If that helps I could try to provide a pcap-file from USB while using lightburn and ffmpeg/smile/whatever so the differences can be analyzed.
Would just need some contact information.
Not working yet, but more potential clues:
- The issue crosses many distros and apps on later Linux kernels/OS versions
- I was (somewhat) able to replicate the issue using Guvcview
sudo apt install guvcview
Opening Guvcview and selecting camera via Video Controls, the image was initially black, and I believe it was on the lowest resolution.
Then by adjusting the resolution the camera started working.
So next “hypothesis” or area to explore is understanding how Lightburn (or underlying library) chooses the stream settings – and whether it might be possible for Lightburn to add UI for selecting resolution, framerate and camera output settings.
to show the video here, upload it on youtube then post here the link
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Additional investigations on this path – does lead me to belive that what is needed is additonal UI settings in LightBurn to adjust camera settings, like in Settings / Camera Resolution area. (again, not 100% but after countless hours discovering this is a common problem for apps and cameras on Linux)
Below are some tools and updated info:
using dmesg able to see error message “cannot get freq at ep 0x84” – exact value at the end changes by camera. You can see this “live” by using:
sudo dmesg -H -L --follow
then physcially disconnect/reconnect camera on USB to see kernel hardware messages for the device. I have multiple cameras, not all display the same error message – and none of them work, so that’s not the “exact” problem – but it was searching for answers on the error message that got me down this path.
My basic summary of solutions I found all seem to follow the basic path of (a) using v4l2-ctl, uvcdynctl, and/or setting modprobe config files to try and permanently set camera options. or (b) using applications such as guvcview, cheese, vlc, etc… where the solution is to modify the camera settings – which does “resolve” the problem for each camera.
So … I’m no longer on the “security” path … and now leaning towards the need for the application to be able to select/set camera options for resolution, format, frame rate, etc.
As pointed out earlier, the same cameras work on Mac (and I’d presume Windows) – but I believe this has to do with how the underlying Linux UVC Video driver exposes the camera to the OS. Older Ubuntu/Linux platforms probably worked… but likely had less camera compatibility (just speculating) … and UVC video driver increased camera interoperability/compatibility … but requires different (more) app controls/logic.
Your initial use of ffmpeg and the video add (in my opinion) credence to what I just posted regarding selection of the resolution etc… in this case, you’re doing it through ffmpeg, but what would be needed for LightBurn would be the option to set these in the UI.
@JohnJohn : Is it possible to get some insight into the underlying camera connection library, code, or something so we can provide additional troubleshooting, investigation or help in debugging?
From research the forum threads, it sounds like (at least at one time) LightBurn was being written in something that is compiled cross platform – but I don’t know what it’s written in to know whether I am able to help… but certainly happy to at least do the legwork to keep pointing in the right direction.
Addendum: Found this topic, and there are others, but hoping to use this to help build the case that the UI would be helpful as it may be a factor in other OS platforms as well – and at the very least – would be useful to have better control over camera settings/options.
I may come back and update further with additional threads that all deal with “no camera image” but where the camera works in other apps on the same OS.
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I’m not on the Dev team so I’m arms-length from the code. I only have hobby-experience and maybe half a dozen undergrad software courses to draw from. My favourite programming language is Solder.
I’ve escalated internally and my camera should be arriving soon. Looking forward to helping if I can.
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I don’t know if this is related but when I could not get my camera operating in KUbuntu 18.04 many LightBurn versions ago, but found it was functional in 16.04 I found it was related to gstreamer version. So to test it I extracted 7z version of LightBurn and created this script. It gets a version of gstreamer form 16.04 from my github repo( this requires git is installed ) and if it doesn’t find the ~/LightBurnLibs directory it creates it and then runs LightBurn with the gst_plugin_system_path set to that directory of gstreamer libs.
YMMV
#!/bin/bash
#
# if LightBurn update feature does not work, try installing libssl1.0-dev
#sudo apt install libssl1.0-dev
HERE=`pwd`
lbDIR=~/.local/share/LightBurn
lbDIR=~/LightBurn
lbCMD=$lbDIR/LightBurn
lbLibsDIR=~/LightBurnLibs
gstLibs=gstreamer-1.0
if [ ! -d $lbLibsDIR/$gstLibs ] ; then
cd
git clone http://github.com/dlarue/LightBurnLibs
cd $HERE
fi
GST_PLUGIN_SYSTEM_PATH=${lbLibsDIR}/${gstLibs} $lbCMD
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Thank for the reply @JohnJohn – to clarify, was looking more for potential “inside” connections as Staff to inquire about library/code dependencies etc. – I’m looking at what @DougL replied with to see if that helps.
did you do an extended device listing to see if you can see what’s different between the two cameras other than pixel count? lsusb -v
Another option in Linux is the plugdev interface where you can setup a rule for a particular device, group of devices, etc and define actions related to device creation. /etc/udev/rules.d is where the rules reside and you can easily specify a device by its USB idProduce and idVendor numbers.
Hi everyone,
We only support Ubuntu 18.4 and 20.4 as those are both well within support ranges, and they run on newer hardware. LightBurn relies on the versions of GlibC and Gstreamer that come with these versions, if you don’t have these, you’re likely to have issues - particularly with camera. If you want to take a crack at using those versions on your particular flavor of Linux, feel free, but we will not be able to support those use cases.
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Will reproduce it the next days with 20.04, quite sure the problem existed before the update to 22.04 but just to be sure.
@Colin thanks for the reply … will go down the GlibC and Gstreamer path here – and hope to not have to try and downgrade Ubuntu. As a developer, I get the frustration of supporting lots of distros –
It would be great if there was some way the LB team could at least commit to testing the Long Term Support (LTS) releases of Ubuntu – and/or state on the website/docs which “flavors” and/or release versions are officially supported.
As @doppelgrau mentioned, from the various discussion threads, it looks like some folks have had the issue since moving from LTS 16.04 to LTS 18.04 … since the main version represents the release year, it seems like a long time to go (as a user) without updating the OS.
Anyway, hope that’s not seen as a complaint – I’m super appreciative of the Linux compatibility – and I get not wanting to support lots of distros – but if Ubuntu is going to be supported, it’d be great if there was a way to commit to supporting the LTS versions (released every 2 years). 
for a while LightBurn was saying they only supported 16.04 LTS but with only a minor tweak of the gstreamer system I’d been running on 18.04 LTS for a few years. And 18.04 is still getting updated and will into 2023. As you say, Lightburn now supports 18.04 AND 20.04 with 20.04 getting support into 2025.
Lots of the stuff I worked on also targeted 18.04 and only recently are some pointing to supporting 20.04. It can be a pain getting stuck in the middle but for a ‘working’ machine staying on a stable platform can be the way to go.
Might I recommend setting up a bootable ISO image in your grub bootloader for when you want to play with the latest Ubuntu software.
Advice taken and understood… but that wasn’t really my point – I’m completely comfortable in admin decisions for my systems, and in this case, I needed to update the platform to solve other issues – I could not find any LightBurn documentation on Linux versions supported … I’m sure it’s there. Still, despite all my searching, I never found it. There are also some folks with camera issues on Windows and Mac, so initially it did not seem like an OS-specific problem.
So my main suggestion for the LB team are:
-
Make supported versions and/or any version limitations known – like perhaps on the Linux installation instructions page – since some users may already be on a version of Ubuntu later than the 2016 LTS release – the installation page says “Ubuntu 16+” – to me the “+” reads as “or later”.
-
If “Ubuntu” is a “supported” distro – then commit to running tests once every two years (with the Ubuntu LTS releases) to see what (if any) features break, and update the installation docs to include any known issues (like, Camera features do not work after 16.04)
Again, just suggestions – it is entirely likely that someone may feel safe in moving to the latest LTS version or already be on a newer version when discovering and downloading LightBurn. It is easy now, in 2022, to say that version 22.04 may be “cutting edge” during the same release year – but I think it’s fair to say that one would not expect that 2016 was the last known (non-work around) version for camera support.
Hope that makes sense … trying to just make helpful suggestions … had I known the camera wouldn’t work in my version, I might have made different OS decisions
All the above said, it sounds like the next step is to figure out what GStreamer libraries need to be installed… thank you for providing part of the clues to this puzzle.
Hey, I was pleasantly surprised to see a LightBurn Staff member say that 18.04 and 20.04 were supported versions. That’s a big deal in my book since I’ve seen it mentioned that the Linux user base for LightBurn is small and isn’t financially much help to fun development or at least that was what it was like a couple of years ago.
Valid point and yes it should be updated to say was was said here, that 18.04 and 20.04 were supported.
As for camera support in Linux it’s quite varied since there are many different camera interfaces. Consumer stuff like USB web cams usually run though the VideoForLinux2 interface last I poked at it but there are a few types of image chips and methods of encoding. Best bet is to find out what’s unique about the camera you are trying to use and then try to figure out where the problem lies. I don’t expect much from the LightBurn devs until there can be fingers pointed at where the problem lies.
And if you’ve got 22.04 installed, I would go for booting a 20.04 ISO and testing there. Something like this in /boot/grub/grub.cfg or better is in /etc/default/grub??? is how I do it so I’m not booting from a USB and it’s pretty quick boot.
menuentry ‘Lubuntu 20.04 ISO’ {
insmod part_gpt
insmod ext2
set isofile=‘complete_path_to_iso/lubuntu-20.04-desktop-amd64.iso’
loopback loop (hd0,gpt1)$isofile
linux (loop)/casper/vmlinuz boot=casper maybe=ubiquity iso-scan/filename=$isofile noprompt noeject
initrd (loop)/casper/initrd
}
We had an internal knowledge session today regarding Linux support, and how we communicate that to you folks (our lovely users).
We will be improving our clarity in our documentation in the next little while, and are always open to suggestions (via our Fider.io Page). Linux users are a small but mighty group of LightBurners and we strive to be clear and available to everyone should questions arise.
Given the super wide area of Linux flavours, building and maintaining a broad amount of OS coverage would be ideal, but does come at a cost . It’s a fine balancing act keeping all OS’es fully compatible (especially with the hellscape that is OS camera permissions/library support) while also developing new features and tools for everyone to use.
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Just tried 20.04.5 LTS from a USB-Stick so 100% pure System, only installed Lightburn.
Same behavior. The camera for my laser is recognized but only black picture, an other camera on my PnP does work.
So the problem is not 22.04 but something else.
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At least now the devs know it’s happening on a system they have been testing on.
Have you tried the different camera settings in the Edit/Settings/Display & Units window?
There’s Camera Resolution( Default, Highest ) and there’s Camera View( B&W, Full Color ).