First rename all images, starting with counter 0000, then use ffmpeg to create the video

# Rename all images in local folder to format IMG_0000.JPG, etc.
zaehler=0; 
for datei in `ls` ; do 
   neuname=$(printf "IMG_%04d.JPG\n" $zaehler); 
   echo "$neuname"; 
   mv $datei $neuname; 
   zaehler=`expr $zaehler + 1`; 
done 

# Convert images to video-stream, using framerate 4
ffmpeg -framerate 4 -i IMG_%04d.JPG -c:v libx264 \
    -profile:v high -crf 20 -pix_fmt yuv420p output.mp4

Recent years I really missed a _good_ flow chart editor for Linux, I am glad I found one yEd of https://www.yworks.com