third_party/WebKit/Source/modules/webaudio/WaveShaperProcessor.cpp

/*
 * Copyright (C) 2011, 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
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 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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#include "modules/webaudio/WaveShaperDSPKernel.h"
#include "modules/webaudio/WaveShaperProcessor.h"
#include "wtf/PtrUtil.h"
#include <memory>

namespace blink {

WaveShaperProcessor::WaveShaperProcessor(float sampleRate,
                                         size_t numberOfChannels)
    : AudioDSPKernelProcessor(sampleRate, numberOfChannels),
      m_oversample(OverSampleNone) {}

WaveShaperProcessor::~WaveShaperProcessor() {
  if (isInitialized())
    uninitialize();
}

std::unique_ptr<AudioDSPKernel> WaveShaperProcessor::createKernel() {
  return wrapUnique(new WaveShaperDSPKernel(this));
}

void WaveShaperProcessor::setCurve(const float* curveData,
                                   unsigned curveLength) {
  DCHECK(isMainThread());

  // This synchronizes with process().
  MutexLocker processLocker(m_processLock);

  if (curveLength == 0 || !curveData) {
    m_curve = nullptr;
    return;
  }

  // Copy the curve data, if any, to our internal buffer.
  m_curve = wrapUnique(new Vector<float>(curveLength));
  memcpy(m_curve->data(), curveData, sizeof(float) * curveLength);
}

void WaveShaperProcessor::setOversample(OverSampleType oversample) {
  // This synchronizes with process().
  MutexLocker processLocker(m_processLock);

  m_oversample = oversample;

  if (oversample != OverSampleNone) {
    for (unsigned i = 0; i < m_kernels.size(); ++i) {
      WaveShaperDSPKernel* kernel =
          static_cast<WaveShaperDSPKernel*>(m_kernels[i].get());
      kernel->lazyInitializeOversampling();
    }
  }
}

void WaveShaperProcessor::process(const AudioBus* source,
                                  AudioBus* destination,
                                  size_t framesToProcess) {
  if (!isInitialized()) {
    destination->zero();
    return;
  }

  bool channelCountMatches =
      source->numberOfChannels() == destination->numberOfChannels() &&
      source->numberOfChannels() == m_kernels.size();
  DCHECK(channelCountMatches);
  if (!channelCountMatches)
    return;

  // The audio thread can't block on this lock, so we call tryLock() instead.
  MutexTryLocker tryLocker(m_processLock);
  if (tryLocker.locked()) {
    // For each channel of our input, process using the corresponding
    // WaveShaperDSPKernel into the output channel.
    for (unsigned i = 0; i < m_kernels.size(); ++i)
      m_kernels[i]->process(source->channel(i)->data(),
                            destination->channel(i)->mutableData(),
                            framesToProcess);
  } else {
    // Too bad - the tryLock() failed. We must be in the middle of a setCurve()
    // call.
    destination->zero();
  }
}

}  // namespace blink