[whatwg] Give guidance about RFC 4281 codecs parameter
Ian Hickson
ian at hixie.ch
Thu Oct 25 18:08:25 PDT 2007
Thanks for the help on RFC4281 stuff, I've updated the spec to match.
On Sun, 14 Oct 2007, Ivo Emanuel Gonçalves 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="avc1.42E030, mp4a.40.2"
>
> 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="dirac, vorbis"">
Thanks, added.
--
Ian Hickson U+1047E )\._.,--....,'``. fL
http://ln.hixie.ch/ U+263A /, _.. \ _\ ;`._ ,.
Things that are impossible just take longer. `._.-(,_..'--(,_..'`-.;.'
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