The WODM_BREAKLOOP message requests a waveform output driver to break an output loop that was created with a WODM_WRITE message.
The driver should return MMSYSERR_NOERROR if the operation succeeds. Otherwise it should return one of the MMSYSERR or WAVERR error codes defined in mmsystem.h. See waveOutBreakLoop return values in the Win32 SDK.
A client sends the WODM_BREAKLOOP message by calling the user-mode driver’s wodMessage entry point, passing the specified parameters.
The driver should stop output of the loop buffers at the end of the next loop iteration.
If the driver receives this message and a loop is not in progress, it should return MMSYSERR_NOERROR.