mediapi/systemd/mediapi-mpv.service.template

[Unit]
Description=mpv video player (KMS/DRM -- the actual player)
# Needs the DRM/HDMI + sound devices present.
After=local-fs.target systemd-udev-settle.service sound.target
Wants=systemd-udev-settle.service
# Keep a login getty off the primary display so nothing else claims tty1.
Conflicts=getty@tty1.service

[Service]
User=${MEDIAPI_USER}
# mpv on KMS/DRM needs: video+render (GPU/DRM), input (remotes/keyboard), audio
# (HDMI/ALSA). It becomes DRM master simply as the first/only DRM client on the
# seat -- no PAM login session and no elevated capabilities required, provided
# nothing else is already holding the GPU. (An older Kodi-based deploy DID hold
# it; install.sh tears any leftover Kodi down before starting this.)
SupplementaryGroups=video render input audio
# Create /run/mediapi (owned by this user) for the IPC socket the app connects to.
RuntimeDirectory=mediapi
StandardInput=null
StandardOutput=journal
StandardError=journal
# --idle keeps mpv running with no file loaded (holds the playlist between clips
# and after the last one), so the service stays up and the app can always reach
# the socket. Playback renders straight on KMS.
ExecStart=/usr/bin/mpv \
  --idle=yes \
  --input-ipc-server=/run/mediapi/mpv.sock \
  --no-terminal \
  --no-input-default-bindings \
  --fullscreen \
  --force-window=yes \
  --keep-open=no \
  --vo=gpu --gpu-context=drm --hwdec=auto \
  --ao=alsa --audio-device=alsa/hdmi:CARD=vc4hdmi0,DEV=0
Restart=on-failure
RestartSec=5

[Install]
WantedBy=multi-user.target