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/*
* Copyright (C) 2012, Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#if ENABLE(WEB_AUDIO) && ENABLE(MEDIA_STREAM)
#include "MediaStreamAudioSourceNode.h"
#include "AudioContext.h"
#include "AudioNodeOutput.h"
#include "Logging.h"
#include <wtf/IsoMallocInlines.h>
#include <wtf/Locker.h>
namespace WebCore {
WTF_MAKE_ISO_ALLOCATED_IMPL(MediaStreamAudioSourceNode);
Ref<MediaStreamAudioSourceNode> MediaStreamAudioSourceNode::create(AudioContext& context, MediaStream& mediaStream, MediaStreamTrack& audioTrack)
{
return adoptRef(*new MediaStreamAudioSourceNode(context, mediaStream, audioTrack));
}
MediaStreamAudioSourceNode::MediaStreamAudioSourceNode(AudioContext& context, MediaStream& mediaStream, MediaStreamTrack& audioTrack)
: AudioNode(context, context.sampleRate())
, m_mediaStream(mediaStream)
, m_audioTrack(audioTrack)
{
setNodeType(NodeTypeMediaStreamAudioSource);
AudioSourceProvider* audioSourceProvider = m_audioTrack->audioSourceProvider();
ASSERT(audioSourceProvider);
audioSourceProvider->setClient(this);
// Default to stereo. This could change depending on the format of the MediaStream's audio track.
addOutput(makeUnique<AudioNodeOutput>(this, 2));
initialize();
}
MediaStreamAudioSourceNode::~MediaStreamAudioSourceNode()
{
AudioSourceProvider* audioSourceProvider = m_audioTrack->audioSourceProvider();
ASSERT(audioSourceProvider);
audioSourceProvider->setClient(nullptr);
uninitialize();
}
void MediaStreamAudioSourceNode::setFormat(size_t numberOfChannels, float sourceSampleRate)
{
float sampleRate = this->sampleRate();
if (numberOfChannels == m_sourceNumberOfChannels && sourceSampleRate == m_sourceSampleRate)
return;
// The sample-rate must be equal to the context's sample-rate.
if (!numberOfChannels || numberOfChannels > AudioContext::maxNumberOfChannels()) {
// process() will generate silence for these uninitialized values.
LOG(Media, "MediaStreamAudioSourceNode::setFormat(%u, %f) - unhandled format change", static_cast<unsigned>(numberOfChannels), sourceSampleRate);
m_sourceNumberOfChannels = 0;
return;
}
// Synchronize with process().
std::lock_guard<Lock> lock(m_processMutex);
m_sourceNumberOfChannels = numberOfChannels;
m_sourceSampleRate = sourceSampleRate;
if (sourceSampleRate == sampleRate)
m_multiChannelResampler = nullptr;
else {
double scaleFactor = sourceSampleRate / sampleRate;
m_multiChannelResampler = makeUnique<MultiChannelResampler>(scaleFactor, numberOfChannels);
}
m_sourceNumberOfChannels = numberOfChannels;
{
// The context must be locked when changing the number of output channels.
AudioContext::AutoLocker contextLocker(context());
// Do any necesssary re-configuration to the output's number of channels.
output(0)->setNumberOfChannels(numberOfChannels);
}
}
void MediaStreamAudioSourceNode::process(size_t numberOfFrames)
{
AudioBus* outputBus = output(0)->bus();
AudioSourceProvider* provider = m_audioTrack->audioSourceProvider();
if (!mediaStream() || !m_sourceNumberOfChannels || !m_sourceSampleRate || !provider) {
outputBus->zero();
return;
}
// Use std::try_to_lock to avoid contention in the real-time audio thread.
// If we fail to acquire the lock then the MediaStream must be in the middle of
// a format change, so we output silence in this case.
std::unique_lock<Lock> lock(m_processMutex, std::try_to_lock);
if (!lock.owns_lock()) {
// We failed to acquire the lock.
outputBus->zero();
return;
}
if (m_sourceNumberOfChannels != outputBus->numberOfChannels()) {
outputBus->zero();
return;
}
if (m_multiChannelResampler.get()) {
ASSERT(m_sourceSampleRate != sampleRate());
m_multiChannelResampler->process(provider, outputBus, numberOfFrames);
} else {
// Bypass the resampler completely if the source is at the context's sample-rate.
ASSERT(m_sourceSampleRate == sampleRate());
provider->provideInput(outputBus, numberOfFrames);
}
}
} // namespace WebCore
#endif // ENABLE(WEB_AUDIO) && ENABLE(MEDIA_STREAM)