Inside Macintosh: QuickTime /

Chapter 2 - Movie Toolbox / Movie Toolbox Reference

Functions That Modify Movie Properties / Working With Movie User Data

GetMediaUserData

The GetMediaUserData function allows your application to obtain access to a media's user data list. You can then use the GetUserData, AddUserData, and RemoveUserData functions (described on page 2-219, page 2-219, and page 2-220, respectively) to manipulate the contents of the user data list. If the data list contains text data, you can use the GetUserDataText, AddUserDataText, and RemoveUserDataText functions (described on page 2-221, page 2-220, and page 2-222, respectively) to work with its contents.

pascal UserData GetMediaUserData (Media theMedia);

theMedia

Specifies the media for this operation. Your application obtains this media identifier from such Movie Toolbox functions as NewTrackMedia and GetTrackMedia (described on page 2-138 and page 2-190, respectively).

DESCRIPTION

The GetMediaUserData function returns a reference to the media's user data list. This reference is valid until you dispose of the media. When you save the media, the Movie Toolbox saves the user data as well. If the function could not locate the media's user data, it sets this returned value to nil.

ERROR CODES

invalidMedia

-2008

This media is corrupted or invalid

Memory Manager errors

SEE ALSO

You can use the GetMovieUserData function to gain access to a movie's user data (described on page 2-215). Similarly, you can use the GetTrackUserData function (described in the previous section) to work with a track's user data.