[FFmpeg-devel] [PATCH 0/6] dv: of inverse weight tables

Reimar Döffinger Reimar.Doeffinger at gmx.de
Sat Oct 25 13:29:36 CEST 2014


On Sat, Oct 25, 2014 at 01:21:47PM +0200, Christophe Gisquet wrote:
> 2014-10-25 13:19 GMT+02:00 Christophe Gisquet <christophe.gisquet at gmail.com>:
> > Patch #3 uses mathematically more correct values, which happens to match
> > another dv implementation (cedocida). It does not seem to affect that
> > much the decoded output, as there is PSNR variations on the 3rd decimal
> > at most. The best I got was, using a resized version of lena.ppm, a PSNR
> > going from 49.35dB to 49.36dB. It would be ok not to integrate it, as
> > one may argue they were devised with the simple_idct implementation in
> > mind (I haven't checked).
> >
> > Patch #4 fixes the actual issue. As I don't want to bother determining
> > how the table was incorrectly mangled, I've preferred regenerating it.
> 
> And here's a program to regenerate it (hopefully I haven't mangled too
> much when testing other stuff).

Maybe as a patch that puts it into tools?
I don't know if that's the right place, but I would kind of prefer to
have these kind of things around.
Probably overkill, but we have libavcodec/tableprint.h that has helpers
to generate files with tables.


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