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Diffstat (limited to 'Source/WebCore/webaudio/AudioNodeOutput.cpp')
| -rw-r--r-- | Source/WebCore/webaudio/AudioNodeOutput.cpp | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/Source/WebCore/webaudio/AudioNodeOutput.cpp b/Source/WebCore/webaudio/AudioNodeOutput.cpp new file mode 100644 index 000000000..4c777e6bd --- /dev/null +++ b/Source/WebCore/webaudio/AudioNodeOutput.cpp @@ -0,0 +1,216 @@ +/* + * Copyright (C) 2010, 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 "AudioNodeOutput.h" + +#include "AudioBus.h" +#include "AudioContext.h" +#include "AudioNodeInput.h" +#include <wtf/Threading.h> + +namespace WebCore { + +AudioNodeOutput::AudioNodeOutput(AudioNode* node, unsigned numberOfChannels) + : m_node(node) + , m_numberOfChannels(numberOfChannels) + , m_desiredNumberOfChannels(numberOfChannels) + , m_internalOutputBus(0) + , m_actualDestinationBus(0) + , m_isEnabled(true) + , m_renderingFanOutCount(0) +{ + m_monoInternalBus = adoptPtr(new AudioBus(1, AudioNode::ProcessingSizeInFrames)); + m_stereoInternalBus = adoptPtr(new AudioBus(2, AudioNode::ProcessingSizeInFrames)); + setInternalBus(); +} + +void AudioNodeOutput::setNumberOfChannels(unsigned numberOfChannels) +{ + ASSERT(context()->isGraphOwner()); + + m_desiredNumberOfChannels = numberOfChannels; + + if (context()->isAudioThread()) { + // If we're in the audio thread then we can take care of it right away (we should be at the very start or end of a rendering quantum). + updateNumberOfChannels(); + } else { + // Let the context take care of it in the audio thread in the pre and post render tasks. + context()->markAudioNodeOutputDirty(this); + } +} + +void AudioNodeOutput::setInternalBus() +{ + switch (m_numberOfChannels) { + case 0: + case 1: + m_internalOutputBus = m_monoInternalBus.get(); + break; + case 2: + m_internalOutputBus = m_stereoInternalBus.get(); + break; + default: + // FIXME: later we can fully implement more than stereo, 5.1, etc. + ASSERT_NOT_REACHED(); + } + + // This may later be changed in pull() to point to an in-place bus with the same number of channels. + m_actualDestinationBus = m_internalOutputBus; +} + +void AudioNodeOutput::updateRenderingState() +{ + updateNumberOfChannels(); + m_renderingFanOutCount = fanOutCount(); +} + +void AudioNodeOutput::updateNumberOfChannels() +{ + ASSERT(context()->isAudioThread() && context()->isGraphOwner()); + + if (m_numberOfChannels != m_desiredNumberOfChannels) { + m_numberOfChannels = m_desiredNumberOfChannels; + setInternalBus(); + propagateChannelCount(); + } +} + +void AudioNodeOutput::propagateChannelCount() +{ + ASSERT(context()->isAudioThread() && context()->isGraphOwner()); + + if (isChannelCountKnown()) { + // Announce to any nodes we're connected to that we changed our channel count for its input. + for (InputsIterator i = m_inputs.begin(); i != m_inputs.end(); ++i) { + AudioNodeInput* input = *i; + AudioNode* connectionNode = input->node(); + connectionNode->checkNumberOfChannelsForInput(input); + } + } +} + +AudioBus* AudioNodeOutput::pull(AudioBus* inPlaceBus, size_t framesToProcess) +{ + ASSERT(context()->isAudioThread()); + ASSERT(m_renderingFanOutCount > 0); + + // Causes our AudioNode to process if it hasn't already for this render quantum. + // We try to do in-place processing (using inPlaceBus) if at all possible, + // but we can't process in-place if we're connected to more than one input (fan-out > 1). + // In this case pull() is called multiple times per rendering quantum, and the processIfNecessary() call below will + // cause our node to process() only the first time, caching the output in m_internalOutputBus for subsequent calls. + + bool isInPlace = inPlaceBus && inPlaceBus->numberOfChannels() == numberOfChannels() && m_renderingFanOutCount == 1; + + // Setup the actual destination bus for processing when our node's process() method gets called in processIfNecessary() below. + m_actualDestinationBus = isInPlace ? inPlaceBus : m_internalOutputBus; + + node()->processIfNecessary(framesToProcess); + return m_actualDestinationBus; +} + +AudioBus* AudioNodeOutput::bus() const +{ + ASSERT(const_cast<AudioNodeOutput*>(this)->context()->isAudioThread()); + ASSERT(m_actualDestinationBus); + return m_actualDestinationBus; +} + +unsigned AudioNodeOutput::renderingFanOutCount() const +{ + return m_renderingFanOutCount; +} + +unsigned AudioNodeOutput::fanOutCount() +{ + ASSERT(context()->isGraphOwner()); + return m_inputs.size(); +} + +void AudioNodeOutput::addInput(AudioNodeInput* input) +{ + ASSERT(context()->isGraphOwner()); + + ASSERT(input); + if (!input) + return; + + m_inputs.add(input); +} + +void AudioNodeOutput::removeInput(AudioNodeInput* input) +{ + ASSERT(context()->isGraphOwner()); + + ASSERT(input); + if (!input) + return; + + m_inputs.remove(input); +} + +void AudioNodeOutput::disconnectAllInputs() +{ + ASSERT(context()->isGraphOwner()); + + // AudioNodeInput::disconnect() changes m_inputs by calling removeInput(). + while (!m_inputs.isEmpty()) { + AudioNodeInput* input = *m_inputs.begin(); + input->disconnect(this); + } +} + +void AudioNodeOutput::disable() +{ + ASSERT(context()->isGraphOwner()); + + if (m_isEnabled) { + for (InputsIterator i = m_inputs.begin(); i != m_inputs.end(); ++i) { + AudioNodeInput* input = *i; + input->disable(this); + } + m_isEnabled = false; + } +} + +void AudioNodeOutput::enable() +{ + ASSERT(context()->isGraphOwner()); + + if (!m_isEnabled) { + for (InputsIterator i = m_inputs.begin(); i != m_inputs.end(); ++i) { + AudioNodeInput* input = *i; + input->enable(this); + } + m_isEnabled = true; + } +} + +} // namespace WebCore + +#endif // ENABLE(WEB_AUDIO) |