ZoneMinder Forums

I have a positively identified bttv card 77. 30fps, 4 channels.

It works fine both using a module and in-kernel with boot options (to set card=77 etc0.

So single monitor setup, it works okay.

If I setup a second monitor (exact settings). Still only one camera plugged in, the first image quality drops and flickers a bit. The second image with no camera plugged in is blank, but flickers ever so often with part of the first camera image on. This happens with blank channels 2 and 3.
Just done this now with cameras attached to 2 active channels, and they flicker a bit, some interlacing issues, then its fine and the image is a little jumpy though, it just does things like this randomly.


I've tried various resolutions, 640x480, 768x576, 320x240. 320 Has no interlacing issue, but the images are still jumpy.


Any suggestions? Both cameras are PAL. I've been told before I think that settings for all channels need to be the same? (which is what I have been doing).


Cameras are sharing 30fps, so I thought maybe this is an issue for the flickering. So I manually set them to a lower fps (10 and 3 each), and both channels (0 and 1) show the image of channel 1... :/

On searching more I found to turn off the V4L_MULTI_BUFFER option can help for certain circumstances.

For me it works, flicker free @ 320 and 640.

Though it causes each camera to run at a low 4.27fps each (both resolutions). Before they would reach just over 10fps each.

Machine spec isn't so bad. 3.0Ghz CPU, 2gb Ram

Does turning it off really make the performance that bad?



Problem is now is the only palette that works is Grey? I've tried them all. (v4l2). Which are considered the most common? RGB24 right?

These are the options I am using (in grub.conf as I am using in-kernel compiled)
kernel /boot/kernel-2.6.30-gentoo-r4 root=/dev/sda3 bttv.card=77 bttv.tuner=-1

Lots of other people use loads more, but this worked so I kept it like it (for now) as the more basic I feel the better.
Although reading I have added and tested this bttv.gbuffers=32 - no difference.