c++ - Qt - multimedia button events not being forwarded to the OS -

i've created default qt application in visual studio 2013 qt add-in. there's no event filter. multimedia button events not being forwarded windows. i've tried override qmainwindow::event , see output:

bool mainwindow::event(qevent *event) {     cout << event->type() << endl;      return qmainwindow::event(event); } 

press:

51 - qevent::shortcutoverride 51 - qevent::shortcutoverride 6  - qevent::keypress 

release:

7  - qevent::keyrelease 

they registered qt application. what's blocking them?

i have notebook multimedia buttons separated function keys , work except volume , volume down buttons. notification (from driver) pops on key-down, volume doesn't change i'm holding button down.