Green static from webcam in Camorama and Skype

[dchenbecker]

This is strange. I have a Creative Webcam Live! (041e:4036) that worked fine in Hardy. Now in Intrepid when I fire up Skype and start video I get green "snow". Same thing when I try camorama, although it almost immediately get an "Unable to capture image" error and it exits. If I specify the "-R" flag to Camorama it won't exit but it still displays snow. I was able to test in Cheese and it works fine, and if I do



gst-launch v4l2src ! video/x-raw-yuv,width=320,height=240 ! ffmpegcolorspace ! ximagesink


I get a functioning window with capture. If I change the source to v4lsrc instead I get the same snow for a second and then it pukes:



gst-launch v4lsrc ! video/x-raw-yuv,width=320,height=240 ! ffmpegcolorspace ! ximagesink
Setting pipeline to PAUSED ...
Pipeline is live and does not need PREROLL ...
Setting pipeline to PLAYING ...
New clock: GstSystemClock
ERROR: from element /GstPipeline:pipeline0/GstV4lSrc:v4lsrc0: Could not synchronize on resource.
Additional debug info:
v4lsrc_calls.c(124): gst_v4lsrc_sync_frame (): /GstPipeline:pipeline0/GstV4lSrc:v4lsrc0:
system error: Invalid argument
Execution ended after 444422603 ns.
Setting pipeline to PAUSED ...
Setting pipeline to READY ...
Setting pipeline to NULL ...
FREEING pipeline ...


I'm not very familiar with the v4l/v4l2 drivers, but it appears that something changed with the v4l driver to break it for this camera.

Thanks,

Derek

[dchenbecker]

Related to this: https://bugs.launchpad.net/debian/+bug/260918

If I use the LD_PRELOAD hack then Skype and Camorama work.

[lodravah]

I have the same problem with my Creative Live! Notebook Pro - Webcam. I have been using Ubuntu for quite some time now, but I am new to this webcam issue. What is this hack, and how does the libv4l relate to this?

[dchenbecker]

Set the LD_PRELOAD to force-load the libv4l1compat library. On my AMD64 machine I do



LD_PRELOAD=/usr/lib32/libv4l/v4l1compat.so skype


On a 32-bit machine you'd do



LD_PRELOAD=/usr/lib/libv4l/v4l1compat.so skype


Note that this doesn't deal with pulseaudio; that's a whole other can of worms with Skype.

Derek

[artesian_spring]

I had the same problem, and can report that the LD_PRELOAD hack works for camorama. Simply call it as:

LD_PRELOAD=/usr/lib/libv4l/v4l1compat.so camorama

When I first tried this with Skype, it didn't work (Skype opened fine, but didn't detect my webcam), but after a few minutes it found the webcam.

So thanks for the instructions :)

For reference, I'm using Ubuntu 9.04 (Jaunty) with a Logitech Quickcam Communicate STX (046d:08d7).

[ManoloM]

Hi there,

I have a similar problem with a Microsoft LifeCam NX-6000. In my case I use Hardy but can't get it to work in either Skype or Cheese. Can I use the same hack?

I tried looking for /usr/lib/libv4l/v4l1compat.so in my system but I can't find it.

I do have:
/usr/lib/pwlib/device/videoinput/v4l_pwplugin.so
/usr/lib/pwlib/device/videoinput/v4l2_pwplugin.so
/usr/lib/pwlib/1.10.10/device/videoinput/v4l_pwplugin.so
and
/usr/lib/pwlib/1.10.10/device/videoinput/v4l2_pwplugin.so

Are any of these libraries the same as /usr/lib/libv4l/v4l1compat.so? If so, can I use the same hack?

thanks,
Manuel

[samandiriel]

I got my webcam to work using the LD_PRELOAD trick... but after I rebooted my machine recently this trick no longer works! I'm getting green static again :*(

Can anyone think of a reason? Could an update I installed have fragged it?

[monraaf]

Set the LD_PRELOAD to force-load the libv4l1compat library. On my AMD64 machine I do



LD_PRELOAD=/usr/lib32/libv4l/v4l1compat.so skype


On a 32-bit machine you'd do



LD_PRELOAD=/usr/lib/libv4l/v4l1compat.so skype



Starting firefox like that allows the Adobe flashplugin to access my webcam again, thanks!

[adonet]

This works for me.
Alas it seems not possible to add this in the quick starter in the Gnome menu. It gives a response that the file or folder doesn't excist.

[akaars]

This works for me.
Alas it seems not possible to add this in the quick starter in the Gnome menu. It gives a response that the file or folder doesn't excist.

My ugly hack for this issue was to add the the command to text file I called skype.sh. After it you have to chmod +x skype.sh and change the link in Menu item to this file.

The strange thing is that this issue still exists more than 1 year and no changes at all :(

[boxholder]

-Right click on applications.
-Select Edit Menus
-For Camorama, click Graphics
-Right click Camorama
-Click Properties
-Replace command camorama with bash -c 'LD_PRELOAD=/usr/lib/libv4l/v4l1compat.so camorama' &

-For Skype, click Internet
-Right click Skype
-Click Properties
-Replace command skype with bash -c 'LD_PRELOAD=/usr/lib/libv4l/v4l1compat.so skype' &

ubuntu lucid

[Skara Brae]

*bump*


-Right click on applications.
-Select Edit Menus
-For Camorama, click Graphics
-Right click Camorama
-Click Properties
-Replace command camorama with bash -c 'LD_PRELOAD=/usr/lib/libv4l/v4l1compat.so camorama' &

I dug up my 2003 "Creative NX Pro" webcam and tried it in "Lucid Lynx" just 5 minutes ago. In Camorama I got the "unable to capture image" error. Then I followed the above explanation.

Boxholder,
Thank you very much: after following your explanation, now (at least) Camorama works.

The colours are not quite good in Camorama (compared to Win XP).

I installed Cheese (just now), in which the colours are (much) better.

-oo-

Yet another thing that makes me like Ubuntu :P