script for downloading yt videos using yt-dlp but with aria2c as the downloader

ytaria.sh

#!/bin/bash
# by lemon.sh

set -euo pipefail

[[ $# -ne 2 ]] && echo "Usage: $0 <youtube link> <output filename>" && exit 1
type yt-dlp &>/dev/null || { echo "Error: yt-dlp is not available."; exit 10; }
type aria2c &>/dev/null || { echo "Error: aria2c is not available."; exit 11; }
type ffmpeg &>/dev/null || { echo "Error: ffmpeg is not available."; exit 12; }

fileprefix="ytaria_${RANDOM}"
compgen -G "$fileprefix*" && { echo "Error: File(s) with prefix '$fileprefix' exist(s)."; exit 2; }

yt-dlp -F "$1"
echo -e "\nSelect 1st codec:"
read -r prim
echo -e "\nSelect 2nd codec [empty for none]:"
read -r secn
[ -z "$secn" ] || secn=+$secn

echo -e "\nGetting the URL(s)..."
urls=$(yt-dlp -gf "$prim$secn" "$1")
IFS=$'\n'
urlarr=($urls)
unset IFS

[[ -v "urlarr[0]" ]] || { echo "Error: Invalid yt-dlp output"; exit 3; }
aria2c -k 1M -x 16 -s 16 -o "$fileprefix+$prim" "${urlarr[0]}"

if [[ -v "urlarr[1]" ]]; then
    aria2c -k 1M -x 16 -s 16 -o "$fileprefix$secn" "${urlarr[1]}"
    doas ffmpeg -i "$fileprefix+$prim" -i "$fileprefix$secn" -c copy "$2"
    rm "$fileprefix+$prim" "$fileprefix$secn"
else
    doas mv "$fileprefix+$prim" "$2"
fi