> I have a board with 8 video inputs based on 1 bt848a. I am able to get > video from the first input. > > I've hacked the bttv-cards.c and added this into bttv_tvcards list: > name: "New Card (bt848a)", > video_inputs: 8, > audio_inputs: 0, > tuner: -1, > svhs: -1, > gpiomask: 0, > muxsel: { 0, 1, 2, 3, 4, 5, 6, 7 }, > audiomux: { 0 }, > needs_tvaudio: 0, > pll: PLL_28, > tuner_type: -1, > > I want to know how can I find out the correct values, like gpiomask and > muxsel. Is there some documentation about this? > Don't know answer to your question, instead have another for you: How to control the gain? In my 4-input card I managed to turn AGC off, but after that the gain was in it's default value (me thinks) resulting in an image all washed out. I checked the Bt878 datasheet and it seems to have a pin or some pins for external gain control voltage. So you need some off-chip circuitry to be able to control gain, which most likely leads to each manufacturer making it their own way. You do need manual control if you're gonna use that 8-input card to rapidly switch channels. Jonk