How to fix this script - recursive ffmpeg encoding - bash

Question

I've downloaded some videos from my course and I think they are too big. I need to reencode them to something better and smaller.
The problem is I made the script but it saves the file in the first folder. I want the output files inside the same folder as the input files. For example:
Folder 1
- script.sh
Folder 2
- file1.mp4
- file1.new
Folder 3
- file2.mp4
- file2.new
I've tried using the for loop only, and it was working actually but I couldn't encode the files recursively. This wouldn't work. Using find solved the problem, but now the output files are all in the same directory, which is the same directory where the script is located (working directory).
IFS=$'\n'; set -f
for i in $(find . -name '*.mp4'); do
if ($width > 600) && ($width < 800); then
echo "$i is a 720p video. Let's encode it to VP9."
notify-send Shrinker "Beginning encoding filename "$i""
ffmpeg -i "$i" -vf mpdecimate,setpts=N/FRAME_RATE/TB -vf scale=1280x720 -b:v 1800k \
-minrate 900k -maxrate 2610k -tile-columns 2 -g 240 -threads 8 \
-quality good -crf 32 -c:v libvpx-vp9 -c:a libopus \
-pass 1 -speed 4 "$(basename "${i/.mp4}")".webm && \
ffmpeg -y -i "$i" -vf mpdecimate,setpts=N/FRAME_RATE/TB -vf scale=1280x720 -b:v 1800k \
-minrate 900k -maxrate 2610k -tile-columns 2 -g 240 -threads 8 \
-quality good -crf 32 -c:v libvpx-vp9 -c:a libopus \
-pass 2 -speed 4 -y "$(basename "${i/.mp4}")".webm
elif ($width > 800) && ($width < 1081) && ($fps < 31.000); then
echo "$i is a 1080p video with 30fps or maybe less. Let's encode it to VP9."
ffmpeg -i "$i" -vf mpdecimate,setpts=N/FRAME_RATE/TB -vf scale=1920x1080 -b:v 1800k \
-minrate 900k -maxrate 2610k -tile-columns 2 -g 240 -threads 8 \
-quality good -crf 31 -c:v libvpx-vp9 -c:a libopus \
-pass 1 -speed 4 "$(basename "${i/.mp4}")".webm && \
ffmpeg -y -i "$i" -vf mpdecimate,setpts=N/FRAME_RATE/TB -vf scale=1920x1080 -b:v 1800k \
-minrate 900k -maxrate 2610k -tile-columns 4 -g 240 -threads 8 \
-quality good -crf 31 -c:v libvpx-vp9 -c:a libopus \
-pass 2 -speed 4 -y "$(basename "${i/.mp4}")".webm
notify-send Shrinker "Beginning encoding filename "$i""
elif ($width > 800) && ($width < 1081) && ($fps > 49.000); then
echo "$i is a 1080p video with 50fps or maybe more. Let's encode it to VP9."
ffmpeg -i "$i" -vf mpdecimate,setpts=N/FRAME_RATE/TB -vf scale=1920x1080 -b:v 3000k \
-minrate 1500k -maxrate 4350k -tile-columns 2 -g 240 -threads 8 \
-quality good -crf 31 -c:v libvpx-vp9 -c:a libopus \
-pass 1 -speed 4 "$(basename "${i/.mp4}")".webm && \
ffmpeg -y -i "$i" -vf mpdecimate,setpts=N/FRAME_RATE/TB -vf scale=1920x1080 -b:v 3000k \
-minrate 1500k -maxrate 4350k -tile-columns 4 -g 240 -threads 8 \
-quality good -crf 31 -c:v libvpx-vp9 -c:a libopus \
-pass 2 -speed 4 -y "$(basename "${i/.mp4}")".webm
notify-send Shrinker "Beginning encoding filename "$i""
else
echo "no file found"
fi
done
My script finds every file and encodes them BUT the output files are saved into folder 1. It should save on folder 2 and folder 3.
I get this:
Folder 1
- script.sh
- file1.webm
- file2.webm
Folder 2
- file1.mp4
Folder 3
- file2.mp4
I want this:
Folder 1
- script.sh
Folder 2
- file1.mp4
- file1.webm
Folder 3
- file2.mp4
- file2.webm