## WOM_CB

Action generated when an audio device receives an event.

[Windows Only]

### Callback

    int function(Ihandle *ih, int state); [in C]
    ih:wom_cb(state: number) -> (ret: number) [in Lua]

ih: identifies the element that activated the event.
state: can be opening=1, done=0, or closing=-1.

### Notes

This callback is used to syncronize video playback with audio. It is sent when the audio device:

Message | Description
--- | ---
opening | is opened by using the waveOutOpen function.
done | is finished with a data block sent by using the waveOutWrite function.
closing | is closed by using the waveOutClose function.

You must use the HWND attribute when calling waveOutOpen in the dwCallback parameter and set fdwOpen to CALLBACK_WINDOW.

### Affects

IupDialog, IupCanvas, IupGLCanvas