(sizes.length == timestampsUs.length);
     Assertions.checkArgument(offsets.length == timestampsUs.length);
     Assertions.checkArgument(flags.length == timestampsUs.length);
@@ -60,6 +70,7 @@ import com.google.android.exoplayer2.util.Util;
     this.maximumSize = maximumSize;
     this.timestampsUs = timestampsUs;
     this.flags = flags;
+    this.durationUs = durationUs;
     sampleCount = offsets.length;
   }