A week ago I was tasked with uploading about 20 different videos to a CMS. Normally for the HTML5 Video element to look nice, you should upload a poster image so that there can be something showing before the video starts to play.

In my case, I had to generate a poster for each of these 20 videos. This would have taken a long time, so I scripted it using FFmpeg!

Here is the script:

#!/usr/bin/env bash

# take in mp4, take screenshot at 5 seconds
# output same filename, but with jpg extension
for FILE in *.mp4
    # save the filename but swap the extension
    ffmpeg -y -i $FILE -f mjpeg -vframes 1 -ss 5 $NEWFILE

If your videos are not mp4 format, just change the extension.

To use this script:

  • save this script as poster.sh
  • put it in the folder with all your video files
  • own the script with chmod +x poster.sh
  • run the script with ./poster.sh

You should see a bunch of text fly in your command line, and a couple of seconds later, the conversion should be done. You will see some nice little posters right beside your videos! And, they will all be nicely named too!