RecA::RecA(QObject *per) : QObject(per){
   outputFile.setFileName("C:/TMP/test.raw");
   outputFile.open(QIODevice::WriteOnly | QIODevice::Truncate);

   QAudioFormat format;

   format.setFrequency(8000);
   format.setChannels(1);
   format.setSampleSize(8);
   format.setCodec("audio/pcm");
   format.setByteOrder(QAudioFormat::LittleEndian);
   format.setSampleType(QAudioFormat::UnSignedInt);

   QAudioDeviceInfo info = QAudioDeviceInfo::defaultInputDevice();
   if (!info.isFormatSupported(format)) {
       qDebug()<<"default format not supported try to use nearest";
       format = info.nearestFormat(format);
   }

   audio = new QAudioInput(format, this);
   audio->start(&outputFile);
   
   QTimer::singleShot(30000, this, SLOT(stopRecording()));
}

 void RecA::stopRecording()
 {
   audio->stop();
   outputFile.close();
   delete audio;
   
}

QT += core gui multimedia

#include <QtCore>
#include <QAudioInput>

int main(int argc, char **argv){
    QApplication app(argc, argv);
    
    QAudioFormat format;
    format.setFrequency(44100);
    format.setChannels(1);
    format.setSampleSize(8);
    format.setCodec("audio/pcm");
    format.setByteOrder(QAudioFormat::LittleEndian);
    format.setSampleType(QAudioFormat::SignedInt);

    InputAudio = new QAudioInput(format, this);
    OutputAudio = new QAudioOutput(format, this);
    InputAudio->start(OutputAudio->start());
    
    return app.exec();
}