TV Control API Specification - Clarification

Hi,

We are progressing with the implementation of TVControl API based on September 2016 draft version (https://www.w3.org/TR/2016/WD-tvcontrol-api-20160915/#tvprogram-interface). We found that TVControl group is still working on the spec and  there is lot of changes in the interfaces in the latest version against September 2016 version.

I have some clarification in the following interfaces (these interfaces are same in September and latest work-in progress versions),
[Query1]
21. TVTunerChangeEvent<https://w3c.github.io/tvcontrol-api/#dom-tvtunerchangeevent> Interface
The TVTunerChangeEvent<https://w3c.github.io/tvcontrol-api/#dom-tvtunerchangeevent> interface represents the event related to the TV/Radio tuner that is added/removed by the device.
interface TVTunerChangeEvent<https://w3c.github.io/tvcontrol-api/#dom-tvtunerchangeevent> : Event<https://dom.spec.whatwg.org/#event> {
    readonly attribute TVTunerChangeEventOperation<https://w3c.github.io/tvcontrol-api/#dom-tvtunerchangeeventoperation> operation<https://w3c.github.io/tvcontrol-api/#dom-tvtunerchangeevent-operation>;
    readonly attribute DOMString<https://www.w3.org/TR/WebIDL-1/#idl-DOMString>                   id<https://w3c.github.io/tvcontrol-api/#dom-tvtunerchangeevent-id>;
};
In most of the cases the tuner devices are fixed, not plug-n-play, so in such cases does the interface implementation is mandatory ? Can be make it as optional ?

[Query2] 12. TVProgram Interface

The TVProgram interface represents a set of properties and operations related to a TV/Radio program (e.g. a DVB or ATSC Event). An instance of a TVProgram corresponds to one showing of that program: if the same program is shown at two different times or on different channels then each showing is represented by a different TVProgram instance.

interface TVProgram {
    sequence<DOMString> getAudioLanguages();
    sequence<DOMString> getSubtitleLanguages();
    sequence<DOMString> getGenres();
    readonly attribute DOMString    eventId;
    readonly attribute TVChannel    channel;
    readonly attribute DOMString    title;
    readonly attribute DOMTimeStamp startTime;
    readonly attribute DOMTimeStamp duration;
    readonly attribute DOMString?   shortDescription;
    readonly attribute DOMString?   longDescription;
    readonly attribute DOMString?   parentalRating;
    readonly attribute boolean      isEncrypted;
    readonly attribute DOMString?   seriesId;
};

             Audio/Subtitle languages info will be based on the channel and has to be read from the PMT/TVCT, in such case do we have to keep getAudioLanguages/getSubtitleLanguages in TVProgram class? Can we move it into TVChannel ?

Best Regards
Haseenamol

Senior Specialist - Broadcast | Embedded Product Design
TATA ELXSI
Neyyar Techno park Campus Trivandrum 695 581 India
Tel +91 471 666 1248
www.tataelxsi.com<http://www.tataelxsi.com/>