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   void SwitchOutputDevice(const std::string& device_id,
  37                           const GURL& security_origin,
  38                           const SwitchOutputDeviceCB& callback) override;
  39   void Initialize(const AudioParameters& params,
  40                   AudioRendererSink::RenderCallback* renderer) override;
  41
  42   // Called by AudioRendererMixer when an error occurs.
  43   void OnRenderError();
  44
  45  protected:
  46   ~AudioRendererMixerInput() override;
  47
  48  private:
  49   friend class AudioRendererMixerInputTest;
  50
  51   bool playing_;
  52   bool initialized_;
  53   double volume_;
  54
  55   // AudioConverter::InputCallback implementation.
  56   double ProvideInput(AudioBus* audio_bus,
  57                       base::TimeDelta buffer_delay) override;
  58
  59   // Callbacks provided during construction which allow AudioRendererMixerInput
  60   // to retrieve a mixer during Initialize() and notify when it's done with it.
  61   GetMixerCB get_mixer_cb_;
  62   RemoveMixerCB remove_mixer_cb_;
  63
  64   // AudioParameters received during Initialize().
  65   AudioParameters params_;
  66
  67   // AudioRendererMixer provided through |get_mixer_cb_| during Initialize(),
  68   // guaranteed to live (at least) until |remove_mixer_cb_| is called.
  69   AudioRendererMixer* mixer_;
  70
  71   // Source of audio data which is provided to the mixer.
  72   AudioRendererSink::RenderCallback* callback_;
  73
  74   // Error callback for handing to AudioRendererMixer.
  75   const base::Closure error_cb_;
  76
  77   DISALLOW_COPY_AND_ASSIGN(AudioRendererMixerInput);
  78 };
  79
  80 }  // namespace media
  81
  82 #endif  // MEDIA_BASE_AUDIO_RENDERER_MIXER_INPUT_H_