[vorbis] Ogg bitstream spec question

[Aaron Knauf]

Michael Smith wrote:

>On Sunday 27 April 2003 11:06, Aaron Knauf wrote:
>  
>
>>Hi,
>>
>>Is it expected that an Ogg logical bitstream might logically serve as
>>the physical bitstream from which other logical bitstreams might be
>>demuxed?  I am not sure that I really see the point of doing this, but
>>it would certainly be possible within the current spec.
>>    
>>
>
>Do you mean something like having an ogg packet which contains an ogg page for 
>some sub-stream or something like that? Of course, the spec doesn't disallow 
>this, since it doesn't say anything about the contents of the packets, but it 
>certainly doesn't encourage it, and I see no reason why you would do so. 
>
>Or maybe you mean something else, and just failed to express your meaning.
>
You understand my meaning correctly.  I cannot immediatley see a use for 
encapsulating an Ogg stream inside another Ogg stream, but that doesn't 
mean it is not useful.  This is essentially the same as IP tunnelling - 
which has an enormous variety of uses.

>
>  
>
>>The trouble is that there are any number of ways to do the low-level
>>muxing of several streams into one logical stream, with respect to
>>paging and packetization.  This makes it harder to write generic code
>>for performing this muxing/demuxing.
>>
>>If some basic packetization/paging rules were defined, such a having one
>>page encoded into one packet it would allow for some useful coding
>>shortcuts to be taken during the decode process.
>>
>>    
>>
>
>We're not going to change the bitstream format so that your implementation can 
>be slightly more convenient. The format is fixed (though future versions may 
>differ, of course).
>
Woah!  What happened to open source?  Community effort?  Listening to 
your users?  You sound like you personally own the Ogg project.  Do you 
speak for everyone at Xiph.Org?  Such a rude rebuff of someone that is 
making a feature suggestion reminds me of the kind of service I get from 
the help desks of closed source products - not what I have become used 
to from the (large number of) other open source projects with which I 
have been involved.  If you want the Ogg project to live beyond your own 
personal input, you might want to reconsider that point of view.

I am more than 70% through the implementation of the Ogg bitstream spec 
(in prep for vorbis decoder and then encoder implementations), which (if 
there is any interest) I intend to make freely available once complete. 
 Isn't this exactly what Xiph.Org professes to encourage?  Or does that 
encouragement extend only as long as you happen to agree with everything 
that I have to say?

FYI - I am not suggesting modifying any existing spec.  Nor am I 
suggesting anything specific to any implementation.  I am /asking/ 
whether or not it is considered useful to tunnel Ogg within Ogg and 
/suggesting/ that an additional spec that defines a standard mechanism 
for tunnelling Ogg within Ogg (similar to the way in which the Vorbis 
spec specifies Vorbis-in-Ogg) would be useful if that were the case.  I 
take it from your obvious bemusement that you do not consider it useful. 
 The usual way to express that sentiment on an open source project is to 
outline the reasons for your disagreement - not to flat out refuse to 
entertain the notion.

ADK

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