mdj wrote:
On May 6, 5:19 pm, "Michael J. Mahon" <mjma...@aol.com> wrote:
There are plenty of chips out there that'll decode NTSC into component forms. I doubt you'd need a lot in the way of support circuitry to drive it.No, it's a mess. There are filters and delay lines involved, so any chip you find will have lots of pins and lots of external components. Chroma separation and demodulation is either an analog process or a pretty complex DSP process, so there's no free lunch.I see. I've not really bothered looking in the gizzards of contemporary television sets - I just figured that by now the chroma processing would be a 'black-box' solution.
Once you go digital, there's a DSP in the signal path, and then NTSC demodulation is just a chunk of software. But building the A/D-DSP-RAM-D/A signal path is not a trivial project. And even then, you need an analog filter before the A/D. Volume production is a wonderful thing... -michael NadaNet file server for Apple II computers! Home page: http://members.aol.com/MJMahon/ "The wastebasket is our most important design tool--and it's seriously underused."