Hi I would like to run a bash script to take screenshots of a video

[nammin]

#!/bin/sh
 
file=$1
times=$2
x=1
 
while [ $x -le $times ]; do
    ffmpeg -ss $(echo "$x * 60" | bc -l) -i "$file" -an -vframes 1 -f image2 -vf "yadif,scale='max(sar,1)*iw':'max(1/sar,1)*ih'" image$(echo "$x").png;
    x=$(( $x + 1 ))
done

usage syntax is like this:
scriptname movie.mkv 20
scriptname is the name of the file you paste the commands in, movie.mkv is the video file, number at the end is the number of screenshots you want