From 1cf8b255dcc5277f274b06e394b3ed7558eae224 Mon Sep 17 00:00:00 2001
From: tonihei <tonihei@google.com>
Date: Fri, 6 Jul 2018 08:32:38 -0700
Subject: [PATCH] Add workaround for unmatched track indices in trex and tkhd.

Both boxes should contain the same list of track indices. However, if only one
track index in each list does not match, we can just assume that these belong
together.

Issue:#4477

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=203481258
---
 RELEASENOTES.md                                  |  3 +++
 .../extractor/mp4/FragmentedMp4Extractor.java    | 16 ++++++++++++++--
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/RELEASENOTES.md b/RELEASENOTES.md
index 3b07445d6d..108026dd7c 100644
--- a/RELEASENOTES.md
+++ b/RELEASENOTES.md
@@ -75,6 +75,9 @@
   `MediaCodecRenderer`, and provide an (optional) `MediaCodecSelector` that
   falls back to less preferred decoders like `MediaCodec.createDecoderByType`
   ([#273](https://github.com/google/ExoPlayer/issues/273)).
+* Add workaround for track index mismatches between trex and tkhd boxes in
+  fragmented MP4 files
+  ([#4477](https://github.com/google/ExoPlayer/issues/4477)).
 
 ### 2.8.2 ###
 
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/FragmentedMp4Extractor.java b/library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/FragmentedMp4Extractor.java
index 0bf42f1839..a61b41dea2 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/FragmentedMp4Extractor.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/FragmentedMp4Extractor.java
@@ -499,7 +499,7 @@ public final class FragmentedMp4Extractor implements Extractor {
       for (int i = 0; i < trackCount; i++) {
         Track track = tracks.valueAt(i);
         TrackBundle trackBundle = new TrackBundle(extractorOutput.track(i, track.type));
-        trackBundle.init(track, defaultSampleValuesArray.get(track.id));
+        trackBundle.init(track, getDefaultSampleValues(defaultSampleValuesArray, track.id));
         trackBundles.put(track.id, trackBundle);
         durationUs = Math.max(durationUs, track.durationUs);
       }
@@ -509,11 +509,23 @@ public final class FragmentedMp4Extractor implements Extractor {
       Assertions.checkState(trackBundles.size() == trackCount);
       for (int i = 0; i < trackCount; i++) {
         Track track = tracks.valueAt(i);
-        trackBundles.get(track.id).init(track, defaultSampleValuesArray.get(track.id));
+        trackBundles
+            .get(track.id)
+            .init(track, getDefaultSampleValues(defaultSampleValuesArray, track.id));
       }
     }
   }
 
+  private DefaultSampleValues getDefaultSampleValues(
+      SparseArray<DefaultSampleValues> defaultSampleValuesArray, int trackId) {
+    if (defaultSampleValuesArray.size() == 1) {
+      // Ignore track id if there is only one track to cope with non-matching track indices.
+      // See https://github.com/google/ExoPlayer/issues/4477.
+      return defaultSampleValuesArray.valueAt(/* index= */ 0);
+    }
+    return Assertions.checkNotNull(defaultSampleValuesArray.get(trackId));
+  }
+
   private void onMoofContainerAtomRead(ContainerAtom moof) throws ParserException {
     parseMoof(moof, trackBundles, flags, extendedTypeScratch);
     // If drm init data is sideloaded, we ignore pssh boxes.