The Tor Browser: comparison content/media/webaudio/blink/ReverbConvolver.cpp

--1:000000000000
+:aa21a4f21581
+/*
+* 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 "ReverbConvolver.h"
+#include "ReverbConvolverStage.h"
+using namespace mozilla;
+template<>
+struct RunnableMethodTraits<WebCore::ReverbConvolver>
+{
+static void RetainCallee(WebCore::ReverbConvolver* obj) {}
+static void ReleaseCallee(WebCore::ReverbConvolver* obj) {}
+};
+namespace WebCore {
+const int InputBufferSize = 8 * 16384;
+// We only process the leading portion of the impulse response in the real-time thread.  We don't exceed this length.
+// It turns out then, that the background thread has about 278msec of scheduling slop.
+// Empirically, this has been found to be a good compromise between giving enough time for scheduling slop,
+// while still minimizing the amount of processing done in the primary (high-priority) thread.
+// This was found to be a good value on Mac OS X, and may work well on other platforms as well, assuming
+// the very rough scheduling latencies are similar on these time-scales.  Of course, this code may need to be
+// tuned for individual platforms if this assumption is found to be incorrect.
+const size_t RealtimeFrameLimit = 8192  + 4096; // ~278msec @ 44.1KHz
+const size_t MinFFTSize = 128;
+const size_t MaxRealtimeFFTSize = 2048;
+ReverbConvolver::ReverbConvolver(const float* impulseResponseData, size_t impulseResponseLength, size_t renderSliceSize, size_t maxFFTSize, size_t convolverRenderPhase, bool useBackgroundThreads)
+: m_impulseResponseLength(impulseResponseLength)
+, m_accumulationBuffer(impulseResponseLength + renderSliceSize)
+, m_inputBuffer(InputBufferSize)
+, m_minFFTSize(MinFFTSize) // First stage will have this size - successive stages will double in size each time
+, m_maxFFTSize(maxFFTSize) // until we hit m_maxFFTSize
+, m_backgroundThread("ConvolverWorker")
+, m_backgroundThreadCondition(&m_backgroundThreadLock)
+, m_useBackgroundThreads(useBackgroundThreads)
+, m_wantsToExit(false)
+, m_moreInputBuffered(false)
+{
+// If we are using background threads then don't exceed this FFT size for the
+// stages which run in the real-time thread.  This avoids having only one or two
+// large stages (size 16384 or so) at the end which take a lot of time every several
+// processing slices.  This way we amortize the cost over more processing slices.
+m_maxRealtimeFFTSize = MaxRealtimeFFTSize;
+// For the moment, a good way to know if we have real-time constraint is to check if we're using background threads.
+// Otherwise, assume we're being run from a command-line tool.
+bool hasRealtimeConstraint = useBackgroundThreads;
+const float* response = impulseResponseData;
+size_t totalResponseLength = impulseResponseLength;
+// The total latency is zero because the direct-convolution is used in the leading portion.
+size_t reverbTotalLatency = 0;
+size_t stageOffset = 0;
+int i = 0;
+size_t fftSize = m_minFFTSize;
+while (stageOffset < totalResponseLength) {
+size_t stageSize = fftSize / 2;
+// For the last stage, it's possible that stageOffset is such that we're straddling the end
+// of the impulse response buffer (if we use stageSize), so reduce the last stage's length...
+if (stageSize + stageOffset > totalResponseLength)
+stageSize = totalResponseLength - stageOffset;
+// This "staggers" the time when each FFT happens so they don't all happen at the same time
+int renderPhase = convolverRenderPhase + i * renderSliceSize;
+bool useDirectConvolver = !stageOffset;
+nsAutoPtr<ReverbConvolverStage> stage(new ReverbConvolverStage(response, totalResponseLength, reverbTotalLatency, stageOffset, stageSize, fftSize, renderPhase, renderSliceSize, &m_accumulationBuffer, useDirectConvolver));
+bool isBackgroundStage = false;
+if (this->useBackgroundThreads() && stageOffset > RealtimeFrameLimit) {
+m_backgroundStages.AppendElement(stage.forget());
+isBackgroundStage = true;
+} else
+m_stages.AppendElement(stage.forget());
+stageOffset += stageSize;
+++i;
+if (!useDirectConvolver) {
+// Figure out next FFT size
+fftSize *= 2;
+}
+if (hasRealtimeConstraint && !isBackgroundStage && fftSize > m_maxRealtimeFFTSize)
+fftSize = m_maxRealtimeFFTSize;
+if (fftSize > m_maxFFTSize)
+fftSize = m_maxFFTSize;
+}
+// Start up background thread
+// FIXME: would be better to up the thread priority here.  It doesn't need to be real-time, but higher than the default...
+if (this->useBackgroundThreads() && m_backgroundStages.Length() > 0) {
+if (!m_backgroundThread.Start()) {
+NS_WARNING("Cannot start convolver thread.");
+return;
+}
+CancelableTask* task = NewRunnableMethod(this, &ReverbConvolver::backgroundThreadEntry);
+m_backgroundThread.message_loop()->PostTask(FROM_HERE, task);
+}
+}
+ReverbConvolver::~ReverbConvolver()
+{
+// Wait for background thread to stop
+if (useBackgroundThreads() && m_backgroundThread.IsRunning()) {
+m_wantsToExit = true;
+// Wake up thread so it can return
+{
+AutoLock locker(m_backgroundThreadLock);
+m_moreInputBuffered = true;
+m_backgroundThreadCondition.Signal();
+}
+m_backgroundThread.Stop();
+}
+}
+size_t ReverbConvolver::sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
+{
+size_t amount = aMallocSizeOf(this);
+amount += m_stages.SizeOfExcludingThis(aMallocSizeOf);
+for (size_t i = 0; i < m_stages.Length(); i++) {
+if (m_stages[i]) {
+amount += m_stages[i]->sizeOfIncludingThis(aMallocSizeOf);
+}
+}
+amount += m_backgroundStages.SizeOfExcludingThis(aMallocSizeOf);
+for (size_t i = 0; i < m_backgroundStages.Length(); i++) {
+if (m_backgroundStages[i]) {
+amount += m_backgroundStages[i]->sizeOfIncludingThis(aMallocSizeOf);
+}
+}
+// NB: The buffer sizes are static, so even though they might be accessed
+//     in another thread it's safe to measure them.
+amount += m_accumulationBuffer.sizeOfExcludingThis(aMallocSizeOf);
+amount += m_inputBuffer.sizeOfExcludingThis(aMallocSizeOf);
+// Possible future measurements:
+// - m_backgroundThread
+// - m_backgroundThreadLock
+// - m_backgroundThreadCondition
+return amount;
+}
+void ReverbConvolver::backgroundThreadEntry()
+{
+while (!m_wantsToExit) {
+// Wait for realtime thread to give us more input
+m_moreInputBuffered = false;
+{
+AutoLock locker(m_backgroundThreadLock);
+while (!m_moreInputBuffered && !m_wantsToExit)
+m_backgroundThreadCondition.Wait();
+}
+// Process all of the stages until their read indices reach the input buffer's write index
+int writeIndex = m_inputBuffer.writeIndex();
+// Even though it doesn't seem like every stage needs to maintain its own version of readIndex
+// we do this in case we want to run in more than one background thread.
+int readIndex;
+while ((readIndex = m_backgroundStages[0]->inputReadIndex()) != writeIndex) { // FIXME: do better to detect buffer overrun...
+// The ReverbConvolverStages need to process in amounts which evenly divide half the FFT size
+const int SliceSize = MinFFTSize / 2;
+// Accumulate contributions from each stage
+for (size_t i = 0; i < m_backgroundStages.Length(); ++i)
+m_backgroundStages[i]->processInBackground(this, SliceSize);
+}
+}
+}
+void ReverbConvolver::process(const float* sourceChannelData, size_t sourceChannelLength,
+float* destinationChannelData, size_t destinationChannelLength,
+size_t framesToProcess)
+{
+bool isSafe = sourceChannelData && destinationChannelData && sourceChannelLength >= framesToProcess && destinationChannelLength >= framesToProcess;
+MOZ_ASSERT(isSafe);
+if (!isSafe)
+return;
+const float* source = sourceChannelData;
+float* destination = destinationChannelData;
+bool isDataSafe = source && destination;
+MOZ_ASSERT(isDataSafe);
+if (!isDataSafe)
+return;
+// Feed input buffer (read by all threads)
+m_inputBuffer.write(source, framesToProcess);
+// Accumulate contributions from each stage
+for (size_t i = 0; i < m_stages.Length(); ++i)
+m_stages[i]->process(source, framesToProcess);
+// Finally read from accumulation buffer
+m_accumulationBuffer.readAndClear(destination, framesToProcess);
+// Now that we've buffered more input, wake up our background thread.
+// Not using a MutexLocker looks strange, but we use a tryLock() instead because this is run on the real-time
+// thread where it is a disaster for the lock to be contended (causes audio glitching).  It's OK if we fail to
+// signal from time to time, since we'll get to it the next time we're called.  We're called repeatedly
+// and frequently (around every 3ms).  The background thread is processing well into the future and has a considerable amount of
+// leeway here...
+if (m_backgroundThreadLock.Try()) {
+m_moreInputBuffered = true;
+m_backgroundThreadCondition.Signal();
+m_backgroundThreadLock.Release();
+}
+}
+void ReverbConvolver::reset()
+{
+for (size_t i = 0; i < m_stages.Length(); ++i)
+m_stages[i]->reset();
+for (size_t i = 0; i < m_backgroundStages.Length(); ++i)
+m_backgroundStages[i]->reset();
+m_accumulationBuffer.reset();
+m_inputBuffer.reset();
+}
+size_t ReverbConvolver::latencyFrames() const
+{
+return 0;
+}
+} // namespace WebCore

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comparison: content/media/webaudio/blink/ReverbConvolver.cpp

content/media/webaudio/blink/ReverbConvolver.cpp