Duplicate frames in animated gif

Question

Is there a way to duplicate frames in an animated gif by a given number? For example, the below gif has four frames.

I want each frame to be repeated three times, in effect sowing it down, as in the example below.

Is there a way to do this using imagemagick, gifsicle or some other open source software that runs on linux desktops in the command line?

(I'm aware that you can set a delay/duration for each frame but in this instance I need to duplicate frames instead of changing their durations)

Answer 1

Reposting (with permission) mathr's answer from Mastodon

Save the code below to script.sh

#!/bin/bash

# 1. get input frame count (note two spaces after the "\")
count=$(gifsicle --info < input.gif | grep "<stdin>" | cut -d\  -f 3)

# 2. define how many times to repeat frames
repeats=5

# 3. construct new frame list
frames=$(for i in $(seq 0 $((count - 1)))
    do 
        for j in $(seq $((repeats)))
            do echo "#$i"
        done
    done
)

# 4. use gifsicle to duplicate frames (note no quotes around $frames)

gifsicle < input.gif $frames > output.gif

On the original gif it produces the following output, where each frame has been repeated 5 times.