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.
5 #ifndef CONTENT_RENDERER_MEDIA_WEBAUDIO_CAPTURER_SOURCE_H_
6 #define CONTENT_RENDERER_MEDIA_WEBAUDIO_CAPTURER_SOURCE_H_
8 #include "base/memory/ref_counted.h"
9 #include "base/synchronization/lock.h"
10 #include "base/threading/thread_checker.h"
11 #include "media/audio/audio_parameters.h"
12 #include "media/base/audio_capturer_source.h"
13 #include "media/base/audio_fifo.h"
14 #include "third_party/WebKit/public/platform/WebAudioDestinationConsumer.h"
15 #include "third_party/WebKit/public/platform/WebVector.h"
19 class WebRtcLocalAudioTrack;
20 class WebRtcLocalAudioSourceProvider;
22 // WebAudioCapturerSource is the missing link between
23 // WebAudio's MediaStreamAudioDestinationNode and WebRtcLocalAudioTrack.
25 // 1. WebKit calls the setFormat() method setting up the basic stream format
26 // (channels, and sample-rate).
27 // 2. consumeAudio() is called periodically by WebKit which dispatches the
28 // audio stream to the WebRtcLocalAudioTrack::Capture() method.
29 class WebAudioCapturerSource
30 : public base::RefCountedThreadSafe<WebAudioCapturerSource>,
31 public WebKit::WebAudioDestinationConsumer {
33 WebAudioCapturerSource();
35 // WebAudioDestinationConsumer implementation.
36 // setFormat() is called early on, so that we can configure the audio track.
37 virtual void setFormat(size_t number_of_channels, float sample_rate) OVERRIDE;
38 // MediaStreamAudioDestinationNode periodically calls consumeAudio().
39 // Called on the WebAudio audio thread.
40 virtual void consumeAudio(const WebKit::WebVector<const float*>& audio_data,
41 size_t number_of_frames) OVERRIDE;
43 // Called when the WebAudioCapturerSource is hooking to a media audio track.
44 // |track| is the sink of the data flow. |source_provider| is the source of
45 // the data flow where stream information like delay, volume, key_pressed,
47 void Start(WebRtcLocalAudioTrack* track,
48 WebRtcLocalAudioSourceProvider* source_provider);
50 // Called when the media audio track is stopping.
54 friend class base::RefCountedThreadSafe<WebAudioCapturerSource>;
55 virtual ~WebAudioCapturerSource();
58 // Used to DCHECK that some methods are called on the correct thread.
59 base::ThreadChecker thread_checker_;
61 // The audio track this WebAudioCapturerSource is feeding data to.
62 // WebRtcLocalAudioTrack is reference counted, and owning this object.
63 // To avoid circular reference, a raw pointer is kept here.
64 WebRtcLocalAudioTrack* track_;
66 // A raw pointer to the source provider to get audio processing params like
67 // delay, volume, key_pressed information.
68 // This |source_provider_| is guaranteed to outlive this object.
69 WebRtcLocalAudioSourceProvider* source_provider_;
71 media::AudioParameters params_;
73 // Wraps data coming from HandleCapture().
74 scoped_ptr<media::AudioBus> wrapper_bus_;
76 // Bus for reading from FIFO and calling the CaptureCallback.
77 scoped_ptr<media::AudioBus> capture_bus_;
79 // Handles mismatch between WebAudio buffer size and WebRTC.
80 scoped_ptr<media::AudioFifo> fifo_;
82 // Synchronizes HandleCapture() with AudioCapturerSource calls.
86 DISALLOW_COPY_AND_ASSIGN(WebAudioCapturerSource);
89 } // namespace content
91 #endif // CONTENT_RENDERER_MEDIA_WEBAUDIO_CAPTURER_SOURCE_H_