[Ffmpeg-devel] Bug in snow revision 1.50 - broken lossless mode

[Yartrebo]

On Wed, 2005-04-13 at 20:52 +0200, Michael Niedermayer wrote:
> Hi
> 
> On Wednesday 13 April 2005 14:53, Yartrebo wrote:
> > In that case, it would be nice to make 5/3 the default for lossless. It
> > really doesn't make snow look good to have the default mode (9/7,
> > lossless) look so ugly.
> 
> the default of option A should not depend on option B, its confusing and 
> problematic, there should be a check for this and the encoder should die with 
> an error if 9/7 is used in lossless mode (patch welcome)
> 
> [...]
I'll send a patch over once I give up on fixing 9/7 + lossless. I feel
like pulling out the big guns and writing a genetic algorithm to attempt
to find the ideal implementation of a reversible 9/7 dwt/idwt transform
that produces the exact same inputs and outputs as your old 9/7
transform.

Right now I fear that lossy mode is ever so slightly compromised and who
knows, the current 9/7 transform might be less than ideal.

Robert