jamulus/src/recorder/cwavestream.cpp

/******************************************************************************\
 * Copyright (c) 2020
 *
 * Author(s):
 *  pljones
 *
 ******************************************************************************
 *
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation; either version 2 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 *
\******************************************************************************/

#include "cwavestream.h"

/******************************************************************************\
* Overrides in global namespace                                                *
\******************************************************************************/

/**
 * @brief operator << Emit a hdr_riff object to a QDataStream
 * @param os a QDataStream
 * @param obj a hdr_riff object
 * @return the QDataStream passed
 */
recorder::CWaveStream& operator<<(recorder::CWaveStream& os, const recorder::HdrRiff& obj)
{
    (QDataStream&)os << obj.chunkId << obj.chunkSize << obj.format;
    return os;
}

/**
 * @brief operator << Emit a fmtSubChunk object to a QDataStream
 * @param os a QDataStream
 * @param obj a fmtSubChunk object
 * @return the QDataStream passed
 */
recorder::CWaveStream& operator<<(recorder::CWaveStream& os, const recorder::FmtSubChunk& obj)
{
    (QDataStream&)os << obj.chunkId
       << obj.chunkSize
       << obj.audioFormat
       << obj.numChannels
       << obj.sampleRate
       << obj.byteRate
       << obj.blockAlign
       << obj.bitsPerSample
          ;
    return os;
}

/**
 * @brief operator << Emit a dataSubChunkHdr object to a QDataStream
 * @param os a QDataStream
 * @param obj a dataSubChunkHdr object
 * @return the QDataStream passed
 */
recorder::CWaveStream& operator<<(recorder::CWaveStream& os, const recorder::DataSubChunkHdr& obj)
{
    (QDataStream&)os << obj.chunkId << obj.chunkSize;
    return os;
}

/******************************************************************************\
* Implementations of recorder.CWaveStream methods                              *
\******************************************************************************/

using namespace recorder;

CWaveStream::CWaveStream(const uint16_t numChannels) :
    QDataStream(),
    numChannels (numChannels),
    initialPos (device()->pos()),
    initialByteOrder (byteOrder())
{
    waveStreamHeaders();
}
CWaveStream::CWaveStream(QIODevice *iod, const uint16_t numChannels) :
    QDataStream(iod),
    numChannels (numChannels),
    initialPos (device()->pos()),
    initialByteOrder (byteOrder())
{
    waveStreamHeaders();
}
CWaveStream::CWaveStream(QByteArray *iod, QIODevice::OpenMode flags, const uint16_t numChannels) :
    QDataStream(iod, flags),
    numChannels (numChannels),
    initialPos (device()->pos()),
    initialByteOrder (byteOrder())
{
    waveStreamHeaders();
}
CWaveStream::CWaveStream(const QByteArray &ba, const uint16_t numChannels) :
    QDataStream(ba),
    numChannels (numChannels),
    initialPos (device()->pos()),
    initialByteOrder (byteOrder())
{
    waveStreamHeaders();
}

void CWaveStream::waveStreamHeaders()
{
    static const HdrRiff scHdrRiff;
           const FmtSubChunk cFmtSubChunk (numChannels);
    static const DataSubChunkHdr scDataSubChunkHdr;

    setByteOrder(LittleEndian);
    *this << scHdrRiff << cFmtSubChunk << scDataSubChunkHdr;
}

void CWaveStream::finalise()
{
    static const uint32_t hdrRiffChunkSize = sizeof(uint32_t) + sizeof(uint32_t) + sizeof(uint32_t);
    static const uint32_t fmtSubChunkSize = sizeof(uint32_t) + sizeof(uint32_t) + sizeof(uint16_t) + sizeof(uint16_t) + sizeof(uint32_t) + sizeof(uint32_t) + sizeof(uint16_t) + sizeof(uint16_t);

    static const uint32_t hdrRiffChunkSizeOffset = sizeof(uint32_t);
    static const uint32_t dataSubChunkHdrChunkSizeOffset = hdrRiffChunkSize + fmtSubChunkSize + sizeof (uint32_t);

    const int64_t currentPos = this->device()->pos();
    const uint32_t fileLength = static_cast<uint32_t>(currentPos - initialPos);

    QDataStream& out = static_cast<QDataStream&>(*this);

    // Overwrite hdr_riff.chunkSize
    this->device()->seek(initialPos + hdrRiffChunkSizeOffset);
    out << static_cast<uint32_t>(fileLength - (hdrRiffChunkSizeOffset + sizeof (uint32_t)));

    // Overwrite dataSubChunkHdr.chunkSize
    this->device()->seek(initialPos + dataSubChunkHdrChunkSizeOffset);
    out << static_cast<uint32_t>(fileLength - (dataSubChunkHdrChunkSizeOffset + sizeof (uint32_t)));

    // and then restore the position and byte order
    this->device()->seek(currentPos);
    setByteOrder(initialByteOrder);
}