[xiph-rtp] About wkc

[Luca Barbato]

One of the remaining points to discuss is about static defined and well 
known configurations. I doesn't make much sense supporting that for 
vorbis and theora, but I got that request.

Current status of the section:

- Define it as an out of band delivery method as any other possible

- The uri provided tell where to fetch the full batch/list of 
Configurations and a checksum is provided to validate it

- Start counting the Ident for wkc from 2^23 (or just use the odd ones, 
depending on which endian you like more)

- you MUST always provide another way to fetch them (compatibility)

Pros:
- Doesn't alter anything in the currently defined structure

Cons:
- It has a fixed set of Idents reserved for wkc

Neutral consideration
- It will provide full configurations so it could even make LESS sense
- Someone could abuse/misuse it, degrading the quality of the encoded files.

Possible improvements

- Specify an optional offset for the Ident count for every Config 
delivery method so that you can reserve just the right amount of Idents 
for each use [keep in mind that everything is a special case of a 
special case (chaining inside the same rtp session) and shouldn't be 
used very often)]

- Redefine a bit the configuration format to
	- Send Configurations w/out the codebooks
	- have a Well known list of codebooks.

Those changes are relatively simple but I'm not so keen in adding 
complexity for a feature that is hard to use properly and that got 
already people against.

I hope to get some feedback about this issue.

lu

-- 

Luca Barbato

Gentoo/linux Developer		Gentoo/PPC Operational Leader
http://dev.gentoo.org/~lu_zero