To make them selectable, they are kept in separate files, and not burned in. DirectVobSub is an application that will run automatically, with many players (such as WMP), whenever the .avi file and the subtitle file have the same name, and are in the same directory. The application will start playing subtitles automatically; adjustments and/or selection of different streams can be done by selecting the application controls, which appear in the "System Tray" area of your Windows Taskbar. DirectVobSub can read several different subtitle formats, not just "vobsub" files, but other formats as well. Some players can also manage subtitle files themselves, such as BSPlayer. Gknot comes with Vobsub; and you have already used it to extract subtitle files for "burning-in" to .avi video. The SubResync application can be used to convert the subtitle images to text, and then converted to other formats if desired. Other tools can also be used to extract subtitles from .vob files, such as Subrip; please click on for a list of Doom9's several subtitle guides.