unable to find mpv's pid

I posted some time ago here: https://www.svp-team.com/forum/viewtopic.php?id=4277

I'm still having this same problem, now I've written a script that makes use of the svpflow libs,
however, at least /I/ am not able to get the same level of performance using those as I am(was)
w/ svp.

I'm still get the same results w/ svp, unable to find mpv's pid, I have re-installed the system, w/
similar results this time around, svp worked for a while, and then suddenly, doesnt.

So, what I wanted to ask was: is there any way I can just manually tell svp the pid of the mpv
process running that I want svp to 'manage'????

Also, I've got all the dependencies needed (including lsof) - it did work for some time til it didnt.