The VideoLAN Forums

I have a usb camera I'm trying to use with my RPi4. On my dev machine running Pop OS everything works great! Trying the exact same thing on the RPi4, I fail to get any image. I'm working python bindings, but the issue is reproducible in VLC itself. Both machines are running 3.0.8

Opening /dev/video/0 from Open Media -> Capture Device with absolutely no options I hear the camera physically "engage", I see the record indicator light come on, but nothing is displayed. The record indicator light stays on until I press stop in VLC. Besides narrowing things down to this basic case, I have tried increased the shared GPU memory 128/256/512 with no luck as well as tried the lower resolutions.

The only relevant error given is "buffer deadlock prevented"

Forgot to mention - camera works as expected in guvcview and other test programs

Appears to be Raspian specific issue. Putting Ubuntu on the Pi everything worked as expected.

Hi, what usb camera is it ? does it do the same for any USB camera ? I could take a look at this sometime.

It's a document camera - Ipezo VZ-R
https://www.ipevo.com/prods/VZ-R_HDMI_8MP_Camera
Unfortunately I don't have any other cameras to try

Ok I got this working -
It's something to do with the VLC package in the Raspian repo, though I don't know enough about this stuff to determine what/why.

raspian repo
purge vlc
install vlc - says ~200kb will be used

using https://www.deb-multimedia.org buster main non-free
purge vlc
install vlc = says ~28mb will be used and downloads a bunch of deps

Everything works as after using that repo

Ok I got this working -
It's something to do with the VLC package in the Raspian repo, though I don't know enough about this stuff to determine what/why.

raspian repo
purge vlc
install vlc - says ~200kb will be used

If the repo provides vlc as multiple packages (one per module), that's only the core.

After I updated my Raspberry PIs 4 i encounter the same problem when i try to capture the h.264 stream to HDD from my Logitech C920 Webcams (with cvlc from the command line)
It worked like a charm before and i never had any problems but with the latest update the capture from my webcams stopped working with following message:

vlc@raspberrypi:~ $ [b350a8f8] main decoder error: buffer deadlock prevented

To reproduce the error I did a clean raspian image install and a fresh vlc install from the standard repository with apt-get install vlc. When i start to capture i now get this buffer deadlock error and the cam isn't recording anything.
This NEVER happened before. An this happens on all my raspberry pi's. And i have 4 cams on 4 raspberry pi's and all stopped working suddenly. I changed nothing except an apt-get upgrade after apt-get update.

So this is to 120% a problem with the vlc packages in the raspbian repository! This is reproducable.

How can I change the repository for vlc to a working one? I need to get this working again asap.

Many thanks!

Any estimated fix on this?

I don't think the Raspian package maintainer(s) follow discussions here, so your question is unlikely to get a satisfactory answer.

Hmm, I get the same error on a fresh ubuntu server installtion with vlc for rpi 4. I guess its not the problem with the raspian repository then...must be a bug in one of the vlc packages.