4 Media Renderers

9.2.900

Racket

4 Media Renderers🔗ℹ

This module provides a device-oriented interface for UPnP and DLNA media renderers. It hides the AVTransport and RenderingControl services used for common playback and volume operations.

procedure
(query-media-renderers [ #:interface interface
#:dns? dns?
#:dlna-only? dlna-only?])
→ (listof media-renderer?)
  interface : (or/c #f string?) = #f
  dns? : boolean? = #f
  dlna-only? : boolean? = #f

Discovers media renderers. When dlna-only? is true, only devices that advertise a DLNA document identifier are returned.

procedure
(get-media-renderer filter-name) → (or/c #f media-renderer?)
filter-name : string?

Returns the first discovered renderer whose name contains filter-name, ignoring case, or #f when no renderer matches.

procedure
(media-renderer? value) → boolean?
value : any/c

Returns #t, if the value is a media-renderer.

procedure
(media-renderer-name renderer) → string?
renderer : media-renderer?

Returns the friendly name advertised by the media renderer.

procedure
(media-renderer-address renderer) → string?
renderer : media-renderer?

Returns the network address from which the renderer was discovered.

procedure
(media-renderer-manufacturer renderer) → (or/c #f string?)
renderer : media-renderer?

Returns the renderer manufacturer, or #f when it was not included in the UPnP device description.

procedure
(media-renderer-model renderer) → (or/c #f string?)
renderer : media-renderer?

Returns the renderer model name, or #f when it was not included in the UPnP device description.

procedure
(media-renderer-dlna? renderer) → boolean?
renderer : media-renderer?

4.1 Playback🔗ℹ

procedure
(media-renderer-play-resource! renderer
uri
[ #:protocol-info protocol-info
#:mime-type mime-type
#:title title
#:artist artist
#:album album
#:genre genre
#:year year
#:track track
#:duration duration
#:size size])
→ any
  renderer : media-renderer?
  uri : string?
  protocol-info : (or/c #f string?) = #f
  mime-type : (or/c #f string?) = #f
  title : string? = "Media"
  artist : (or/c #f string?) = #f
  album : (or/c #f string?) = #f
  genre : (or/c #f string?) = #f
  year : (or/c #f exact-nonnegative-integer?) = #f
  track : (or/c #f exact-nonnegative-integer?) = #f
  duration : (or/c #f number?) = #f
  size : (or/c #f exact-nonnegative-integer?) = #f

Resolves missing DLNA HTTP capabilities, generates DIDL-Lite for the resource, and starts playback. A wildcard fourth field in protocol-info is replaced with the server’s contentFeatures.dlna.org response when available. Successful capability responses are cached by URI.

procedure
(media-renderer-play-uri! renderer
uri
[ #:metadata metadata
#:next-uri next-uri
#:next-metadata next-metadata]) → any
  renderer : media-renderer?
  uri : string?
  metadata : string? = ""
  next-uri : (or/c #f string?) = #f
  next-metadata : string? = ""

Sets uri as the current resource and starts playback.

Supply DIDL-Lite in metadata. Although AVTransport permits an empty string, some renderers do not enable seeking without resource metadata. Use media-file-server-didl-lite for resources published by this package.

When next-uri is supplied, it is installed with SetNextAVTransportURI before playback starts. A supporting renderer can open and buffer the next resource while the current resource is playing, allowing a gapless or near-gapless transition. Supply matching DIDL-Lite in next-metadata.

procedure
(media-renderer-play! renderer) → any
renderer : media-renderer?

Resumes playback after it has been paused.

procedure
(media-renderer-next-uri-supported? renderer) → boolean?
renderer : media-renderer?

Reports whether the renderer advertises the optional SetNextAVTransportURI action.

procedure
(media-renderer-set-next-uri! renderer
uri
[ #:metadata metadata]) → any
  renderer : media-renderer?
  uri : string?
  metadata : string? = ""

Sets the resource that follows the currently playing resource. The action describes one next resource, not a complete queue. After playback advances to that resource, call this function again to preload the following track. Use metadata that describes uri, not the current resource.

procedure
(media-renderer-set-next-resource!
renderer
uri
[ #:protocol-info protocol-info
#:mime-type mime-type
#:title title
#:artist artist
#:album album
#:genre genre
#:year year
#:track track
#:duration duration
#:size size])
→ any
  renderer : media-renderer?
  uri : string?
  protocol-info : (or/c #f string?) = #f
  mime-type : (or/c #f string?) = #f
  title : string? = "Media"
  artist : (or/c #f string?) = #f
  album : (or/c #f string?) = #f
  genre : (or/c #f string?) = #f
  year : (or/c #f exact-nonnegative-integer?) = #f
  track : (or/c #f exact-nonnegative-integer?) = #f
  duration : (or/c #f number?) = #f
  size : (or/c #f exact-nonnegative-integer?) = #f

Resolves and describes an external resource like media-renderer-play-resource!, then installs it as the next URI.

procedure
(media-renderer-pause! renderer) → any
renderer : media-renderer?

procedure
(media-renderer-stop! renderer) → any
renderer : media-renderer?

procedure
(media-renderer-seek! renderer seconds) → any
renderer : media-renderer?
seconds : exact-nonnegative-integer?

procedure
(media-renderer-status renderer) → symbol?
renderer : media-renderer?

procedure
(media-renderer-position renderer) → transport-position?
renderer : media-renderer?

procedure
(transport-position-track position)
→ exact-nonnegative-integer?
position : transport-position?

procedure
(transport-position-seconds position) → (or/c #f number?)
position : transport-position?

procedure
(transport-position-duration position) → (or/c #f number?)
position : transport-position?

procedure
(transport-position-uri position) → (or/c #f string?)
position : transport-position?

4.2 Volume and mute🔗ℹ

procedure
(media-renderer-volume renderer) → exact-nonnegative-integer?
renderer : media-renderer?

procedure
(media-renderer-set-volume! renderer
volume) → any
renderer : media-renderer?
volume : exact-nonnegative-integer?

procedure
(media-renderer-muted? renderer) → boolean?
renderer : media-renderer?

procedure
(media-renderer-set-muted! renderer muted?) → any
renderer : media-renderer?
muted? : boolean?

1	Introduction
2	UPn P Devices and Services
3	DIDL-Lite Metadata
4	Media Renderers
5	Media Servers
6	Publishing Media Files
7	AVTransport
8	Rendering Control
9	Connection Manager
10	Content Directory
	Index