content/renderer/media/renderer_webaudiodevice_impl.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 CONTENT_RENDERER_MEDIA_MEDIA_RENDERER_WEBAUDIODEVICE_IMPL_H_
   6 #define CONTENT_RENDERER_MEDIA_MEDIA_RENDERER_WEBAUDIODEVICE_IMPL_H_
   7
   8 #include "base/memory/ref_counted.h"
   9 #include "base/threading/thread_checker.h"
  10 #include "media/audio/audio_parameters.h"
  11 #include "media/base/audio_renderer_sink.h"
  12 #include "third_party/WebKit/public/platform/WebAudioDevice.h"
  13 #include "third_party/WebKit/public/platform/WebVector.h"
  14
  15 namespace media {
  16 class AudioOutputDevice;
  17 }
  18
  19 namespace content {
  20
  21 class RendererWebAudioDeviceImpl
  22     : public blink::WebAudioDevice,
  23       public media::AudioRendererSink::RenderCallback {
  24  public:
  25   RendererWebAudioDeviceImpl(const media::AudioParameters& params,
  26                              blink::WebAudioDevice::RenderCallback* callback,
  27                              int session_id);
  28   virtual ~RendererWebAudioDeviceImpl();
  29
  30   // blink::WebAudioDevice implementation.
  31   virtual void start();
  32   virtual void stop();
  33   virtual double sampleRate();
  34
  35   // AudioRendererSink::RenderCallback implementation.
  36   virtual int Render(media::AudioBus* dest,
  37                      int audio_delay_milliseconds) OVERRIDE;
  38
  39   virtual void OnRenderError() OVERRIDE;
  40
  41  private:
  42   const media::AudioParameters params_;
  43
  44   // Weak reference to the callback into WebKit code.
  45   blink::WebAudioDevice::RenderCallback* const client_callback_;
  46
  47   // To avoid the need for locking, ensure the control methods of the
  48   // blink::WebAudioDevice implementation are called on the same thread.
  49   base::ThreadChecker thread_checker_;
  50
  51   // When non-NULL, we are started.  When NULL, we are stopped.
  52   scoped_refptr<media::AudioOutputDevice> output_device_;
  53
  54   // ID to allow browser to select the correct input device for unified IO.
  55   int session_id_;
  56
  57   DISALLOW_COPY_AND_ASSIGN(RendererWebAudioDeviceImpl);
  58 };
  59
  60 }  // namespace content
  61
  62 #endif  // CONTENT_RENDERER_MEDIA_MEDIA_RENDERER_WEBAUDIODEVICE_IMPL_H_