Developer:Davaar:InfoService

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Revision as of 16:18, 18 November 2010 by Grahamd (talk | contribs) (XML Description)
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Architectural Overview

The Info Service provides source-independent information concerning the currently playing media.

The information provided is based on the concept of a track, which has a uri and metadata in DIDL-Lite form.

The track may also have detailed information concerning bit-rate, sample-rate, bit-depth, etc.

These details may not be known immediately when a track changes. Typically they are cleared at this point and become available shortly afterwards.

The track may also have metatext: dynamic textual information concerning the track, which may change as the track is played.

Again, metatext is cleared when a new track begins and changes as the track is played.

Metatext is typically used to convey broadcast information from internet radio stations.

Counters

Counters are used to manage the changing of the Track, Details, and Metatext information.

When a track changes, the Track Count is incremented, the Uri and Metadata are set, the Details Count is set to zero, the Details are defaulted to blank and zero values, the Metatext Count is set to zero, and the Metatext is set to blank.

Subsequent updates to the Details and Metatext are accompanied by increments in their respective Counters.

The Counters action can be used by clients that are unable to partake in UPnP eventing in order to establish changes in the information provided by the Info Service.

Track

Reports current track information concerning the current media:

  • Uri
  • Metadata

Details

Reports details concerning the current media:

  • Duration
  • Bit Rate
  • Bit Depth
  • Sample Rate
  • Lossless
  • Codec Name

Metatext

Reports dynamic textual information concerning the current media.

This currently amounts to broadcast information from internet radio stations, but the same mechanism could be used for other purposes in the future.

XML Description

  • Domain  : av.openhome.org
  • Name  : Info
  • Version : 1

Info Service Description (XML)

Migration Guide From Cara

The domain for the Info service changed to av.openhome.org

Counters Action

The arguments have changed their names as follows:

  • aTrackCount -> TrackCount
  • aDetailsCount -> DetailsCount
  • aMetatextCount -> MetatextCount

Track Action

The arguments have changed their names as follows:

  • aUri -> Uri
  • aMetadata -> Metadata

Details Action

The arguments have changed their names as follows:

  • aDuration -> Duration
  • aBitRate -> BitRate
  • aBitDepth -> BitDepth
  • aSampleRate -> SampleRate
  • aLossless -> Lossless
  • aCodecName -> CodecName

Metatext Action

The argument has changed its name as follows:

  • aMetatext -> Value