Create symbolic link out of find result (find -exexdir and -ln )

Question

I want to use the find command to look for files and create symbolic links for every result, if a condition matches. The script nearly works. Just the ln -s $f $destDir; command doesnt. ln always wants to create the link in the same directory where the found files is. error" File exists"

In detail: I use find to look for special files. (this works) find $startSearchDir find -L $startSearchDir \( -iname '*.avi' -or -iname '*.mp4' \) -size -3000k .

within the results and within the special folder, I check a (movie) file for duration by using "mediainfo". (this works) -execdir sh -c 'f="{}"; D=$(LC_ALL=C.UTF-8 /opt/bin/bc <<< $(mediainfo --Inform="Video;%Duration%" "$f")/1000); If the duration equals my condition if [ $D -le 3 ] then ln -s $f $destDir; fi ' \; a symbolic link should be added at the destination Path. (the if part works, I can printf or echo the result $f) but the ln -s $f $destDir part doesnt work.

all together in one line: find -L $startSearchDir \( -iname '*.avi' -or -iname '*.mp4' \) -size -3000k -execdir sh -c 'f="{}"; D=$(LC_ALL=C.UTF-8 /opt/bin/bc <<< $(mediainfo --Inform="Video;%Duration%" "$f")/1000); if [ $D -le 3 ]; then ln -s $f $destDir; fi ' \;

and the relevant part of my script

#!/bin/bash
set -euo pipefail

startSearchDir='/share/Multimedia2/VideoLink/tmp/a/'
destDir='/share/Multimedia2/VideoLink/tmp/b/'

rm -r $destDir
mkdir $destDir
path1=" ";


#find $startSearchDir  -type f -size -3000k \( -iname '*.avi' -or -iname '*.mp4' \) | xargs -I {} ln -s {}  $destDir ;
    

find -L $startSearchDir \( -iname '*.avi' -or -iname '*.mp4' \) -size -3000k  -execdir sh  -c 'f="{}"; D=$(LC_ALL=C.UTF-8 /opt/bin/bc <<< $(mediainfo --Inform="Video;%Duration%" "$f")/1000); if [ $D -le 3 ]; then path1=$(realpath "$f"); echo $path1; $(ln -s $path1 $destDir); fi '  \;

#find -L $startSearchDir \( -iname '*.avi' -or -iname '*.mp4' \) -size -3000k  -exec ln -s '{}' $destDir ';'


find -L $startSearchDir \( -iname '*.avi' -or -iname '*.mp4' \) -size -3000k  -execdir sh  -c 'f="{}"; D=$(LC_ALL=C.UTF-8 /opt/bin/bc <<< $(mediainfo --Inform="Video;%Duration%" "$f")/1000); if [ $D -le 3 ]; then ln -s $f $destDir; fi '  \;

As you can see in the script, I have tried different approches to get "ln" to work. I have tried "realpath" to create a variable that stores the full path.

With xargs I can create symbolic links. Also with find -exec as long as I just use one command. Together with if and the mediainfo part within the subshell, I fail.

What do I have to change, to tell "ln" the correct source and destination Path?