ffmpeg - Create a video from image frame with a start and a count

You do this by stating the number of frames you want with -vframes 100:

ffmpeg -start_number 1 -i test_%d.jpg -vframes 100 -vcodec mpeg4 test.avi

• You might need to specify other parameters such as pix_fmt, etc. depending on other factors, and usually one uses something like test_%05d.jpg with the numbered sequence having preceding zeroes with five digits; if you don't have it in that format you might need to use a globbing pattern.

This always works well for me:

ffmpeg -i yourfile.mp4 -r 1 -ss 15 -t 16 -f image2 snapshot.jpg
                                ^     ^ 
                                ^     ^
                              start  end
                               time   time

• yourfile.mp4: movie clip
• snapshot.jpg: new image file
• IMPORTANT: leave image2 alone, as it was the only way to get what I wanted

Time is in seconds only; If it's 2 minutes ahead of the reel, then it's 120.
One image file is always one-second worth, thus calculate your desired image by that approach.