Source/WebCore/platform/audio/AudioDSPKernelProcessor.cpp

/*
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#include "config.h"

#if ENABLE(WEB_AUDIO)

#include "AudioDSPKernelProcessor.h"

#include "AudioDSPKernel.h"

namespace WebCore {

// setNumberOfChannels() may later be called if the object is not yet in an "initialized" state.
AudioDSPKernelProcessor::AudioDSPKernelProcessor(float sampleRate, unsigned numberOfChannels)
    : AudioProcessor(sampleRate, numberOfChannels)
    , m_hasJustReset(true)
{
}

void AudioDSPKernelProcessor::initialize()
{
    if (isInitialized())
        return;

    ASSERT(!m_kernels.size());

    // Create processing kernels, one per channel.
    for (unsigned i = 0; i < numberOfChannels(); ++i)
        m_kernels.append(createKernel());
        
    m_initialized = true;
    m_hasJustReset = true;
}

void AudioDSPKernelProcessor::uninitialize()
{
    if (!isInitialized())
        return;
        
    m_kernels.clear();

    m_initialized = false;
}

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

    bool channelCountMatches = source->numberOfChannels() == destination->numberOfChannels() && source->numberOfChannels() == m_kernels.size();
    ASSERT(channelCountMatches);
    if (!channelCountMatches)
        return;
        
    for (unsigned i = 0; i < m_kernels.size(); ++i)
        m_kernels[i]->process(source->channel(i)->data(), destination->channel(i)->mutableData(), framesToProcess);
}

// Resets filter state
void AudioDSPKernelProcessor::reset()
{
    if (!isInitialized())
        return;

    // Forces snap to parameter values - first time.
    // Any processing depending on this value must set it to false at the appropriate time.
    m_hasJustReset = true;

    for (unsigned i = 0; i < m_kernels.size(); ++i)
        m_kernels[i]->reset();
}

void AudioDSPKernelProcessor::setNumberOfChannels(unsigned numberOfChannels)
{
    if (numberOfChannels == m_numberOfChannels)
        return;
        
    ASSERT(!isInitialized());
    if (!isInitialized())
        m_numberOfChannels = numberOfChannels;
}

double AudioDSPKernelProcessor::tailTime() const
{
    // It is expected that all the kernels have the same tailTime.
    return !m_kernels.isEmpty() ? m_kernels.first()->tailTime() : 0;
}

double AudioDSPKernelProcessor::latencyTime() const
{
    // It is expected that all the kernels have the same latencyTime.
    return !m_kernels.isEmpty() ? m_kernels.first()->latencyTime() : 0;
}

} // namespace WebCore

#endif // ENABLE(WEB_AUDIO)