From a50d31a70b975d16bd863ded771451b6157675ad 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 3df15654e0..93c5c344bc 100644
--- a/RELEASENOTES.md
+++ b/RELEASENOTES.md
@@ -15,6 +15,9 @@
   ([#4403](https://github.com/google/ExoPlayer/issues/4413)).
 * Add support for multiple audio and video tracks in MPEG-PS streams
   ([#4406](https://github.com/google/ExoPlayer/issues/4406)).
+* 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.