Inside Macintosh: QuickTime /

Chapter 2 - Movie Toolbox / Movie Toolbox Reference

Time Base Functions / Creating and Disposing of Time Bases

GetTimeBaseMasterTimeBase

You can use the GetTimeBaseMasterTimeBase function to determine the master time base that is assigned to a time base. A time base derives its time from either a clock component or from another time base. If a time base derives its time from another time base, you can use this function to obtain the identifier for that master time base.

pascal TimeBase GetTimeBaseMasterTimeBase (TimeBase tb);

tb

Specifies the time base for this operation. Your application obtains this time base identifier from the NewTimeBase function (described on page 2-297).

DESCRIPTION

The GetTimeBaseMasterTimeBase function returns a reference to the master time base that provides a time source to this time base. If a master time base is not assigned to the time base, this function sets the returned reference to nil. In this case, the time base relies on a clock component for its time source. Use the GetTimeBaseMasterClock function, which is described on page 2-300, to obtain the component instance reference to that clock component.

ERROR CODES

None

SEE ALSO

You can use the SetTimeBaseMasterTimeBase function, which is described in the previous section, to assign a master time base to a time base.