Use passthrough decoder for (E)AC3 formats

media/base/android/media_codec_util.cc

Index: media/base/android/media_codec_util.cc
diff --git a/media/base/android/media_codec_util.cc b/media/base/android/media_codec_util.cc
index 3bb4fc7d39b02243dcf7fa9194457dcee9235f35..ffd2409070df4ab9d49d0f1dc355b98bbb2b4641 100644
--- a/media/base/android/media_codec_util.cc
+++ b/media/base/android/media_codec_util.cc
@@ -41,10 +41,12 @@ const char kOpusMimeType[] = "audio/opus";
 const char kVorbisMimeType[] = "audio/vorbis";
 const char kAc3MimeType[] = "audio/ac3";
 const char kEac3MimeType[] = "audio/eac3";
+const char kBitstreamAudioMimeType[] = "audio/raw";
 const char kAvcMimeType[] = "video/avc";
 const char kHevcMimeType[] = "video/hevc";
 const char kVp8MimeType[] = "video/x-vnd.on2.vp8";
 const char kVp9MimeType[] = "video/x-vnd.on2.vp9";
+
 }  // namespace
 
 static CodecProfileLevel MediaCodecProfileLevelToChromiumProfileLevel(
@@ -98,6 +100,9 @@ static bool IsEncoderSupportedByDevice(const std::string& android_mime_type) {
 
 // static
 std::string MediaCodecUtil::CodecToAndroidMimeType(AudioCodec codec) {
+  if (IsPassthroughAudioFormat(codec))
+    return kBitstreamAudioMimeType;
+
   switch (codec) {
     case kCodecMP3:
       return kMp3MimeType;
@@ -360,6 +365,11 @@ bool MediaCodecUtil::IsSetOutputSurfaceSupported() {
 }
 
 // static
+bool MediaCodecUtil::IsPassthroughAudioFormat(AudioCodec codec) {
+  return (codec == kCodecAC3 || codec == kCodecEAC3);

[DaleCurtis, 2017/05/04 19:05:44]

Drop unnecessary parens.

[AndyWu, 2017/05/06 01:46:48]

Done.

+}
+
+// static
 bool MediaCodecUtil::CodecNeedsFlushWorkaround(MediaCodecBridge* codec) {
   int sdk_int = base::android::BuildInfo::GetInstance()->sdk_int();
   std::string codec_name = codec->GetName();