I've got some AVI videos (compressed with Huffyuv) made with Flash at 50fps, but I want to convert this into 50Hz interlaced MPEG2 video for a SVCD (well, a CVD really). I've tried just encoding the 50fps video straight into MPEG2 but with TMPGEnc it just wouldn't let me do it, and with bbMPEG (my TMPGEnc 30-day MPEG2 trial's run out now!), but it just encoded it at half speed. The only thing I seem to be able to do with VirtualDub is just convert it to progressive 25fps, i.e. removing every other frame.

Is there any way I can make this into interlaced MPEG2? There must be some way, surely. Do I have to convert it into interlaced AVI first, or what, and how do I go about that anyway?