[ogg-dev] oggpcm2 sample rate

[Conrad Parker]

Hi,

I've added parsing of OggPCM (draft 2) headers to liboggz, which allows
seeking and granule->time mappings in OggPCM2 files, and to the tools:

	- oggzinfo displays the samplerate and number of channels
        - oggzdump displays timestamps
	- oggz-validate can validate files with OggPCM2 logical
	  bitstreams
	- oggzrip, oggzdump, oggzdiff can operate on only PCM logical
	  bitstreams through the [--content-type pcm, -c pcm] option

This capability is currently available in liboggz SVN (rev:2062) and
should be available in the next liboggz release (0.9.5).

This has also been installed on http://validator.annodex.org/ , allowing
online validation of OggPCM2 files.

Thanks to Zen (illi) for providing an example OggPCM2 file, produced
with a recent version of his DirectShow filters.

cheers,

Conrad.

On Sun, Feb 12, 2006 at 11:32:18AM +1100, Silvia.Pfeiffer at csiro.au wrote:
> Hi,
> 
> I'd support the view of freezing the main header, since it helps in actually getting some implementation happening and it seems fully agreed on by everyone. FAIK, Zen has already started an implementation and if you, Conrad, implement, too, there is enough code to do validation.
> 
> What do you expect now to make it an "officially frozen" specification? Publish it on the main website at xiph.org?
> 
> What can be done at this point IMHO is to put a note onto the wiki page that the first header is frozen and that implementations are in progress. And make a statement on the remaining issues and discussions thereof on the discussion page.
> 
> I support OggPCM2 as the only PCM format in Ogg, since the majority of discussion, contributions, and now implementations from the community came into this format and we cannot use the same identifier ("PCM") on two different specifications. Also, I haven't seen an implementation of OggPCM yet.
> 
> Cheers,
> Silvia.
> 
> -----Original Message-----
> From:	ogg-dev-bounces at xiph.org on behalf of Jean-Marc Valin
> Sent:	Fri 2/10/2006 11:41 AM
> To:	Conrad Parker
> Cc:	ogg-dev at xiph.org
> Subject:	Re: [ogg-dev] oggpcm2 sample rate
> Hi,
> 
> I also think that outside of the extra headers, OggPCM2 is ready to be
> implemented. I suggest we make the main part (no extra headers)
> "officiel" now. We could always add stuff later on by bumping the minor
> number if really needed. If we go this way, I also suggest we rename it
> to OggPCM just to make sure it doesn't get confusing with the original
> OggPCM.
> 
> Does anyone see a good reason *not* to go forward with that?
> 
> 	Jean-Marc
> 
> On Fri, 2006-02-10 at 10:00 +1100, Conrad Parker wrote:
> > Hi,
> > 
> > although the OggPCM2 draft states that it is a work in progress, it also
> > states that the main points of contention are in optional headers.
> > 
> > I'd like to add OggPCM2 seeking support to liboggz, which will also
> > display correct timestamps in oggzdump and allow oggz-validate to run
> > on OggPCM2 files for testing, while implementations are being
> > developed.
> > 
> > In order to do this, only the Main Header Packet needs to be parsed;
> > hence without requesting that the whole format be frozen, it would be
> > useful to freeze a version of the main header format. (Without
> > releasing the whole format, it will be useful to freeze even just the
> > position of the "Sampling rate" field).
> > 
> > Can we state that? It'd be the first step to start testing implementations
> > of the channel mappings and conversion stuff ...
> > 
> > Conrad.
> > _______________________________________________
> > ogg-dev mailing list
> > ogg-dev at xiph.org
> > http://lists.xiph.org/mailman/listinfo/ogg-dev
> > 
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