ogg dev - Jun 2010 - Skeleton 4.0 final draft

On 31 May 2010 20:51, Chris Pearce <chris at pearce.org.nz> wrote:
> Ok, thanks Silvia. I'll keep working on OggIndex/Skeleton 4.0 without
> the new granulepos fields, and if they're ready in time I'll
include
> them, otherwise they can wait until Skeleton 4.x.
I was waiting for Monty so summarize his ideas too, but from the irc
discussion, it sounds like the extra field description is (a) more
complicated than I thought when I brought it up in January and (b) the
current Dirac mapping has fixed widths for everything, so it's not
necessary to specify it in skeleton for Dirac to work. So, I second
going ahead without adding anything special to support reordered
codecs.

 -r

Hey all,

I've created a new wiki.xiph.org page for Skeleton 4 which includes 
OggIndex. It's here:

http://wiki.xiph.org/Ogg_Skeleton_4

It would be nice if interested parties could take a look, and make sure 
it all makes sense, is coherent, clear etc.

I removed the new granulepos-related fields we were discussing, until we 
can clearly define what's needed. Skeleton 4 now has compulsory
"Role"
and "Name" message header fields.

I have no plans to change the 'index' packet format further.

Sebastian Dr?ge tells me he's implemented OggIndex support in gstreamer! 
Woot!

I have updated my OggIndex program to produce files in this format, and 
I'm currently rebasing my OggIndex-support Firefox patch.

Chris P.

I'm happy with it.

How are you creating the new message header fields? A default role of
audio/main and video/main on the first tracks? And a default of
"audio_1" and "video_1" on the name? Or is it enforced as
parameters
on the command line?

Cheers,
Silvia.

On Fri, Jun 11, 2010 at 10:16 AM, Chris Pearce <chris at pearce.org.nz>
wrote:
> ?Hey all,
>
> I've created a new wiki.xiph.org page for Skeleton 4 which includes
> OggIndex. It's here:
>
> http://wiki.xiph.org/Ogg_Skeleton_4
>
> It would be nice if interested parties could take a look, and make sure
> it all makes sense, is coherent, clear etc.
>
> I removed the new granulepos-related fields we were discussing, until we
> can clearly define what's needed. Skeleton 4 now has compulsory
"Role"
> and "Name" message header fields.
>
> I have no plans to change the 'index' packet format further.
>
> Sebastian Dr?ge tells me he's implemented OggIndex support in
gstreamer!
> Woot!
>
> I have updated my OggIndex program to produce files in this format, and
> I'm currently rebasing my OggIndex-support Firefox patch.
>
> Chris P.
> _______________________________________________
> ogg-dev mailing list
> ogg-dev at xiph.org
> http://lists.xiph.org/mailman/listinfo/ogg-dev
>

On 06/10/2010 08:16 PM, Chris Pearce wrote:
> I have no plans to change the 'index' packet format further.
I have proposed an alternative formulation of the index packet at

http://github.com/bemasc/OggIndex/blob/master/Proposed-modified-spec.txt

That repository also contains a working implementation of the alternative
formulation.  I have reviewed the details with Chris extensively.

I believe that this formulation (which I have dubbed "Skeleton A-mod"
in
an effort to avoid confusion) offers a significant advantage in employing
a simple lossy coding scheme that does not greatly impact seeking
performance.  This technique reduces the amount of space required for the
index by a large factor, typically at least 4.  It also provides a more
explicit guarantee about the location of target information relative to
the seek point, and is designed to work well for rolling-intra streams.

I appreciate that Chris may be more interested in getting the system
standardized quickly than in designing the optimal standard; I think this
is a respectable position.  I am not very familiar with Xiph.org's
procedures for standardization, so I await advice from others on how to
proceed.

--Ben

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 198 bytes
Desc: OpenPGP digital signature
Url :
http://lists.xiph.org/pipermail/ogg-dev/attachments/20100610/5acf8f67/attachment.pgp