Oh, I just noticed in depends on the game. I could observe the behavior mentioned in the description above on "The Last Express" game (from gog.com). I believe the game native resolution is 640x480.
scaler not taken into account on Linux
Indeed, deadbeef is pretty nice. Thanks for the info !
Thanks for the reply Benjamin. I will try to compile the plugin manually then.
I attached the dockerfile used to build the fflament/sc68-build-ubuntu1904 image
Not able to compile sc68-vlc plugin