Cleanup of the mixer interface.

webrtc/modules/audio_mixer/audio_mixer.h

 /*
  *  Copyright (c) 2011 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.
  */
 
 #ifndef WEBRTC_MODULES_AUDIO_MIXER_AUDIO_MIXER_H_
 #define WEBRTC_MODULES_AUDIO_MIXER_AUDIO_MIXER_H_
 
 #include <memory>
 
-#include "webrtc/modules/include/module.h"
 #include "webrtc/modules/include/module_common_types.h"
 
 namespace webrtc {
 
 class AudioMixer {
  public:
   static const int kMaximumAmountOfMixedAudioSources = 3;
-  enum Frequency {
-    kNbInHz = 8000,
-    kWbInHz = 16000,
-    kSwbInHz = 32000,
-    kFbInHz = 48000,
-    kDefaultFrequency = kWbInHz
-  };
-
   // A callback class that all mixer participants must inherit from/implement.
   class Source {
    public:
     enum class AudioFrameInfo {
       kNormal,  // The samples in audio_frame are valid and should be used.
       kMuted,   // The samples in audio_frame should not be used, but should be
       // implicitly interpreted as zero. Other fields in audio_frame
       // may be read and should contain meaningful values.
       kError  // audio_frame will not be used.
     };
 
     struct AudioFrameWithMuted {
       AudioFrame* audio_frame;
       AudioFrameInfo audio_frame_info;
     };
 
     // The implementation of GetAudioFrameWithMuted should update
     // audio_frame with new audio every time it's called. Implementing
     // classes are allowed to return the same AudioFrame pointer on
     // different calls. The pointer must stay valid until the next
     // mixing call or until this audio source is disconnected from the
     // mixer.
-    virtual AudioFrameWithMuted GetAudioFrameWithMuted(int32_t id,
-                                                       int sample_rate_hz) = 0;
+    virtual AudioFrameWithMuted GetAudioFrameWithMuted(int sample_rate_hz) = 0;
 
    protected:
     virtual ~Source() {}
   };
 
   // Factory method. Constructor disabled.
-  static std::unique_ptr<AudioMixer> Create(int id);
+  static std::unique_ptr<AudioMixer> Create();
   virtual ~AudioMixer() {}
 
   // Add/remove audio sources as candidates for mixing.
   virtual int32_t SetMixabilityStatus(Source* audio_source, bool mixable) = 0;
-  // Returns true if an audio source is a candidate for mixing.
-  virtual bool MixabilityStatus(const Source& audio_source) const = 0;
-
-  // Inform the mixer that the audio source should always be mixed and not
-  // count toward the number of mixed audio sources. Note that an audio source
-  // must have been added to the mixer (by calling SetMixabilityStatus())
-  // before this function can be successfully called.
-  virtual int32_t SetAnonymousMixabilityStatus(Source* audio_source,
-                                               bool mixable) = 0;
 
   // Performs mixing by asking registered audio sources for audio. The
-  // mixed result is placed in the provided AudioFrame. Can only be
+  // mixed result is placed in the provided AudioFrame. Will only be

[the sun, 2016/10/10 14:19:52]

With this comment, it seems the thread expectations are missing from the other
methods.

   // called from a single thread. The rate and channels arguments
   // specify the rate and number of channels of the mix result.
-  virtual void Mix(int sample_rate,
+  virtual void Mix(int sample_rate_hz,
                    size_t number_of_channels,
                    AudioFrame* audio_frame_for_mixing) = 0;
-
-  // Returns true if the audio source is mixed anonymously.
-  virtual bool AnonymousMixabilityStatus(const Source& audio_source) const = 0;
-
-  // Output level functions for VoEVolumeControl. Return value
-  // between 0 and 9 is returned by voe::AudioLevel.
-  virtual int GetOutputAudioLevel() = 0;
-
-  // Return value between 0 and 0x7fff is returned by voe::AudioLevel.
-  virtual int GetOutputAudioLevelFullRange() = 0;
-
- protected:
-  AudioMixer() {}
-
- private:
-  RTC_DISALLOW_COPY_AND_ASSIGN(AudioMixer);
 };
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_AUDIO_MIXER_AUDIO_MIXER_H_