| /* | |
| * 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 "platform/audio/AudioBus.h" | |
| #include "platform/audio/Reverb.h" | |
| #include "platform/audio/VectorMath.h" | |
| #include "wtf/MathExtras.h" | |
| #include "wtf/PtrUtil.h" | |
| #include <math.h> | |
| #include <memory> | |
| #if OS(MACOSX) | |
| using namespace std; | |
| #endif | |
| namespace blink { | |
| using namespace VectorMath; | |
| // Empirical gain calibration tested across many impulse responses to ensure | |
| // perceived volume is same as dry (unprocessed) signal | |
| const float GainCalibration = -58; | |
| const float GainCalibrationSampleRate = 44100; | |
| // A minimum power value to when normalizing a silent (or very quiet) impulse | |
| // response | |
| const float MinPower = 0.000125f; | |
| static float calculateNormalizationScale(AudioBus* response) { | |
| // Normalize by RMS power | |
| size_t numberOfChannels = response->numberOfChannels(); | |
| size_t length = response->length(); | |
| float power = 0; | |
| for (size_t i = 0; i < numberOfChannels; ++i) { | |
| float channelPower = 0; | |
| vsvesq(response->channel(i)->data(), 1, &channelPower, length); | |
| power += channelPower; | |
| } | |
| power = sqrt(power / (numberOfChannels * length)); | |
| // Protect against accidental overload | |
| if (std::isinf(power) || std::isnan(power) || power < MinPower) | |
| power = MinPower; | |
| float scale = 1 / power; | |
| scale *= powf( | |
| 10, GainCalibration * | |
| 0.05f); // calibrate to make perceived volume same as unprocessed | |
| // Scale depends on sample-rate. | |
| if (response->sampleRate()) | |
| scale *= GainCalibrationSampleRate / response->sampleRate(); | |
| // True-stereo compensation | |
| if (response->numberOfChannels() == 4) | |
| scale *= 0.5f; | |
| return scale; | |
| } | |
| Reverb::Reverb(AudioBus* impulseResponse, | |
| size_t renderSliceSize, | |
| size_t maxFFTSize, | |
| size_t numberOfChannels, | |
| bool useBackgroundThreads, | |
| bool normalize) { | |
| float scale = 1; | |
| if (normalize) { | |
| scale = calculateNormalizationScale(impulseResponse); | |
| if (scale) | |
| impulseResponse->scale(scale); | |
| } | |
| initialize(impulseResponse, renderSliceSize, maxFFTSize, numberOfChannels, | |
| useBackgroundThreads); | |
| // Undo scaling since this shouldn't be a destructive operation on | |
| // impulseResponse. | |
| // FIXME: What about roundoff? Perhaps consider making a temporary scaled copy | |
| // instead of scaling and unscaling in place. | |
| if (normalize && scale) | |
| impulseResponse->scale(1 / scale); | |
| } | |
| void Reverb::initialize(AudioBus* impulseResponseBuffer, | |
| size_t renderSliceSize, | |
| size_t maxFFTSize, | |
| size_t numberOfChannels, | |
| bool useBackgroundThreads) { | |
| m_impulseResponseLength = impulseResponseBuffer->length(); | |
| // The reverb can handle a mono impulse response and still do stereo | |
| // processing | |
| size_t numResponseChannels = impulseResponseBuffer->numberOfChannels(); | |
| m_convolvers.reserveCapacity(numberOfChannels); | |
| int convolverRenderPhase = 0; | |
| for (size_t i = 0; i < numResponseChannels; ++i) { | |
| AudioChannel* channel = impulseResponseBuffer->channel(i); | |
| std::unique_ptr<ReverbConvolver> convolver = WTF::wrapUnique( | |
| new ReverbConvolver(channel, renderSliceSize, maxFFTSize, | |
| convolverRenderPhase, useBackgroundThreads)); | |
| m_convolvers.push_back(std::move(convolver)); | |
| convolverRenderPhase += renderSliceSize; | |
| } | |
| // For "True" stereo processing we allocate a temporary buffer to avoid | |
| // repeatedly allocating it in the process() method. It can be bad to | |
| // allocate memory in a real-time thread. | |
| if (numResponseChannels == 4) | |
| m_tempBuffer = AudioBus::create(2, MaxFrameSize); | |
| } | |
| void Reverb::process(const AudioBus* sourceBus, | |
| AudioBus* destinationBus, | |
| size_t framesToProcess) { | |
| // Do a fairly comprehensive sanity check. | |
| // If these conditions are satisfied, all of the source and destination | |
| // pointers will be valid for the various matrixing cases. | |
| bool isSafeToProcess = sourceBus && destinationBus && | |
| sourceBus->numberOfChannels() > 0 && | |
| destinationBus->numberOfChannels() > 0 && | |
| framesToProcess <= MaxFrameSize && | |
| framesToProcess <= sourceBus->length() && | |
| framesToProcess <= destinationBus->length(); | |
| ASSERT(isSafeToProcess); | |
| if (!isSafeToProcess) | |
| return; | |
| // For now only handle mono or stereo output | |
| if (destinationBus->numberOfChannels() > 2) { | |
| destinationBus->zero(); | |
| return; | |
| } | |
| AudioChannel* destinationChannelL = destinationBus->channel(0); | |
| const AudioChannel* sourceChannelL = sourceBus->channel(0); | |
| // Handle input -> output matrixing... | |
| size_t numInputChannels = sourceBus->numberOfChannels(); | |
| size_t numOutputChannels = destinationBus->numberOfChannels(); | |
| size_t numReverbChannels = m_convolvers.size(); | |
| if (numInputChannels == 2 && numReverbChannels == 2 && | |
| numOutputChannels == 2) { | |
| // 2 -> 2 -> 2 | |
| const AudioChannel* sourceChannelR = sourceBus->channel(1); | |
| AudioChannel* destinationChannelR = destinationBus->channel(1); | |
| m_convolvers[0]->process(sourceChannelL, destinationChannelL, | |
| framesToProcess); | |
| m_convolvers[1]->process(sourceChannelR, destinationChannelR, | |
| framesToProcess); | |
| } else if (numInputChannels == 1 && numOutputChannels == 2 && | |
| numReverbChannels == 2) { | |
| // 1 -> 2 -> 2 | |
| for (int i = 0; i < 2; ++i) { | |
| AudioChannel* destinationChannel = destinationBus->channel(i); | |
| m_convolvers[i]->process(sourceChannelL, destinationChannel, | |
| framesToProcess); | |
| } | |
| } else if (numInputChannels == 1 && numReverbChannels == 1 && | |
| numOutputChannels == 2) { | |
| // 1 -> 1 -> 2 | |
| m_convolvers[0]->process(sourceChannelL, destinationChannelL, | |
| framesToProcess); | |
| // simply copy L -> R | |
| AudioChannel* destinationChannelR = destinationBus->channel(1); | |
| bool isCopySafe = destinationChannelL->data() && | |
| destinationChannelR->data() && | |
| destinationChannelL->length() >= framesToProcess && | |
| destinationChannelR->length() >= framesToProcess; | |
| ASSERT(isCopySafe); | |
| if (!isCopySafe) | |
| return; | |
| memcpy(destinationChannelR->mutableData(), destinationChannelL->data(), | |
| sizeof(float) * framesToProcess); | |
| } else if (numInputChannels == 1 && numReverbChannels == 1 && | |
| numOutputChannels == 1) { | |
| // 1 -> 1 -> 1 | |
| m_convolvers[0]->process(sourceChannelL, destinationChannelL, | |
| framesToProcess); | |
| } else if (numInputChannels == 2 && numReverbChannels == 4 && | |
| numOutputChannels == 2) { | |
| // 2 -> 4 -> 2 ("True" stereo) | |
| const AudioChannel* sourceChannelR = sourceBus->channel(1); | |
| AudioChannel* destinationChannelR = destinationBus->channel(1); | |
| AudioChannel* tempChannelL = m_tempBuffer->channel(0); | |
| AudioChannel* tempChannelR = m_tempBuffer->channel(1); | |
| // Process left virtual source | |
| m_convolvers[0]->process(sourceChannelL, destinationChannelL, | |
| framesToProcess); | |
| m_convolvers[1]->process(sourceChannelL, destinationChannelR, | |
| framesToProcess); | |
| // Process right virtual source | |
| m_convolvers[2]->process(sourceChannelR, tempChannelL, framesToProcess); | |
| m_convolvers[3]->process(sourceChannelR, tempChannelR, framesToProcess); | |
| destinationBus->sumFrom(*m_tempBuffer); | |
| } else if (numInputChannels == 1 && numReverbChannels == 4 && | |
| numOutputChannels == 2) { | |
| // 1 -> 4 -> 2 (Processing mono with "True" stereo impulse response) | |
| // This is an inefficient use of a four-channel impulse response, but we | |
| // should handle the case. | |
| AudioChannel* destinationChannelR = destinationBus->channel(1); | |
| AudioChannel* tempChannelL = m_tempBuffer->channel(0); | |
| AudioChannel* tempChannelR = m_tempBuffer->channel(1); | |
| // Process left virtual source | |
| m_convolvers[0]->process(sourceChannelL, destinationChannelL, | |
| framesToProcess); | |
| m_convolvers[1]->process(sourceChannelL, destinationChannelR, | |
| framesToProcess); | |
| // Process right virtual source | |
| m_convolvers[2]->process(sourceChannelL, tempChannelL, framesToProcess); | |
| m_convolvers[3]->process(sourceChannelL, tempChannelR, framesToProcess); | |
| destinationBus->sumFrom(*m_tempBuffer); | |
| } else { | |
| // Handle gracefully any unexpected / unsupported matrixing | |
| // FIXME: add code for 5.1 support... | |
| destinationBus->zero(); | |
| } | |
| } | |
| void Reverb::reset() { | |
| for (size_t i = 0; i < m_convolvers.size(); ++i) | |
| m_convolvers[i]->reset(); | |
| } | |
| size_t Reverb::latencyFrames() const { | |
| return !m_convolvers.isEmpty() ? m_convolvers.front()->latencyFrames() : 0; | |
| } | |
| } // namespace blink |