MIDM_START

Sent to a MIDI input driver to begin MIDI input.

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.

DWORD dwParam1

Unused.

DWORD dwParam2

Unused.

This message should reset the time stamp to zero. If this message is received after input has been started, the driver should just return MMSYSERR_NOERROR.