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[whatwg] Give guidance about RFC 4281 codecs parameter

From: Ian Hickson <ian@hixie.ch>
Date: Fri, 26 Oct 2007 01:08:25 +0000 (UTC)
Message-ID: <Pine.LNX.4.62.0710260101390.10579@hixie.dreamhostps.com>

Thanks for the help on RFC4281 stuff, I've updated the spec to match.

On Sun, 14 Oct 2007, Ivo Emanuel Gon?alves wrote:
> 
> This information is not accurate anymore according to the Internet 
> Draft[1] Xiph is working on to help solve the mess.
> 
> video/ogg should be used for any kind of visual material inside Ogg. 
> audio/ogg should be used for audio material in Ogg.
> 
> These media types have a SHOULD requirement for Skeleton to help 
> interoperability.  There is one exception in audio/ogg for that 
> requirement, which is related to serving Vorbis- or Speex-only files 
> that need backward compatibility.  This separation is explained in the 
> I-D.

Thanks, fixed.


> application/ogg is to be used in special cases where video/ogg or 
> audio/ogg are not recommended.  Imagine scientific applications that 
> require dozens of multiplexed signals.  Content served under 
> application/ogg MUST have a Skeleton logical stream.

I haven't mentioned application/ogg, it seems unlikely people will use 
those streams with <video> on any kind of regular basis.


On Wed, 24 Oct 2007, Silvia Pfeiffer wrote:
> 
> Here is what effect it has on the WHAT-WG spec: [...]

Excelent, thanks!!! Updated the spec to match.


On Mon, 15 Oct 2007, Dave Singer wrote:
> >
> > Assuming level 3, I assume that the correct example here would be:
> > 
> >   H.264 Simple baseline profile video (main and extended video compatible)
> >   level 3 and Low-Complexity AAC audio in MP4 container
> > 
> >     type="video/mp4; codecs=&quot;avc1.42E030, mp4a.40.2&quot;
> 
> Hex/decimal confusion here.  Level_idc is *ten* times the level number, 
> so level 3 == level_idc 30 == 0x1E.

Fixed.


> we should tell authors to follow the RFC, and not pretend to be 
> authoritative.... :-)

If the RFC had examples, I'd be all about this. As it stands, though, 
given how much difficulty _I'm_ having with this, I don't think it wise to 
let authors figure it out if we want them to do it at all!


On Wed, 24 Oct 2007, Silvia Pfeiffer wrote:
> 
> I don't know about Dirac inside mpeg, but here's what it would look like 
> inside Ogg together with vorbis for example:
> 
>    <source src="video.ogv" type="video/ogg; codecs=&quot;dirac, vorbis&quot;">

Thanks, added.

-- 
Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'
Received on Thursday, 25 October 2007 18:08:25 UTC

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