media/base/audio_renderer_mixer_input.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef MEDIA_BASE_AUDIO_RENDERER_MIXER_INPUT_H_
   6 #define MEDIA_BASE_AUDIO_RENDERER_MIXER_INPUT_H_
   7
   8 #include <string>
   9 #include <vector>
  10
  11 #include "base/callback.h"
  12 #include "media/base/audio_converter.h"
  13 #include "media/base/audio_renderer_sink.h"
  14
  15 namespace media {
  16
  17 class AudioRendererMixer;
  18
  19 class MEDIA_EXPORT AudioRendererMixerInput
  20     : NON_EXPORTED_BASE(public AudioRendererSink),
  21       public AudioConverter::InputCallback {
  22  public:
  23   typedef base::Callback<AudioRendererMixer*(
  24       const AudioParameters& params)> GetMixerCB;
  25   typedef base::Callback<void(const AudioParameters& params)> RemoveMixerCB;
  26
  27   AudioRendererMixerInput(
  28       const GetMixerCB& get_mixer_cb, const RemoveMixerCB& remove_mixer_cb);
  29
  30   // AudioRendererSink implementation.
  31   void Start() override;
  32   void Stop() override;
  33   void Play() override;
  34   void Pause() override;
  35   bool SetVolume(double volume) override;
  36   OutputDevice* GetOutputDevice() override;
  37   void Initialize(const AudioParameters& params,
  38                   AudioRendererSink::RenderCallback* renderer) override;
  39
  40   // Called by AudioRendererMixer when an error occurs.
  41   void OnRenderError();
  42
  43  protected:
  44   ~AudioRendererMixerInput() override;
  45
  46  private:
  47   friend class AudioRendererMixerInputTest;
  48
  49   bool playing_;
  50   bool initialized_;
  51   double volume_;
  52
  53   // AudioConverter::InputCallback implementation.
  54   double ProvideInput(AudioBus* audio_bus,
  55                       base::TimeDelta buffer_delay) override;
  56
  57   // Callbacks provided during construction which allow AudioRendererMixerInput
  58   // to retrieve a mixer during Initialize() and notify when it's done with it.
  59   GetMixerCB get_mixer_cb_;
  60   RemoveMixerCB remove_mixer_cb_;
  61
  62   // AudioParameters received during Initialize().
  63   AudioParameters params_;
  64
  65   // AudioRendererMixer provided through |get_mixer_cb_| during Initialize(),
  66   // guaranteed to live (at least) until |remove_mixer_cb_| is called.
  67   AudioRendererMixer* mixer_;
  68
  69   // Source of audio data which is provided to the mixer.
  70   AudioRendererSink::RenderCallback* callback_;
  71
  72   // Error callback for handing to AudioRendererMixer.
  73   const base::Closure error_cb_;
  74
  75   DISALLOW_COPY_AND_ASSIGN(AudioRendererMixerInput);
  76 };
  77
  78 }  // namespace media
  79
  80 #endif  // MEDIA_BASE_AUDIO_RENDERER_MIXER_INPUT_H_