MiniDLNA server 
https://hub.docker.com/r/vladgh/minidlna/

docker run -d --net=host \
  -v /home/pi/Music:/media/audio \
  -v /home/pi/Videos:/media/video \
  -e MINIDLNA_MEDIA_DIR_1=A,/media/audio \
  -e MINIDLNA_MEDIA_DIR_2=V,/media/video \
  -e MINIDLNA_FRIENDLY_NAME=RPI4 \
  vladgh/minidlna


To refresh and restart
sudo minidlnad -R
sudo service minidlna restart