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Re: [mediaqueries] Media Source Extensions and device capabilities

From: Tab Atkins Jr. <jackalmage@gmail.com>
Date: Tue, 23 Sep 2014 12:10:54 -0700
Message-ID: <CAAWBYDB93B8n=H1BJ399bLafn-vv_YLTdboMb3GpH9Q=FO4LrA@mail.gmail.com>
To: Mark Watson <watsonm@netflix.com>
Cc: "www-style@w3.org" <www-style@w3.org>
On Tue, Sep 23, 2014 at 9:22 AM, Mark Watson <watsonm@netflix.com> wrote:
> Hi Tab,
>
> I am not really a CSS expert, so that is why I posted the underlying
> requirement without presuming a CSS solution.
>
> But, naively, I would think that if we had a "device pixels" unit (dpx)
> corresponding to physical device pixels, we could construct a media query
> along the lines of "min-height: 1080dpx". This could be used to annotate a
> <source> element on an HTMLMediaElement or with window.mediaMatch() to
> obtain events as the window is moved to / from displays with HD resolution.

A combination of 'width'/'height' and 'resolution' MQs would
accomplish this, if necessary.

> Likewise, one could imagine, "min-audio-channels: 6", although as per the
> previous discussion of this there are some details to work out as to exactly
> what is meant by "audio channel" here. As with video, the requirement is to
> avoid *where possible* delivering media which is just going to be down-mixed
> or down-scaled. So, for audio, the "min-audio-channels: 6" might fail to
> match only if the UA knows for sure that 6-channel audio will be down-mixed.

Right, this is the sort of thing that sounds reasonable.  What I meant
in my request is seeing what kind of <video> markup might be used if
such a MQ existed.

~TJ
Received on Tuesday, 23 September 2014 19:11:42 UTC

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