border="-show_region 1"
encopts="-r 30 -vcodec libx264 -pix_fmt yuv420p -s $res -movflags +faststart"
rect_encopts="-r 30 -c:v libx264 -preset slow -crf 18 -codec:a libmp3lame"
ext="mp4"
ffaudio="-f pulse -ac 2 -i default"