Inside Macintosh: QuickTime /

Chapter 2 - Movie Toolbox / Movie Toolbox Reference

Functions That Modify Movie Properties / Working With Movie User Data

SetUserDataItem

The SetUserDataItem allows your application to set an item in a user data list. You specify the user data list, the data to be set, the size of the data to be set, and the data's type value.

pascal OSErr SetUserDataItem (UserData theUserData, 
                              void *data, long size, long udType,
                              long index);

theUserData

Specifies the user data list for this operation. You obtain this item reference by calling the GetMovieUserData, GetTrackUserData, or GetMediaUserData function (described on page 2-215, page 2-216, and page 2-217, respectively).

data

Contains a pointer to the data item to be set in a user data list.

size

Specifies the size of the information pointed to by the data parameter.

udType

Specifies the type value assigned to the new item.

index

Specifies the item's index value. This parameter must specify an item in the user data list identified by the parameter theUserData. An index value of 0 or 1 implies the first item, which is created if it doesn't
already exist.

DESCRIPTION

You must provide the size of the information specified in the data parameter because the data may be embedded inside a larger data structure or may be on the stack.

SPECIAL CONSIDERATIONS

The data pointer must be locked, since SetUserDataItem may move memory.

SEE ALSO

The SetUserDataItem function is a pointer-based version of AddUserData, which is described on page 2-219.

ERROR CODES

Memory Manager errors