Pkg config in effects

[dolanor]

I was trying to compile EffecTV on my ubuntu 20.04, but it failed because it asked to have sdl-config on my box

gcc -DDEFAULT_VIDEO_DEVICE=\""/dev/video0"\"  -O3 -fomit-frame-pointer -funroll-loops -I.. -I../v4lutils `sdl-config --cflags` -Wall -c -o dumb.o dumb.c
/bin/sh: 1: sdl-config: not found

It would work by installing libsdl1.2-dev on my box, but it felt wrong so I found that there were wrong references in the /effects/Makefile. Here is the fix.