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// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "content/renderer/media/renderer_webaudiodevice_impl.h"
#include "base/command_line.h"
#include "base/logging.h"
#include "content/renderer/media/audio_device_factory.h"
#include "content/renderer/render_view_impl.h"
#include "media/audio/audio_output_device.h"
#include "media/base/media_switches.h"
#include "third_party/WebKit/Source/WebKit/chromium/public/WebFrame.h"
#include "third_party/WebKit/Source/WebKit/chromium/public/WebView.h"
using WebKit::WebAudioDevice;
using WebKit::WebFrame;
using WebKit::WebVector;
using WebKit::WebView;
namespace content {
RendererWebAudioDeviceImpl::RendererWebAudioDeviceImpl(
const media::AudioParameters& params,
WebAudioDevice::RenderCallback* callback)
: params_(params),
client_callback_(callback) {
DCHECK(client_callback_);
}
RendererWebAudioDeviceImpl::~RendererWebAudioDeviceImpl() {
DCHECK(!output_device_);
}
void RendererWebAudioDeviceImpl::start() {
DCHECK(thread_checker_.CalledOnValidThread());
if (output_device_)
return; // Already started.
// Assumption: This method is being invoked within a V8 call stack. CHECKs
// will fail in the call to frameForCurrentContext() otherwise.
//
// Therefore, we can perform look-ups to determine which RenderView is
// starting the audio device. The reason for all this is because the creator
// of the WebAudio objects might not be the actual source of the audio (e.g.,
// an extension creates a object that is passed and used within a page).
WebFrame* const web_frame = WebFrame::frameForCurrentContext();
WebView* const web_view = web_frame ? web_frame->view() : NULL;
RenderViewImpl* const render_view =
web_view ? RenderViewImpl::FromWebView(web_view) : NULL;
output_device_ = AudioDeviceFactory::NewOutputDevice(
render_view ? render_view->routing_id() : MSG_ROUTING_NONE);
output_device_->Initialize(params_, this);
output_device_->Start();
// Note: Default behavior is to auto-play on start.
}
void RendererWebAudioDeviceImpl::stop() {
DCHECK(thread_checker_.CalledOnValidThread());
if (output_device_) {
output_device_->Stop();
output_device_ = NULL;
}
}
double RendererWebAudioDeviceImpl::sampleRate() {
return params_.sample_rate();
}
int RendererWebAudioDeviceImpl::Render(media::AudioBus* dest,
int audio_delay_milliseconds) {
RenderIO(NULL, dest, audio_delay_milliseconds);
return dest->frames();
}
void RendererWebAudioDeviceImpl::RenderIO(media::AudioBus* source,
media::AudioBus* dest,
int audio_delay_milliseconds) {
// Make the client callback for an I/O cycle.
if (client_callback_) {
// Wrap the input pointers using WebVector.
size_t source_channels =
source ? static_cast<size_t>(source->channels()) : 0;
WebVector<float*> web_audio_source_data(source_channels);
for (size_t i = 0; i < source_channels; ++i)
web_audio_source_data[i] = source->channel(i);
// Wrap the output pointers using WebVector.
WebVector<float*> web_audio_dest_data(
static_cast<size_t>(dest->channels()));
for (int i = 0; i < dest->channels(); ++i)
web_audio_dest_data[i] = dest->channel(i);
client_callback_->render(web_audio_source_data,
web_audio_dest_data,
dest->frames());
}
}
void RendererWebAudioDeviceImpl::OnRenderError() {
// TODO(crogers): implement error handling.
}
} // namespace content
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