Ok, first off, some history, I'm a embedded system builder and have been using ATI Radeon HD 4600 Series video cards since about 2008 because it allows us to use VGA, DVI, and S-Video for Composite and Component outputs out of the video card. This card allowed us a budget way to adapt to many different inputs that these systems may have to hook up to because of the environments they go into. These places are restaurants, bars, nightclubs, hotels, wine bars.. basically anything commercial really and they usually only have analog inputs because they run wires for 100s of feet and digital just doesn't go that far without re-wiring with Cat5 and having extenders sending the signal out, not many do that and aren't willing to upgrade to do that especially since component sends out HD just fine which will suffice for them.
So now on to my issue. ATI has seemed to discontinue these cards and I can't source them anywhere, my last purchase I ordered 50 4670 cards from Best Buy but those are going quickly as well because they are on sale and just trying to get rid of stock.
What is the future for analog output (S-Video specifically) for the ATI video cards? Are they going away completely? Does ATI have any embedded system options that they continue to make these cards for embedded system builders?
Your best bet would be to contact a product manager at AMD or nvidia. Only they can tell you where their industry is headed. As for a solution, you will need to search for a smaller manufacturer that might still produce video cards likes this (e.g., Chinese manufacturer). If you only need a VGA, then Matrox still produces several series of cards (G series) with both analog and digital output. They may even be open to the idea of building you a video card with an s-video output if you are willing to commit to enough units.