In the early days of high-end video, up-conversion or video processing was done via a black box external component. Ultra-high-end digital video players like Meridian-Faroudja, DVDO and Runco today still use external video processing to get the best image money can, but it's far more common to see video processing inside components like as Blu-ray players, cable boxes, AV receivers, AV preamps, flat-screen plasma and LCDs, or right inside a video projector.
The advances made in chip-based video processing in the last five years have been amazing and much of the internal video processing has improved dramatically, meaning legacy DVD-Video discs played back through a new Blu-ray player are likely to look significantly better than if played back through an older DVD-Video player, thanks to internal video processing.
Many receivers also feature internal video processors. Check out our AV Receiver Review section for more information.