webkit/media/webaudiosourceprovider_impl.cc

   1 // Copyright (c) 2013 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 "webkit/media/webaudiosourceprovider_impl.h"
   6
   7 #include <vector>
   8
   9 #include "base/logging.h"
  10 #include "third_party/WebKit/Source/WebKit/chromium/public/WebAudioSourceProviderClient.h"
  11
  12 using WebKit::WebVector;
  13
  14 namespace webkit_media {
  15
  16 WebAudioSourceProviderImpl::WebAudioSourceProviderImpl(
  17     const scoped_refptr<media::AudioRendererSink>& sink)
  18     : is_initialized_(false),
  19       channels_(0),
  20       sample_rate_(0),
  21       is_running_(false),
  22       renderer_(NULL),
  23       client_(NULL),
  24       sink_(sink) {
  25 }
  26
  27 WebAudioSourceProviderImpl::~WebAudioSourceProviderImpl() {}
  28
  29 void WebAudioSourceProviderImpl::setClient(
  30     WebKit::WebAudioSourceProviderClient* client) {
  31   base::AutoLock auto_lock(sink_lock_);
  32
  33   if (client && client != client_) {
  34     // Detach the audio renderer from normal playback.
  35     sink_->Stop();
  36
  37     // The client will now take control by calling provideInput() periodically.
  38     client_ = client;
  39
  40     if (is_initialized_) {
  41       // The client needs to be notified of the audio format, if available.
  42       // If the format is not yet available, we'll be notified later
  43       // when Initialize() is called.
  44
  45       // Inform WebKit about the audio stream format.
  46       client->setFormat(channels_, sample_rate_);
  47     }
  48   } else if (!client && client_) {
  49     // Restore normal playback.
  50     client_ = NULL;
  51     // TODO(crogers): We should call sink_->Play() if we're
  52     // in the playing state.
  53   }
  54 }
  55
  56 void WebAudioSourceProviderImpl::provideInput(
  57     const WebVector<float*>& audio_data, size_t number_of_frames) {
  58   DCHECK(client_);
  59
  60   if (renderer_ && is_initialized_ && is_running_) {
  61     // Wrap WebVector as std::vector.
  62     std::vector<float*> v(audio_data.size());
  63     for (size_t i = 0; i < audio_data.size(); ++i)
  64       v[i] = audio_data[i];
  65
  66     scoped_ptr<media::AudioBus> audio_bus = media::AudioBus::WrapVector(
  67         number_of_frames, v);
  68
  69     // TODO(crogers): figure out if we should volume scale here or in common
  70     // WebAudio code.  In any case we need to take care of volume.
  71     renderer_->Render(audio_bus.get(), 0);
  72     return;
  73   }
  74
  75   // Provide silence if the source is not running.
  76   for (size_t i = 0; i < audio_data.size(); ++i)
  77     memset(audio_data[i], 0, sizeof(*audio_data[0]) * number_of_frames);
  78 }
  79
  80 void WebAudioSourceProviderImpl::Start() {
  81   base::AutoLock auto_lock(sink_lock_);
  82   if (!client_)
  83     sink_->Start();
  84   is_running_ = true;
  85 }
  86
  87 void WebAudioSourceProviderImpl::Stop() {
  88   base::AutoLock auto_lock(sink_lock_);
  89   if (!client_)
  90     sink_->Stop();
  91   is_running_ = false;
  92 }
  93
  94 void WebAudioSourceProviderImpl::Play() {
  95   base::AutoLock auto_lock(sink_lock_);
  96   if (!client_)
  97     sink_->Play();
  98   is_running_ = true;
  99 }
 100
 101 void WebAudioSourceProviderImpl::Pause(bool flush) {
 102   base::AutoLock auto_lock(sink_lock_);
 103   if (!client_)
 104     sink_->Pause(flush);
 105   is_running_ = false;
 106 }
 107
 108 bool WebAudioSourceProviderImpl::SetVolume(double volume) {
 109   base::AutoLock auto_lock(sink_lock_);
 110   if (!client_)
 111     sink_->SetVolume(volume);
 112   return true;
 113 }
 114
 115 void WebAudioSourceProviderImpl::Initialize(
 116     const media::AudioParameters& params,
 117     RenderCallback* renderer) {
 118   base::AutoLock auto_lock(sink_lock_);
 119   CHECK(!is_initialized_);
 120   renderer_ = renderer;
 121
 122   sink_->Initialize(params, renderer);
 123
 124   // Keep track of the format in case the client hasn't yet been set.
 125   channels_ = params.channels();
 126   sample_rate_ = params.sample_rate();
 127
 128   if (client_) {
 129     // Inform WebKit about the audio stream format.
 130     client_->setFormat(channels_, sample_rate_);
 131   }
 132
 133   is_initialized_ = true;
 134 }
 135
 136 }  // namespace webkit_media