Какая часть конфига Вам не понятна?
# set this to the directory you want scanned.
# * if have multiple directories, you can have multiple media_dir= lines
# * if you want to restrict a media_dir to a specific content type, you
# can prepend the type, followed by a comma, to the directory:
# + "A" for audio (eg. media_dir=A,/home/jmaggard/Music)
# + "V" for video (eg. media_dir=V,/home/jmaggard/Videos)
# + "P" for images (eg. media_dir=P,/home/jmaggard/Pictures)
media_dir=/opt