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