Arch Linux User Repository

For those getting the "video decoder not found" message, you simply need to install the ffmpeg4.4 package and should be good to go.

Ok, I wanted to come back and provide an update for anyone else that encounters the same thing I did: It wasn't the GPU, I borrowed my RTX5500 from the working system and the problem persisted so that proved it wasn't driver related.

I dug deeper into all of the output of OBS when launched from the terminal and I noticed a complaint about a missing VLC module. This confused me as I never needed to install VLC for OBS Studio to work in the past but I realized that all of my other working systems had VLC present so I thought I'd give it a shot. Sure enough, after I installed VLC media player the message finally cleared up and I can see my cameras again directly. I'm not 100% sure why this fixed my problem though I assume there's some decoder that it includes that, once installed, provided other apps with the missing decoder module that in turn made the NDI streams work again.

Additionally, I'm not sure if obs-studio or obs-ndi needs to add VLC as a required dependency but now that I know how to resolve the issue I wanted to at least share my knowledge with others who might be in the same boat I was in.

To provide an update on my last reported issued, I'm even more stumped than when I posted my original message. I have another working system who can see the output from any of my 3 different NDI cameras and it works perfectly. Bound and determined to identify why this fresh, newly installed system from scratch is producing this oddball "Video decoder not found" error I decided to compare the installed packages between what's installed on the working system vs. what's installed on the fresh but not-working system.

These are the related packages from the working system:

local/libindi 2.0.4-1
local/libndi-bin 5.5.3-2
local/obs-ndi 4.11.1-1
local/sndio 1.9.0-1
local/obs-studio 29.1.3-1

Here are the packages on the brand new system:

local/libindi 2.0.4-1
local/libndi-bin 5.5.3-2
local/obs-ndi 4.11.1-1
local/sndio 1.9.0-1
local/obs-studio 29.1.3-1

As you can see I have identical package versions. I then got the idea of testing NDI's core functionality on the new system by enabling the NDI Output from the working system and setting it as a source on the new system and I can see the output of my test camera however when I go back to the view test camera on the new system I'm right back to that error message. This tells me that NDI seems to be mostly working on the new system as well but I can't find any logs that tell me there's a problem with the NDI source, including when I run OBS from the terminal and review the output.

In regards to the PC hardware the motherboards are identical, both are recent AMD chipsets. The only difference I can deduce between the working and not-working PCs is that I have an AMD video card in the working PC and an NVIDIA card in the not-working PC. Can anyone comment if the GPU drivers can produce a result such as this?

Any tips? Am I really the only one dealing with this?

More details: I've tried the following packages to look for changes:

- Replaced libndi-bin with libndi-git (broke NDI support entirely)
- Replaced libndi-git with ndi-sdk (restored NDI support but the message persists)
- Replaced ndi-sdk with ndi-advanced-sdk (same result, message persists)

I've verified that this is happening with NDI SDK 5.5.3 as well as NDI SDK 5.6.0.

Next up I'm going to see if borrowing the AMD video card helps here as I think decoding is handled by the GPU drivers.

I'm on a clean install and while everything installs fine I'm getting an error in OBS with a graphical message that says "NDI(R) Video decoder not found. Please visit ndi.tv/formats for help and information." Have we seen this already?

@TomCatT, you can git clone this package, modify the pkgver in the PKGBUILD file and run the command: updpkgsums && makepkg -cfrsi

note: you might need to install a few dependencies like pacman-contrib etc.

alternatively an aur helper should allow you to modify a PKGBUILD allowing you to update the pkgver and also skip the integrity check.

I need to test some and would like to know how can I downgrade to 4.10?

@xenhat that's an option however libndi-bin is a build provided with obs-ndi and is available on the aur, so i wanted to give users an option to source that as well.

@emileet I can confirm that installing ndi-sdk fixes the warning, and the NDItm source shows up in OBS. Should the dependencies be updated to explicitly require ndi-sdk?

@dhtseany you should install ndi-sdk as your libndi dependency. i believe libndi-bin is outdated and only supports ndi4.