I\'m using this shell command to make thumbnail from VIDEO_FILE from 123 second and save it to THUMBNAIL_FILE.
ffmpeg -i VIDEO_FILE -r 1 -ss 123 -f image2 THUMB
it has happened to me also, changing the argument order fixes this problem. tested on a 1.4GB 90 minute mp4 video - took about 1-2 seconds. before that it took MINUTES...
try this:
ffmpeg -ss 123 -i "VIDEO_FILE" "THUMBNAIL_FILE" -r 1 -vframes 1 -an -vcodec mjpeg
A small enhancement to Kirzilla's code: If you want to create PNG files (with compression), you can use the following code:
mplayer VIDEO_FILE -ss 00:10:11 -frames 1 -vo png:z=9:outdir=THUMBNAILS_DIRECTORY
This will probably create better thumbnails but of course with a larger size than JPEG.
Ffmpeg is not really good with creating thumbnails as I investigated. People recommend to use mplayer (by ffmpeg creators).
mplayer VIDEO_FILE -ss 00:10:11 -frames 1 -vo jpeg:outdir=THUMBNAILS_DIRECTORY