How to change webcam brightness in Linux ?

[jmelson]

Hi, I'm running Ubuntu 18.04.4 (Linux 4.15.0-136-generic x86_64) on a Dell desktop. I just got a webcam, ID 1224:2a25, and the picture on zoom and webex calls is too bright, into saturation.

Both uvcdynctrl and v4l2-ctl can't find any controls for this device.
v4l2-ctl -D says;
 (not using libv4l2), driver uvcvideo

uvcdynctrl -c says :
no controls found

Does anyone know how to access the video settings for the camera?

Thanks,

Jon

[PKTKS]

Hi, I'm running Ubuntu 18.04.4 (Linux 4.15.0-136-generic x86_64) on a Dell desktop. I just got a webcam, ID 1224:2a25, and the picture on zoom and webex calls is too bright, into saturation.

Both uvcdynctrl and v4l2-ctl can't find any controls for this device.
v4l2-ctl -D says;
 (not using libv4l2), driver uvcvideo

uvcdynctrl -c says :
no controls found

Does anyone know how to access the video settings for the camera?

Thanks,

Jon

There are 2 very different ways of doing this on *NIX...

The more "modern" (and highly dependable on fab willing support..)
is via  the uvc  interface.. in which  guvcview (http://guvcview.sourceforge.net/)
*SHOULD*  provide you with advertised cam controls.. (*IF* the fab
care doing this at all.. or just placed their shitty applet to windoooze bummers)

The old way in which broadcast TVs were still prevalent...
and webcam DVB and RF stations are supported via V4L..
in which  all xvideo controls are exposed (including saturation..etc)
regardless the  fab willingness..  the master applet is XAWTV

https://www.kraxel.org/blog/linux/xawtv/
https://www.linuxtv.org/wiki/index.php/Xawtv


Folks devoted in TV and video setups probably still have them working..
like me... running XAWTV 4  over xvideo and V4L2..

Still working fine although phased out..  abandon-ware mostly
but still compiles absolute fine into a decent well made *NIX machine.

Probably not suited to *BUNTUS and POTTERIX_py  "moderns"

several cmd tools are built in.. like v4lctl, rootv, radio, record, webcam..

so even if the fab give a shit to user support.. the v4l interface
can still adjust all image settings...

unfortunately is phased out .. being replaced by  these "desk gizmos"
dedicated to tube based browsing..

Paul

[Nominal Animal]

Does uvcdynctrl -l list more than one device?

AFAIK, 1224:2a25 (Jieli Technology) seems to have a problematic UVC implementation.  It is quite possible that they work around it by using their own "not-exactly-UVC" driver in Windows.

[jmelson]

Does uvcdynctrl -l list more than one device?

AFAIK, 1224:2a25 (Jieli Technology) seems to have a problematic UVC implementation.  It is quite possible that they work around it by using their own "not-exactly-UVC" driver in Windows.

No, just /dev/video0

Now, in lsusb -v you get like 5 pages of stuff, so it seems like it supports several video streams.

Yes, this webcam does seem to have a bit of a problematic implementation, for sure.

Jon