-filter_complex “[1]lut=a=val*0.5[a];[0][a]overlay=main_w-overlay_w-10:main_h-overlay_h-10“ -codec:v libx264 -r 29 -pix_fmt yuv420p -profile:v baseline -level 3 -b:v 3500k -s 320×240 -codec:a aac -strict experimental -ac 2 -b:a 64k

A few videos were being stucked on queue list… and I wasn’t finding the problem.
Looks like ffmpeg acts a little weird with “.

I’v replaced the ” with ‘ and the problem was fixed.