ClockSetTimeBase(IM: QC)

Inside Macintosh: QuickTime Components /

Chapter 11 - Clock Components / Clock Components Reference

Clock Component Functions / Managing the Time

ClockSetTimeBase
The Movie Toolbox calls your component's ClockSetTimeBase function when an application creates a time base that uses your clock component. The tb parameter indicates the time base that is associated with your clock.
pascal ComponentResult ClockSetTimeBase (ComponentInstance aClock,
                                          TimeBase tb);
aClock
Specifies the clock for the operation. Applications obtain this identifier from the Component Manager's OpenComponent function.
tb
Specifies the time base that is associated with the clock.

DESCRIPTION
Your clock component may need to know its time base if the rate or time value of the time base can be changed without using Movie Toolbox functions. This could be the case if your clock supports an external clock. Under these circumstances, the Movie Toolbox cannot use the ClockRateChanged and ClockTimeChanged functions (described on page 11-14 and page 11-13, respectively) to alert your component to changes in its environment. Instead, your component can use the time base provided here to seed the GetFirstCallBack function, described on page 11-18, and then scan all its associated callback functions.