I converted a couple of sequences of JPEGs into movies; the first had 554 images, the second had 665.

I tried integer delays (i.e. values for the

**-delay**switch) from 2 to 11 and found that:

- 2, 3 and 4 all ended up with a delay of exactly 0.04 seconds between frames (equivalent, I believe, to
**-delay 4**) in both movies, based upon the number of frames and the duration ffprobe (and my movie player, though this rounds to the nearest second) reported for the movie; - 5, 6, and 7 all ended up with a delay of exactly 0.08 seconds (which is what I'd expect from
**-delay 8**) in both movies; - 8, 9 and 10 all ended up with a delay of exactly 0.12 seconds (which is what I'd expect from
**-delay 12**) in both movies; and - 11 ended up with a delay of exactly 0.16 seconds (which is what I'd expect from
**-delay 16**) in both movies.

Thanks in advance of any thoughts.