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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 #include "content/renderer/media/webaudio_capturer_source.h" | |
6 | |
7 #include "base/logging.h" | |
8 #include "base/time/time.h" | |
9 #include "content/renderer/media/webrtc_local_audio_track.h" | |
10 | |
11 using media::AudioBus; | |
12 using media::AudioFifo; | |
13 using media::AudioParameters; | |
14 using media::ChannelLayout; | |
15 using media::CHANNEL_LAYOUT_MONO; | |
16 using media::CHANNEL_LAYOUT_STEREO; | |
17 | |
18 static const int kMaxNumberOfBuffersInFifo = 5; | |
19 | |
20 namespace content { | |
21 | |
22 WebAudioCapturerSource::WebAudioCapturerSource( | |
23 const blink::WebMediaStreamSource& blink_source) | |
24 : track_(NULL), | |
25 audio_format_changed_(false), | |
26 blink_source_(blink_source) { | |
27 } | |
28 | |
29 WebAudioCapturerSource::~WebAudioCapturerSource() { | |
30 DCHECK(thread_checker_.CalledOnValidThread()); | |
31 removeFromBlinkSource(); | |
32 } | |
33 | |
34 void WebAudioCapturerSource::setFormat( | |
35 size_t number_of_channels, float sample_rate) { | |
36 DCHECK(thread_checker_.CalledOnValidThread()); | |
37 DVLOG(1) << "WebAudioCapturerSource::setFormat(sample_rate=" | |
38 << sample_rate << ")"; | |
39 | |
40 // If the channel count is greater than 8, use discrete layout. However, | |
41 // anything beyond 8 is ignored by the subsequent (WebRTC) audio pipeline. | |
42 ChannelLayout channel_layout = | |
43 number_of_channels > 8 ? media::CHANNEL_LAYOUT_DISCRETE | |
44 : media::GuessChannelLayout(number_of_channels); | |
45 | |
46 base::AutoLock auto_lock(lock_); | |
47 | |
48 // Set the format used by this WebAudioCapturerSource. We are using 10ms data | |
49 // as buffer size since that is the native buffer size of WebRtc packet | |
50 // running on. | |
51 params_.Reset(media::AudioParameters::AUDIO_PCM_LOW_LATENCY, channel_layout, | |
52 sample_rate, 16, sample_rate / 100); | |
53 | |
54 // Take care of the discrete channel layout case. | |
55 params_.set_channels_for_discrete(number_of_channels); | |
56 | |
57 audio_format_changed_ = true; | |
58 | |
59 wrapper_bus_ = AudioBus::CreateWrapper(params_.channels()); | |
60 capture_bus_ = AudioBus::Create(params_); | |
61 | |
62 fifo_.reset(new AudioFifo( | |
63 params_.channels(), | |
64 kMaxNumberOfBuffersInFifo * params_.frames_per_buffer())); | |
65 } | |
66 | |
67 void WebAudioCapturerSource::Start(WebRtcLocalAudioTrack* track) { | |
68 DCHECK(thread_checker_.CalledOnValidThread()); | |
69 DCHECK(track); | |
70 base::AutoLock auto_lock(lock_); | |
71 track_ = track; | |
72 } | |
73 | |
74 void WebAudioCapturerSource::Stop() { | |
75 DCHECK(thread_checker_.CalledOnValidThread()); | |
76 { | |
77 base::AutoLock auto_lock(lock_); | |
78 track_ = NULL; | |
79 } | |
80 // removeFromBlinkSource() should not be called while |lock_| is acquired, | |
81 // as it could result in a deadlock. | |
82 removeFromBlinkSource(); | |
83 } | |
84 | |
85 void WebAudioCapturerSource::consumeAudio( | |
86 const blink::WebVector<const float*>& audio_data, | |
87 size_t number_of_frames) { | |
88 base::AutoLock auto_lock(lock_); | |
89 if (!track_) | |
90 return; | |
91 | |
92 // Update the downstream client if the audio format has been changed. | |
93 if (audio_format_changed_) { | |
94 track_->OnSetFormat(params_); | |
95 audio_format_changed_ = false; | |
96 } | |
97 | |
98 wrapper_bus_->set_frames(number_of_frames); | |
99 | |
100 // Make sure WebKit is honoring what it told us up front | |
101 // about the channels. | |
102 DCHECK_EQ(params_.channels(), static_cast<int>(audio_data.size())); | |
103 | |
104 for (size_t i = 0; i < audio_data.size(); ++i) | |
105 wrapper_bus_->SetChannelData(i, const_cast<float*>(audio_data[i])); | |
106 | |
107 // Handle mismatch between WebAudio buffer-size and WebRTC. | |
108 int available = fifo_->max_frames() - fifo_->frames(); | |
109 if (available < static_cast<int>(number_of_frames)) { | |
110 NOTREACHED() << "WebAudioCapturerSource::Consume() : FIFO overrun."; | |
111 return; | |
112 } | |
113 | |
114 // Compute the estimated capture time of the first sample frame of audio that | |
115 // will be consumed from the FIFO in the loop below. | |
116 base::TimeTicks estimated_capture_time = base::TimeTicks::Now() - | |
117 fifo_->frames() * base::TimeDelta::FromSeconds(1) / params_.sample_rate(); | |
118 | |
119 fifo_->Push(wrapper_bus_.get()); | |
120 while (fifo_->frames() >= capture_bus_->frames()) { | |
121 fifo_->Consume(capture_bus_.get(), 0, capture_bus_->frames()); | |
122 track_->Capture(*capture_bus_, estimated_capture_time, false); | |
123 | |
124 // Advance the estimated capture time for the next FIFO consume operation. | |
125 estimated_capture_time += | |
126 capture_bus_->frames() * base::TimeDelta::FromSeconds(1) / | |
127 params_.sample_rate(); | |
128 } | |
129 } | |
130 | |
131 // If registered as audio consumer in |blink_source_|, deregister from | |
132 // |blink_source_| and stop keeping a reference to |blink_source_|. | |
133 // Failure to call this method when stopping the track might leave an invalid | |
134 // WebAudioCapturerSource reference still registered as an audio consumer on | |
135 // the blink side. | |
136 void WebAudioCapturerSource::removeFromBlinkSource() { | |
137 if (!blink_source_.isNull()) { | |
138 blink_source_.removeAudioConsumer(this); | |
139 blink_source_.reset(); | |
140 } | |
141 } | |
142 | |
143 } // namespace content | |
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