Inside Macintosh: QuickTime /

Chapter 2 - Movie Toolbox / Movie Toolbox Reference

Functions for Getting and Playing Movies / Movie Posters and Movie Previews

GetTrackUsage

The GetTrackUsage function allows your application to determine whether a track is used in a movie, its preview, its poster, or a combination of these. Your application can specify how a track is used by calling the SetTrackUsage function, which is described in the previous section.

pascal long GetTrackUsage (Track theTrack);

theTrack

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

DESCRIPTION

The GetTrackUsage function returns a long integer that contains flags indicating the track's usage. The following flags are defined (unused flags are set to 0):

trackUsageInMovie

The track is used in the movie. If this flag is set to 1, the track is used in the movie.

trackUsageInPreview

The track is used in the movie preview. If this flag is set to 1, the track is used in the preview.

trackUsageInPoster

The track is used in the movie poster. If this flag is set to 1, the track is used in the poster.

ERROR CODES

invalidTrack

-2009

This track is corrupted or invalid