Audio decoder example.
Change-Id: I0f9fb755ef8bc6f66696a06996ac7a9f13de69cc Reviewed-by: Michael Goddard <michael.goddard@nokia.com>
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Lev Zelenskiy
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Qt by Nokia
Qt by Nokia
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192
examples/audiodecoder/wavefilewriter.cpp
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192
examples/audiodecoder/wavefilewriter.cpp
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/****************************************************************************
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**
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** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
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** Contact: http://www.qt-project.org/
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**
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** This file is part of the examples of the Qt Toolkit.
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**
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** $QT_BEGIN_LICENSE:BSD$
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** You may use this file under the terms of the BSD license as follows:
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**
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** "Redistribution and use in source and binary forms, with or without
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** modification, are permitted provided that the following conditions are
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** met:
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** * Redistributions of source code must retain the above copyright
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** notice, this list of conditions and the following disclaimer.
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** * Redistributions in binary form must reproduce the above copyright
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** notice, this list of conditions and the following disclaimer in
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** the documentation and/or other materials provided with the
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** distribution.
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** * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor
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** the names of its contributors may be used to endorse or promote
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** products derived from this software without specific prior written
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** permission.
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**
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** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
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**
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** $QT_END_LICENSE$
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**
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****************************************************************************/
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#include "wavefilewriter.h"
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struct Q_PACKED chunk
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{
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char id[4];
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quint32 size;
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};
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struct Q_PACKED RIFFHeader
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{
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chunk descriptor; // "RIFF"
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char type[4]; // "WAVE"
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};
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struct Q_PACKED WAVEHeader
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{
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chunk descriptor;
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quint16 audioFormat;
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quint16 numChannels;
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quint32 sampleRate;
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quint32 byteRate;
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quint16 blockAlign;
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quint16 bitsPerSample;
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};
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struct Q_PACKED DATAHeader
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{
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chunk descriptor;
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};
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struct Q_PACKED CombinedHeader
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{
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RIFFHeader riff;
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WAVEHeader wave;
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DATAHeader data;
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};
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static const int HeaderLength = sizeof(CombinedHeader);
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WaveFileWriter::WaveFileWriter(QObject *parent)
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: QObject(parent)
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, m_dataLength(0)
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{
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}
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WaveFileWriter::~WaveFileWriter()
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{
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close();
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}
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bool WaveFileWriter::open(const QString& fileName, const QAudioFormat& format)
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{
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if (file.isOpen())
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return false; // file already open
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if (format.codec() != "audio/pcm" || format.sampleType() != QAudioFormat::SignedInt)
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return false; // data format is not supported
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file.setFileName(fileName);
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if (!file.open(QIODevice::WriteOnly))
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return false; // unable to open file for writing
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if (!writeHeader(format))
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return false;
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m_format = format;
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return true;
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}
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bool WaveFileWriter::write(const QAudioBuffer& buffer)
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{
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if (buffer.format() != m_format)
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return false; // buffer format has changed
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qint64 written = file.write((const char*)buffer.constData(), buffer.byteCount());
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m_dataLength += written;
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return written == buffer.byteCount();
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}
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bool WaveFileWriter::close()
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{
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bool result = false;
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if (file.isOpen()) {
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Q_ASSERT(m_dataLength < INT_MAX);
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result = writeDataLength();
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m_dataLength = 0;
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file.close();
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}
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return result;
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}
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bool WaveFileWriter::writeHeader(const QAudioFormat& format)
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{
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// check if format is supported
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if (format.byteOrder() == QAudioFormat::BigEndian || format.sampleType() != QAudioFormat::SignedInt)
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return false;
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CombinedHeader header;
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memset(&header, 0, HeaderLength);
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#ifndef Q_LITTLE_ENDIAN
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// only implemented for LITTLE ENDIAN
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return false;
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#else
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// RIFF header
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memcpy(header.riff.descriptor.id, "RIFF", 4);
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header.riff.descriptor.size = 0; // this will be updated with correct duration:
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// m_dataLength + HeaderLength - 8
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// WAVE header
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memcpy(header.riff.type, "WAVE", 4);
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memcpy(header.wave.descriptor.id, "fmt ", 4);
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header.wave.descriptor.size = quint32(16);
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header.wave.audioFormat = quint16(1);
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header.wave.numChannels = quint16(format.channels());
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header.wave.sampleRate = quint32(format.sampleRate());
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header.wave.byteRate = quint32(format.sampleRate() * format.channels() * format.sampleSize() / 8);
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header.wave.blockAlign = quint16(format.channels() * format.sampleSize() / 8);
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header.wave.bitsPerSample = quint16(format.sampleSize());
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// DATA header
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memcpy(header.data.descriptor.id,"data", 4);
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header.data.descriptor.size = 0; // this will be updated with correct data length: m_dataLength
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return (file.write(reinterpret_cast<const char *>(&header), HeaderLength) == HeaderLength);
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#endif
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}
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bool WaveFileWriter::writeDataLength()
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{
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#ifndef Q_LITTLE_ENDIAN
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// only implemented for LITTLE ENDIAN
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return false;
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#endif
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if (file.isSequential())
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return false;
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// seek to RIFF header size, see header.riff.descriptor.size above
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if (!file.seek(4))
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return false;
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quint32 length = m_dataLength + HeaderLength - 8;
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if (file.write(reinterpret_cast<const char *>(&length), 4) != 4)
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return false;
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// seek to DATA header size, see header.data.descriptor.size above
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if (!file.seek(40))
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return false;
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return file.write(reinterpret_cast<const char *>(&m_dataLength), 4) == 4;
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}
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