Extract A Single Image From A Video Using FFMPEG

Dead handy, this:

ffmpeg -ss 0.5 -i inputfile.mp4 -t 1 -s 480x300 -f image2 imagefile.jpg

The various options:

  • -t 1: limit to 1 frame extracted
  • -ss 0.5: point of movie to extract from (ie seek to 0.5 seconds)
  • -s 480x300: frame size of image to output (image resized to fit dimensions)
  • -f image2: forces format

I use this to generate preview stills for jwplayer to use. Dead handy!

Edit: Thanks to reader DieBagger who pointed out it is much faster to place the seek argument before the input file.

13 Replies to “Extract A Single Image From A Video Using FFMPEG”

  1. time ffmpeg -i wrong-way-fixed.mp4 -ss 125 \
     -t 1 -s 480x300 -f image2 /dev/null
    
    real    0m1.151s
    user    0m1.110s
    sys     0m0.030s
    
    
    time ffmpeg -ss 125 -i wrong-way-fixed.mp4 -t 1 \
    -s 480x300 -f image2 /dev/null
    
    real    0m0.050s
    user    0m0.040s
    sys     0m0.010s

    Well, there’s a quite clear difference there! It would be good to know exactly why it works this way though.

  2. Putting the -ss before the -i is faster (and less precise) because ffmpeg does not decode the video to find the frame. I think this has something to do with keyframes. Because of this I have found it to be problematic with some videos that will produce a gray frame, whereas putting the -ss after the -i will work fine (though of course much slower).

  3. i extracted the frames but they were not of good quality, pixels are getting scattered.
    So if any one have any idea for the good solution plz suggest me and my querry is->

    ffmpeg -i input.mp4 -r 25 -s 1280*720 -f image2 frame_%d.jpg

  4. You can use -ss both before and after the -i. The -ss before will skip to the nearest keyframe before the specified time. What you can do (and possibly use a simple wrapper script to generate this) is

    T=3456 # total seconds to skip
    ffmpeg -ss $((T-20)) -i file.mp4 -ss 20 … out.mp4

    Quite possibly adding -ss 0 after the -i file.mp4 also improves things. Certainly if I extract a 10 second segment using

    ffmpeg -ss 1234 -i file.mp4 -t 10 … out.mp4

    the output file (sometimes) isn’t quite right (for example the length isn’t exactly 10 seconds).

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