webcam *only* works in Skype

cfr · 2012-04-29 14:34:31

I've been trying to get skype working off and on which basically requires two things before I start: (1) internal mic; (2) webcam. I have not yet managed to get (1) working. However, (2) was working out-of-the-box. When I first tried it, I got a picture of me and I think the LED came on as well.

Now, the LED does not light up and I get a square of blackness in place of an image. This is using KDE's test facility in system settings. (I'm using this because it worked fine with this test before.)

I didn't have to do anything to get it working before but I figured that might have changed. So I started to work my way through the webcam wiki page but I've got a bit stuck.

I think that the relevant line from lsusb is:

Bus 002 Device 004: ID 064e:e285 Suyin Corp.

I couldn't find exactly this in the hardware lists for drivers but, since it worked before, I figure it must be one of the included drivers. Looking through the lists, uvcvideo seemed the most likely as that supports integrated webcams in similar laptops with ids starting 064e.

lsmod | grep video seems to confirm this:

uvcvideo               67853  0 
videobuf2_vmalloc       2276  1 uvcvideo
videobuf2_memops        2182  1 videobuf2_vmalloc
videobuf2_core         20415  1 uvcvideo
videodev               83373  1 uvcvideo
v4l2_compat_ioctl32     8348  1 videodev
media                  10469  2 videodev,uvcvideo
usbcore               146847  5 ehci_hcd,usbhid,btusb,uvcvideo
video                  11243  1 i915
i2c_core               20593  6 drm,drm_kms_helper,i2c_algo_bit,i915,i2c_i801,videodev

Moreover, the device is created at /dev/video0 and the webcam shows up fine in KDE's list of multimedia devices. That also shows me it is using /dev/video0 and uvcvideo driver. Moreover, I can't find anything in the logs.

I'm a bit stuck because the wiki at this point pretty much assumes things are working and moves onto configuration. It doesn't say what to do if everything looks OK (device created, modules automatically loaded etc.) but you just get black and no LED.

Can anybody tell me if this should work or what I should look into next? The most relevant forum post I've found is https://bbs.archlinux.org/viewtopic.php?id=132774 but unfortunately the OP in that case didn't know what had fixed the problem. Google has not turned up anything useful or, rather, nothing which I recognise as useful which definitely is not the same thing...

Note that I do not know with which kernel I last tested the webcam successfully - I just know it was working "a while ago" and isn't now.

EDIT: Forgot to mention that I am in the video group and that the permissions on /dev/video0 are:

crw-rw----+ 1 root video 81, 0 Apr 29 00:50 /dev/video0

getfacl: Removing leading '/' from absolute path names
# file: dev/video0
# owner: root
# group: video
user::rw-
user:<me>:rw-
group::rw-
mask::rw-
other::---

EDIT 2: I just realised that the output of lsmod | grep v4l in the post I linked looks rather different from mine. The output there includes lines for v4l2_common, videodev and i2c_core whereas I get only one line for a 32 bit compatibility module:

v4l2_compat_ioctl32     8348  1 videodev

I don't know if this is just because things have changed in later kernels or if this is a clue as to what might be wrong.

EDIT 3: Really confused now. It turns out the camera works in Skype complete with LED, picture etc. So I now have the camera working in Skype (which I can't use because I can't figure the mic out) but not elsewhere.

I assume this has something to do with the fact that Skype is 32bit? Is it possible to get the camera working generally in 64bit and 32bit applications (assuming that really is the problem)?

Last edited by cfr (2012-04-30 01:31:17)

Arch Linux

#1 2012-04-29 14:34:31

webcam only works in Skype

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