ffmpeg -hide_banner -i Helicopter.mp4 -threads 0 -vf "scale=426:240" -c:v libx264 -preset slow -profile:v main -level 4 -g 60 -keyint_min 60 -x264-params "keyint=60:min-keyint=60:no-scenecut" -b:v 300k -maxrate 300k -bufsize 600k -r:v 30 -an -y -f mp4 Helicopter_240p_300.mp4

Unrecognized option 'x264-params'.
Error splitting the argument list: Option not found