From that error message, it looks like I am at least passing the correct
information to ffmpeg (across the command line), but ffmpeg is somehow
unable to find the relevant plugin which is installed on my machine. For
any LV2 experts out there, here are the contents of my file:
> I did not have the "lv2ls" command, so I installed it like this:
> sudo apt-get install --yes lilv-utils
> Unfortunately when I execute "lv2ls", it shows that I have no plugins
> installed (i.e. it does not return anything).
> But this is where I can see the plugin files on my system:
> root@22f908a93c0b:/data# *ll /usr/local/lib/lv2/sdenoise.lv2*
> total 160
> drwxr-xr-x 2 root root 4096 May 9 21:55 ./
> drwxr-xr-x 3 root root 4096 May 9 21:55 ../
> -rwxr-xr-x 1 root root 229 May 9 21:55 manifest.ttl*
> -rwxr-xr-x 1 root root 147216 May 9 21:55 sdenoise.so*
> -rwxr-xr-x 1 root root 1991 May 9 21:55 sdenoise.ttl*
> And you already know what's in that *manifest.ttl* file (from my prior
> I must be doing something wrong but I don't know what it is.
Your system is borked, reinstall it.
Seriously if lv2ls does not list plugins then there are not available to lv2.