W3C home > Mailing lists > Public > public-media-capture@w3.org > December 2011

Re "Device Selection" issues

From: Bryan Sullivan <blsaws@gmail.com>
Date: Wed, 14 Dec 2011 09:26:25 -0800
Message-ID: <CAA2gsfo=HJ=vWLWTHAFqasQ04-EnadHTJxxSwi7OK=7J7mOpgg@mail.gmail.com>
To: public-media-capture@w3.org
In https://dvcs.w3.org/hg/dap/raw-file/tip/media-stream-capture/scenarios.html

Re "The specification should provide guidance on what set of devices
are to be made available—should it be the set of potential devices, or
the set of "currently available" devices (which I recommended since
the non-available devices can't be utilized by the developer's code,
thus it doesn't make much sense to include them). ":
[bryan] I believe that in the browser use case, it is not necessary to
return a set of devices, only the one that the user selected. Thus
whether a device is "available" (meaning known by the system, and able
to be connected to at the current time) is something that could
presented through the browser UI and include other info (e.g.
description of the device e.g. "front"/"back"/"internal"/"USB"/"Front
Door"/...) as known. Providing a list of cameras requires then that
the app be capable of some decision making, and thus requires more
info which again is a privacy concern (resulting in a potential
two-stage prompt: "Do you allow this app to know what cameras are
connected" then "Do you allow this app to connect to the 'front'
camera?").

Re "A device selection API should expose device capability rather than
by device identity. Device identity is a poor practice because it
leads to device-dependent testing code (for example, if "Name Brand
Device", then…) similar to the problems that exist today on the web as
a result of user-agent detection. A better model is to enable
selection based on capabilities. Additionally, knowing the GUID or
hardware name is not helpful to web developers as part of a scenario
other than device identification (perhaps for purposes of providing
device-specific help/troubleshooting, for example).":
[bryan] As above, I think for first-pass simplicity at least
(especially for the browser use cases which the charter is limited
to), that we don't need device selection as an API feature. The UA
should handle selection through a UI.

-- 
Thanks,
Bryan Sullivan
Received on Wednesday, 14 December 2011 17:27:00 GMT

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