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/base/audio_renderer_mixer_input.h"
6
7#include "base/bind.h"
8#include "base/logging.h"
9#include "media/base/audio_renderer_mixer.h"
10
11namespace media {
12
13AudioRendererMixerInput::AudioRendererMixerInput(
14    const GetMixerCB& get_mixer_cb, const RemoveMixerCB& remove_mixer_cb)
15    : playing_(false),
16      initialized_(false),
17      volume_(1.0f),
18      get_mixer_cb_(get_mixer_cb),
19      remove_mixer_cb_(remove_mixer_cb),
20      mixer_(NULL),
21      callback_(NULL),
22      error_cb_(base::Bind(
23          &AudioRendererMixerInput::OnRenderError, base::Unretained(this))) {
24}
25
26AudioRendererMixerInput::~AudioRendererMixerInput() {
27  DCHECK(!playing_);
28  DCHECK(!mixer_);
29}
30
31void AudioRendererMixerInput::Initialize(
32    const AudioParameters& params,
33    AudioRendererSink::RenderCallback* callback) {
34  DCHECK(callback);
35  DCHECK(!initialized_);
36
37  params_ = params;
38  callback_ = callback;
39  initialized_ = true;
40}
41
42void AudioRendererMixerInput::Start() {
43  DCHECK(initialized_);
44  DCHECK(!playing_);
45  DCHECK(!mixer_);
46  mixer_ = get_mixer_cb_.Run(params_);
47
48  // Note: OnRenderError() may be called immediately after this call returns.
49  mixer_->AddErrorCallback(error_cb_);
50}
51
52void AudioRendererMixerInput::Stop() {
53  // Stop() may be called at any time, if Pause() hasn't been called we need to
54  // remove our mixer input before shutdown.
55  if (playing_) {
56    mixer_->RemoveMixerInput(this);
57    playing_ = false;
58  }
59
60  if (mixer_) {
61    // TODO(dalecurtis): This is required so that |callback_| isn't called after
62    // Stop() by an error event since it may outlive this ref-counted object. We
63    // should instead have sane ownership semantics: http://crbug.com/151051
64    mixer_->RemoveErrorCallback(error_cb_);
65    remove_mixer_cb_.Run(params_);
66    mixer_ = NULL;
67  }
68}
69
70void AudioRendererMixerInput::Play() {
71  DCHECK(initialized_);
72  DCHECK(mixer_);
73
74  if (playing_)
75    return;
76
77  mixer_->AddMixerInput(this);
78  playing_ = true;
79}
80
81void AudioRendererMixerInput::Pause() {
82  DCHECK(initialized_);
83  DCHECK(mixer_);
84
85  if (!playing_)
86    return;
87
88  mixer_->RemoveMixerInput(this);
89  playing_ = false;
90}
91
92bool AudioRendererMixerInput::SetVolume(double volume) {
93  volume_ = volume;
94  return true;
95}
96
97double AudioRendererMixerInput::ProvideInput(AudioBus* audio_bus,
98                                             base::TimeDelta buffer_delay) {
99  int frames_filled = callback_->Render(
100      audio_bus, static_cast<int>(buffer_delay.InMillisecondsF() + 0.5));
101
102  // AudioConverter expects unfilled frames to be zeroed.
103  if (frames_filled < audio_bus->frames()) {
104    audio_bus->ZeroFramesPartial(
105        frames_filled, audio_bus->frames() - frames_filled);
106  }
107
108  return frames_filled > 0 ? volume_ : 0;
109}
110
111void AudioRendererMixerInput::OnRenderError() {
112  callback_->OnRenderError();
113}
114
115}  // namespace media
116