C++ (Qt)
void Widget::callConnected(){
 
 
  callA=qobject_cast<QXmppCall*>(sender());
  ui->plainTextEdit->appendPlainText("Call connected!");
 
 
/// output
 audioOutput = new QAudioOutput(QAudioDeviceInfo::defaultOutputDevice().preferredFormat(), this);
  connect(audioOutput,SIGNAL(stateChanged(QAudio::State)),this,SLOT(stateChanged(QAudio::State)));
 audioOutput->start(callA);
 
/// input
QAudioInput *input=new QAudioInput(QAudioDeviceInfo::defaultInputDevice().preferredFormat(),this);
  input->start(callA);
}//callConnected