dreamcast vcds

[Megalexxx]

I guess your video aren't coded the right way.
Gypplay should tell you which format you need to use.

I found that in readme.txt :
.mpg (MPEG-1 only)
.mpeg (MPEG-1 only)
.dat (MPEG-1 only)
.avi (no odd codecs!)
.m1v (MPEG-1 video, no audio)
.asf (no odd codecs! MPEG-4/DivX is NOT supported!)
.sfd (v1.01 SFD format works, but no audio. Newer SFDs not supported.)