Webcam video device not found on Slackware-Current

enorbet · 08-25-2021, 03:46 AM

Quote:

Originally Posted by mfoley

Figured out how to download webcamoid from gitHub (green "Code" button). The README.md file says, "Visit the [wiki](https://github.com/webcamoid/webcamoid/wiki) for a comprehensive compile and install instructions." Went there. Instructions were:

Again, sorry to be an idiot. Not use to gitHub builds. What am I doing wrong?

It's not you being an idiot , it's me. I did you wrong by forgetting that I had used the .run installer from my ~/Downloads/Webcamoid directory and moved the installed directory to $HOME/webcamoid where the webcamoid.sh file is located. My sincere, red-faced apology.

Attempting some measure of redemption, here's what I have:

In my ~/Downloads/Webcamoid/ directory I have the src.tar.gz which I downloaded HERE https://github.com/webcamoid/webcamoid/releases

FWIW I'm using 8.7 but I noticed 8.8 is out now so I may try that. The "Code" access is on upper left now.
EDIT: Bad news. 8.8 seems to require a newer qt-compat32 for "standalone" so I'm sticking with 8.7 for now.

Unpacking that will give you a .run installer for a standalone install, which will produce a webcamoid.sh launcher script

Again my sincere apology for forgetting my process. I think I just copied the unpacked directory file from my 14.2 install to Current and ran the .run from there. It's been over a years since I downloaded and installed in 14.2 so I'm not mean nor crazy, just apparently forgetful.

BTW the setup menu in webcamoid has a lot of options even a selection of preferred interfaces (YUYV,MJPG,RGB,BGR,YU12, and YV12), resolution, several color controls, latency, refresh rate and more... actually a lot more. Changes apply almost immediately so feel free to experiment.

Now if I can just stop flicker in Zoom..... (not related to webcamoid)

Oh yeah... also you can test your ability to webcam like this

Code:

  mplayer tv:// -tv driver=v4l2:width=800:height=600:device=/dev/video0:fps=30:outfmt=yuy2

If that doesn't work as is and you don't understand how to mod to suit go here...

--- https://www.geekyhacker.com/2013/08/...y-your-webcam/

enorbet · 08-25-2021, 04:47 AM

OK EZ-PZ Way

Go Here ---- https://webcamoid.github.io/

and choose the "Portable" download. Unpack and run the webcamoid.sh file. Done!

Aside - I must've drunk the largest ever crushged ice drink or the thickest, coldest milk shake in history earlier for surely I experienced an epic Brain Freeze - DOH!

mfoley · 08-25-2021, 03:39 PM

Code:

# ./webcamoid.sh
qt.qpa.xcb: could not connect to display 
qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, xcb.

./webcamoid.sh: line 8:  9721 Aborted                 webcamoid "$@"

I'll keep playing. I'll also try the suggestions in your previous post #16.

Note that my Slackware-Current update level is as of July 4th with kernel 5.12.14. I updated yesterday to 5.13.12, but had 3 desktop freeze-up just that day whereas I've had pretty much no problem for the past 3 months. So, this webcam stuff may have to wait until a future update runs better on my system.

chris.willing · 08-25-2021, 05:08 PM

Did you log in as ordinary user and then su'd to run ./webcamoid.sh? That often accounts for errors like "could not connect to display".

chris

enorbet · 08-25-2021, 08:17 PM

Quote:

Originally Posted by mfoley

Code:

# ./webcamoid.sh
qt.qpa.xcb: could not connect to display 
qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, xcb.

./webcamoid.sh: line 8:  9721 Aborted                 webcamoid "$@"

I'll keep playing. I'll also try the suggestions in your previous post #16.

Note that my Slackware-Current update level is as of July 4th with kernel 5.12.14. I updated yesterday to 5.13.12, but had 3 desktop freeze-up just that day whereas I've had pretty much no problem for the past 3 months. So, this webcam stuff may have to wait until a future update runs better on my system.

As much as I'm confidant the time and effort spent getting Webcamoid working is well worth it, I'm quite curious if whast your results were running that mplayer command noted here ====>> https://www.geekyhacker.com/2013/08/...y-your-webcam/

mfoley · 08-26-2021, 12:06 AM

Quote:

Originally Posted by enorbet

As much as I'm confidant the time and effort spent getting Webcamoid working is well worth it, I'm quite curious if whast your results were running that mplayer command noted here ====>> https://www.geekyhacker.com/2013/08/...y-your-webcam/

the libmp3lame.so.0 library was missing, so I installed slackpkg lame-3.100-x86_64-4 and tried again:

Code:

$ mplayer tv:// -tv driver=v4l2:width=800:height=600:device=/dev/video0:fps=30:outfmt=yuy2
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: unable to open '/dev/video0': Device or resource busy
v4l2: ioctl set mute failed: Bad file descriptor
v4l2: 0 frames successfully processed, 0 frames dropped.

Exiting... (End of file)

This "unable to open '/dev/video0'" is rather a common theme on all webcam apps I've tried, but no one seems to have a suggested solution for that yet.

Later ...

Switched my webcam to a USB 3.0 port and tried again using /dev/video2 (on the 3.0 hub):

Code:

 mplayer tv:// -tv driver=v4l2:width=800:height=600:device=/dev/video2:fps=30:outfmt=yuy2
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] 800x600 => 800x600 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: ch16: krec 0 pushes 1 bufs 11 relocs 0
nouveau: ch16: buf 00000000 00000002 00000004 00000004 00000000
nouveau: ch16: buf 00000001 00000006 00000004 00000000 00000004
nouveau: ... (lots of these)
nouveau:        0x00000002
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.

Different anyway!

kgha · 08-26-2021, 01:35 AM

Quote:

Originally Posted by mfoley

the libmp3lame.so.0 library was missing, so I installed slackpkg lame-3.100-x86_64-4 and tried again:

Makes me wonder about your setup. IIRC you have written earlier that you made a fresh -current install from a DVD upgraded July 4. If so, libmp3lame.so.0 shouldn't be missing, since the lame package has been part of slackware -current since 2017. Have you picked and chosen among the slackware packages when installing? That might be the reason behind your various issues. Also, a lot of things have happened in -current during the weeks after July 4, so an upgrade (including install-new) might be a prudent step to take.

enorbet · 08-26-2021, 02:11 AM

Maybe it's just that I want every last bit of performance in graphics but despite being quite impressed that nouveau even exists and that it does as well as it sometimes does (with some cards) at the very least I'd have to try nvidia's own driver. Even if you have some philosophical preference about proprietary software it's free and it's really solid so possibly worthwhile even if just to eliminate the possibility of any conflict or inconsistency... and you can always go back if that doesn't solve the issue.

mfoley · 08-26-2021, 10:36 AM

Quote:

Originally Posted by kgha

Makes me wonder about your setup. IIRC you have written earlier that you made a fresh -current install from a DVD upgraded July 4. If so, libmp3lame.so.0 shouldn't be missing, since the lame package has been part of slackware -current since 2017. Have you picked and chosen among the slackware packages when installing? That might be the reason behind your various issues. Also, a lot of things have happened in -current during the weeks after July 4, so an upgrade (including install-new) might be a prudent step to take.

The original DVD itself was from May, about 4 months ago and I've been doing slackpkg updates approximately monthly. I did update at the end of July, but the kernel was the same (5.12.14). I upgraded to to 5.13.12 earlier this week consequent to this and other threads I posted, but as mentioned, my desktop crashed several times a day with the new upgrade (not the first time) so I reverted back to 5.12.14. No, I do not pick among the packages when installing. It was a scratch install of -Current, not an upgrade to 14.2.

Your comment brings up a question I was going to post in a different thread, but maybe you can answer. I've also noticed that if I removepkg, 'slackpkg upgrade-all' no longer tries to upgrade it, even if it's not blacklisted. Does 'slackpkg upgrade-all' just upgrade already installed packages only? If so, then any 'new' packages added to -Current since my DVD download in May would never get installed. If that is the case, should I then do:

slackpkg update
slackpkg upgrade-all
slackpkg install-new

ALWAYS when doing an upgrade? If so, is that the correct order or should install-new come before upgrade-all?

Quote:

Originally Posted by enorbet

Maybe it's just that I want every last bit of performance in graphics but despite being quite impressed that nouveau even exists and that it does as well as it sometimes does (with some cards) at the very least I'd have to try nvidia's own driver. Even if you have some philosophical preference about proprietary software it's free and it's really solid so possibly worthwhile even if just to eliminate the possibility of any conflict or inconsistency... and you can always go back if that doesn't solve the issue.

Normally I like using the "as-shipped" version of things, which is not always possible, especially with things like video drivers. I have 4 video monitors and did use the NVIDIA drivers for several years when running 14.2. However, I also needed to run Xinerama to get all 4 monitors to show; otherwise I got only two. I believe I did try using the NVIDIA drivers when I first installed -Current back in May, but it would only show two monitors (I think). Xinerama is old and, while it did work with -Current to show all 4 monitors, there were lots of other problems related to Xinerama including the inability to move tabs in Firefox and drop-down menus in LibreOffice. See https://www.linuxquestions.org/quest...rs-4175680767/, post #13. With the nouveau driver, everthing just worked; 4 monitors, no firefox-tab-dragging problem, etc. My philosophy is if the "as-shipped" stuff works, don't mess (if it's not broke, don't fix it). Actually, the main motivation for upgrading from 14.2 to -Current was because of this Xinerama tab-dragging crashing problem.

allend · 08-26-2021, 12:10 PM

Another data point from my machine with the same device and also using the nouveau driver where the display opens and works

Code:

bash-5.1$ mplayer tv:// driver=v4l2:width=800:height:600:device=/dev/video0:fps=30:outfmtyuy2
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
Could not find matching colorspace - retrying with -vf scale...
Opening video filter: [scale]
Movie-Aspect is undefined - no prescaling applied.
[swscaler @ 0x55b13aad18c0] bicubic scaler, from yuyv422 to yuv420p using MMXEXT
[swscaler @ 0x55b13aad18c0] using unscaled yuyv422 -> yuv420p special converter
VO: [xv] 640x480 => 640x480 Planar YV12 
Selected video codec: [rawyuy2] vfm: raw (RAW YUY2)
==========================================================================
Audio: no sound
Starting playback...
v4l2: select timeout
V:   0.0   2/  2 ??% ??% ??,?% 0 0 
v4l2: select timeout
V:   0.0 510/510 ??% ??% ??,?% 0 0 
v4l2: ioctl set mute failed: Invalid argument
v4l2: 506 frames successfully processed, 4838 frames dropped.

Exiting... (Quit)

This suggests a display driver issue.

mfoley · 08-26-2021, 12:34 PM

Quote:

Originally Posted by allend

Another data point from my machine with the same device and also using the nouveau driver where the display opens and works

[deleted]

This suggests a display driver issue.

Interesting suggestion. In my posts where I was insisting all this (same camera, same computer) worked with 14.2, it is true that I was using the NVIDIA drivers and Xinerama with 14.2 and am using only nouveau on -Current.

As an experiment (later, too busy right now) I'll install the NVIDIA driver on -Current and see if any of these camera apps work that way. In the end, however, I'd much prefer Slackware ultimately support webcam hardware via its standard driver release.

Hard to imagine, though, that NO Slackware-Current users are using webcams without special video drivers. Maybe they just don't check this thread.

splungent · 08-26-2021, 02:56 PM

Hi Everyone,

Allend's code

Quote:

mplayer -tv device=/dev/video0 tv://

worked for me.

Dell XPS 18 with Slackware 15.

mfoley · 08-26-2021, 03:11 PM

Quote:

Originally Posted by splungent

Hi Everyone,

Allend's codeworked for me.

Dell XPS 18 with Slackware 15.

What video driver are you using?

splungent · 08-26-2021, 03:36 PM

Hi mfoley,

I'm not by my computer, so I will get you that information first thing tomorrow!

enorbet · 08-26-2021, 05:13 PM

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.