Re: Cloning and sharing of MediaStreamTracks - worth it?

Jim,

I think we need to clarify all of this. But perhaps the best way is that 
Dan - who has been spending a lot of time on this lately - writes up a 
proposal (taking into account what was said during the telco the other 
day), and that we take it from there.

Br,
Stefan

On 5/10/13 2:01 PM, Jim Barnett wrote:
> Stefan, From pervious emails, I thought that you were saying that
> constraints/settings are always applied to the source _object_, i.e.
> that settings are implemented by changing the state of the underlying
> device.  Martin is saying that they are never applied to the source
> object (but instead realized in software in the Track.)  The
> difference is that in your model (as I understood it) a setting
> applied to one Track will affect the observed output of all other
> Tracks that share the same source.  In Martin's model, a setting
> applied to one Track will not affect the output of other Tracks.
>
> And Harald's  model seems to be: maybe it does, maybe it doesn't, who
> knows? Life is short, it's up to the UA.
>
> I think we need to be clear on which of these models we are using, or
> the discussion will keep going in circles.  As an example, in
> Tuesday's call when the 'zoom' setting came up, it was clear that
> many people wanted it to apply to the camera's native zoom ability,
> and not to be some post-processing sleight of hand.  In Martin's
> model that would not be allowed.  If it is allowed, I think that  it
> would have to affect the output of all Tracks that share the source.
> Which is it?
>
> - Jim
>
> -----Original Message----- From: Stefan Håkansson LK
> [mailto:stefan.lk.hakansson@ericsson.com] Sent: Friday, May 10, 2013
> 2:17 AM To: Jim Barnett Cc: Martin Thomson;
> public-media-capture@w3.org; Harald Tveit Alvestrand; Robert
> O'Callahan Subject: Re: Cloning and sharing of MediaStreamTracks -
> worth it?
>
> On 5/10/13 12:09 AM, Jim Barnett wrote:
>> Well, we'd better agree on this  soon or we'll be chasing our
>> tails forever.  People have radically different understandings of
>> what a Track actually does. I think that's one reason that the
>> discussions of cloning and constraints/settings never seems to
>> progress.
>
> Jim, I agree fully. But I don't think Martin and I really differ. I
> think we're both saying that
>
> * enabled and the set of constraints are track properties * mute and
> the media are source properties. The app can get info about the media
> currently generated by probing the state of the source serving the
> track:
> http://dev.w3.org/2011/webrtc/editor/getusermedia.html#source-states
>
>
> Stefan
>>
>> -Jim
>>
>> *From:*Martin Thomson [mailto:martin.thomson@gmail.com] *Sent:*
>> Thursday, May 09, 2013 4:09 PM *To:* Jim Barnett *Cc:*
>> public-media-capture@w3.org; Harald Tveit Alvestrand; Stefan
>> Håkansson LK; Robert O'Callahan *Subject:* RE: Cloning and sharing
>> of MediaStreamTracks - worth it?
>>
>> "Jim Barnett" <Jim.Barnett@genesyslab.com
>> <mailto:Jim.Barnett@genesyslab.com>> wrote:
>>>
>>> But see Stefan's email; _everything_ is a source attribute
>>> except
>> for 'enabled'.  I don't think that Track is doing much work.
>>
>> That isn't the model that I described. A large part of the state
>> of the source is actually transparent. The set of constraints,
>> enabled, and, consequently, the precise form of the track output
>> are track properties.
>>
>> As far as I can tell, the only concrete properties the source has
>> are invariant: mute, the media itself. The rest are derived from
>> the set of constraints provided by the enabled tracks that the
>> source serves. Those are the properties I'm interested in cloning.
>>
>
>
>

Received on Friday, 10 May 2013 17:30:07 UTC