Fix extraction of PCM (sowt) in MP4/MOV

The sample size from the stsd box takes precedence over the sample size in the
stsz box.

Also remove assumption that C.INDEX_UNSET is -1 in ChunkIterator (which is a
no-op change).

Issue: #4228

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=196661751

RELEASENOTES.md

@@ -11,6 +11,8 @@
     ([#2843](https://github.com/google/ExoPlayer/issues/2843)).
     ([#2843](https://github.com/google/ExoPlayer/issues/2843)).
 * Fix crash when switching surface on Moto E(4)
 * Fix crash when switching surface on Moto E(4)
   ([#4134](https://github.com/google/ExoPlayer/issues/4134)).
   ([#4134](https://github.com/google/ExoPlayer/issues/4134)).
+* Audio: Fix extraction of PCM in MP4/MOV
+  ([#4228](https://github.com/google/ExoPlayer/issues/4228)).
 
 
 ### 2.8.0 ###
 ### 2.8.0 ###
 
 

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

@@ -189,11 +189,13 @@ import java.util.List;
       }
       }
     }
     }
 
 
-    // True if we can rechunk fixed-sample-size data. Note that we only rechunk raw audio.
-    boolean isRechunkable = sampleSizeBox.isFixedSampleSize()
-        && MimeTypes.AUDIO_RAW.equals(track.format.sampleMimeType)
-        && remainingTimestampDeltaChanges == 0 && remainingTimestampOffsetChanges == 0
-        && remainingSynchronizationSamples == 0;
+    // Fixed sample size raw audio may need to be rechunked.
+    boolean isFixedSampleSizeRawAudio =
+        sampleSizeBox.isFixedSampleSize()
+            && MimeTypes.AUDIO_RAW.equals(track.format.sampleMimeType)
+            && remainingTimestampDeltaChanges == 0
+            && remainingTimestampOffsetChanges == 0
+            && remainingSynchronizationSamples == 0;
 
 
     long[] offsets;
     long[] offsets;
     int[] sizes;
     int[] sizes;
@@ -203,7 +205,7 @@ import java.util.List;
     long timestampTimeUnits = 0;
     long timestampTimeUnits = 0;
     long duration;
     long duration;
 
 
-    if (!isRechunkable) {
+    if (!isFixedSampleSizeRawAudio) {
       offsets = new long[sampleCount];
       offsets = new long[sampleCount];
       sizes = new int[sampleCount];
       sizes = new int[sampleCount];
       timestamps = new long[sampleCount];
       timestamps = new long[sampleCount];
@@ -296,7 +298,8 @@ import java.util.List;
         chunkOffsetsBytes[chunkIterator.index] = chunkIterator.offset;
         chunkOffsetsBytes[chunkIterator.index] = chunkIterator.offset;
         chunkSampleCounts[chunkIterator.index] = chunkIterator.numSamples;
         chunkSampleCounts[chunkIterator.index] = chunkIterator.numSamples;
       }
       }
-      int fixedSampleSize = sampleSizeBox.readNextSampleSize();
+      int fixedSampleSize =
+          Util.getPcmFrameSize(track.format.pcmEncoding, track.format.channelCount);
       FixedSampleSizeRechunker.Results rechunkedResults = FixedSampleSizeRechunker.rechunk(
       FixedSampleSizeRechunker.Results rechunkedResults = FixedSampleSizeRechunker.rechunk(
           fixedSampleSize, chunkOffsetsBytes, chunkSampleCounts, timestampDeltaInTimeUnits);
           fixedSampleSize, chunkOffsetsBytes, chunkSampleCounts, timestampDeltaInTimeUnits);
       offsets = rechunkedResults.offsets;
       offsets = rechunkedResults.offsets;
@@ -1224,7 +1227,7 @@ import java.util.List;
       stsc.setPosition(Atom.FULL_HEADER_SIZE);
       stsc.setPosition(Atom.FULL_HEADER_SIZE);
       remainingSamplesPerChunkChanges = stsc.readUnsignedIntToInt();
       remainingSamplesPerChunkChanges = stsc.readUnsignedIntToInt();
       Assertions.checkState(stsc.readInt() == 1, "first_chunk must be 1");
       Assertions.checkState(stsc.readInt() == 1, "first_chunk must be 1");
-      index = C.INDEX_UNSET;
+      index = -1;
     }
     }
 
 
     public boolean moveNext() {
     public boolean moveNext() {