Re-add AC3/EAC3 audio demuxing support

media/formats/mp4/mp4_stream_parser.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/formats/mp4/mp4_stream_parser.h"
 
 #include "base/callback.h"
 #include "base/callback_helpers.h"
 #include "base/logging.h"
 #include "base/time/time.h"
@@ skipping 197 matching lines @@
       RCHECK(!samp_descr.audio_entries.empty());
 
       // It is not uncommon to find otherwise-valid files with incorrect sample
       // description indices, so we fail gracefully in that case.
       if (desc_idx >= samp_descr.audio_entries.size())
         desc_idx = 0;
       const AudioSampleEntry& entry = samp_descr.audio_entries[desc_idx];
       const AAC& aac = entry.esds.aac;
 
       if (!(entry.format == FOURCC_MP4A ||
+#if defined(ENABLE_AC3_EAC3_AUDIO_DEMUXING)
+            entry.format == FOURCC_A52  ||
+            entry.format == FOURCC_A52b ||
+            entry.format == FOURCC_AC3  ||
+            entry.format == FOURCC_AC_3 ||
+            entry.format == FOURCC_EAC3 ||
+#endif
             (entry.format == FOURCC_ENCA &&
              entry.sinf.format.format == FOURCC_MP4A))) {
         MEDIA_LOG(log_cb_) << "Unsupported audio format 0x"
                            << std::hex << entry.format << " in stsd box.";
         return false;
       }
 
       uint8 audio_type = entry.esds.object_type;
+#if defined(ENABLE_AC3_EAC3_AUDIO_DEMUXING)
+      if (audio_type == kForbidden &&
+          (entry.format == FOURCC_EAC3 || entry.format == FOURCC_A52b)) {
+        audio_type = kEAC3;
+      }
+      if (audio_type == kForbidden &&
+          (entry.format == FOURCC_A52 || entry.format == FOURCC_AC3 ||
+           entry.format == FOURCC_AC_3)) {
+        audio_type = kAC3;
+      }
+#endif
       DVLOG(1) << "audio_type " << std::hex << static_cast<int>(audio_type);
       if (audio_object_types_.find(audio_type) == audio_object_types_.end()) {
         MEDIA_LOG(log_cb_) << "audio object type 0x" << std::hex << audio_type
                            << " does not match what is specified in the"
                            << " mimetype.";
         return false;
       }
 
       AudioCodec codec = kUnknownAudioCodec;
       ChannelLayout channel_layout = CHANNEL_LAYOUT_NONE;
       int sample_per_second = 0;
       std::vector<uint8> extra_data;
       // Check if it is MPEG4 AAC defined in ISO 14496 Part 3 or
       // supported MPEG2 AAC varients.
       if (ESDescriptor::IsAAC(audio_type)) {
         codec = kCodecAAC;
         channel_layout = aac.GetChannelLayout(has_sbr_);
         sample_per_second = aac.GetOutputSamplesPerSecond(has_sbr_);
 #if defined(OS_ANDROID)
         extra_data = aac.codec_specific_data();
 #endif
+#if defined(ENABLE_AC3_EAC3_AUDIO_DEMUXING)
+      } else if (audio_type == kAC3) {
+        codec = kCodecAC3;
+        channel_layout = GuessChannelLayout(entry.channelcount);
+        sample_per_second = entry.samplerate;
+      } else if (audio_type == kEAC3) {
+        codec = kCodecEAC3;
+        channel_layout = GuessChannelLayout(entry.channelcount);
+        sample_per_second = entry.samplerate;
+#endif
       } else {
         MEDIA_LOG(log_cb_) << "Unsupported audio object type 0x" << std::hex
                            << audio_type << " in esds.";
         return false;
       }
 
       SampleFormat sample_format;
       if (entry.samplesize == 8) {
         sample_format = kSampleFormatU8;
       } else if (entry.samplesize == 16) {
@@ skipping 369 matching lines @@
       runs.AdvanceSample();
     }
     runs.AdvanceRun();
   }
 
   return true;
 }
 
 }  // namespace mp4
 }  // namespace media