Xvid Video Compression

If you use virtualdub to compress a video with the Xvid encoder you might come accross this error.

Cannot start video compression:

An unknown error occured (may be corrupt data).
(error code - 100)

The problem is that the input video dimentions must be even. My input video was 638x397, so re-recording the video again at 638x388 fixed the error and the video encoded OK.