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

Christophe Gisquet christophe.gisquet at gmail.com
Sat Oct 25 13:21:47 CEST 2014

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).

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