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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)
#include "modules/webaudio/MediaStreamAudioSourceNode.h"
#include "platform/Logging.h"
#include "modules/webaudio/AudioContext.h"
#include "modules/webaudio/AudioNodeOutput.h"
#include "wtf/Locker.h"
namespace blink {
MediaStreamAudioSourceNode* MediaStreamAudioSourceNode::create(AudioContext* context, MediaStream* mediaStream, MediaStreamTrack* audioTrack, PassOwnPtr<AudioSourceProvider> audioSourceProvider)
{
return new MediaStreamAudioSourceNode(context, mediaStream, audioTrack, audioSourceProvider);
}
MediaStreamAudioSourceNode::MediaStreamAudioSourceNode(AudioContext* context, MediaStream* mediaStream, MediaStreamTrack* audioTrack, PassOwnPtr<AudioSourceProvider> audioSourceProvider)
: AudioSourceNode(NodeTypeMediaStreamAudioSource, context, context->sampleRate())
, m_mediaStream(mediaStream)
, m_audioTrack(audioTrack)
, m_audioSourceProvider(audioSourceProvider)
, m_sourceNumberOfChannels(0)
{
// Default to stereo. This could change depending on the format of the
// MediaStream's audio track.
addOutput(AudioNodeOutput::create(this, 2));
initialize();
}
MediaStreamAudioSourceNode::~MediaStreamAudioSourceNode()
{
ASSERT(!isInitialized());
}
void MediaStreamAudioSourceNode::dispose()
{
uninitialize();
AudioSourceNode::dispose();
}
void MediaStreamAudioSourceNode::setFormat(size_t numberOfChannels, float sourceSampleRate)
{
if (numberOfChannels != m_sourceNumberOfChannels || sourceSampleRate != sampleRate()) {
// The sample-rate must be equal to the context's sample-rate.
if (!numberOfChannels || numberOfChannels > AudioContext::maxNumberOfChannels() || sourceSampleRate != sampleRate()) {
// process() will generate silence for these uninitialized values.
WTF_LOG(Media, "MediaStreamAudioSourceNode::setFormat(%u, %f) - unhandled format change", static_cast<unsigned>(numberOfChannels), sourceSampleRate);
m_sourceNumberOfChannels = 0;
return;
}
// Synchronize with process().
MutexLocker locker(m_processLock);
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();
if (!audioSourceProvider()) {
outputBus->zero();
return;
}
if (!mediaStream() || m_sourceNumberOfChannels != outputBus->numberOfChannels()) {
outputBus->zero();
return;
}
// Use a tryLock() 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.
MutexTryLocker tryLocker(m_processLock);
if (tryLocker.locked())
audioSourceProvider()->provideInput(outputBus, numberOfFrames);
else {
// We failed to acquire the lock.
outputBus->zero();
}
}
void MediaStreamAudioSourceNode::trace(Visitor* visitor)
{
visitor->trace(m_mediaStream);
visitor->trace(m_audioTrack);
AudioSourceNode::trace(visitor);
AudioSourceProviderClient::trace(visitor);
}
} // namespace blink
#endif // ENABLE(WEB_AUDIO)
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