Cleanup of the mixer interface.

webrtc/modules/audio_mixer/audio_mixer_impl.h

Index: webrtc/modules/audio_mixer/audio_mixer_impl.h
diff --git a/webrtc/modules/audio_mixer/audio_mixer_impl.h b/webrtc/modules/audio_mixer/audio_mixer_impl.h
index 5aa697865ff61e43fad1372d69196fadf184b3a3..5dff58d67573756dbec8dc7295c509e808daff3b 100644
--- a/webrtc/modules/audio_mixer/audio_mixer_impl.h
+++ b/webrtc/modules/audio_mixer/audio_mixer_impl.h
@@ -16,6 +16,7 @@
 
 #include "webrtc/base/thread_annotations.h"
 #include "webrtc/base/thread_checker.h"
+#include "webrtc/base/scoped_ref_ptr.h"

[the sun, 2016/10/10 13:35:49]

nit: s comes before t in western european alphabets

[aleloi, 2016/10/10 14:02:27]

Done.

 #include "webrtc/modules/audio_mixer/audio_mixer.h"
 #include "webrtc/modules/audio_processing/include/audio_processing.h"
 #include "webrtc/modules/include/module_common_types.h"
@@ -41,15 +42,20 @@ class AudioMixerImpl : public AudioMixer {
 
   // AudioProcessing only accepts 10 ms frames.
   static const int kFrameDurationInMs = 10;
+  static const int kMaximumAmountOfMixedAudioSources = 3;
   static const int kDefaultFrequency = 48000;
 
-  static std::unique_ptr<AudioMixerImpl> Create();
+  static rtc::scoped_refptr<AudioMixerImpl> Create();

[aleloi, 2016/10/10 13:06:31]

When we move the interface to webrtc/api, we can add a 'create_mixer.h' with
'rtc::scoped_refptr<AudioMixer> CreateTopTreeMixer()' that calls this function.
Alternatively, I can add it to this CL.

[the sun, 2016/10/10 13:35:49]

It's ok to do it separately. Once you get around to it, for consistency, name
the file "builtin_audio_mixer.h", and also you will want to throw in an 'h' at a
strategic point in the function name. :)

[aleloi, 2016/10/10 14:02:27]

Acknowledged.

+
+  explicit AudioMixerImpl(std::unique_ptr<AudioProcessing> limiter);

[aleloi, 2016/10/10 13:06:31]

A refcounted object must have a public constructor.

[the sun, 2016/10/10 13:35:49]

No, protected should be enough if you're using rtc::RefCountedObject

[aleloi, 2016/10/10 14:02:27]

Done.

 
   ~AudioMixerImpl() override;
 
   // AudioMixer functions
-  int32_t SetMixabilityStatus(Source* audio_source, bool mixable) override;
-  void Mix(int sample_rate,
+  bool AddSource(Source* audio_source) override;
+  bool RemoveSource(Source* audio_source) override;
+
+  void Mix(int sample_rate_hz,
            size_t number_of_channels,
            AudioFrame* audio_frame_for_mixing) override;
 
@@ -59,8 +65,6 @@ class AudioMixerImpl : public AudioMixer {
   bool GetAudioSourceMixabilityStatusForTest(Source* audio_source) const;
 
  private:
-  explicit AudioMixerImpl(std::unique_ptr<AudioProcessing> limiter);
-
   // Set/get mix frequency
   void SetOutputFrequency(int frequency);
   int OutputFrequency() const;
@@ -68,8 +72,7 @@ class AudioMixerImpl : public AudioMixer {
   // Compute what audio sources to mix from audio_source_list_. Ramp
   // in and out. Update mixed status. Mixes up to
   // kMaximumAmountOfMixedAudioSources audio sources.
-  AudioFrameList GetNonAnonymousAudio() EXCLUSIVE_LOCKS_REQUIRED(crit_);
-
+  AudioFrameList GetAudioFromSources() EXCLUSIVE_LOCKS_REQUIRED(crit_);
 
   // Add/remove the MixerAudioSource to the specified
   // MixerAudioSource list.
@@ -90,7 +93,6 @@ class AudioMixerImpl : public AudioMixer {
   // List of all audio sources. Note all lists are disjunct
   SourceStatusList audio_source_list_ GUARDED_BY(crit_);  // May be mixed.
 
-  size_t num_mixed_audio_sources_ GUARDED_BY(crit_);
   // Determines if we will use a limiter for clipping protection during
   // mixing.
   bool use_limiter_ ACCESS_ON(&thread_checker_);