Allow mp3 audio codec for mpeg2ts containers in MSE

media/formats/mp2t/mp2t_stream_parser.cc

Index: media/formats/mp2t/mp2t_stream_parser.cc
diff --git a/media/formats/mp2t/mp2t_stream_parser.cc b/media/formats/mp2t/mp2t_stream_parser.cc
index 615f5c46e19138cdeae0ac382aefc49da2625517..eea80da84e954df4687cb7a0db20729c7f28d31d 100644
--- a/media/formats/mp2t/mp2t_stream_parser.cc
+++ b/media/formats/mp2t/mp2t_stream_parser.cc
@@ -48,6 +48,8 @@ const int64_t kSampleAESPrivateDataIndicatorAAC = 0x61616364;
 enum StreamType {
   // ISO-13818.1 / ITU H.222 Table 2.34 "Stream type assignments"
   kStreamTypeMpeg1Audio = 0x3,
+  // ISO/IEC 13818-3 Audio (MPEG-2)
+  kStreamTypeMpeg2Audio = 0x4,

[servolk, 2017/03/23 23:24:59]

+dougsteed@: Doug, I've added the stream_type=4 in here, this should work for
the test streams you mentioned offline. I don't have the ITU H.222 spec, but
many publicly-available sources seem to agree that 3 is ISO/IEC 11172-3 (MPEG-1
audio), while 4 is ISO/IEC 13818-3 (MPEG-2 audio), e.g.:
https://en.wikipedia.org/wiki/Program-specific_information#Elementary_stream_...
http://www.etherguidesystems.com/help/sdos/mpeg/semantics/mpeg-2/stream_type....

[dougsteed, 2017/03/24 02:14:47]

So the formats are compatible? Note that the parser is called EsParserMpeg1Audio
but now it is being asked to parse both.

   kStreamTypeAAC = 0xf,
   kStreamTypeAVC = 0x1b,
 #if BUILDFLAG(ENABLE_HLS_SAMPLE_AES)
@@ -421,7 +423,8 @@ void Mp2tStreamParser::RegisterPes(int pmt_pid,
                        pes_pid),
             sbr_in_mimetype_));
     is_audio = true;
-  } else if (stream_type == kStreamTypeMpeg1Audio) {
+  } else if (stream_type == kStreamTypeMpeg1Audio ||
+             stream_type == kStreamTypeMpeg2Audio) {
     es_parser.reset(new EsParserMpeg1Audio(
         base::Bind(&Mp2tStreamParser::OnAudioConfigChanged,
                    base::Unretained(this), pes_pid),