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Re: [Bug 24015] Add callback to indicate when available media devices change

From: Stefan Håkansson LK <stefan.lk.hakansson@ericsson.com>
Date: Thu, 15 May 2014 11:12:54 +0000
To: "praveen.j@samsung.com" <praveen.j@samsung.com>, Dominique Hazael-Massieux <dom@w3.org>
CC: Sam Dutton <dutton@google.com>, "public-media-capture@w3.org" <public-media-capture@w3.org>
Message-ID: <1447FA0C20ED5147A1AA0EF02890A64B1CFE4F39@ESESSMB209.ericsson.se>
On 2014-05-12 07:29, Praveen R Jadhav wrote:
> Implementations like navigator.geolocation.watchPosition makes sense
> when there is a continuous update as in case of location
> co-ordinates(ex: travelling in a car). Also, these attributes have wide
> range of values.
>
> In case of WebRTC calls, you have limited no. of media input/output
> devices and they are either plugged or unplugged. Polling
> mechanism in this scenario will be a burden on overall system. Callback
> mechanism should be fine.

I'm not sure what you mean - do you think adding a callback the way Dom 
proposes is a good idea?

>
> Regards,
>
> Praveen
>
> ------- *Original Message* -------
>
> *Sender* : Stefan Håkansson LK<stefan.lk.hakansson@ericsson.com>
>
> *Date* : May 10, 2014 13:24 (GMT+05:30)
>
> *Title* : Re: [Bug 24015] Add callback to indicate when available media
> devices change
>
> On 2014-05-09 18:08, Dominique Hazael-Massieux wrote:
>  > Le mercredi 18 décembre 2013 ā 10:59 +0000, Stefan Håkansson LK a écrit
>  > (about
>  >
> http://dev.w3.org/2011/webrtc/editor/getusermedia.html#idl-def-MediaDeviceInfoCallback)
>  >
>  >>>> Agreed, but after actually working with the API I think that
>  >>> polling is clumsy;
>  >>> to get the behavior described below, you would have to poll the API
>  >>> about every
>  >>> second for the entire lifetime of the call.
>  >
>  >>> Agree: an event would be more efficient and cleaner to code than
>  >>> polling.
>  >
>  >> I agree, this would be much cleaner.
>  >
>  > https://www.w3.org/Bugs/Public/show_bug.cgi?id=24015 has a proposal for
>  > an event on navigator to avoid polling; I don't think that navigator
>  > implements the event listener interface, so it probably doesn't make
>  > sense to add it just for this.
>  >
>  > This could be moved to be a global event (i.e. on the window object);
>  > but I wonder if instead we could say that the MediaDeviceInfoCallback
>  > should be automatically invoked each time the list of media input and
>  > output devices change (roughly the same way navigator.watchPosition
>  > invokes its callback when the user position changes).
>  >
>  > Thoughts?
>
> I think following the pattern of watchPosition makes sense.
>
>  >
>  > Dom
>  >
>  >
>
>


Received on Thursday, 15 May 2014 11:13:20 UTC

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