W3C home > Mailing lists > Public > public-media-capture@w3.org > January 2012

RE: Scenarios doc updated

From: Travis Leithead <travis.leithead@microsoft.com>
Date: Fri, 20 Jan 2012 08:35:03 +0000
To: Randell Jesup <randell-ietf@jesup.org>, "public-media-capture@w3.org" <public-media-capture@w3.org>
Message-ID: <9768D477C67135458BF978A45BCF9B38381F3F3B@TK5EX14MBXW604.wingroup.windeploy.ntdev.microsoft.com>
More updates pushed to the doc this evening (part 1/3)

>>> * There is no scenario that uses the screen of the device as input. To
>>> give some background, screen sharing is a use case for webrtc (use case
>>> 4.7.2 in
>>> http://datatracker.ietf.org/doc/draft-ietf-rtcweb-use-cases-and-
>>> requirements/?include_text=1).
>>> Some experimentation has been carried out, using getUserMedia, and it
>>> was found being a viable way forward (using "screen" as hint). I don't
>>> know how this should be handled vis a vi the Media Capture TF, but it
>>> seems to me that it should be included. What do others think?
>> Good scenario, I'll see if I can incorporate it into an existing scenario
>as a variation; if not, I'll spin up another scenario for it.
>
>GetUserMedia should consider the option of selecting a camera (and which
>one or ones), a file in place of a camera, (perhaps) an image, or the
>screen/window/tab.  Which options are offered (in particular screen, but
>maybe file/image) can be hinted.  I'm not sure I'd want to mandate that
>screen (or window or tab) be available, but I do want to know how an
>implementation would select those.

Added this scenario as a variation of 2.5



>>> * There is no scenario with several cam's used in parallel, in section
>>> 4.2.9 of
>>> http://datatracker.ietf.org/doc/draft-ietf-rtcweb-use-cases-and-
>>> requirements/?include_text=1
>>> two cameras are used in parallel for part of the session. Perhaps this
>>> is too constrained, but I think something where more than one is used
>>> should be in the doc.
>> Scenario 2.4 (Video diary at the Coliseum) uses two webcams in parallel,
>but only records from one of them at a time. How would you suggest that be
>changed?
>
>Well, WebRTC supports multiple video and audio streams incoming *and*
>outgoing, so it will be needed for that (the 'hockey' example).  For
>media capture, this would apply to the video diary as well - recording
>both the view seen, and the face of the commentator for later use
>insetting or editing.  Or someone recording a sports event from the
>sideline using two webcams, or two people at the same computer each with
>a webcam pointed at them (one built in, one on a cable to the coworker
>sitting next to or across from them).  Etc.

I added this scenario as a variation to 2.4. On a personal note, I think that more than two webcam scenarios are an extreme minority for most "typical users". While the idea of supporting it is interesting from a pedagogical standpoint, the reality is that it's just not necessary. If you really _need_ to control multiple cameras are you really going to use a web browser for that? Hence the scenario is running on "special hardware" which gave me an out to support parallel recording (must have dedicated chipsets for each HD video recording stream--your typical hardware will barf under those conditions).
Received on Friday, 20 January 2012 08:35:59 GMT

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