| /* |
| * 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 "modules/webaudio/AudioDestinationNode.h" |
| #include "modules/webaudio/AudioNodeInput.h" |
| #include "modules/webaudio/AudioNodeOutput.h" |
| #include "modules/webaudio/BaseAudioContext.h" |
| #include "platform/audio/AudioUtilities.h" |
| #include "platform/audio/DenormalDisabler.h" |
| #include "wtf/Atomics.h" |
| |
| namespace blink { |
| |
| AudioDestinationHandler::AudioDestinationHandler(AudioNode& node, |
| float sampleRate) |
| : AudioHandler(NodeTypeDestination, node, sampleRate), |
| m_currentSampleFrame(0) { |
| addInput(); |
| } |
| |
| AudioDestinationHandler::~AudioDestinationHandler() { |
| DCHECK(!isInitialized()); |
| } |
| |
| void AudioDestinationHandler::render(AudioBus* sourceBus, |
| AudioBus* destinationBus, |
| size_t numberOfFrames) { |
| // We don't want denormals slowing down any of the audio processing |
| // since they can very seriously hurt performance. This will take care of all |
| // AudioNodes because they all process within this scope. |
| DenormalDisabler denormalDisabler; |
| |
| // Need to check if the context actually alive. Otherwise the subsequent |
| // steps will fail. If the context is not alive somehow, return immediately |
| // and do nothing. |
| // |
| // TODO(hongchan): because the context can go away while rendering, so this |
| // check cannot guarantee the safe execution of the following steps. |
| DCHECK(context()); |
| if (!context()) |
| return; |
| |
| context()->deferredTaskHandler().setAudioThreadToCurrentThread(); |
| |
| // If the destination node is not initialized, pass the silence to the final |
| // audio destination (one step before the FIFO). This check is for the case |
| // where the destination is in the middle of tearing down process. |
| if (!isInitialized()) { |
| destinationBus->zero(); |
| return; |
| } |
| |
| // Let the context take care of any business at the start of each render |
| // quantum. |
| context()->handlePreRenderTasks(); |
| |
| // Prepare the local audio input provider for this render quantum. |
| if (sourceBus) |
| m_localAudioInputProvider.set(sourceBus); |
| |
| DCHECK_GE(numberOfInputs(), 1u); |
| if (numberOfInputs() < 1) { |
| destinationBus->zero(); |
| return; |
| } |
| // This will cause the node(s) connected to us to process, which in turn will |
| // pull on their input(s), all the way backwards through the rendering graph. |
| AudioBus* renderedBus = input(0).pull(destinationBus, numberOfFrames); |
| |
| if (!renderedBus) { |
| destinationBus->zero(); |
| } else if (renderedBus != destinationBus) { |
| // in-place processing was not possible - so copy |
| destinationBus->copyFrom(*renderedBus); |
| } |
| |
| // Process nodes which need a little extra help because they are not connected |
| // to anything, but still need to process. |
| context()->deferredTaskHandler().processAutomaticPullNodes(numberOfFrames); |
| |
| // Let the context take care of any business at the end of each render |
| // quantum. |
| context()->handlePostRenderTasks(); |
| |
| // Advance current sample-frame. |
| size_t newSampleFrame = m_currentSampleFrame + numberOfFrames; |
| releaseStore(&m_currentSampleFrame, newSampleFrame); |
| } |
| |
| // ---------------------------------------------------------------- |
| |
| AudioDestinationNode::AudioDestinationNode(BaseAudioContext& context) |
| : AudioNode(context) {} |
| |
| AudioDestinationHandler& AudioDestinationNode::audioDestinationHandler() const { |
| return static_cast<AudioDestinationHandler&>(handler()); |
| } |
| |
| unsigned long AudioDestinationNode::maxChannelCount() const { |
| return audioDestinationHandler().maxChannelCount(); |
| } |
| |
| } // namespace blink |