Webcam video device not found on Slackware-Current
SlackwareThis Forum is for the discussion of Slackware Linux.
Notices
Welcome to LinuxQuestions.org, a friendly and active Linux Community.
You are currently viewing LQ as a guest. By joining our community you will have the ability to post topics, receive our newsletter, use the advanced search, subscribe to threads and access many other special features. Registration is quick, simple and absolutely free. Join our community today!
Note that registered members see fewer ads, and ContentLink is completely disabled once you log in.
If you have any problems with the registration process or your account login, please contact us. If you need to reset your password, click here.
Having a problem logging in? Please visit this page to clear all LQ-related cookies.
Get a virtual cloud desktop with the Linux distro that you want in less than five minutes with Shells! With over 10 pre-installed distros to choose from, the worry-free installation life is here! Whether you are a digital nomad or just looking for flexibility, Shells can put your Linux machine on the device that you want to use.
Exclusive for LQ members, get up to 45% off per month. Click here for more info.
@mfoley
Regarding upgrades,install-new should be first, before upgrade-all. And used on the changelog base.
I would suggest to 'install slackware' if you tinkered with packages before. Best would work with synced slackware repo with --install-new to be sure.
Remember also that series mean quite nothing while trying to manage minimal install (for instance I have to install a lot in x on a headless install never running any gui).
I have a Wacom 13 display that is my common 3rd monitor which allows me to annotate my lectures on the screen.
One monitor displays the output from OpenBoard running on the Wacom and I capture that.
It is either captured with OBS studio and recorded or sent to something like Zoom, etc.
Sometimes I am forced to stream to more complex software like Go To Webinar for which I will bring a 4th monitor to watch out for wtf that GoToWebinar is doing and keep it at bay.
I have a NikonZ6 which does work natively with Linux gphoto2 but the best results for me are obtained by using an HDMI capture device like an Elgato CamLink HDMI to USB. Linux recognizes the CamLink as a v4L2 device and it shows up in OBSstudio, Skype, Zoom, etc. I set the NikonZ6 on video mode for the best results. It is best to keep the tweaking of the camera simple (for me). I like running all of this in Slackware --current and the NVIDIA .run installer works just fine for me. Some of my customers in China use the Tencent streaming software which is actually a fork/knockoff of Zoom. At that point I am obligated to switch to Windows11 and use the Sparkocam Nikon driver for the camera since Tencent is not Linux-friendly. I still am using the Nvidia drivers. I could not do all of this with a conventional laptop so I have a luggable box that is dust-proofed, filtered, and water-cooled. I have a box with wheels for taking it on the train or airplane as carry-on luggage all over Asia. The CamLink device is very cool as it will accept any HDMI output (camera, video, computer video-out, etc) and is very responsive. The Elgato software that comes with it is utter garbage and a nuisance. V4L2 and OBS studio work beautifully with the device fortunately and if you have the Sparkocam in Windoze you can use HDMI or usb camera output. This comment may be a bit far afield from the OP's question but it is one example of how video is done with --current and it might be helpful to someone. I always go with the complete install and update of -current. I do have one app that is broken (SPSS22) with the latest update of -current but everything else is peachy.
Regarding the use of multiple monitors with the nvidia driver, it is my understanding there are at least 2 ways to make that work. One can make "n" entries for screens in xorg.conf or read the manual in the proprietary driver by doing "NVIDIA-foo.run --extract-only" which will create the directory and all the docs. Those docs from nvidia are written well and extremely useful for deep customizing work of all kinds. I can't tell you how multi-monitors is accomplished since I haven't run multiples since I last had two CRTs, but I do use "coolbits" as outlined in the docs for control of thermals and performance.
As I mentioned, I used the NVIDIA drivers when running 14.2. NVIDIA has a great tool: nvidia-settings, which gives a graphical representation of the monitors and lets you drag them to where you want to correspond to your physical setup. It then generates the appropriate xorg.conf. The only problem was that I ended up with one BIG monitor, not 4 separate discrete monitors. That problem was solved using NVIDIA's Xinerama app. However, that app apparently hasn't been updated in a long while and newer versions of some programs (Firefox, LibreOffice) have problems when Xinerama is used. I have several threads with details about this, here's one https://www.linuxquestions.org/quest...rs-4175609420/
I was relieved with I didn't need anything special with -Current and the "standard" nouveau driver. I still have no problems in day-to-day usage, but given the feedback in this thread I'd like to try the NVIDIA driver and see if that makes a difference with webcam software.
To that end I did try installing the NVIDIA driver with my Slackware-Current (kernel 5.12.14), but it was missing several kernel modules and could not build. I will back everything up, upgrade Slackware, with install-new, and try again. If modules are still missing I'll wipe the drive and reinstall Slackware-Current from scratch.
Regnad Kcin: your post gives me hope that the NVIDIA drivers will work for me.
Aeterna: thanks for all those v4l2-ctl commands. I will try them before and after I install the NVIDIA driver.
splungent: Thanks for the feedback on your video driver. NOT nouveau.
root@you:/home/yourdirectory/Downloads# sh NVIDIA-Linux-x86_64-470.57.02.run
On the first time running it, you will get an option to disable the Nouveau driver. Accept the changes and you may need to reboot or restart something,
and run the program again with the Nouveau driver now blacklisted.
Just go through the prompts and the .run installer should go with no deps if you have -current. You will need to re-install the NVIDIA driver after each kernel update, otherwise x will not start. The NVIDIA-settings tool allow the arrangement of the displays.
There is a similar tool in Plasma5 Settings, and XFCE has its own tool which works well.
Last edited by Regnad Kcin; 08-28-2021 at 11:54 AM.
There is something screwy with the OP Slackware-Current installation. Any USB UVC webcam that worked on Slackware-14.2 will work in Slackware-current.
BTW, telling the OP to try another webcam program when wxcam or guvcview doesn't work (/dev/videoX not found) is silliness bordering on stupidity - as is the aside on GPU drivers.
on a FULL INSTALL OF SLACKWARE-CURRENT (always install FULL when troubleshooting), with lsusb detecting OP's webcam(a Logitech), you do not need any 3rd party software to test the webcam. Everything needed is included OOTB. I've used Logitech webcams for years, even an antique Logitech 640x480 webcam, until I upgraded this year to a Creative Live! Cam Sync 1080p. For v4l2, the UVC driver (included in ever kernel since 2.x something), will almost always use /dev/videoX, with X = 0,1,2,.. depending on the number of devices.
Use the Qt V4L2 Test Utility in the "Multimedia" menu (in Xfce, similar in KDE, see attached). The File - Open Device lets you hunt for working device names. You may also need to play with capture formats, frame rate, etc. Review your webcam documentation. Formats MJPG, YUV422, etc are NOT always autodetected.
To test, use just
Code:
mplayer tv:// -tv driver=v4l2
This lets the mplayer/uvcvideo negotiate default parameters. If you add size, format etc you will kick errors making you think the cam is not working.
Kamoso is a POS webcam app that requires you to install 'gst-plugins-bad' before you can use it. Terrible program (you have to use v4l2-ctl commands to set size, frame rate etc prior to running). No idea why Pat included it.
Heck on a proper Slackware installation you can also just do:
Code:
$ mplayer tv://
MPlayer 20210418-10.3.0 (C) 2000-2021 MPlayer Team
Playing tv://.
TV file format detected.
Selected driver: v4l2
name: Video 4 Linux 2 input
author: Martin Olschewski <olschewski@zpr.uni-koeln.de>
comment: first try, more to come ;-)
v4l2: your device driver does not support VIDIOC_G_STD ioctl, VIDIOC_G_PARM was used instead.
Selected device: Live! Cam Sync 1080p: Live! Cam
Capabilities: video capture streaming
supported norms:
inputs: 0 = Camera 1;
Current input: 0
Current format: MJPEG
tv.c: norm_from_string(pal): Bogus norm parameter, setting default.
v4l2: ioctl enum norm failed: Inappropriate ioctl for device
Error: Cannot set norm!
Selected input hasn't got a tuner!
v4l2: ioctl set mute failed: Invalid argument
==========================================================================
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
libavcodec version 58.134.100 (external)
[mjpeg @ 0x7fb1d9d97280]Requested frame threading with a custom get_buffer2() implementation which is not marked as thread safe. This is not supported anymore, make your callback thread-safe.
Selected video codec: [ffmjpeg] vfm: ffmpeg (FFmpeg MJPEG)
==========================================================================
Audio: no sound
Starting playback...
Could not find matching colorspace - retrying with -vf scale...
Opening video filter: [scale]
Movie-Aspect is undefined - no prescaling applied.
[swscaler @ 0x7fb1da6d1120]bicubic scaler, from yuv422p to yuyv422 using MMXEXT
[swscaler @ 0x7fb1da6d1120]using unscaled yuv422p -> yuyv422 special converter
VO: [vdpau] 640x480 => 640x480 Packed YUY2
Movie-Aspect is undefined - no prescaling applied.
VO: [vdpau] 640x480 => 640x480 Packed YUY2
V: 0.0 93/ 93 ??% ??% ??,?% 0 0
If vdpau is not installed or doesn't work (it should radeon, amdgpu, nouveau, Nvidia), then try 'xv' which will work on ANYTHING post 1995.
Code:
$ mplayer tv:// -vo xv
MPlayer 20210418-10.3.0 (C) 2000-2021 MPlayer Team
Playing tv://.
TV file format detected.
Selected driver: v4l2
name: Video 4 Linux 2 input
author: Martin Olschewski <olschewski@zpr.uni-koeln.de>
comment: first try, more to come ;-)
v4l2: your device driver does not support VIDIOC_G_STD ioctl, VIDIOC_G_PARM was used instead.
Selected device: Live! Cam Sync 1080p: Live! Cam
Capabilities: video capture streaming
supported norms:
inputs: 0 = Camera 1;
Current input: 0
Current format: MJPEG
tv.c: norm_from_string(pal): Bogus norm parameter, setting default.
v4l2: ioctl enum norm failed: Inappropriate ioctl for device
Error: Cannot set norm!
Selected input hasn't got a tuner!
v4l2: ioctl set mute failed: Invalid argument
==========================================================================
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
libavcodec version 58.134.100 (external)
[mjpeg @ 0x7f2c96110280]Requested frame threading with a custom get_buffer2() implementation which is not marked as thread safe. This is not supported anymore, make your callback thread-safe.
Selected video codec: [ffmjpeg] vfm: ffmpeg (FFmpeg MJPEG)
==========================================================================
Audio: no sound
Starting playback...
Could not find matching colorspace - retrying with -vf scale...
Opening video filter: [scale]
Movie-Aspect is undefined - no prescaling applied.
[swscaler @ 0x7f2c96a4a120]bicubic scaler, from yuv422p to yuv420p using MMXEXT
VO: [xv] 640x480 => 640x480 Planar YV12
Movie-Aspect is undefined - no prescaling applied.
VO: [xv] 640x480 => 640x480 Planar YV12
V: 0.0 57/ 57 ??% ??% ??,?% 0 0
if you can't get it to work, STOP and THINK. Slackware doesn't needed anything special for decades to be able to use webcams. Unless you are using firewire - that is a whole 'nuther can o' worms.
...is silliness bordering on stupidity - as is the aside on GPU drivers.
As you are a former maintainer at SBo, please explain why the difference in the output from the same mplayer commmand from the same device through the nouveau driver in post #21 and post #25 is not relevant.
This updated my kernel from 5.12.14 to 5.13.13. I then tried installing the NVIDIA driver 460.39, which was from last February. Unfortunately I got the same results as with 5.12.14:
Code:
-> The command `cd ./kernel; /usr/bin/make -k -j8 NV_KERNEL_MODULES="nvidia-modeset" NV_EXCLUDE_KERNEL_MODULES="nvidia-uvm " SYSSRC="/lib/modules/5.13.13/source" SYSOUT="/lib/modules/5.13.13/build"` failed with the following output:
make[1]: Entering directory '/usr/src/linux-5.13.13'
MODPOST /tmp/selfgz8320/NVIDIA-Linux-x86_64-460.39/kernel/Module.symvers
ERROR: modpost: "nvidia_unregister_module" [/tmp/selfgz8320/NVIDIA-Linux-x86_64-460.39/kernel/nvidia-modeset.ko] undefined!
make[2]: Target '__modpost' not remade because of errors.
On the first try, I had to use the switch --no-unified-memory because it couldn't find the nvidia-uvm module. The 2nd time I tried it couldn't find nvidia-modeset.ko. So, I cannot build my NVIDIA driver right now. The next step I should take on this would be to see if there is a more recent driver for my GT-170 cards. However, things seem to work just fine on the standard nouveau driver, which I'd prefer because as Regnad Kcin mentioned, you have to re-install the NVIDIA driver after each upgrade.
The better news is wxcam is working! Yeah!
But, to comment on kingbeowulf's extensive and informative posting ...
Quote:
Originally Posted by kingbeowulf
There is something screwy with the OP Slackware-Current installation. Any USB UVC webcam that worked on Slackware-14.2 will work in Slackware-current.
[deleted]
on a FULL INSTALL OF SLACKWARE-CURRENT (always install FULL when troubleshooting), with lsusb detecting OP's webcam(a Logitech), you do not need any 3rd party software to test the webcam. Everything needed is included OOTB. I've used Logitech webcams for years, even an antique Logitech 640x480 webcam, until I upgraded this year to a Creative Live! Cam Sync 1080p. For v4l2, the UVC driver (included in ever kernel since 2.x something), will almost always use /dev/videoX, with X = 0,1,2,.. depending on the number of devices.
I always do a full install Slackware except for the 'Games' (although X games get installed anyway).
Quote:
Use the Qt V4L2 Test Utility in the "Multimedia" menu (in Xfce, similar in KDE, see attached). The File - Open Device lets you hunt for working device names. You may also need to play with capture formats, frame rate, etc. Review your webcam documentation. Formats MJPG, YUV422, etc are NOT always autodetected.
To test, use just
Code:
mplayer tv:// -tv driver=v4l2
This lets the mplayer/uvcvideo negotiate default parameters. If you add size, format etc you will kick errors making you think the cam is not working.
Kamoso is a POS webcam app that requires you to install 'gst-plugins-bad' before you can use it. Terrible program (you have to use v4l2-ctl commands to set size, frame rate etc prior to running). No idea why Pat included it.
Although though I was skeptical, I did find 'QT V4L2 test Utility' in the XFCE Application Finder, and it worked fine! I'm going to save this link for future "upgrades". So I can quickly test the webcam without building wxcam.
Quote:
Heck on a proper Slackware installation you can also just do:
Code:
$ mplayer tv://
MPlayer 20210418-10.3.0 (C) 2000-2021 MPlayer Team
[deleted]
if you can't get it to work, STOP and THINK. Slackware doesn't needed anything special for decades to be able to use webcams. Unless you are using firewire - that is a whole 'nuther can o' worms.
Unfortunately, this didn't work for me:
Code:
$ DISPLAY=:0 mplayer tv:// -tv driver=v4l2
MPlayer 20210418-10.3.0 (C) 2000-2021 MPlayer Team
Playing tv://.
TV file format detected.
Selected driver: v4l2
name: Video 4 Linux 2 input
author: Martin Olschewski <olschewski@zpr.uni-koeln.de>
comment: first try, more to come ;-)
v4l2: your device driver does not support VIDIOC_G_STD ioctl, VIDIOC_G_PARM was used instead.
Selected device: UVC Camera (046d:0825)
Capabilities: video capture streaming
supported norms:
inputs: 0 = Camera 1;
Current input: 0
Current format: YUYV
tv.c: norm_from_string(pal): Bogus norm parameter, setting default.
v4l2: ioctl enum norm failed: Inappropriate ioctl for device
Error: Cannot set norm!
Selected input hasn't got a tuner!
v4l2: ioctl set mute failed: Invalid argument
v4l2: ioctl query control failed: Invalid argument
==========================================================================
Opening video decoder: [raw] RAW Uncompressed Video
Movie-Aspect is undefined - no prescaling applied.
VO: [vdpau] 640x480 => 640x480 Packed YUY2
Selected video codec: [rawyuy2] vfm: raw (RAW YUY2)
==========================================================================
Audio: no sound
Starting playback...
v4l2: select timeout
nouveau: kernel rejected pushbuf: No such device
nouveau: ch8: krec 0 pushes 1 bufs 11 relocs 0
nouveau: ch8: buf 00000000 00000002 00000004 00000004 00000000
nouveau: 0x200181c2
(repeated a few million times ...)
nouveau: 0x1000f010
mplayer: ../nouveau/pushbuf.c:728: nouveau_pushbuf_data: Assertion `kref' failed.
MPlayer interrupted by signal 6 in module: filter_video
- MPlayer crashed. This shouldn't happen.
It can be a bug in the MPlayer code _or_ in your drivers _or_ in your
gcc version. If you think it's MPlayer's fault, please read
DOCS/HTML/en/bugreports.html and follow the instructions there. We can't and
won't help unless you provide this information when reporting a possible bug.
The camera window flashes up briefly (no image) then I get the above output. Not really a big deal because wxcam works, which means the camera interface is working. I have not yet tested ZOOM (which is my main use for this), but I'm more confident about that.
kingbeowulf: BTW - ffplay also worked.
I started this camera testing with kernel 5.13.12, but that probably didn't work because of not doing the install-new properly. I reverted back to 5.12.14 because my desktop started freezing several time a day and I had pretty much no problem with this through 5.12.14. This problem has resumed with 5.13.13 (3 freeze-up so far today and it's not even noon yet), but not an issue for this thread. This desktop freezing problem was why I switched to XFCE from KDE in the first place (which fixed the problem at the time). Unfortunately, the problem is manifesting itself with XFCE now. If it gets too irritating, I'll have to revert back to 5.12.14 and await future fixes.
I'll leave this thread open a bit longer in case anyone has any further comments.
There is something screwy with the OP Slackware-Current installation. Any USB UVC webcam that worked on Slackware-14.2 will work in Slackware-current.
BTW, telling the OP to try another webcam program when wxcam or guvcview doesn't work (/dev/videoX not found) is silliness bordering on stupidity - as is the aside on GPU drivers.
Obviously you're 1st sentence is spot on but that is part of what prompted the action you dismiss as stupid in the 2nd. As you later noted Kamoso "is a POS" that won't work without extra libraries not included in a Full Recommended Install... neither do wxcam or guvcview. They are SBO packages and if dependencies are missed or if a package was "migrated" from 14.2 to Current, those are fail points. My suggestion for Webcamoid was supposed to be running a simple standalone .run script and I had problems recalling the location of that standalone script so it became unnecessarily convoluted. That was a mistake... BUT I also included CLI access just as you did. The driver issue likely popped up because nouveau is by no means comprehensive and so it is worth a try to eliminate that possible flaw.
To write that off as "silliness bordering on stupidity" was simply rude and unnecessary, especially given your acknowledging something was "rotten in Denmark" due to mistaken slackpkg upgrades. Your actual solution is clear and simple, but it is not "The One True Way", kingbeowulf.
note to all:
when using mplayer and vdpau, with nouveau as GPU driver, you may experience issues with some video formats, esp. webcams. This is a known issue with nouveau. check with xv, as I said. From the prior mplayer posts, the CLI output was vdpau=not working, xv=working. vdpau was once exclusive to Nvidia binary driver, for a specific video decoder, then open sourced. See https://en.wikipedia.org/wiki/VDPAU for details. You'll to look at the usb module code to see why USB 2 and USB 3 were different (ehci_hcd vs xhci_hcd)
kamoso is POS not just for gst-plugins-bad (that I can live with), but for the horrible interface design, with no way to select from the multiple webcam streams.
When I say "silliness bordering on stupidity", I call it like I see it. Slackware already included a standalone test utility. Not only that, no one seemed to bother to actually read the mplayer CLI output. Just because you HAVE vdpau does not mean you can USE vdpau. There are several other mplayer renderers available.
We can have chat with HR later if my language and attitude offends. I'm a frequent visitor - even have a reserved chair.
@kingbeowulf - Thanks for pointing to the VDPAU versus Xv video decoder difference.
Quote:
have 4 video monitors
and
Quote:
my GT-170 cards
Suggests that should read nVidia GT 710.
That has GPU Name GKU208B and Kepler architecture, according to this.
That fits under nouveau code name NVE0 and would be expected to have VDPAU support with the nouveau driver as it falls within the VP5 video engine.
There are some tips on the use of VDPAU at the bottom of the page in my last link.
LinuxQuestions.org is looking for people interested in writing
Editorials, Articles, Reviews, and more. If you'd like to contribute
content, let us know.
