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/audio_renderer_mixer_manager.h"
6
7 #include "base/bind.h"
8 #include "base/bind_helpers.h"
9 #include "content/renderer/media/audio_device_factory.h"
10 #include "media/audio/audio_output_device.h"
11 #include "media/base/audio_hardware_config.h"
12 #include "media/base/audio_renderer_mixer.h"
13 #include "media/base/audio_renderer_mixer_input.h"
14
15 namespace content {
16
AudioRendererMixerManager(media::AudioHardwareConfig * hardware_config)17 AudioRendererMixerManager::AudioRendererMixerManager(
18 media::AudioHardwareConfig* hardware_config)
19 : hardware_config_(hardware_config),
20 sink_for_testing_(NULL) {
21 }
22
~AudioRendererMixerManager()23 AudioRendererMixerManager::~AudioRendererMixerManager() {
24 DCHECK(mixers_.empty());
25 }
26
CreateInput(int source_render_view_id)27 media::AudioRendererMixerInput* AudioRendererMixerManager::CreateInput(
28 int source_render_view_id) {
29 return new media::AudioRendererMixerInput(
30 base::Bind(
31 &AudioRendererMixerManager::GetMixer, base::Unretained(this),
32 source_render_view_id),
33 base::Bind(
34 &AudioRendererMixerManager::RemoveMixer, base::Unretained(this),
35 source_render_view_id));
36 }
37
SetAudioRendererSinkForTesting(media::AudioRendererSink * sink)38 void AudioRendererMixerManager::SetAudioRendererSinkForTesting(
39 media::AudioRendererSink* sink) {
40 sink_for_testing_ = sink;
41 }
42
GetMixer(int source_render_view_id,const media::AudioParameters & params)43 media::AudioRendererMixer* AudioRendererMixerManager::GetMixer(
44 int source_render_view_id,
45 const media::AudioParameters& params) {
46 const MixerKey key(source_render_view_id, params);
47 base::AutoLock auto_lock(mixers_lock_);
48
49 AudioRendererMixerMap::iterator it = mixers_.find(key);
50 if (it != mixers_.end()) {
51 it->second.ref_count++;
52 return it->second.mixer;
53 }
54
55 // On ChromeOS and Linux we can rely on the playback device to handle
56 // resampling, so don't waste cycles on it here.
57 #if defined(OS_CHROMEOS) || defined(OS_LINUX)
58 int sample_rate = params.sample_rate();
59 #else
60 int sample_rate = hardware_config_->GetOutputSampleRate();
61 #endif
62
63 // Create output parameters based on the audio hardware configuration for
64 // passing on to the output sink. Force to 16-bit output for now since we
65 // know that works well for WebAudio and WebRTC.
66 media::AudioParameters output_params(
67 media::AudioParameters::AUDIO_PCM_LOW_LATENCY, params.channel_layout(),
68 sample_rate, 16, hardware_config_->GetOutputBufferSize());
69
70 // If we've created invalid output parameters, simply pass on the input params
71 // and let the browser side handle automatic fallback.
72 if (!output_params.IsValid())
73 output_params = params;
74
75 media::AudioRendererMixer* mixer;
76 if (sink_for_testing_) {
77 mixer = new media::AudioRendererMixer(
78 params, output_params, sink_for_testing_);
79 } else {
80 mixer = new media::AudioRendererMixer(
81 params, output_params, AudioDeviceFactory::NewOutputDevice(
82 source_render_view_id));
83 }
84
85 AudioRendererMixerReference mixer_reference = { mixer, 1 };
86 mixers_[key] = mixer_reference;
87 return mixer;
88 }
89
RemoveMixer(int source_render_view_id,const media::AudioParameters & params)90 void AudioRendererMixerManager::RemoveMixer(
91 int source_render_view_id,
92 const media::AudioParameters& params) {
93 const MixerKey key(source_render_view_id, params);
94 base::AutoLock auto_lock(mixers_lock_);
95
96 AudioRendererMixerMap::iterator it = mixers_.find(key);
97 DCHECK(it != mixers_.end());
98
99 // Only remove the mixer if AudioRendererMixerManager is the last owner.
100 it->second.ref_count--;
101 if (it->second.ref_count == 0) {
102 delete it->second.mixer;
103 mixers_.erase(it);
104 }
105 }
106
107 } // namespace content
108