Yes it may look weird, but basically it is an improvement her, because it is finally a lookup in a small QMap: QMap<QString, VisualPlayPosition*> VisualPlayPosition::m_listVisualPlayPosition; 

And it is called from: 
void BpmControl::slotControlBeatSync(double v)
void BpmControl::slotControlBeatSync(double v)
which does not live in the engine thread. 

But there is room for improvement: 
What about introducing pOtherEngineBuffer->getVisualPlayPos() to avoid the QMap lookup?