WebRtcVoiceEngine: Use AudioDecoderFactory to generate recv codecs.

webrtc/media/engine/webrtcvoiceengine.h

 /*
  *  Copyright (c) 2004 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 113 matching lines @@
   bool ApplyOptions(const AudioOptions& options);
   void SetDefaultDevices();
 
   // webrtc::TraceCallback:
   void Print(webrtc::TraceLevel level, const char* trace, int length) override;
 
   void StartAecDump(const std::string& filename);
   int CreateVoEChannel();
   webrtc::AudioDeviceModule* adm();
 
+  AudioCodecs CollectRecvCodecs() const;

[ivoc, 2016/07/05 14:43:51]

I would prefer not to abbreviate "Recv" in the method name (unless this is
commonly done?).

[ossu, 2016/07/05 15:31:57]

It's done eeeeverywhere, except where it isn't. :)
We really should move for uniformity at some point. In this part of the code,
it's common with recv, though, and it does update recv_codecs_, which makes its
name apt.

+
   rtc::ThreadChecker signal_thread_checker_;
   rtc::ThreadChecker worker_thread_checker_;
 
   // The audio device manager.
   rtc::scoped_refptr<webrtc::AudioDeviceModule> adm_;
   rtc::scoped_refptr<webrtc::AudioDecoderFactory> decoder_factory_;
   // The primary instance of WebRtc VoiceEngine.
   std::unique_ptr<VoEWrapper> voe_wrapper_;
   rtc::scoped_refptr<webrtc::AudioState> audio_state_;
-  std::vector<AudioCodec> codecs_;
+  std::vector<AudioCodec> send_codecs_;
+  std::vector<AudioCodec> recv_codecs_;
   std::vector<WebRtcVoiceMediaChannel*> channels_;
   webrtc::Config voe_config_;
   bool is_dumping_aec_ = false;
 
   webrtc::AgcConfig default_agc_config_;
   // Cache received extended_filter_aec, delay_agnostic_aec, experimental_ns and
   // intelligibility_enhancer values, and apply them in case they are missing
   // in the audio options. We need to do this because SetExtraOptions() will
   // revert to defaults for options which are not provided.
   rtc::Optional<bool> extended_filter_aec_;
@@ skipping 148 matching lines @@
   std::map<uint32_t, WebRtcAudioReceiveStream*> recv_streams_;
   std::vector<webrtc::RtpExtension> recv_rtp_extensions_;
 
   SendCodecSpec send_codec_spec_;
 
   RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(WebRtcVoiceMediaChannel);
 };
 }  // namespace cricket
 
 #endif  // WEBRTC_MEDIA_ENGINE_WEBRTCVOICEENGINE_H_