wavfile.cpp Example File
spectrum/app/wavfile.cpp/**************************************************************************** ** ** Copyright (C) 2013 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 <qendian.h> #include <QVector> #include <QDebug> #include "utils.h" #include "wavfile.h" struct chunk { char id[4]; quint32 size; }; struct RIFFHeader { chunk descriptor; // "RIFF" char type[4]; // "WAVE" }; struct WAVEHeader { chunk descriptor; quint16 audioFormat; quint16 numChannels; quint32 sampleRate; quint32 byteRate; quint16 blockAlign; quint16 bitsPerSample; }; struct DATAHeader { chunk descriptor; }; struct CombinedHeader { RIFFHeader riff; WAVEHeader wave; }; WavFile::WavFile(QObject *parent) : QFile(parent) , m_headerLength(0) { } bool WavFile::open(const QString &fileName) { close(); setFileName(fileName); return QFile::open(QIODevice::ReadOnly) && readHeader(); } const QAudioFormat &WavFile::fileFormat() const { return m_fileFormat; } qint64 WavFile::headerLength() const { return m_headerLength; } bool WavFile::readHeader() { seek(0); CombinedHeader header; bool result = read(reinterpret_cast<char *>(&header), sizeof(CombinedHeader)) == sizeof(CombinedHeader); if (result) { if ((memcmp(&header.riff.descriptor.id, "RIFF", 4) == 0 || memcmp(&header.riff.descriptor.id, "RIFX", 4) == 0) && memcmp(&header.riff.type, "WAVE", 4) == 0 && memcmp(&header.wave.descriptor.id, "fmt ", 4) == 0 && (header.wave.audioFormat == 1 || header.wave.audioFormat == 0)) { // Read off remaining header information DATAHeader dataHeader; if (qFromLittleEndian<quint32>(header.wave.descriptor.size) > sizeof(WAVEHeader)) { // Extended data available quint16 extraFormatBytes; if (peek((char*)&extraFormatBytes, sizeof(quint16)) != sizeof(quint16)) return false; const qint64 throwAwayBytes = sizeof(quint16) + qFromLittleEndian<quint16>(extraFormatBytes); if (read(throwAwayBytes).size() != throwAwayBytes) return false; } if (read((char*)&dataHeader, sizeof(DATAHeader)) != sizeof(DATAHeader)) return false; // Establish format if (memcmp(&header.riff.descriptor.id, "RIFF", 4) == 0) m_fileFormat.setByteOrder(QAudioFormat::LittleEndian); else m_fileFormat.setByteOrder(QAudioFormat::BigEndian); int bps = qFromLittleEndian<quint16>(header.wave.bitsPerSample); m_fileFormat.setChannelCount(qFromLittleEndian<quint16>(header.wave.numChannels)); m_fileFormat.setCodec("audio/pcm"); m_fileFormat.setSampleRate(qFromLittleEndian<quint32>(header.wave.sampleRate)); m_fileFormat.setSampleSize(qFromLittleEndian<quint16>(header.wave.bitsPerSample)); m_fileFormat.setSampleType(bps == 8 ? QAudioFormat::UnSignedInt : QAudioFormat::SignedInt); } else { result = false; } } m_headerLength = pos(); return result; }
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