# racket-audio-dlna

`racket-audio-dlna` plays local audio files on UPnP/DLNA media renderers.
It combines TagLib metadata from `racket-audio` with the HTTP server,
DIDL-Lite support, and renderer controls from `racket-upnp`.

```racket
#lang racket/base

(require racket-audio-dlna
         racket-upnp)

(define renderer
  (get-media-renderer "Denon"))

(define player
  (make-dlna-player renderer))

(dlna-player-play!
 player
 "/muziek/radiohead/in-rainbows.flac")

(dlna-player-set-next-file!
 player
 "/muziek/radiohead/bodysnatchers.flac")
```

The constructor determines the local address used to reach the renderer and
starts a media file server on port 8080. The address, port, and URL path can be
overridden when required:

```racket
(make-dlna-player
 renderer
 #:listen-ip "10.7.3.108"
 #:port 8081
 #:path "/music/")
```

## Controls

```racket
(dlna-player-pause! player)
(dlna-player-resume! player)
(dlna-player-seek! player 120)
(dlna-player-seek-percentage! player 50)
(dlna-player-volume! player 35)
(dlna-player-muted! player #t)
(dlna-player-stop! player)
```

`dlna-player-info` returns a cached snapshot:

```racket
(define info (dlna-player-info player))

(dlna-info-state info)
(dlna-info-position info)
(dlna-info-duration info)
(dlna-info-volume info)
(dlna-info-reachable? info)
```

Transport state and position are refreshed by a background thread. Position is
advanced locally between polls. Volume and mute state use a slower cache.
Commands update the cache immediately after the renderer accepts them.

Use `#:refresh? #t` for a synchronous refresh:

```racket
(dlna-player-info player #:refresh? #t)
```

Close the player when it is no longer needed:

```racket
(dlna-player-close! player)
```

Closing stops playback, removes published files, stops the web server, and
terminates the polling thread.