From what I've googled for and read, there are two Matrox MPEG-2 I-frame codecs - one for HD and one for SD. The SD version is software-based whereas the HD version was (perhaps still is) tied to Matrox's hardware.
You may be able to find a compatible SD version from one of the links
here. AFAIK, the Fourcc code for the Matrox is MMES.
Another route is for you to confirm with Matrox (perhaps via their forums, or direct query) the type of codec (HD or SD) that the equipment you are producing for requires before you put your money down.
