[FFmpeg-devel] rectification filter

Michael Niedermayer michaelni at gmx.at
Sun Aug 10 17:50:13 CEST 2014

On Sun, Aug 10, 2014 at 03:36:04PM +0200, Nicolas George wrote:
> Le tridi 23 thermidor, an CCXXII, Paul B Mahol a écrit :
> > It is not mandatory(but it would be nice) to add other methods to have
> > this filter included into libavfilter.
> Is it really a good idea? We would end up with various interpolation /
> anti-aliasing algorithms implemented in each filter that needs it, none of
> them with the same set of architecture optimizations and each with its own
> set of bugs and misfeatures.

> Until someone comes up with a really satisfactory solution, I believe the
> simple solution of suggesting users to upscale before the filter and
> downscale after, using the optimized lswr scalers, is better.

thats not practical
a 1024x768 image would need to be upscaled to 262144x196608 to get
8bit precission from a nearest neighbor resampler as basis

also see vf_perspective.c which supports bilinear and bicubic
interpolation, these surely could be shared and exist already.

of course we could push it with just nearest neighbor and work on that
later, but i dont think only nearest neighbor and leaving it at that
is a reasonable choice, its too poor quality wise


Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Many that live deserve death. And some that die deserve life. Can you give
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