Re: Future of SourceType - Call For Consensus?

On 07/06/2014 09:52 PM, Eric Rescorla wrote:
> Yeah, I'm not enthusiastic about this. I'm sensitive to your point about
> unused extension points, but seeing as we know we want to do screen
> capture, I suggest we just take the opportunity to get that right now.

One of the things we've talked about for a long time, but don't have, is 
a (short) extension spec that says "here's how we do screen capture".

We know the security section of this needs careful writing, but it might 
be simpler to get a spec out that shows the rest of the stuff - 
including the use of SourceTypeEnum as a choice mechanism.
I think the Depth spec does a fairly good job of showing that the spec 
is open to extension via more media types, without turning into a 
dependency for getusermedia-1.0; a screen capture spec could do the same 
thing for SourceType.

(Because of the issue with enums that we discovered with FacingMode, it 
has to be cast to a DOMString in the constraints API, but that's a 
different topic.)

Can you think of a way to get someone to volunteer to write such a spec?




>
> -Ekr
>
>
>
> On Fri, Jul 4, 2014 at 1:01 AM, Harald Alvestrand 
> <harald@alvestrand.no <mailto:harald@alvestrand.no>> wrote:
>
>     At the moment, we have 3 bugs that touch on SourceType, listed here:
>
>     https://www.w3.org/Bugs/Public/buglist.cgi?quicksearch=sourcetype&list_id=40270
>
>     Reminder: SourceType is this enum:
>
>     enum SourceTypeEnum {
>         "none",
>         "camera",
>         "microphone"
>     };
>
>     At the moment, we have no part of the spec that depends on this -
>     the only thing you can do with it is to read the attribute on a
>     track, and ask for specific types via a constraint (which is
>     useless for "none", and only has a single possible value for video
>     and audio tracks).
>
>     It's been suggested as a future extension point (such as
>     specifying "I want a screen capture"), but experience with future
>     extension points is that it's very easy to get them wrong unless
>     you already know the extension you want when you design them.
>
>     We've had very little comment on the bugs so far - so I'm trying
>     for a call on the list:
>
>     ***Proposal: SourceType should be removed from getusermedia
>     version 1.0.***
>
>     If we don't hear anyone arguing in favour of keeping it for a week
>     (July 11), we'll take that as permission to remove (there's always
>     the possibility to reinstate).
>
>     If we get arguments ..... we'll take it from there.
>
>            Harald, chair hat on
>
>
>
>