Inside Macintosh: QuickTime /

Chapter 2 - Movie Toolbox / Movie Toolbox Reference

Functions for Editing Movies / Adding Samples to Media Structures

BeginMediaEdits

The BeginMediaEdits function starts a media-editing session.

pascal OSErr BeginMediaEdits (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

You use the BeginMediaEdits function to notify the Movie Toolbox that you are going to add sample data to a media. In response, the Movie Toolbox determines whether the media can be updated. For example, if the media data are stored on disk, the Movie Toolbox opens the disk file with write permissions. If the media is stored on a read-only storage medium, such as a CD-ROM disc, the Movie Toolbox does not start an editing session and returns an error.

Use the EndMediaEdits function, which is described in the next section, to end a media-editing session.

You must call BeginMediaEdits before you add samples to a media with the AddMediaSample function (described on page 2-256). Under some circumstances, you must start a media-editing session before calling the InsertTrackSegment function (described on page 2-246).

ERROR CODES

invalidMedia

-2008

This media is corrupted or invalid

File system errors