Qt Reference Documentation

# GEAudioOut.cpp Example File

demos/mobile/quickhit/ga_src/GEAudioOut.cpp

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     #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;
     };