How to Import Matrox AVI Files into Vegas Pro 8

[SCDVD]

I have some HDV footage that I got from an associate that was captured as Matrox AVI using a Matrox Matrox RT.X2 card. My associate is a Premiere Pro CS3 user. He no longer has the HDV tapes or my task would be simple - just capture from tape. The Matrox AVI files are encoded usiing a proprietary codec. I bought a Matrox M.Key which ia a USB dongle that allows the files to play in Windows Media Player. My problem is that Vegas Pro 8 does not use the Matrox codec so I have audio but no video when I import the files into Vegas. I have but don't use Premiere Elements 4 on my system. The Matrox files import just fine into Elements.

How can I get these files into Vegas without losing quality or winding up with huge files? I also have Cineform Neo Scene but it doesn't convert AVI files. I have almost six hours of footage so lossless AVI is too unwieldy; so is frame serving. If I did frame serve, I would have to use Elements to do so and I don't know if it can handle it. Even if it did, I would still wind up with huge files. it's one thing to work with a ten minute video but almost six hours of HD is another problem.

[Midzuki]

If those AVI files contain MPEG-video,
I presume ffdshow is able to decode them properly

Or you could remux them into .MPG with ffmpeg ...