Inside Macintosh: QuickTime /

Chapter 2 - Movie Toolbox / Movie Toolbox Reference

Time Base Functions / Working With Times

SubtractTime

The SubtractTime function subtracts one time from another. You must specify the times in time structures.

pascal void SubtractTime (TimeRecord *dst, const TimeRecord *src);

dst

Contains a pointer to a time structure. This time structure contains one of the operands for the subtraction. The SubtractTime function returns the result of the subtraction into this time structure.

src

Contains a pointer to a time structure. The Movie Toolbox subtracts this value from the time or duration specified by the dst parameter.

DESCRIPTION

If these times are relative to different time scales or time bases, the SubtractTime function converts the times as appropriate to yield reasonable results. However, the time bases for both time values must rely on the same time source.

The result value is formatted based on the operands as follows:

dst	src	Result
Time value	Duration	Duration
Duration	Duration	Duration
Time value	Time value	Duration

ERROR CODES

None

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