Implementations I've seen on "other" platforms transfers the data across the PCI bus directly to the video board, wonder why they chose this way ?
The two most popular PC cards, the Sigma Designs Hollywood and the Cifelli cifePEG (Cinemaster), don't transfer the video data across the PCI bus. The Hollywood uses a VGA pass-through cable, and the cifePEG uses the VGA feature connector. A few manufacturers, such as Matrox, offered MPEG-2 daughter boards as video card add-ons. In most newer PCs, MPEG-2 decompression is done in software with the video card (nVidia and ATI being the leading chipset manufacturers) providing hardware acceleration for motion compensation and a few other math intensive functions.
For authoring on the PC, you're best off using a card like the cifePEG and a nice NTSC/PAL monitor. The leading DVD authoring package, Scenarist, relies on the cifePEG and the newer Sigma Designs NetStream cards for MPEG-2 decoding.
But we're talking Amiga here. . . . It sounds like hardware MPEG-2 decompression on classic Amigas is going to be an expensive hack. :-(
Trev