The VirtualDub frameserver supports:
VirtualDub video filters
Audio displacement/skew correction
Audio source multiplexing
Range editing (such as selection and deletion)
Unsupported features are:
Inverse telecine (3:2 pulldown removal)
Audio conversion and interleaving
Compression—both for video and audio
Filters that introduce a lag (e.g. temporal smoother)
The above list gives you a good idea of what is possible with the VirtualDub frameserver. AviSynth is very extensive due to the high number of plug-ins available out there; with respect to VirtualDub, it isn’t so much what you can do but what you
cannot do with it, for example:
Capturing video
Audio and video multiplexing
Video or audio compressing
Range editing
The list is not exhaustive and I should point out that a frameserver is very different in nature to VirtualDub itself: It will deliver uncompressed frames to the target application. Therefore compressing is fundamentally impossible. This also renders multiplexing and...