I was trying to extract one every N frames from a video using ffmpeg. I tried using this command:
ffmpeg -i input.mp4 -vf "select=not(mod(n\,10))" 1_every_10/img_%03d.jpg
I wanted to verify that it is working as expected. So I extracted all frames using: ffmpeg -i input.mp4 -vf "select=not(mod(n\,1))" all/img_%03d.jpg
And then I tried to see if 2nd image from the first command matches image number 20 from the second command, and it didn't match. Confirmed both visually and using diff command like
diff all/img_020.jpg 1_every_10/img_002.jpg
Binary files all/img_020.jpg and 1_every_10/img_002.jpg differ
Anyone knows what could be going on? Thanks!