GEAudioOut.cpp Example File

 /****************************************************************************
 **
 ** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
 ** All rights reserved.
 ** Contact: Nokia Corporation (qt-info@nokia.com)
 **
 ** This file is part of the QtDeclarative module 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 Nokia Corporation 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 <QtCore/qstring.h>
 #include <QAudioOutput>

 #include "GEAudioOut.h"

 using namespace GE;
 //using namespace QTM_NAMESPACE;

 /*
 #ifndef Q_OS_WIN32
 QTM_USE_NAMESPACE
 #endif
 */

 const int CHANNELS = 2;
 const QString CODEC = "audio/pcm";
 const QAudioFormat::Endian BYTEORDER = QAudioFormat::LittleEndian;
 const QAudioFormat::SampleType SAMTYPE = QAudioFormat::SignedInt;

 AudioOut::AudioOut( QObject *parent, GE::IAudioSource *source ) : QThread(parent) {         // qobject
     m_source = source;
     QAudioFormat format;
     format.setFrequency(AUDIO_FREQUENCY);
     format.setChannels(CHANNELS);
     format.setSampleSize(AUDIO_SAMPLE_BITS);
     format.setCodec(CODEC);
     format.setByteOrder(BYTEORDER);
     format.setSampleType(SAMTYPE);

     QAudioDeviceInfo info(QAudioDeviceInfo::defaultOutputDevice());
     if (!info.isFormatSupported(format))
         format = info.nearestFormat(format);

     m_audioOutput = new QAudioOutput(info,format);

 #ifdef Q_WS_MAEMO_5
     m_audioOutput->setBufferSize(20000);
     m_sendBufferSize = 5000;
 #else
     m_audioOutput->setBufferSize(16000);
     m_sendBufferSize = 4000;
 #endif

     m_outTarget = m_audioOutput->start();

     m_sendBuffer = new AUDIO_SAMPLE_TYPE[ m_sendBufferSize ];
     m_samplesMixed = 0;

     m_runstate=0;

 #ifndef Q_OS_SYMBIAN
     start();
 #else
     m_audioOutput->setNotifyInterval(5);
     connect(m_audioOutput,SIGNAL(notify()),SLOT(audioNotify()));
 #endif

 };

 AudioOut::~AudioOut() {
     if (m_runstate==0) m_runstate = 1;
     if (QThread::isRunning() == false) m_runstate = 2;
     while (m_runstate!=2) { msleep(50); }       // wait until the thread is finished
     m_audioOutput->stop();
     delete m_audioOutput;
     delete [] m_sendBuffer;
 };

 void AudioOut::audioNotify() {
     tick();
 };

 void AudioOut::tick() {
         // fill data to buffer as much as free space is available..
     int samplesToWrite = m_audioOutput->bytesFree() / (CHANNELS*AUDIO_SAMPLE_BITS/8);
     samplesToWrite*=2;

     if (samplesToWrite > m_sendBufferSize) samplesToWrite = m_sendBufferSize;
     if (samplesToWrite<=0) return;
     int mixedSamples = m_source->pullAudio( m_sendBuffer, samplesToWrite );
     m_outTarget->write( (char*)m_sendBuffer, mixedSamples*2 );

 };

 void AudioOut::run() {
     if (!m_source) { m_runstate=2; return; }
     int sleepTime = m_sendBufferSize * 340 / AUDIO_FREQUENCY;
     if (sleepTime<2) sleepTime = 2;

     while (m_runstate==0) {
         tick();
         msleep(sleepTime);
     };
     m_runstate = 2;
 };