Source/WebCore/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
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 * 1.  Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
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 *    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;
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#include "config.h"

#if ENABLE(WEB_AUDIO)

#include "WaveShaperProcessor.h"

#include "WaveShaperDSPKernel.h"

namespace WebCore {
    
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 std::make_unique<WaveShaperDSPKernel>(this);
}

void WaveShaperProcessor::setCurve(Float32Array* curve)
{
    // This synchronizes with process().
    std::lock_guard<Lock> lock(m_processMutex);

    m_curve = curve;
}

void WaveShaperProcessor::setOversample(OverSampleType oversample)
{
    // This synchronizes with process().
    std::lock_guard<Lock> lock(m_processMutex);

    m_oversample = oversample;

    if (oversample != OverSampleNone) {
        for (auto& audioDSPKernel : m_kernels) {
            WaveShaperDSPKernel& kernel = static_cast<WaveShaperDSPKernel&>(*audioDSPKernel);
            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();
    ASSERT(channelCountMatches);
    if (!channelCountMatches)
        return;

    // The audio thread can't block on this lock, so we use std::try_to_lock instead.
    std::unique_lock<Lock> lock(m_processMutex, std::try_to_lock);
    if (!lock.owns_lock()) {
        // Too bad - the try_lock() failed. We must be in the middle of a setCurve() call.
        destination->zero();
        return;
    }

    // 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);
}

} // namespace WebCore

#endif // ENABLE(WEB_AUDIO)