Hi;
Have a look at here (decoding subsection), there are HW mpeg decoder IC manufacturers and their part numbers; H.264/MPEG-4 AVC products and implementations - Wikipedia, the free encyclopedia
ie ST's STB7100 output MPEG video as HDMI/DVI interface.
By the way todays TV sets uses single integrated chips (including MPEG decoder, video processor, scaler, LVDS transmitter for TFT panel)
I think it is rare a chip that takes MPEG and outputs parallel RGB digital video.
Good luck