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/*
* 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 "platform/audio/AudioResampler.h"
#include "wtf/MathExtras.h"
#include "wtf/PtrUtil.h"
#include <algorithm>
namespace blink {
const double AudioResampler::MaxRate = 8.0;
AudioResampler::AudioResampler() : m_rate(1.0) {
m_kernels.push_back(WTF::makeUnique<AudioResamplerKernel>(this));
m_sourceBus = AudioBus::create(1, 0, false);
}
AudioResampler::AudioResampler(unsigned numberOfChannels) : m_rate(1.0) {
for (unsigned i = 0; i < numberOfChannels; ++i)
m_kernels.push_back(WTF::makeUnique<AudioResamplerKernel>(this));
m_sourceBus = AudioBus::create(numberOfChannels, 0, false);
}
void AudioResampler::configureChannels(unsigned numberOfChannels) {
unsigned currentSize = m_kernels.size();
if (numberOfChannels == currentSize)
return; // already setup
// First deal with adding or removing kernels.
if (numberOfChannels > currentSize) {
for (unsigned i = currentSize; i < numberOfChannels; ++i)
m_kernels.push_back(WTF::makeUnique<AudioResamplerKernel>(this));
} else
m_kernels.resize(numberOfChannels);
// Reconfigure our source bus to the new channel size.
m_sourceBus = AudioBus::create(numberOfChannels, 0, false);
}
void AudioResampler::process(AudioSourceProvider* provider,
AudioBus* destinationBus,
size_t framesToProcess) {
ASSERT(provider);
if (!provider)
return;
unsigned numberOfChannels = m_kernels.size();
// Make sure our configuration matches the bus we're rendering to.
bool channelsMatch = (destinationBus &&
destinationBus->numberOfChannels() == numberOfChannels);
ASSERT(channelsMatch);
if (!channelsMatch)
return;
// Setup the source bus.
for (unsigned i = 0; i < numberOfChannels; ++i) {
// Figure out how many frames we need to get from the provider, and a
// pointer to the buffer.
size_t framesNeeded;
float* fillPointer =
m_kernels[i]->getSourcePointer(framesToProcess, &framesNeeded);
ASSERT(fillPointer);
if (!fillPointer)
return;
m_sourceBus->setChannelMemory(i, fillPointer, framesNeeded);
}
// Ask the provider to supply the desired number of source frames.
provider->provideInput(m_sourceBus.get(), m_sourceBus->length());
// Now that we have the source data, resample each channel into the
// destination bus.
// FIXME: optimize for the common stereo case where it's faster to process
// both left/right channels in the same inner loop.
for (unsigned i = 0; i < numberOfChannels; ++i) {
float* destination = destinationBus->channel(i)->mutableData();
m_kernels[i]->process(destination, framesToProcess);
}
}
void AudioResampler::setRate(double rate) {
if (std::isnan(rate) || std::isinf(rate) || rate <= 0.0)
return;
m_rate = std::min(AudioResampler::MaxRate, rate);
}
void AudioResampler::reset() {
unsigned numberOfChannels = m_kernels.size();
for (unsigned i = 0; i < numberOfChannels; ++i)
m_kernels[i]->reset();
}
} // namespace blink
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