Source/modules/webaudio/AudioBuffer.cpp

/*
 * Copyright (C) 2010 Google Inc. All rights reserved.
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 *     notice, this list of conditions and the following disclaimer.
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 *     notice, this list of conditions and the following disclaimer in the
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 *     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
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#include "config.h"

#if ENABLE(WEB_AUDIO)

#include "modules/webaudio/AudioBuffer.h"

#include "core/dom/ExceptionCode.h"
#include "core/platform/audio/AudioBus.h"
#include "core/platform/audio/AudioFileReader.h"
#include "modules/webaudio/AudioContext.h"

namespace WebCore {

PassRefPtr<AudioBuffer> AudioBuffer::create(unsigned numberOfChannels, size_t numberOfFrames, float sampleRate)
{
    if (sampleRate < 22050 || sampleRate > 96000 || numberOfChannels > AudioContext::maxNumberOfChannels() || !numberOfFrames)
        return 0;
    
    return adoptRef(new AudioBuffer(numberOfChannels, numberOfFrames, sampleRate));
}

PassRefPtr<AudioBuffer> AudioBuffer::createFromAudioFileData(const void* data, size_t dataSize, bool mixToMono, float sampleRate)
{
    RefPtr<AudioBus> bus = createBusFromInMemoryAudioFile(data, dataSize, mixToMono, sampleRate);
    if (bus.get())
        return adoptRef(new AudioBuffer(bus.get()));

    return 0;
}

AudioBuffer::AudioBuffer(unsigned numberOfChannels, size_t numberOfFrames, float sampleRate)
    : m_gain(1.0)
    , m_sampleRate(sampleRate)
    , m_length(numberOfFrames)
{
    ScriptWrappable::init(this);
    m_channels.reserveCapacity(numberOfChannels);

    for (unsigned i = 0; i < numberOfChannels; ++i) {
        RefPtr<Float32Array> channelDataArray = Float32Array::create(m_length);
        m_channels.append(channelDataArray);
    }
}

AudioBuffer::AudioBuffer(AudioBus* bus)
    : m_gain(1.0)
    , m_sampleRate(bus->sampleRate())
    , m_length(bus->length())
{
    ScriptWrappable::init(this);
    // Copy audio data from the bus to the Float32Arrays we manage.
    unsigned numberOfChannels = bus->numberOfChannels();
    m_channels.reserveCapacity(numberOfChannels);
    for (unsigned i = 0; i < numberOfChannels; ++i) {
        RefPtr<Float32Array> channelDataArray = Float32Array::create(m_length);
        channelDataArray->setRange(bus->channel(i)->data(), m_length, 0);
        m_channels.append(channelDataArray);
    }
}

void AudioBuffer::releaseMemory()
{
    m_channels.clear();
}

Float32Array* AudioBuffer::getChannelData(unsigned channelIndex, ExceptionCode& ec)
{
    if (channelIndex >= m_channels.size()) {
        ec = SyntaxError;
        return 0;
    }

    return m_channels[channelIndex].get();
}

Float32Array* AudioBuffer::getChannelData(unsigned channelIndex)
{
    if (channelIndex >= m_channels.size())
        return 0;

    return m_channels[channelIndex].get();
}

void AudioBuffer::zero()
{
    for (unsigned i = 0; i < m_channels.size(); ++i) {
        if (getChannelData(i))
            getChannelData(i)->zeroRange(0, length());
    }
}

} // namespace WebCore

#endif // ENABLE(WEB_AUDIO)