[whatwg] Give guidance about RFC 4281 codecs parameter

Xiph has taken on board the many comments received over the last years
wrt MIME types and file extensions and is working on this more
appropriate I-D for MIME types cited by Ivo.

Here is what effect it has on the WHAT-WG spec:

The spec:
> Theora video and Vorbis audio in Ogg container
>    <source src="video.ogg" type="application/ogg; codecs=&quot;theora, vorbis&quot;">

The new way:
Theora video and Vorbis audio in Ogg container
    <source src="video.ogv" type="video/ogg; codecs=&quot;theora, vorbis&quot;">

The spec:
> Theora video and Speex audio in Ogg container
>    <source src="video.ogg" type="application/ogg; codecs=&quot;theora, speex&quot;">

The new way:
Theora video and Speex audio in Ogg container
   <source src="video.ogv" type="video/ogg; codecs=&quot;theora, speex&quot;">

The spec:
> Vorbis audio alone in Ogg container
>    <source src="video.ogg" type="application/ogg; codecs=vorbis">

The new way:
Vorbis audio alone in Ogg container
   <source src="audio.ogg" type="audio/ogg; codecs=vorbis">
  or
   <source src="audio.oga" type="audio/ogg; codecs=vorbis"> (preferred)


Also further examples are:

* Speex audio alone in Ogg container
   <source src="audio.spx" type="audio/ogg; codecs=speex">
  or
   <source src="audio.oga" type="audio/ogg; codecs=speex"> (preferred)

* Flac audio alone in Ogg container
   <source src="audio.oga" type="audio/ogg; codecs=flac">


Regards,
Silvia.


On 10/14/07, Ivo Emanuel Gon?alves <justivo at gmail.com> wrote:
> On 10/13/07, Ian Hickson <ian at hixie.ch> wrote:
> > > Recent discussion at Xiph around http://www.ietf.org/rfc/rfc4281
> > > suggests the use of the following parameters:
> > >
> > > # application/ogg; codecs="theora, vorbis"   for Ogg Theora/Vorbis files
> > > # application/ogg; codecs="theora, speex"   for Ogg Theora/Speex files
> > > # application/ogg; codecs="vorbis"                 for Ogg Vorbis files
> > >
> > > and also use the disposition parameter:
> > >
> > > # application/ogg; disposition=moving-image; codecs="theora, vorbis"
> > > # application/ogg; disposition=sound; codecs="speex"
> > >
> > > Skeleton and the use of these MIME parameters should make things clear
> > > for the application developers.
>
> 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.
>
> 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.
>
> -Ivo
>
> [1] https://trac.xiph.org/browser/experimental/ivo/drafts/draft-xiph-rfc3534bis.txt
>

Received on Tuesday, 23 October 2007 16:39:24 UTC