fixed the processing of aac files into mp4 containers

main.sh

@@ -41,7 +41,7 @@ fi
 
 echo "Wrapping aac files in mp4 containers. Placing it in the same directory as the original file."
 
-fd '' -e 'aac' "$d" | parallel -n 1 -P $(nproc) 'filename={} && ffmpeg -i ${filename: -4}.aac -c:a copy ${filename: -4}.mp4'
+fd '' -e 'aac' "$d" | parallel -n 1 -P $(nproc) 'filename={} && ffmpeg -i ${filename: 0:-4}.aac -c:a copy ${filename: 0:-4}.mp4'
 
 echo "aac to mp4 conversion complete. Proceeding to create folders under $d/exif_media."
 mkdir -p "$O/exif_media/"{audio,photo,video}