Inside Macintosh: QuickTime /

Chapter 2 - Movie Toolbox / Movie Toolbox Reference

Functions That Modify Movie Properties / Working With Media Samples

GetTrackDataSize

The GetTrackDataSize function allows your application to determine the size, in bytes, of the sample data in a segment of a track.

pascal long GetTrackDataSize (Track theTrack, TimeValue startTime, 
   
                              TimeValue duration);

theTrack

Specifies the track for this operation. You obtain this track identifier from such Movie Toolbox functions as NewMovieTrack and GetMovieTrack (described on page 2-136 and page 2-188, respectively).

startTime

Contains a time value specifying the starting point of the segment.

duration

Contains a time value that specifies the duration of the segment.

DESCRIPTION

The GetTrackDataSize function returns a long integer that contains the size, in bytes, of the track's sample data that lies in the specified segment.

This function counts each use of a sample. That is, if a track uses a given sample more than once, the size of that sample is included in the returned size value one time for each use. Consequently, the returned size is greater than or equal to the actual size of the track's sample data.

ERROR CODES

invalidTrack	-2009	This track is corrupted or invalid
invalidDuration	-2014	This duration value is invalid
invalidTime	-2015	This time value is invalid