obs-studio: add support for srt protocol

[BenediktSeidl]

Motivation for this change

https://obsproject.com/wiki/ advertises support of SRT Protocol, and the nixos package, but the nix package does not include support for the SRT Protocol.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review wip"
• Tested execution of obs in ./result/bin/
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.

[r-rmcgibbo]

Result of nixpkgs-review pr 116173 at 0cef0e9 run on x86_64-linux 1

1 package failed to build (new failures):

• obs-ndi

5 packages built successfully:

• obs-gstreamer
• obs-move-transition
• obs-studio
• obs-v4l2sink
• obs-wlrobs

[SuperSandro2000]

Did we already check if inherit srt works here?

[BenediktSeidl]

I tried it and it did not work. As I have absolutely no idea how to debug the error message i switched back to the override version.

diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 906e90a8249..6f9433dace7 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -24395,7 +24395,9 @@ in
 
   oberon-risc-emu = callPackage ../misc/emulators/oberon-risc-emu { };
 
-  obs-studio = libsForQt5.callPackage ../applications/video/obs-studio { };
+  obs-studio = libsForQt5.callPackage ../applications/video/obs-studio {
+    ffmpeg = ffmpeg-full { inherit srt; };
+  };
 
   obs-wlrobs = callPackage ../applications/video/obs-studio/wlrobs.nix { };

[nix-shell:~/Code/nixpkgs]$ nix-build -A obs-studio --show-trace
error: while evaluating the attribute 'buildInputs' of the derivation 'obs-studio-26.1.2' at /home/obs/Code/nixpkgs/pkgs/stdenv/generic/make-derivation.nix:192:11:
while evaluating 'getOutput' at /home/obs/Code/nixpkgs/lib/attrsets.nix:482:23, called from undefined position:
while evaluating anonymous function at /home/obs/Code/nixpkgs/pkgs/stdenv/generic/make-derivation.nix:143:17, called from undefined position:
attempt to call something which is not a function but a set, at /home/obs/Code/nixpkgs/pkgs/top-level/all-packages.nix:24399:14

[MatthewCroughan]

@SuperSandro2000 I was going to submit a patch that changes the build inputs of obs-studio from ffmpeg to ffmpeg-full. Would this be better? That works fine.

However, obs-studio isn't the only package effected by this. So is mpv, which also allows you to listen and call srt streams.

mpv srt://0.0.0.0:9000?mode=listener

You can then use obs-studio to stream to this by putting the following in as a stream url:

srt://127.0.0.1:9000?mode=caller.

Maybe we should just be compiling srt into ffmpeg by default? There are going to be applications that need this functionality going forward.

[MatthewCroughan]

Essentially, this patch should be added to ffmpeg as well as ffmpeg-full 47801af

[SuperSandro2000]

@ofborg eval

[SuperSandro2000]

I was going to submit a patch that changes the build inputs of obs-studio from ffmpeg to ffmpeg-full. Would this be better? That works fine.

That would cleanup the package a bit and we could also do this here.

Maybe we should just be compiling srt into ffmpeg by default? There are going to be applications that need this functionality going forward.

I am not sure if this is needed in the default ffmpeg and if that feature is widely used. ffmpeg is probably pretty big already and we should only include it if it is a common feature expected to work.

[stale]

I marked this as stale due to inactivity. → More info

[fpletz]

SRT support in ffmpeg is now enabled by default: #120577