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Diffstat (limited to 'Source/WebCore/webaudio/AudioChannelSplitter.cpp')
-rw-r--r-- | Source/WebCore/webaudio/AudioChannelSplitter.cpp | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/Source/WebCore/webaudio/AudioChannelSplitter.cpp b/Source/WebCore/webaudio/AudioChannelSplitter.cpp new file mode 100644 index 0000000..f4fa041 --- /dev/null +++ b/Source/WebCore/webaudio/AudioChannelSplitter.cpp @@ -0,0 +1,84 @@ +/* + * 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 "AudioChannelSplitter.h" + +#include "AudioNodeInput.h" +#include "AudioNodeOutput.h" + +namespace WebCore { + +// This is considering that 5.1 (6 channels) is the largest we'll ever deal with. +// It can easily be increased to support more if the web audio specification is updated. +const unsigned NumberOfOutputs = 6; + +AudioChannelSplitter::AudioChannelSplitter(AudioContext* context, double sampleRate) + : AudioNode(context, sampleRate) +{ + addInput(adoptPtr(new AudioNodeInput(this))); + + // Create a fixed number of outputs (able to handle the maximum number of channels fed to an input). + for (unsigned i = 0; i < NumberOfOutputs; ++i) + addOutput(adoptPtr(new AudioNodeOutput(this, 1))); + + setType(NodeTypeChannelSplitter); + + initialize(); +} + +void AudioChannelSplitter::process(size_t framesToProcess) +{ + AudioBus* source = input(0)->bus(); + ASSERT(source); + ASSERT_UNUSED(framesToProcess, framesToProcess == source->length()); + + unsigned numberOfSourceChannels = source->numberOfChannels(); + + ASSERT(numberOfOutputs() == NumberOfOutputs); + for (unsigned i = 0; i < NumberOfOutputs; ++i) { + AudioBus* destination = output(i)->bus(); + ASSERT(destination); + + if (i < numberOfSourceChannels) { + // Split the channel out if it exists in the source. + // It would be nice to avoid the copy and simply pass along pointers, but this becomes extremely difficult with fanout and fanin. + destination->channel(0)->copyFrom(source->channel(i)); + } else if (output(i)->renderingFanOutCount() > 0) { + // Only bother zeroing out the destination if it's connected to anything + destination->zero(); + } + } +} + +void AudioChannelSplitter::reset() +{ +} + +} // namespace WebCore + +#endif // ENABLE(WEB_AUDIO) |