This message is sent to a waveform output device to break a playback loop.
DWORD dwParam1
Unused.
DWORD dwParam2
Unused.
The return value is an error code, or zero (MMSYSERR_NOERROR) if the operation is successful. Possible error codes are:
MMSYSERR_NOTENABLED
The driver failed to load or initialize.
The driver should play to the end of the current iteration of the loop before breaking.
Waveform looping is controlled by the dwLoops and dwFlags fields in the WAVEHDR structures passed to the driver with the WODM_WRITE message. The WHDR_BEGINLOOP and WHDR_ENDLOOP flags in the dwFlags field specify the beginning and ending data blocks for looping. The dwLoops field in the WAVEHDR structure for the first block in the loop specifies the number of loops.
Calling this function when nothing is playing or looping should have no effect and the driver should return MMSYSERR_NOERROR.