How to change the aspect ratio for converted files?
You can click on "Video Effect Settings" available at the main interface, then change the aspect ratio or customize the output size.
Can I convert source files to VOB files?
For the time being, DVDFab Video Converter does not support to convert source files to VOB files. We will support that in future versions.
Note: DVDFab DVD Creator converts all kinds of video files into standard DVD format, which is VOB encoded, you may give that a shot.
How to add external subtitles for the converted file?
You can add the external subtitle for converted files in "External Subtitle Settings" window. This feature is available at the Main Interface.