To M56: Use ffmpeg for opus decoding, no need to maintain our decoder.

chromecast/media/cma/decoder/cast_audio_decoder_linux.cc

 // Copyright 2015 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 "chromecast/media/cma/decoder/cast_audio_decoder.h"
 
 #include <stdint.h>
 #include <limits>
 #include <queue>
 #include <utility>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/single_thread_task_runner.h"
 #include "chromecast/media/cma/base/decoder_buffer_adapter.h"
 #include "chromecast/media/cma/base/decoder_buffer_base.h"
 #include "chromecast/media/cma/base/decoder_config_adapter.h"
 #include "media/base/audio_buffer.h"
 #include "media/base/audio_bus.h"
 #include "media/base/cdm_context.h"
 #include "media/base/channel_layout.h"
 #include "media/base/channel_mixer.h"
 #include "media/base/decoder_buffer.h"
 #include "media/base/sample_format.h"
 #include "media/filters/ffmpeg_audio_decoder.h"
-#include "media/filters/opus_audio_decoder.h"
 
 namespace chromecast {
 namespace media {
 
 namespace {
 
-const int kOpusSamplingRate = 48000;
-const uint8_t kFakeOpusExtraData[19] = {
-  'O', 'p', 'u', 's', 'H', 'e', 'a', 'd',  // offset 0, OpusHead
-  0,  // offset 8, version
-  2,  // offset 9, channels
-  0, 0,  // offset 10, skip
-  static_cast<uint8_t>(kOpusSamplingRate & 0xFF),  // offset 12, LE
-  static_cast<uint8_t>((kOpusSamplingRate >> 8) & 0xFF),
-  static_cast<uint8_t>((kOpusSamplingRate >> 16) & 0xFF),
-  static_cast<uint8_t>((kOpusSamplingRate >> 24) & 0xFF),
-  0, 0,  // offset 16, gain
-  0,  // offset 18, stereo mapping
-};
-
 const int kOutputChannelCount = 2;  // Always output stereo audio.
 const int kMaxChannelInput = 2;
 
 class CastAudioDecoderImpl : public CastAudioDecoder {
  public:
   CastAudioDecoderImpl(
       const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
       const InitializedCallback& initialized_callback,
       OutputFormat output_format)
       : task_runner_(task_runner),
@@ skipping 15 matching lines @@
     // the decoder will report kDecodeError when decoding.
     config_.encryption_scheme = Unencrypted();
 
     if (config_.channel_number == 1) {
       // If the input is mono, create a ChannelMixer to convert mono to stereo.
       // TODO(kmackay) Support other channel format conversions?
       mixer_.reset(new ::media::ChannelMixer(::media::CHANNEL_LAYOUT_MONO,
                                              ::media::CHANNEL_LAYOUT_STEREO));
     }
     base::WeakPtr<CastAudioDecoderImpl> self = weak_factory_.GetWeakPtr();
-    if (config.codec == media::kCodecOpus) {
-      // Insert fake extradata to make OpusAudioDecoder work with v2mirroring.
-      if (config_.extra_data.empty() &&
-          config_.samples_per_second == kOpusSamplingRate &&
-          config_.channel_number == 2)
-        config_.extra_data.assign(
-            kFakeOpusExtraData,
-            kFakeOpusExtraData + sizeof(kFakeOpusExtraData));
-      decoder_.reset(new ::media::OpusAudioDecoder(task_runner_));
-    } else {
-      decoder_.reset(new ::media::FFmpegAudioDecoder(
-          task_runner_, make_scoped_refptr(new ::media::MediaLog())));
-    }
+    decoder_.reset(new ::media::FFmpegAudioDecoder(
+        task_runner_, make_scoped_refptr(new ::media::MediaLog())));
     decoder_->Initialize(
         media::DecoderConfigAdapter::ToMediaAudioDecoderConfig(config_),
         nullptr, base::Bind(&CastAudioDecoderImpl::OnInitialized, self),
         base::Bind(&CastAudioDecoderImpl::OnDecoderOutput, self));
     // Unfortunately there is no result from decoder_->Initialize() until later
     // (the pipeline status callback is posted to the task runner).
   }
 
   // CastAudioDecoder implementation:
   bool Decode(const scoped_refptr<media::DecoderBufferBase>& data,
@@ skipping 189 matching lines @@
       return 2;
     case CastAudioDecoder::OutputFormat::kOutputPlanarFloat:
       return 4;
   }
   NOTREACHED();
   return 1;
 }
 
 }  // namespace media
 }  // namespace chromecast