Is SRT not working in version 25.0.8 as an input at least? It works in Windows 10, but not in Ubuntu/Lubuntu 20.04. I can play the stream with ffplay, so I know that my version of ffmpeg will play it and I have the correct URL. My ffmpeg is self compiled to add the SRT capability and installed in ~/bin and not in the normal location. It works as a command from the command line.