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/virtual_audio_output_stream.h"
6
7 #include "base/logging.h"
8 #include "media/audio/virtual_audio_input_stream.h"
9
10 namespace media {
11
VirtualAudioOutputStream(const AudioParameters & params,VirtualAudioInputStream * target,const AfterCloseCallback & after_close_cb)12 VirtualAudioOutputStream::VirtualAudioOutputStream(
13 const AudioParameters& params, VirtualAudioInputStream* target,
14 const AfterCloseCallback& after_close_cb)
15 : params_(params), target_input_stream_(target),
16 after_close_cb_(after_close_cb), callback_(NULL), volume_(1.0f) {
17 DCHECK(params_.IsValid());
18 DCHECK(target);
19
20 // VAOS can be constructed on any thread, but will DCHECK that all
21 // AudioOutputStream methods are called from the same thread.
22 thread_checker_.DetachFromThread();
23 }
24
~VirtualAudioOutputStream()25 VirtualAudioOutputStream::~VirtualAudioOutputStream() {
26 DCHECK(!callback_);
27 }
28
Open()29 bool VirtualAudioOutputStream::Open() {
30 DCHECK(thread_checker_.CalledOnValidThread());
31 return true;
32 }
33
Start(AudioSourceCallback * callback)34 void VirtualAudioOutputStream::Start(AudioSourceCallback* callback) {
35 DCHECK(thread_checker_.CalledOnValidThread());
36 DCHECK(!callback_);
37 callback_ = callback;
38 target_input_stream_->AddOutputStream(this, params_);
39 }
40
Stop()41 void VirtualAudioOutputStream::Stop() {
42 DCHECK(thread_checker_.CalledOnValidThread());
43 if (callback_) {
44 target_input_stream_->RemoveOutputStream(this, params_);
45 callback_ = NULL;
46 }
47 }
48
Close()49 void VirtualAudioOutputStream::Close() {
50 DCHECK(thread_checker_.CalledOnValidThread());
51
52 Stop();
53
54 // If a non-null AfterCloseCallback was provided to the constructor, invoke it
55 // here. The callback is moved to a stack-local first since |this| could be
56 // destroyed during Run().
57 if (!after_close_cb_.is_null()) {
58 const AfterCloseCallback cb = after_close_cb_;
59 after_close_cb_.Reset();
60 cb.Run(this);
61 }
62 }
63
SetVolume(double volume)64 void VirtualAudioOutputStream::SetVolume(double volume) {
65 DCHECK(thread_checker_.CalledOnValidThread());
66 volume_ = volume;
67 }
68
GetVolume(double * volume)69 void VirtualAudioOutputStream::GetVolume(double* volume) {
70 DCHECK(thread_checker_.CalledOnValidThread());
71 *volume = volume_;
72 }
73
ProvideInput(AudioBus * audio_bus,base::TimeDelta buffer_delay)74 double VirtualAudioOutputStream::ProvideInput(AudioBus* audio_bus,
75 base::TimeDelta buffer_delay) {
76 // Note: This method may be invoked on any one thread, depending on the
77 // platform.
78 DCHECK(callback_);
79
80 const int frames = callback_->OnMoreData(audio_bus, AudioBuffersState());
81 if (frames < audio_bus->frames())
82 audio_bus->ZeroFramesPartial(frames, audio_bus->frames() - frames);
83
84 return frames > 0 ? volume_ : 0;
85 }
86
87 } // namespace media
88