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Re: [mediaqueries4] Media queries for multichannel audio ?

From: Mark Watson <watsonm@netflix.com>
Date: Wed, 20 Mar 2013 15:03:48 +0000
To: "florian@rivoal.net" <florian@rivoal.net>
CC: "www-style@w3.org" <www-style@w3.org>
Message-ID: <AF2B3C9F-D2D0-4BA7-8ED6-A64199B81A2C@netflix.com>
Florian, all,

How do I progress this issue ? Do I need to file a bug ? (where?) Do I need to join the WG ?

There are also two other issues I'm interested in with respect to TVs:
- output frame rate (no point giving 60fps content to a 30fps display)
- screen dimensions in physical pixels (no point giving HD content to an SD display)

For the latter one, I am unsure about whether this can be derived from the existing width/height and resolution properties. Width and Height seem to be in CSS pixels which are explicitly defined with reference to "computer displays", so it is unlearn what is a CSS pixel on a TV.

Best regards,


On Mar 19, 2013, at 10:10 AM, Henrik Andersson wrote:

> Mark Watson skriver:
>> On Mar 19, 2013, at 9:42 AM, Henrik Andersson wrote:
>>> Mark Watson skriver:
>>>> Hi everyone,
>>>> Has there been any dissuasion of media queries for audio media ?
>>>> Specifically, I am interested in discovering whether the attached audio device supports multi-channel audio (5.1, 7.1 etc.) so that I can choose an appropriate resource.
>>>> I believe it would be sufficient to have a 'channel count' property which is just an integer count of the number of audio channels supported by the output device.
>>>> Thanks!
>>>> Mark Watson
>>> I'd like to add that it could be useful to know if there is a limit to
>>> the number of mixer channels available. Some platforms use hardware
>>> mixers that have a limited amount of channels.
>> Actually, I am interested in the number of physical speakers - or more specifically the number of channels actually output from the device.
>> I have a multichannel stream and a professionally downmixed stereo stream and if there are only two output channels I'd rather provide the stereo stream than have the device do its own downmixing.
>> I distinguish between the number of physical speakers and the number of output channels because there are setups where the audio output is making proper use of the 6 output channels but has less than 6 speakers (for example soundbars, where there is audio processing which tries to simulate the effect of surround speakers using phase manipulations etc.). I consider those setups as having 6 output channels. But if the device is doing straight downmixing to stereo, I'd rather provide the professional stereo stream (which is also less bandwidth).
> To clarify, I am not saying that your case is the same as mine. I just
> wanted to add a related thing that could be useful to detect. Some
> devices simply have limits on the number of sounds they can play at the
> same time.
Received on Wednesday, 20 March 2013 15:04:23 UTC

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