From da663aa0812f346d68b172ba6f7c59caa00b3523 Mon Sep 17 00:00:00 2001
From: aquilescanta <aquilescanta@google.com>
Date: Fri, 23 Oct 2020 14:11:49 +0100
Subject: [PATCH] Avoid chunkless preparation if the codec mapping is ambiguous

Issue: #7877
PiperOrigin-RevId: 338659937
---
 .../google/android/exoplayer2/util/Util.java  | 12 +++++++++
 .../exoplayer2/source/hls/HlsMediaPeriod.java | 26 ++++++++++---------
 2 files changed, 26 insertions(+), 12 deletions(-)

diff --git a/library/common/src/main/java/com/google/android/exoplayer2/util/Util.java b/library/common/src/main/java/com/google/android/exoplayer2/util/Util.java
index 745c44395f..441ce84f8d 100644
--- a/library/common/src/main/java/com/google/android/exoplayer2/util/Util.java
+++ b/library/common/src/main/java/com/google/android/exoplayer2/util/Util.java
@@ -1485,6 +1485,18 @@ public final class Util {
         + ") " + ExoPlayerLibraryInfo.VERSION_SLASHY;
   }
 
+  /** Returns the number of codec strings in {@code codecs} whose type matches {@code trackType}. */
+  public static int getCodecCountOfType(@Nullable String codecs, int trackType) {
+    String[] codecArray = splitCodecs(codecs);
+    int count = 0;
+    for (String codec : codecArray) {
+      if (trackType == MimeTypes.getTrackTypeOfCodec(codec)) {
+        count++;
+      }
+    }
+    return count;
+  }
+
   /**
    * Returns a copy of {@code codecs} without the codecs whose track type doesn't match {@code
    * trackType}.
diff --git a/library/hls/src/main/java/com/google/android/exoplayer2/source/hls/HlsMediaPeriod.java b/library/hls/src/main/java/com/google/android/exoplayer2/source/hls/HlsMediaPeriod.java
index 5e0709228d..0089f68bf4 100644
--- a/library/hls/src/main/java/com/google/android/exoplayer2/source/hls/HlsMediaPeriod.java
+++ b/library/hls/src/main/java/com/google/android/exoplayer2/source/hls/HlsMediaPeriod.java
@@ -603,6 +603,12 @@ public final class HlsMediaPeriod implements MediaPeriod, HlsSampleStreamWrapper
       }
     }
     String codecs = selectedPlaylistFormats[0].codecs;
+    int numberOfVideoCodecs = Util.getCodecCountOfType(codecs, C.TRACK_TYPE_VIDEO);
+    int numberOfAudioCodecs = Util.getCodecCountOfType(codecs, C.TRACK_TYPE_AUDIO);
+    boolean codecsStringAllowsChunklessPreparation =
+        numberOfAudioCodecs <= 1
+            && numberOfVideoCodecs <= 1
+            && numberOfAudioCodecs + numberOfVideoCodecs > 0;
     HlsSampleStreamWrapper sampleStreamWrapper =
         buildSampleStreamWrapper(
             C.TRACK_TYPE_DEFAULT,
@@ -614,18 +620,16 @@ public final class HlsMediaPeriod implements MediaPeriod, HlsSampleStreamWrapper
             positionUs);
     sampleStreamWrappers.add(sampleStreamWrapper);
     manifestUrlIndicesPerWrapper.add(selectedVariantIndices);
-    if (allowChunklessPreparation && codecs != null) {
-      boolean variantsContainVideoCodecs = Util.getCodecsOfType(codecs, C.TRACK_TYPE_VIDEO) != null;
-      boolean variantsContainAudioCodecs = Util.getCodecsOfType(codecs, C.TRACK_TYPE_AUDIO) != null;
+    if (allowChunklessPreparation && codecsStringAllowsChunklessPreparation) {
       List<TrackGroup> muxedTrackGroups = new ArrayList<>();
-      if (variantsContainVideoCodecs) {
+      if (numberOfVideoCodecs > 0) {
         Format[] videoFormats = new Format[selectedVariantsCount];
         for (int i = 0; i < videoFormats.length; i++) {
           videoFormats[i] = deriveVideoFormat(selectedPlaylistFormats[i]);
         }
         muxedTrackGroups.add(new TrackGroup(videoFormats));
 
-        if (variantsContainAudioCodecs
+        if (numberOfAudioCodecs > 0
             && (masterPlaylist.muxedAudioFormat != null || masterPlaylist.audios.isEmpty())) {
           muxedTrackGroups.add(
               new TrackGroup(
@@ -640,7 +644,7 @@ public final class HlsMediaPeriod implements MediaPeriod, HlsSampleStreamWrapper
             muxedTrackGroups.add(new TrackGroup(ccFormats.get(i)));
           }
         }
-      } else if (variantsContainAudioCodecs) {
+      } else /* numberOfAudioCodecs > 0 */ {
         // Variants only contain audio.
         Format[] audioFormats = new Format[selectedVariantsCount];
         for (int i = 0; i < audioFormats.length; i++) {
@@ -651,9 +655,6 @@ public final class HlsMediaPeriod implements MediaPeriod, HlsSampleStreamWrapper
                   /* isPrimaryTrackInVariant= */ true);
         }
         muxedTrackGroups.add(new TrackGroup(audioFormats));
-      } else {
-        // Variants contain codecs but no video or audio entries could be identified.
-        throw new IllegalArgumentException("Unexpected codecs attribute: " + codecs);
       }
 
       TrackGroup id3TrackGroup =
@@ -693,7 +694,7 @@ public final class HlsMediaPeriod implements MediaPeriod, HlsSampleStreamWrapper
         continue;
       }
 
-      boolean renditionsHaveCodecs = true;
+      boolean codecStringsAllowChunklessPreparation = true;
       scratchPlaylistUrls.clear();
       scratchPlaylistFormats.clear();
       scratchIndicesList.clear();
@@ -704,7 +705,8 @@ public final class HlsMediaPeriod implements MediaPeriod, HlsSampleStreamWrapper
           scratchIndicesList.add(renditionIndex);
           scratchPlaylistUrls.add(rendition.url);
           scratchPlaylistFormats.add(rendition.format);
-          renditionsHaveCodecs &= rendition.format.codecs != null;
+          codecStringsAllowChunklessPreparation &=
+              Util.getCodecCountOfType(rendition.format.codecs, C.TRACK_TYPE_AUDIO) == 1;
         }
       }
 
@@ -720,7 +722,7 @@ public final class HlsMediaPeriod implements MediaPeriod, HlsSampleStreamWrapper
       manifestUrlsIndicesPerWrapper.add(Ints.toArray(scratchIndicesList));
       sampleStreamWrappers.add(sampleStreamWrapper);
 
-      if (allowChunklessPreparation && renditionsHaveCodecs) {
+      if (allowChunklessPreparation && codecStringsAllowChunklessPreparation) {
         Format[] renditionFormats = scratchPlaylistFormats.toArray(new Format[0]);
         sampleStreamWrapper.prepareWithMasterPlaylistInfo(
             new TrackGroup[] {new TrackGroup(renditionFormats)}, /* primaryTrackGroupIndex= */ 0);