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author | Steve Block <steveblock@google.com> | 2011-05-06 11:45:16 +0100 |
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committer | Steve Block <steveblock@google.com> | 2011-05-12 13:44:10 +0100 |
commit | cad810f21b803229eb11403f9209855525a25d57 (patch) | |
tree | 29a6fd0279be608e0fe9ffe9841f722f0f4e4269 /Source/WebCore/platform/audio/ReverbConvolverStage.cpp | |
parent | 121b0cf4517156d0ac5111caf9830c51b69bae8f (diff) | |
download | external_webkit-cad810f21b803229eb11403f9209855525a25d57.zip external_webkit-cad810f21b803229eb11403f9209855525a25d57.tar.gz external_webkit-cad810f21b803229eb11403f9209855525a25d57.tar.bz2 |
Merge WebKit at r75315: Initial merge by git.
Change-Id: I570314b346ce101c935ed22a626b48c2af266b84
Diffstat (limited to 'Source/WebCore/platform/audio/ReverbConvolverStage.cpp')
-rw-r--r-- | Source/WebCore/platform/audio/ReverbConvolverStage.cpp | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/Source/WebCore/platform/audio/ReverbConvolverStage.cpp b/Source/WebCore/platform/audio/ReverbConvolverStage.cpp new file mode 100644 index 0000000..e722813 --- /dev/null +++ b/Source/WebCore/platform/audio/ReverbConvolverStage.cpp @@ -0,0 +1,165 @@ +/* + * 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. + * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of + * its contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY APPLE 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 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 "ReverbConvolverStage.h" + +#include "VectorMath.h" +#include "ReverbAccumulationBuffer.h" +#include "ReverbConvolver.h" +#include "ReverbInputBuffer.h" +#include <wtf/OwnPtr.h> +#include <wtf/PassOwnPtr.h> + +namespace WebCore { + +using namespace VectorMath; + +ReverbConvolverStage::ReverbConvolverStage(float* impulseResponse, size_t responseLength, size_t reverbTotalLatency, size_t stageOffset, size_t stageLength, + size_t fftSize, size_t renderPhase, size_t renderSliceSize, ReverbAccumulationBuffer* accumulationBuffer) + : m_fftKernel(fftSize) + , m_accumulationBuffer(accumulationBuffer) + , m_accumulationReadIndex(0) + , m_inputReadIndex(0) + , m_impulseResponseLength(responseLength) +{ + ASSERT(impulseResponse); + ASSERT(accumulationBuffer); + + m_fftKernel.doPaddedFFT(impulseResponse + stageOffset, stageLength); + m_convolver = adoptPtr(new FFTConvolver(fftSize)); + m_temporaryBuffer.resize(renderSliceSize); + + // The convolution stage at offset stageOffset needs to have a corresponding delay to cancel out the offset. + size_t totalDelay = stageOffset + reverbTotalLatency; + + // But, the FFT convolution itself incurs fftSize / 2 latency, so subtract this out... + size_t halfSize = fftSize / 2; + ASSERT(totalDelay >= halfSize); + if (totalDelay >= halfSize) + totalDelay -= halfSize; + + // We divide up the total delay, into pre and post delay sections so that we can schedule at exactly the moment when the FFT will happen. + // This is coordinated with the other stages, so they don't all do their FFTs at the same time... + int maxPreDelayLength = std::min(halfSize, totalDelay); + m_preDelayLength = totalDelay > 0 ? renderPhase % maxPreDelayLength : 0; + if (m_preDelayLength > totalDelay) + m_preDelayLength = 0; + + m_postDelayLength = totalDelay - m_preDelayLength; + m_preReadWriteIndex = 0; + m_framesProcessed = 0; // total frames processed so far + + m_preDelayBuffer.resize(m_preDelayLength < fftSize ? fftSize : m_preDelayLength); +} + +void ReverbConvolverStage::processInBackground(ReverbConvolver* convolver, size_t framesToProcess) +{ + ReverbInputBuffer* inputBuffer = convolver->inputBuffer(); + float* source = inputBuffer->directReadFrom(&m_inputReadIndex, framesToProcess); + process(source, framesToProcess); +} + +void ReverbConvolverStage::process(float* source, size_t framesToProcess) +{ + ASSERT(source); + if (!source) + return; + + // Deal with pre-delay stream : note special handling of zero delay. + + float* preDelayedSource; + float* temporaryBuffer; + bool isTemporaryBufferSafe = false; + if (m_preDelayLength > 0) { + // Handles both the read case (call to process() ) and the write case (memcpy() ) + bool isPreDelaySafe = m_preReadWriteIndex + framesToProcess <= m_preDelayBuffer.size(); + ASSERT(isPreDelaySafe); + if (!isPreDelaySafe) + return; + + isTemporaryBufferSafe = framesToProcess <= m_temporaryBuffer.size(); + + preDelayedSource = m_preDelayBuffer.data() + m_preReadWriteIndex; + temporaryBuffer = m_temporaryBuffer.data(); + } else { + // Zero delay + preDelayedSource = source; + temporaryBuffer = m_preDelayBuffer.data(); + + isTemporaryBufferSafe = framesToProcess <= m_preDelayBuffer.size(); + } + + ASSERT(isTemporaryBufferSafe); + if (!isTemporaryBufferSafe) + return; + + int writeIndex = 0; + + if (m_framesProcessed < m_preDelayLength) { + // For the first m_preDelayLength frames don't process the convolver, instead simply buffer in the pre-delay. + // But while buffering the pre-delay, we still need to update our index. + m_accumulationBuffer->updateReadIndex(&m_accumulationReadIndex, framesToProcess); + } else { + // Now, run the convolution (into the delay buffer). + // An expensive FFT will happen every fftSize / 2 frames. + // We process in-place here... + m_convolver->process(&m_fftKernel, preDelayedSource, temporaryBuffer, framesToProcess); + + // Now accumulate into reverb's accumulation buffer. + writeIndex = m_accumulationBuffer->accumulate(temporaryBuffer, framesToProcess, &m_accumulationReadIndex, m_postDelayLength); + } + + // Finally copy input to pre-delay. + if (m_preDelayLength > 0) { + memcpy(preDelayedSource, source, sizeof(float) * framesToProcess); + m_preReadWriteIndex += framesToProcess; + + ASSERT(m_preReadWriteIndex <= m_preDelayLength); + if (m_preReadWriteIndex >= m_preDelayLength) + m_preReadWriteIndex = 0; + } + + m_framesProcessed += framesToProcess; +} + +void ReverbConvolverStage::reset() +{ + m_convolver->reset(); + m_preDelayBuffer.zero(); + m_accumulationReadIndex = 0; + m_inputReadIndex = 0; + m_framesProcessed = 0; +} + +} // namespace WebCore + +#endif // ENABLE(WEB_AUDIO) |