Single BT cards with multiple inputs (e.g. multiplexed)

[derrickj]

Hi,

After writing my basic own frame diff software, I've decided to upgrade to ZM for both my own, and my sailing club's use.

For a test system I've purchased a £25 four input card from GrandTec. As expected for the price, this has a single digitiser (Conexant Bt878 clone) with a built in 4-channel multiplexor.
http://www.grandtec.com/eguard.htm

This works well on Fedora FC2 and I can use a V4L app to switch between the 4 inputs without any problems. Having only a single digitiser or course means only one monitored input at once.

The question is, does ZM have a means of supporting a single digitiser card as several independant channels? Can the four muxed inputs be defined separately with ZM switching to 1, waiting for a stable image, capture & compare, switch to 2, etc?

I did find a comment elsewhere about switching times being slow and limiting frame rate on other hardware. This seems about right as the video signal takes several frames to stabilise.

I'm guessing that using the API it might be possible to add inputs (e.g. a printer port hack) to allow a hardware PIR to trigger a channel switch and capture (much in the same way as the X10 interface seems to be able to).

I've not tried ZM with it yet but for the cash the card works fine and altough the motion detection frame rate will no doubt be terrible (1fps doesn't bother me), it is a first step. The card also has a few spare pins led to a 14w DIL socket that looks intriguing- from the 4 SMD jumpers these could be inputs.

Any one tried a mux'ed card please?

thanks,

James

[lazyleopard]

At non-interlaced resolutions multiplexed cards work just fine provided all cameras on the card are run at the same settings (resolution, colour type, contrast, brightness etc...) Obviously the available frame-rate gets shared between the cameras.

At interlaced resolutions the frame rate will be adversely affected by the need to wait on average half a frame extra for the image to stabilize properly.

[bikerfreak]

I have a similar card and was wondering what insmod options did you have to set to get the cards to work? Using bttv, modprobe on RedHat hangs as it tries to detect a tuner and audio. I have to control-C out of the modprobe. When I run xawtv, all I see is a bunch of static.

If someone has experienced a similar problem, please let me know.

Thanks

[ryanb100]

Does anyone have a UK source for the Grandtec cards? or something similar that works with ZM. Has anyone had any success with the GEOVISION cards.



thanks