hard to choose delay and framerate so that it is original speed

[freddii]

for this program: framerate=1/(delay*10/1000)=100/delay => delay=100/framerate

so the only useable combinations for original speed are: delay=5 and framerate=20 delay=4 and framerate=25 delay=2 and framerate=50

[leafo]

A gif is a very limited file format, especially with regard to delay between frames. if you need something accurate then I recommend encoding to mp4.