[vorbis-dev] rehuff

OmegaDan dan at morrione.net
Tue Jan 23 15:33:07 PST 2001



May I ask a question? 

Why is the vorbis code generating non-optimal huffman
codes in the first palce?   I seem to recall there is
a greedy algorithim that always produces an optimal
huffman tree? ...

OD

--- Segher Boessenkool <segher at wanadoo.nl> wrote:
> Hiya,
> 
> Here is the sources to my "rehuff" program.
> 
> ./rehuff in.ogg out.ogg
> 
> does a lossless recoding of a vorbis stream. (It
> generates optimal
> huffman codes for the particular stream).
> 
> This code is meant for developers only, until
> someone is kind
> enough to provide good build and configure support
> for it.
> I won't. And no installation help questions please.
> 
> There is a little patch in here, which makes stream
> serialno
> handling easier for decoder programs. This is not
> the right way
> to do it(tm); anyone with better ideas please
> implement. The idea
> is that packet level routines shouldn't have to
> bother with page
> level stuff.
> 
> Oh, and you need to remove the "static" from the
> _vorbis_pack_XXX
> routines in your vorbis source to build rehuff.
> 
> There is a Makefile supplied, but you'll probably
> need to fiddle
> with it a bit.
> 
> Have fun,
> 
> Segher.
> 
> p.s. bit savings results for average streams:
> 
> beta1 5%
> beta2 2%
> beta3 1.3%
> beta4 2%

> ATTACHMENT part 2 application/octet-stream
x-mac-type=54455854; x-mac-creator=74747874;
name=rehuff.tar.bz2

__________________________________________________
Do You Yahoo!?
Yahoo! Auctions - Buy the things you want at great prices. 
http://auctions.yahoo.com/

--- >8 ----
List archives:  http://www.xiph.org/archives/
Ogg project homepage: http://www.xiph.org/ogg/
To unsubscribe from this list, send a message to 'vorbis-dev-request at xiph.org'
containing only the word 'unsubscribe' in the body.  No subject is needed.
Unsubscribe messages sent to the list will be ignored/filtered.



More information about the Vorbis-dev mailing list