Media and audio

MPRIS media players from the session bus, and PipeWire nodes for volume, mute and default devices.

MPRIS — `vw/mpris.hpp`

Player state is refreshed from player signals on a background thread; position is extrapolated between them.

Function	Meaning
`active()`	the player to show: a playing one (preferring one with artwork), else the last active, else the first
`players()`	every player
`available()`	whether there is an active player
`previous()`, `play_pause()`, `next()`	controls on the active player; false when it cannot
`set_position(seconds)`	seeks the active player
`event_fd()`, `drain_events()`	rebuild on changes

Player has service, name, title, artist, album, art_url, lyrics (when the player exposes them), track_id, playback_status, position, length (seconds) and can_go_previous, can_play, can_pause, can_go_next.

PipeWire — `vw/pipewire.hpp`

Function	Meaning
`available()`, `error()`	connection state
`nodes(filter)`	`all`, `sinks`, `sources` or `streams`
`default_sink()`, `default_source()`	the defaults
`set_volume(id, volume)`	perceptual volume, 0 to 4 (1 is 100%; cubic, like desktop sliders)
`set_mute(id, muted)`, `toggle_mute(id)`	mute
`set_default_sink(id)`, `set_default_source(id)`	change defaults

Node has id, name, description, media_class, app_name, state, channel_volumes, muted, can_control, plus volume() (perceptual) and linear_volume(). Writes return a Result {ok, error}.