Developer:Davaar:InfoService

Architecture Overview

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

This 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 Details, which describe the bit-rate, sample-rate, bit-depth, etc.

These Details may not be known at the point of a track changing. Typically are cleared at the point of track change and become available shortly afterwards.

Furthermore, the Track might have Metatext, such as karaoke lyrics or broadcast information in the case of an internet radio station. Again, this Metatext is typically cleared at the point of track change and changes any number of times as the track is being played.

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.

API Reference

Info Service Description (XML)

Migration Guide From Cara

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