QBuffer buffer;
    buffer.open(QIODevice::ReadWrite);
    QAudioOutput* out_audio;
    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::defaultOutputDevice());
    if (!info.isFormatSupported(format)) {
        //qWarning()<<".";
        QMessageBox::critical(0,"Error","raw audio format not supported by backend, cannot play audio",QMessageBox::Ok);
        return;
        }
    out_audio = new QAudioOutput(format, this);
    QByteArray byteArray;
    for(int i = 0;i<30000;i++)
        byteArray[i] = (char)100*sin((float)6.28*i*1000.0/48000.0);
    buffer.write(byteArray);
    buffer.close();
    out_audio->start(&buffer);