[FFmpeg-devel] [PATCH][RFC] Lagarith Decoder.

Loren Merritt lorenm
Thu Sep 17 16:08:37 CEST 2009

On Thu, 17 Sep 2009, Nathan Caldwell wrote:

> Finally got a chance to look into this, and found the problem, but I'm
> not sure how to fix it.
> What happens is on this clip when the probabilities get scaled in
> lag_read_prob_header(), one of the values gets rounded up instead of
> rounding down like reference does. For the offending value reference
> gives 0x6ff while the code below gives 0x700.

The obvious way is to do software emulation of ieee754 64bit float math 
(or is that intel 80bit float math? or does the reference implementation 
do different things depending on whether it's compiled for x87 or not?)

--Loren Merritt

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