Hi to all!.
My linux box is Ubuntu 9.04 AMD64, kernel 2.6.29.6.
Skype 2.0.0.72 and 2.1.0.47 have the same problem: I can't see my cam preview and I can't see the other cam, but the other see perfectly my cam.
With other programs like cheese and guvcview my cam works like a charm.
If I start skype from a terminal, when I try to open my cam I receive this error:

X Error, request 133, minor 18, error code 8 BadMatch (invalid parameter attributes)

thousand of times.

What can I do?

Can you let us know what video card you have, including the driver you are using under Linux if known.

And also, attach a text file with the output from the 'xvinfo' command?

Thanks,
Andrew.

Thank you Andypoo.

The video card is
02:00.0 VGA compatible controller: nVidia Corporation GeForce 8400 GS (rev a1)

The driver I use is
NVIDIA-Linux-x86_64-185.18.14

xvinfo output attached.

Are you using any compiz extensions or other graphics accelerators that run on top of X?

Andrew.

Yes I'm using compiz, but I've always used it and skype has always worked fine.
Anyway I tried to disable compiz and skype has the same behaviour with cam image.

I remembered today that I installed cvs version of v4l drivers from www.linuxtv.org. That's because I installed a tv card that needed the drivers up-to-date to work fine.
So since from last march I installed Ubuntu jaunty beta with kernel 2.6.29.1 custom (the custom kernel was requested because otherwise my mobo wasn't able to manage the fan coolers). Skype was working fine, after that I installed the cvs version of the v4l drivers. Skype kept working fine.
Last june (if I remember well) I upgraded to kernel 2.6.29.4 due to a security update and in july 2.6.29.6 (same reason). After the last update I was forced to update the v4l to the new cvs because the tv card was not working properly with the new kernel.
Unfortunately I can't say in which moment skype stopped to work with linuxtv, for sure at the beginning of july it was not working, before to upgrade the kernel to 2.6.29.6 and the new v4l driver.
Now I installed skype 2.1.0.47 and I tried as well the last cvs of v4l but no way.
At the opposite, tv card and other programs using linuxtv still work fine.

Hello, this is exactly what is happening to me also. As soon as I push the test button in the webcam test area the same message appears multiple times. In the past I struggled making it to work and what I did is compile the latest v4l driver, and something else I did which I don't remember well. After that it worked fine for some time.
Maybe after some update of kernel or other software the webcam in skype broke.
I also tried the latest cvs v4l without luck. Outside skype the webcam works just fine.
I'm also using compiz, but it used to worked fine on top of compiz before.

I used the loading of the v4l1compat.so library as mentioned in other posts with no difference.

Any idea?

same problem here.. it worked until about 3 days ago. My GK is nvidia as well.

Had a similar problem. Using the following script worked for me:

#!/bin/bash
export XLIB_SKIP_ARGB_VISUALS=1
env LD_PRELOAD=/usr/lib/libv4l/v4l1compat.so skype

Many thanks to Vincent Segui, that fixed my problem.

Thanks! In my case only "export XLIB_SKIP_ARGB_VISUALS=1" was necessary. I want to add that I don't have any unusual v4l versions installed, only the ones offered by the standard ubuntu 9.04 repos. I believe the problem started after the last qt updates (only security) but I cannot prove it since I don't have the old packages and they are offered only by ubuntu/main repo. Also this problem seems to be related to the nvidia gks since I have exactly the same packages/versions installed on an ati/amd based laptop without any issues.

That did it Vincent! thanks!

export BLABLA fixed it here, too (gentoo)

Using just the "export XLIB_SKIP_ARGB_VISUALS=1" command also solved this issue for me, but it introduced a new issue. When I go to the webcam test in Skype's options the video now shows, but it's reversed left-to-right. Any specific reason this would be happening?

I confirm the fix also. "export XLIB_SKIP_ARGB_VISUALS=1" make me be able to see, not only be seen!