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 "media/audio/null_audio_sink.h"
6
7 #include "base/bind.h"
8 #include "base/single_thread_task_runner.h"
9 #include "media/audio/fake_audio_consumer.h"
10 #include "media/base/audio_hash.h"
11
12 namespace media {
13
NullAudioSink(const scoped_refptr<base::SingleThreadTaskRunner> & task_runner)14 NullAudioSink::NullAudioSink(
15 const scoped_refptr<base::SingleThreadTaskRunner>& task_runner)
16 : initialized_(false),
17 playing_(false),
18 callback_(NULL),
19 task_runner_(task_runner) {
20 }
21
~NullAudioSink()22 NullAudioSink::~NullAudioSink() {}
23
Initialize(const AudioParameters & params,RenderCallback * callback)24 void NullAudioSink::Initialize(const AudioParameters& params,
25 RenderCallback* callback) {
26 DCHECK(!initialized_);
27 fake_consumer_.reset(new FakeAudioConsumer(task_runner_, params));
28 callback_ = callback;
29 initialized_ = true;
30 }
31
Start()32 void NullAudioSink::Start() {
33 DCHECK(task_runner_->BelongsToCurrentThread());
34 DCHECK(!playing_);
35 }
36
Stop()37 void NullAudioSink::Stop() {
38 DCHECK(task_runner_->BelongsToCurrentThread());
39
40 // Stop may be called at any time, so we have to check before stopping.
41 if (fake_consumer_)
42 fake_consumer_->Stop();
43 }
44
Play()45 void NullAudioSink::Play() {
46 DCHECK(task_runner_->BelongsToCurrentThread());
47 DCHECK(initialized_);
48
49 if (playing_)
50 return;
51
52 fake_consumer_->Start(base::Bind(
53 &NullAudioSink::CallRender, base::Unretained(this)));
54 playing_ = true;
55 }
56
Pause()57 void NullAudioSink::Pause() {
58 DCHECK(task_runner_->BelongsToCurrentThread());
59
60 if (!playing_)
61 return;
62
63 fake_consumer_->Stop();
64 playing_ = false;
65 }
66
SetVolume(double volume)67 bool NullAudioSink::SetVolume(double volume) {
68 // Audio is always muted.
69 return volume == 0.0;
70 }
71
CallRender(AudioBus * audio_bus)72 void NullAudioSink::CallRender(AudioBus* audio_bus) {
73 DCHECK(task_runner_->BelongsToCurrentThread());
74
75 int frames_received = callback_->Render(audio_bus, 0);
76 if (!audio_hash_ || frames_received <= 0)
77 return;
78
79 audio_hash_->Update(audio_bus, frames_received);
80 }
81
StartAudioHashForTesting()82 void NullAudioSink::StartAudioHashForTesting() {
83 DCHECK(!initialized_);
84 audio_hash_.reset(new AudioHash());
85 }
86
GetAudioHashForTesting()87 std::string NullAudioSink::GetAudioHashForTesting() {
88 return audio_hash_ ? audio_hash_->ToString() : std::string();
89 }
90
91 } // namespace media
92