Inside Macintosh: QuickTime /

Chapter 2 - Movie Toolbox / Movie Toolbox Reference

Functions That Modify Movie Properties / Working With Movie User Data

GetUserDataItem

The GetUserDataItem function returns a specified user data item. GetUserDataItem is a pointer-based version of the GetUserData function, which is described on page 2-219.

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

theUserData

Specifies the user data list for this operation. You obtain this list 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 that is to receive the data from the specified item.

size

Specifies the size of the item.

udType

Specifies the item's type value.

index

Specifies the item's index value. This parameter must specify an item in the user data list identified by the parameter theUserData.

DESCRIPTION

If the size field provided doesn't match the exact size of the actual user data item, an error is returned. In this case, you should use GetUserData instead. GetUserDataItem is useful for retrieving small, fixed-size pieces of user data without having to create a handle. You can pass 0 or 1 for the index parameter to indicate the first item.

ERROR CODES

userDataItemNotFound

-2026

Cannot locate this user data item

Memory Manager errors