[FFmpeg-devel] [PATCH] Mimic decoder

[Michael Niedermayer]

On Fri, Mar 21, 2008 at 11:01:07PM -0300, Ramiro Polla wrote:
[...]
> >>> 2) Is there any way to enable the bitexact option so that output will be
> >>> consistent across platforms?
> >> Is there anything not bitexact in this decoder? I thought bitexact only 
> >> mattered for encoders with date/time and version info...
> > 
> > Bit exactness is a big problem whenever the letters 'D', 'C', and 'T'
> > are involved. The results are different on x86_32 and PPC (similar, but
> > not bit exact). For more:
> > 
> >   http://guru.multimedia.cx/the-mpeg124-and-h26123-idct/
> 
> How do other codecs (like jpeg) deal with this issue when bitexact is 
> asked for? When I grep for CODEC_FLAG_BITEXACT I don't get much results 
> that seem to work around this.

If -idct simple is use on the command line the simple C idct should be used
and that should give te same output an all archs, dunno if mike forgot that
or there is an actual bug
[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Democracy is the form of government in which you can choose your dictator
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