[theora-dev] Specific code questions

Monty xiphmont at xiph.org
Sat Sep 14 14:27:55 PDT 2002



> First off, CBitman looks like it has endianness issues; it's packing
> into host-order 32 bit arrays (the comments and symbol names seem to
> indicate that this was originally byte-based packing code that got
> upped to 32 bit.  Either that or someone is a bit confused about a
> byte being 32 bits...)

Ah, Write32ToBuffer is doign the flipping.  What an odd little bitpacker.

(At one point I wrote a 32 bit version of the Ogg bitpacker that did
byte flipping when necessary, and it turned out to be slower than the
8 bit packer we use now.  Also, you have the lowest level bithandling
operations split between several C modules; this will kill any chance
at compiler optimization).

Anyway, it appears that the bitpacker used by VP3 is the exact
opposite packing order used by Ogg... Ah well.

Monty
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