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Diffstat (limited to 'examples/multimedia/audiodecoder/wavefilewriter.cpp')
| -rw-r--r-- | examples/multimedia/audiodecoder/wavefilewriter.cpp | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/examples/multimedia/audiodecoder/wavefilewriter.cpp b/examples/multimedia/audiodecoder/wavefilewriter.cpp new file mode 100644 index 000000000..e13476ddd --- /dev/null +++ b/examples/multimedia/audiodecoder/wavefilewriter.cpp @@ -0,0 +1,192 @@ +/**************************************************************************** +** +** Copyright (C) 2012 Digia Plc and/or its subsidiary(-ies). +** Contact: http://www.qt-project.org/legal +** +** This file is part of the examples of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:BSD$ +** You may use this file under the terms of the BSD license as follows: +** +** "Redistribution and use in source and binary forms, with or without +** modification, are permitted provided that the following conditions are +** met: +** * Redistributions of source code must retain the above copyright +** notice, this list of conditions and the following disclaimer. +** * 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. +** * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names +** of its contributors may be used to endorse or promote products derived +** from this software without specific prior written permission. +** +** +** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 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 THE COPYRIGHT +** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "wavefilewriter.h" + +struct Q_PACKED chunk +{ + char id[4]; + quint32 size; +}; + +struct Q_PACKED RIFFHeader +{ + chunk descriptor; // "RIFF" + char type[4]; // "WAVE" +}; + +struct Q_PACKED WAVEHeader +{ + chunk descriptor; + quint16 audioFormat; + quint16 numChannels; + quint32 sampleRate; + quint32 byteRate; + quint16 blockAlign; + quint16 bitsPerSample; +}; + +struct Q_PACKED DATAHeader +{ + chunk descriptor; +}; + +struct Q_PACKED CombinedHeader +{ + RIFFHeader riff; + WAVEHeader wave; + DATAHeader data; +}; +static const int HeaderLength = sizeof(CombinedHeader); + + +WaveFileWriter::WaveFileWriter(QObject *parent) + : QObject(parent) + , m_dataLength(0) +{ +} + +WaveFileWriter::~WaveFileWriter() +{ + close(); +} + +bool WaveFileWriter::open(const QString& fileName, const QAudioFormat& format) +{ + if (file.isOpen()) + return false; // file already open + + if (format.codec() != "audio/pcm" || format.sampleType() != QAudioFormat::SignedInt) + return false; // data format is not supported + + file.setFileName(fileName); + if (!file.open(QIODevice::WriteOnly)) + return false; // unable to open file for writing + + if (!writeHeader(format)) + return false; + + m_format = format; + return true; +} + +bool WaveFileWriter::write(const QAudioBuffer &buffer) +{ + if (buffer.format() != m_format) + return false; // buffer format has changed + + qint64 written = file.write((const char *)buffer.constData(), buffer.byteCount()); + m_dataLength += written; + return written == buffer.byteCount(); +} + +bool WaveFileWriter::close() +{ + bool result = false; + if (file.isOpen()) { + Q_ASSERT(m_dataLength < INT_MAX); + result = writeDataLength(); + + m_dataLength = 0; + file.close(); + } + return result; +} + +bool WaveFileWriter::writeHeader(const QAudioFormat &format) +{ + // check if format is supported + if (format.byteOrder() == QAudioFormat::BigEndian || format.sampleType() != QAudioFormat::SignedInt) + return false; + + CombinedHeader header; + memset(&header, 0, HeaderLength); + +#ifndef Q_LITTLE_ENDIAN + // only implemented for LITTLE ENDIAN + return false; +#else + // RIFF header + memcpy(header.riff.descriptor.id, "RIFF", 4); + header.riff.descriptor.size = 0; // this will be updated with correct duration: + // m_dataLength + HeaderLength - 8 + // WAVE header + memcpy(header.riff.type, "WAVE", 4); + memcpy(header.wave.descriptor.id, "fmt ", 4); + header.wave.descriptor.size = quint32(16); + header.wave.audioFormat = quint16(1); + header.wave.numChannels = quint16(format.channelCount()); + header.wave.sampleRate = quint32(format.sampleRate()); + header.wave.byteRate = quint32(format.sampleRate() * format.channelCount() * format.sampleSize() / 8); + header.wave.blockAlign = quint16(format.channelCount() * format.sampleSize() / 8); + header.wave.bitsPerSample = quint16(format.sampleSize()); + + // DATA header + memcpy(header.data.descriptor.id,"data", 4); + header.data.descriptor.size = 0; // this will be updated with correct data length: m_dataLength + + return (file.write(reinterpret_cast<const char *>(&header), HeaderLength) == HeaderLength); +#endif +} + +bool WaveFileWriter::writeDataLength() +{ +#ifndef Q_LITTLE_ENDIAN + // only implemented for LITTLE ENDIAN + return false; +#endif + + if (file.isSequential()) + return false; + + // seek to RIFF header size, see header.riff.descriptor.size above + if (!file.seek(4)) + return false; + + quint32 length = m_dataLength + HeaderLength - 8; + if (file.write(reinterpret_cast<const char *>(&length), 4) != 4) + return false; + + // seek to DATA header size, see header.data.descriptor.size above + if (!file.seek(40)) + return false; + + return file.write(reinterpret_cast<const char *>(&m_dataLength), 4) == 4; +} |