[TriLUG] Logitech QuickCam - no video device found

[William Sutton]

I have a puzzling problem which is causing me some grief.  I bought a 
Logitech QuickCam Chat in hopes of having a working webcam.  According to 
various pages, this is doable.  Gentoo-Wiki has a howto on the subject[1].

Following the directions, I got videodev compiled into the kernel as a 
module, emerged the latest (unstable) version of spca5xx[2] (required for 
newer versions of the QuickCam[3] (such as mine[4])), and the latest 
stable version of qc-usb[5] (for the quickcam module).

I re-emerged mplayer with support for video4linux (see use flags[6]), and 
when that did not work, emerged the latest stable version of gqcam.

At this point, I *think* everything should be in order, but both gqcam and 
mplayer refuse to see the /dev/video (or, what it is symlinked to, 
/dev/video0) as a valid device.  My user is in the video group in both 
/etc/group and /etc/gshadow, and the devices have the following 
permissions:

kenobi dev # ls -l video* 
lrwxrwxrwx  1 root video      6 Jan 17 11:16 video -> video0
crw-rw----  1 root video 81,  0 Jul 26 13:12 video0
crw-rw----  1 root video 81,  1 Jul 26 13:12 video1
[snipped]

kernel is gentoo-sources 2.6.14-gentoo-r5 (SMP) for Xeon.  System is more 
or less latest gentoo (maybe a week out of sync).  According to everything 
I've read/followed, this ought to work.

While tracking down the error message ("/dev/video: No such device"), I 
found a number of similar problems for Linux software ranging from cameras 
to MythTV.  One email list entry was of particular interest[7]:

"Some apps don't work as they seem to be looking for /dev/video0 or 
/dev/dvb/adapter0/video0. Some weeks ago someone on the linuxtv 
(video4linux) mailing list posted that these cards don't have a video 
adapter, the card puts its video on the bus and it's displayed by the 
video card. I had tried mythtv, xawtv4, tvtime, dvr and mplayer, but 
they didn't work. If I remember correctly, no video0 seemed to be the 
problem, xawtv gave sound but complained of no video0, tvtime couldn't 
find the channels and dvr (latest cvs version) wouldn't start because 
there is no video0."

I find that troubling.  This is a USB device--not an S-Video input.  It 
should not require a TV card to work (I don't have one[8]).

If anyone has some suggestions, I would be appreciative.  I've about run 
out of ideas for what to do, short of (1) hook it up to a Windows PC or 
(2) take it back to the store.

William

notes follow
--------------------
[1] http://gentoo-wiki.com/HOWTO_logitech_quickcam_on_2.6.x_kernel
[2] media-video/spca5xx-20060101
[3] http://mxhaard.free.fr/spca5xx.html (entry for 0x046d and 0x092c)
[4] lsusb shows my device as "Bus 002 Device 002: ID 046d:092c Logitech, 
Inc."
[5] media-video/qc-usb-0.6.3
[6] "-gnome gtk -qt -kde -arts alsa -ogg -vorbis apache2 -bonobo cdr 
matrox dts dvd dvdread v4l v4l2"
[7] http://www.linuxtv.org/pipermail/linux-dvb/2005-May/002045.html
[8] Matrox G450 AGP dual-head card, no tv tuner fanciness with later 
versions