A cue point is a location in the media that issues an MM_MCICUEPOINT notification message whenever it is encountered. The message is returned to the window specified when the cue point was set. Although a cue point is specified in the current time format with setcuepoint, the MM_MCICUEPOINT message is always returned in MMTIME units. MMTIME units are used because the time format set when the cue point is set and the time format set when the cue point is reached may be different. An application specific value can also be associated with a particular cue point for return in the MM_MCICUEPOINT message. The value can be anything which has meaning to the application. Generally, up to 20 cue points can be set.
set video1 time format frames setcuepoint video1 on at 1500 return 1 setcuepoint video1 on at 4000 return 2
An MM_MCIPOSITIONCHANGE notification message is issued at periodic intervals as time elapses in the media for a particular device context. The message is returned to the window specified when the position advise was set with setpositionadvise. Only one position advise can be set for a device context. As with setcuepoint, the position specified is assumed to be in the currently selected time format while the position reported in the MM_MCIPOSITIONCHANGE notification is in MMTIME units.
For more information on cue points and position advises, see Cue Points and Position Advises.
setpositionadvise video1 on every 100
Because videodisc players are external devices and not part of the computer system, the IBM videodisc media driver can guarantee the accuracy of setcuepoint and setpositionadvise functions only within 10 frames, rather than the desired 100 milliseconds (3 frames) of the specified value.