Difference between revisions of "Developer:Davaar:InfoService"

From LinnDocs
Jump to: navigation, search
(Migration Guide From Cara)
(Replaced content with "See http://www.openhome.org/wiki/Av:Developer:InfoService")
Line 1: Line 1:
= Architectural Overview =
+
See http://www.openhome.org/wiki/Av:Developer:InfoService
 
 
The Info service provides 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 format. Some time after the track changes further information becomes available such as the bit-rate, sample-rate, bit-depth, etc. Optionally a track may contain dynamic textual information (known as metatext) that is updated as the track is played. Metatext is typically used to convey broadcast information from internet radio stations.
 
 
 
= Actions =
 
==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.
 
 
 
= Technical Details =
 
<code>
 
    Domain  : av.openhome.org
 
    Name    : Info
 
    Version : 1
 
</code>
 
[http://oss.linn.co.uk/trac/browser/Main/LibUpnpCil/Services/Openhome/Info1.xml Info Service Description (XML)]
 
 
 
= Migration Guide From Cara =
 
 
 
The domain for the Info service has changed to av.openhome.org
 
 
 
== Actions ==
 
=== Counters ===
 
The arguments have changed their names as follows:
 
 
 
* aTrackCount -> TrackCount
 
* aDetailsCount -> DetailsCount
 
* aMetatextCount -> MetatextCount
 
 
 
=== Track ===
 
The arguments have changed their names as follows:
 
 
 
* aUri -> Uri
 
* aMetadata -> Metadata
 
 
 
=== Details ===
 
The arguments have changed their names as follows:
 
 
 
* aDuration -> Duration
 
* aBitRate -> BitRate
 
* aBitDepth -> BitDepth
 
* aSampleRate -> SampleRate
 
* aLossless -> Lossless
 
* aCodecName -> CodecName
 
 
 
=== Metatext ===
 
The argument has changed its name as follows:
 
 
 
* aMetatext -> Value
 

Revision as of 13:35, 24 March 2015