content/renderer/media/webrtc_local_audio_renderer.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_WEBRTC_LOCAL_AUDIO_RENDERER_H_
   6 #define CONTENT_RENDERER_MEDIA_WEBRTC_LOCAL_AUDIO_RENDERER_H_
   7
   8 #include <vector>
   9
  10 #include "base/callback.h"
  11 #include "base/memory/ref_counted.h"
  12 #include "base/message_loop/message_loop_proxy.h"
  13 #include "base/synchronization/lock.h"
  14 #include "base/threading/thread_checker.h"
  15 #include "content/common/content_export.h"
  16 #include "content/public/renderer/media_stream_audio_sink.h"
  17 #include "content/renderer/media/media_stream_audio_renderer.h"
  18 #include "content/renderer/media/webrtc_audio_device_impl.h"
  19 #include "content/renderer/media/webrtc_local_audio_track.h"
  20 #include "third_party/WebKit/public/platform/WebMediaStreamTrack.h"
  21
  22 namespace media {
  23 class AudioBus;
  24 class AudioBlockFifo;
  25 class AudioOutputDevice;
  26 class AudioParameters;
  27 }
  28
  29 namespace content {
  30
  31 class WebRtcAudioCapturer;
  32
  33 // WebRtcLocalAudioRenderer is a MediaStreamAudioRenderer designed for rendering
  34 // local audio media stream tracks,
  35 // http://dev.w3.org/2011/webrtc/editor/getusermedia.html#mediastreamtrack
  36 // It also implements media::AudioRendererSink::RenderCallback to render audio
  37 // data provided from a WebRtcLocalAudioTrack source.
  38 // When the audio layer in the browser process asks for data to render, this
  39 // class provides the data by implementing the MediaStreamAudioSink
  40 // interface, i.e., we are a sink seen from the WebRtcAudioCapturer perspective.
  41 // TODO(henrika): improve by using similar principles as in RTCVideoRenderer
  42 // which register itself to the video track when the provider is started and
  43 // deregisters itself when it is stopped.
  44 // Tracking this at http://crbug.com/164813.
  45 class CONTENT_EXPORT WebRtcLocalAudioRenderer
  46     : NON_EXPORTED_BASE(public MediaStreamAudioRenderer),
  47       NON_EXPORTED_BASE(public MediaStreamAudioSink),
  48       NON_EXPORTED_BASE(public media::AudioRendererSink::RenderCallback) {
  49  public:
  50   // Creates a local renderer and registers a capturing |source| object.
  51   // The |source| is owned by the WebRtcAudioDeviceImpl.
  52   // Called on the main thread.
  53   WebRtcLocalAudioRenderer(const blink::WebMediaStreamTrack& audio_track,
  54                            int source_render_view_id,
  55                            int source_render_frame_id,
  56                            int session_id,
  57                            int frames_per_buffer);
  58
  59   // MediaStreamAudioRenderer implementation.
  60   // Called on the main thread.
  61   virtual void Start() OVERRIDE;
  62   virtual void Stop() OVERRIDE;
  63   virtual void Play() OVERRIDE;
  64   virtual void Pause() OVERRIDE;
  65   virtual void SetVolume(float volume) OVERRIDE;
  66   virtual base::TimeDelta GetCurrentRenderTime() const OVERRIDE;
  67   virtual bool IsLocalRenderer() const OVERRIDE;
  68
  69   const base::TimeDelta& total_render_time() const {
  70     return total_render_time_;
  71   }
  72
  73  protected:
  74   virtual ~WebRtcLocalAudioRenderer();
  75
  76  private:
  77   // MediaStreamAudioSink implementation.
  78
  79   // Called on the AudioInputDevice worker thread.
  80   virtual void OnData(const int16* audio_data,
  81                       int sample_rate,
  82                       int number_of_channels,
  83                       int number_of_frames) OVERRIDE;
  84
  85   // Called on the AudioInputDevice worker thread.
  86   virtual void OnSetFormat(const media::AudioParameters& params) OVERRIDE;
  87
  88   // media::AudioRendererSink::RenderCallback implementation.
  89   // Render() is called on the AudioOutputDevice thread and OnRenderError()
  90   // on the IO thread.
  91   virtual int Render(media::AudioBus* audio_bus,
  92                      int audio_delay_milliseconds) OVERRIDE;
  93   virtual void OnRenderError() OVERRIDE;
  94
  95   // Initializes and starts the |sink_| if
  96   //  we have received valid |source_params_| &&
  97   //  |playing_| has been set to true &&
  98   //  |volume_| is not zero.
  99   void MaybeStartSink();
 100
 101   // Sets new |source_params_| and then re-initializes and restarts |sink_|.
 102   void ReconfigureSink(const media::AudioParameters& params);
 103
 104   // The audio track which provides data to render. Given that this class
 105   // implements local loopback, the audio track is getting data from a capture
 106   // instance like a selected microphone and forwards the recorded data to its
 107   // sinks. The recorded data is stored in a FIFO and consumed
 108   // by this class when the sink asks for new data.
 109   // This class is calling MediaStreamAudioSink::AddToAudioTrack() and
 110   // MediaStreamAudioSink::RemoveFromAudioTrack() to connect and disconnect
 111   // with the audio track.
 112   blink::WebMediaStreamTrack audio_track_;
 113
 114   // The render view and frame in which the audio is rendered into |sink_|.
 115   const int source_render_view_id_;
 116   const int source_render_frame_id_;
 117   const int session_id_;
 118
 119   // MessageLoop associated with the single thread that performs all control
 120   // tasks.  Set to the MessageLoop that invoked the ctor.
 121   const scoped_refptr<base::MessageLoopProxy> message_loop_;
 122
 123   // The sink (destination) for rendered audio.
 124   scoped_refptr<media::AudioOutputDevice> sink_;
 125
 126   // Contains copies of captured audio frames.
 127   scoped_ptr<media::AudioBlockFifo> loopback_fifo_;
 128
 129   // Stores last time a render callback was received. The time difference
 130   // between a new time stamp and this value can be used to derive the
 131   // total render time.
 132   base::TimeTicks last_render_time_;
 133
 134   // Keeps track of total time audio has been rendered.
 135   base::TimeDelta total_render_time_;
 136
 137   // The audio parameters of the capture source.
 138   // Must only be touched on the main thread.
 139   media::AudioParameters source_params_;
 140
 141   // The audio parameters used by the sink.
 142   // Must only be touched on the main thread.
 143   media::AudioParameters sink_params_;
 144
 145   // Set when playing, cleared when paused.
 146   bool playing_;
 147
 148   // Protects |loopback_fifo_|, |playing_| and |sink_|.
 149   mutable base::Lock thread_lock_;
 150
 151   // The preferred buffer size provided via the ctor.
 152   const int frames_per_buffer_;
 153
 154   // The preferred device id of the output device or empty for the default
 155   // output device.
 156   const std::string output_device_id_;
 157
 158   // Cache value for the volume.
 159   float volume_;
 160
 161   // Flag to indicate whether |sink_| has been started yet.
 162   bool sink_started_;
 163
 164   // Used to DCHECK that some methods are called on the capture audio thread.
 165   base::ThreadChecker capture_thread_checker_;
 166
 167   DISALLOW_COPY_AND_ASSIGN(WebRtcLocalAudioRenderer);
 168 };
 169
 170 }  // namespace content
 171
 172 #endif  // CONTENT_RENDERER_MEDIA_WEBRTC_LOCAL_AUDIO_RENDERER_H_