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Re: Do we need a powerNetworkFrequency constraint?

From: Martin Thomson <martin.thomson@gmail.com>
Date: Tue, 25 Aug 2015 08:13:12 -0700
Message-ID: <CABkgnnUEB4SP-FQ3qcs-GaU0eymecCm81+XNChOBQ1vB8_o=pA@mail.gmail.com>
To: Harald Alvestrand <harald@alvestrand.no>
Cc: public-media-capture@w3.org
Is there any sense in distinguishing between "guess for me" and "don't try
to suppress flicker"?
On Aug 24, 2015 10:48 PM, "Harald Alvestrand" <harald@alvestrand.no> wrote:

> Most cameras seem to have some place in their API where you set the line
> power frequency of the area you live in; this is used to suppress
> flicker from fluorescent or LED-based lighting fixtures.
>
> Many times, the OS or the browser can make a guess at the right power
> frequency based on environment factors like timezone or location, and
> everything's OK.
>
> But sometimes it's wrong. And it makes people unhappy.
>
> One option is to have a way to override the setting from the application
> if needed; we can, for instance, have a tri-state constraint, mirroring
> the camera APIs:
>
> powerNetworkFrequency = "50Hz", "60Hz", "default"
>
> (I don't see a case for allowing "powerNetworkFrequency=200", which
> would be the case if we made it a number.... even though there are
> railway power grids at 16 2/3 Hz, they're rare enough that we should
> ignore them for simplicity's case).
>
> What do people think?
>
> (Also filed as https://github.com/w3c/mediacapture-main/issues/234)
>
> Harald
>
> --
> Surveillance is pervasive. Go Dark.
>
>
>
>
Received on Tuesday, 25 August 2015 15:13:39 UTC

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