W3C home > Mailing lists > Public > whatwg@whatwg.org > April 2007

[whatwg] Give guidance about RFC 4281 codecs parameter

From: Dave Singer <singer@apple.com>
Date: Mon, 9 Apr 2007 12:07:22 -0700
Message-ID: <p0624081ec2403f45190a@[10.0.1.3]>
At 11:59  -0700 9/04/07, Charles Iliya Krempeaux wrote:
>Hello,
>
>On 4/9/07, Dave Singer <<mailto:singer at apple.com>singer at apple.com> wrote:
>
>WARNING:  I have CC'd the co-authors of the RFC, as I think they 
>might like to see the discussion, comment on my answers, and 
>possibly correct me.  I also have a question whether there is a typo 
>in the RFC...
>
>* * * * *
>
>
>Henry
>
>these are all great questions.  Let me see how many I can answer.
>
>Overall, the RFC was struggling with the issue that there is no 
>'uniform' naming of codecs;  the namespace for codecs is dependent 
>on the container format, so products that do container conversion 
>have to have tables of code matches.  ugh.  That's why the RFC is as 
>it is.
>
>The RFC suggests that updated information would be done with RFCs, 
>which is a little heavy.  The RFC as written formally applies to 
>3GPP files and 3GPP2 files, but the definitions are applicable for 
>all ISO-family files.
>
>As you'll see below, 3GPP has also defined it for avc1 in MP4-family 
>containers, but no spec. or registration authority provides a 
>pointer.  We might want to ask IANA whether we could add something 
>to the MIME registry.
>
>
>At 11:37  +0300 8/04/07, Henri Sivonen wrote:
>
>>
>>  * Theora video and Vorbis audio in Ogg container. (application/ogg; .ogg)
>>  * Dirac video and Vorbis audio in Ogg container. (application/ogg; .ogg)
>>  * Theora video and Vorbis audio in Matroska container. 
>>(video/x-matroska; .mkv)
>>  * Dirac video and Vorbis audio in Matroska container. 
>>(video/x-matroska; .mkv)
>>
>
>My understanding is that the Ogg container is 'specific' to these 
>codecs, and therefore the codecs parameter is not needed.  But I am 
>not an Ogg or Matroska expert;  perhaps they could chime in?
>
>
>No.  The containers are independent of the codecs put inside.
>
>However, whether software, that supports Ogg or Matroska containers 
>will actually be able to "play" other codecs is another issue 
>altogether.
>
>[...]
>

so a defined 'codecs' parameter might be prudent, perhaps.  Thanks 
for the correction.
-- 
David Singer
Apple Computer/QuickTime
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.whatwg.org/pipermail/whatwg-whatwg.org/attachments/20070409/2c7bc27a/attachment.htm>
Received on Monday, 9 April 2007 12:07:22 UTC

This archive was generated by hypermail 2.4.0 : Wednesday, 22 January 2020 16:58:54 UTC