Inside Macintosh: QuickTime /

Chapter 2 - Movie Toolbox / Movie Toolbox Reference

Functions That Modify Movie Properties / Working With Movie Spatial Characteristics

GetTrackLayer

The GetTrackLayer function allows your application to retrieve a track's layer.

pascal short GetTrackLayer (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 GetTrackLayer function returns an integer that contains the track's layer number. Tracks are numbered from -32,768 through 32,767. You can use layers to control
how tracks are combined to create a movie. The Movie Toolbox displays layers by layer number. That is, the Movie Toolbox displays higher-numbered layers first, placing lower-numbered layers on top of them. If your movie has more than one track in the same layer, the Movie Toolbox displays those layers in order by track index value, displaying higher-numbered tracks first.

ERROR CODES

invalidTrack

-2009

This track is corrupted or invalid

SEE ALSO

You can set a track's layer number by calling the SetTrackLayer function, which is described in the previous section.