Gifsicle commands (how to remove animation frames)?

Question

Command line

please help with the gifsicle manual , I
figured out some parameters, but I don’t understand how to delete, say, every 2nd frame in the animation.
or everything after 50
tried
gifsicle -b anim.gif --delete #50- -o anim.gif
or do you need to extract all the frames>delete the necessary>collect back?
you can extract it like this, but I don’t know what to do next
gifsicle --explode anim.gif

Answer 1

PS
I still couldn't master gifsicle , but I found a more universal way through ffmpeg ,
you can both cut from video and change gif .
cut out 5 sec. fragment starting from 90sec. from Full HD video 1920*1080 38.240 fps 3 000 Kbps the animation file turned out to be very large 28.1 MB (28102149 bytes) we will add parameters to reduce the number of frames and resolution.ffmpeg -ss 90 -t 5 -i "video.mp4" "default.gif"
the file has become much smaller than 2.4 MB (2428084 bytes)
by default, without the -gifflags -transdiff parameters , the created animation will be optimized,
and if we do not need it, then add them to the command

ffmpeg -ss 90 -t 5 -i "video.mp4"  -vf fps=10,scale=720:-1  -gifflags -transdiff -y "without_optimmize.gif"

so now the file has become a little more than 3.9 MB (3924420 bytes)
in the same way you can convert one gif file to another by changing the necessary parameters,
for example: take the very first file default.gif 28.1 MB (28102149 bytes)
in my it has 192 frames ≈ (38.240 fps x 5 sec.), if I want to delete every 4,
then we count (38-38 / 4 ≈ 29 ) and substitute fps = 29 into the parameter

ffmpeg  -i "default.gif" -vf fps=29:-1 -y "default_to_29fps.gif

and through the parameters trim=start_frame=12:end_frame=431 , you can set the start / end frame by frame,

ffmpeg -ss 90 -t 5 -i "video.mp4"  -vf trim=start_frame=12:end_frame=73,fps=10,scale=720:-1 -y "frames_12-73.gif"

the rest , ffmpeg commands/examples, you can peep here and there
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