Hardware MPEG
From MythTV Official Wiki
Hardware MPEG video capture cards are capture/tuner cards wtih onboard MPEG 2 (or MPEG 4) video compression processors. As opposed to Analog Framebuffer Cards, they take up much less processor horsepower, since the CPU doesn't have to do the compression (the card's processor does that), and therefore more of them can be used on a single machine simultaneously.
One does still have to be concerned with the amount of allowable PCI bus traffic in a single chassis, even when using this sort of tuner card.
See Analog Hardware Encoder Cards for a list of cards for which a description exists on this wiki!
