Stitching movie stills

I had an idea for stitching stills from a movie together to make a
panoramic image using Hugin. I separated the movie into stills using
Avidemux and then tried to get it to automoatically stitch them
together but it kept asking me for the HFOV of the first two images
and then I had to manually use the algorithm to add points (the G key)
to all 240 images.

I suspect I get this error because there is no lense or camera data as
they're just image stills, but I could be wrong. Is there any way to
automate the pressing of the G key for all of the images?

Thanks