1/* 2 * Copyright (C) 2010, Google Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY 14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 15 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 16 * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY 17 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 18 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 19 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON 20 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 22 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 23 */ 24 25#include "config.h" 26 27#if ENABLE(WEB_AUDIO) 28 29#include "modules/webaudio/ChannelSplitterNode.h" 30 31#include "modules/webaudio/AudioContext.h" 32#include "modules/webaudio/AudioNodeInput.h" 33#include "modules/webaudio/AudioNodeOutput.h" 34 35namespace blink { 36 37ChannelSplitterNode* ChannelSplitterNode::create(AudioContext* context, float sampleRate, unsigned numberOfOutputs) 38{ 39 if (!numberOfOutputs || numberOfOutputs > AudioContext::maxNumberOfChannels()) 40 return 0; 41 42 return adoptRefCountedGarbageCollectedWillBeNoop(new ChannelSplitterNode(context, sampleRate, numberOfOutputs)); 43} 44 45ChannelSplitterNode::ChannelSplitterNode(AudioContext* context, float sampleRate, unsigned numberOfOutputs) 46 : AudioNode(context, sampleRate) 47{ 48 addInput(); 49 50 // Create a fixed number of outputs (able to handle the maximum number of channels fed to an input). 51 for (unsigned i = 0; i < numberOfOutputs; ++i) 52 addOutput(AudioNodeOutput::create(this, 1)); 53 54 setNodeType(NodeTypeChannelSplitter); 55 initialize(); 56} 57 58void ChannelSplitterNode::process(size_t framesToProcess) 59{ 60 AudioBus* source = input(0)->bus(); 61 ASSERT(source); 62 ASSERT_UNUSED(framesToProcess, framesToProcess == source->length()); 63 64 unsigned numberOfSourceChannels = source->numberOfChannels(); 65 66 for (unsigned i = 0; i < numberOfOutputs(); ++i) { 67 AudioBus* destination = output(i)->bus(); 68 ASSERT(destination); 69 70 if (i < numberOfSourceChannels) { 71 // Split the channel out if it exists in the source. 72 // It would be nice to avoid the copy and simply pass along pointers, but this becomes extremely difficult with fanout and fanin. 73 destination->channel(0)->copyFrom(source->channel(i)); 74 } else if (output(i)->renderingFanOutCount() > 0) { 75 // Only bother zeroing out the destination if it's connected to anything 76 destination->zero(); 77 } 78 } 79} 80 81} // namespace blink 82 83#endif // ENABLE(WEB_AUDIO) 84