RE: [tvcontrol-api] Why retrieve a list of tuners instead of just one tuner?

Thanks for updating the definitions.

1.  Introducing the notion of IP multicast may lead to different APIs to resolve the list of TVChannels available from these different types of sources?


2. I would keep the definitions as generic as possible. The penultimate sentence looks like a repeat of what's being said in the second sentence.  I would keep the last sentence of the definition of TVSource out.

- **TVSource**: a logical source of TV/Radio channels. This may
represent a physical tuner or a "virtual" tuner for IP multicast. The
TVSource exposes the list of TVChannel objects available through that
source. For devices with more than one type of tuner (e.g. cable and
terrestrial), each tuner type may be represented by a different
TVSource. 

TBD: if associated to TVTuner: DVB Network and Multiplex, ATSC?? 

3. The definition of TVChannel -> DVB Service, ATSC??

- **TVChannel**: represents a single TV or radio channel and provides
metadata about it. A TVChannel objectis one among possibly several channels
 available through one TVSource. If the same channel (e.g. VH1)
 is available through two different sources (e.g. over cable and
terrestrial) then each TVSource will return a different TVChannel
object.

4. Mediastream (if we want to reuse definitions)

A TVChannel is consumed as **TVMediaStream** composed of one or more MediaStreamTracks (audio, video, data, etc. -> DVB Components, ATSC??) This can be passed to an HTML5 media
 element to play the channel. A TVMediaStream is obtained from a
TVSource, and when a TVMediaStream object is created it means that all
 of the resources needed to receive and present that channel have been
 successfully allocated. 

To be rediscussed when we have progressed on the API?
 [[[[A TVMediaStream object may be re-used when
selecting a different channel, to indicate that tuning and decoding
resources currently used to present that TVMediaStream may be re-used
for the new channel.]]]] 

5. TVProgram -> DVB Event -> ATSC??
A TVProgram is an editorial object available at a given time on a given TVChannel

________________________________________
From: Steve Morris via GitHub [sysbot+gh@w3.org]
Sent: 11 November 2016 16:32
To: public-tvcontrol@w3.org
Subject: Re: [tvcontrol-api] Why retrieve a list of tuners instead of just one tuner?

I've tried re-phrasing the definitions from up-thread to more
accurately reflect the discussions around TVMediaStream from TPAC.
I've left TVTuner out of this for now, because I don't think we're
close enough to agreement on that at the moment.

- **TVSource**: a logical source of TV/Radio channels. This may
represent a physical tuner or a "virtual" tuner for IP multicast. The
TVSource exposes the list of TVChannel objects available through that
source. For devices with more than one type of tuner (e.g. cable and
terrestrial), each tuner type may be represented by a different
TVSource. A TVSource is not a physical tuner - it is a way of
discovering channels, getting the corresponding TVChannel objects and
obtaining the resources to present them. Because there is not a
one-to-one mapping between a TVSource and a tuner, more than one
channel from a given TVSource may be presented at the same time if the
 device has enough resources.

- **TVChannel**: represents a single TV or radio channel and provides
metadata about it. Each TVChannel object represents a single channel
that is available through one TVSource. If the same channel (e.g. VH1)
 is available through two different sources (e.g. over cable and
terrestrial) then each TVSource will return a different TVChannel
object.

- **TVMediaStream**: represents the stream data for all components
within a channel being presented. This can be passed to an HTML5 media
 element to play the channel. A TVMediaStream is obtained from a
TVSource, and when a TVMediaStream object is created it means that all
 of the resources needed to receive and present that channel have been
 successfully allocated.  A TVMediaStream object may be re-used when
selecting a different channel, to indicate that tuning and decoding
resources currently used to present that TVMediaStream may be re-used
for the new channel.

One thing that springs to mind is that in this model a TVMediaStream
can also act as a representation of the set of resources needed to
receive, decode and present the channel that it's currently being used
 for.  I'm not sure how or if we can use that information, but it's
something that may prove useful so I thought I'd bring it to people's
attention.

--
GitHub Notification of comment by stevem-tw
Please view or discuss this issue at
https://github.com/w3c/tvcontrol-api/issues/4#issuecomment-259982530
using your GitHub account

------------------------------------------------------------------------------

**************************************************
This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed.
If you have received this email in error, please notify the system manager. This footnote also confirms that this email message has been swept by the mailgateway
**************************************************

Received on Saturday, 12 November 2016 14:51:39 UTC