| /* |
| * 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 WebCore { |
| |
| PassRefPtr<MediaStreamAudioSourceNode> MediaStreamAudioSourceNode::create(AudioContext* context, MediaStream* mediaStream, MediaStreamTrack* audioTrack, AudioSourceProvider* audioSourceProvider) |
| { |
| return adoptRef(new MediaStreamAudioSourceNode(context, mediaStream, audioTrack, audioSourceProvider)); |
| } |
| |
| MediaStreamAudioSourceNode::MediaStreamAudioSourceNode(AudioContext* context, MediaStream* mediaStream, MediaStreamTrack* audioTrack, AudioSourceProvider* audioSourceProvider) |
| : AudioSourceNode(context, context->sampleRate()) |
| , m_mediaStream(mediaStream) |
| , m_audioTrack(audioTrack) |
| , m_audioSourceProvider(audioSourceProvider) |
| , m_sourceNumberOfChannels(0) |
| { |
| ScriptWrappable::init(this); |
| // Default to stereo. This could change depending on the format of the MediaStream's audio track. |
| addOutput(adoptPtr(new AudioNodeOutput(this, 2))); |
| |
| setNodeType(NodeTypeMediaStreamAudioSource); |
| |
| initialize(); |
| } |
| |
| MediaStreamAudioSourceNode::~MediaStreamAudioSourceNode() |
| { |
| uninitialize(); |
| } |
| |
| 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. |
| 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::reset() |
| { |
| } |
| |
| } // namespace WebCore |
| |
| #endif // ENABLE(WEB_AUDIO) |