[Ffmpeg-devel] Compilation with --enable-theora fails

[Måns Rullgård]

Michael Niedermayer <michaelni at gmx.at> writes:

> Hi
>
> On Wednesday 11 May 2005 20:42, Rich Felker wrote:
> [...]
>> ogg2's vorbis demuxing for an example, although that's currently buggy
>> (using int16 is stupid/limited). 
>
> yes
>
>> We had a discussion on IRC last night 
>> about how to fix it (basically duplicating the vorbis header packing
>> used as a defacto standard in Matroska) which someone will probably
>> implement soon.
>
> i agree, but not because the solution is good, just becasue it
> avoids the mess of 2 different ways to store the headers
>
> the packing used for the vorbis headers (as in libavformat/matroska.c) has 
> overhead of 
> O(n/255) 
> while get/put_v borrowed from nut.c would have 
> O(log2(n)/7)
>
> so for 128-254 your suggestion would be 1 byte while 2 for get/put_v
> for all others get/put_v would be equal or shorter
>
> for 1mb put/get_v would need 3 bytes while your suggestion would need 4113 
> bytes

IMHO, simply using 32 bits would be perfectly acceptable.  A header
size of 4GB seems rather unlikely, and an overhead of 4 bytes per file
isn't really anything to make fuss about.

Also IMHO, the matroska method should not be encouraged.

-- 
M?ns Rullg?rd
mru at inprovide.com