[FFmpeg-devel] rectification filter

[Daniel Oberhoff]

Am 11.08.2014 um 00:20 schrieb Michael Niedermayer <michaelni at gmx.at>:

> On Sun, Aug 10, 2014 at 08:36:37PM +0200, Daniel Oberhoff wrote:
>> 
>> 
>> Von meinem iPhone gesendet
>> 
>>> Am 10.08.2014 um 17:50 schrieb Michael Niedermayer <michaelni at gmx.at>:
>>> 
>>>> 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
>> 
>> I would like to push now, and try to generate a refactoring patch possibly within the week. 
> 
> sure, feel free to push and send a pull request, or if you prefer
> i can allso apply the patch if you post the latest verision

I am not sure about pull requests (would have to read up on how to do that properly) so rigjht now I would prefer it by patch:



Is that ok?

Best and thanks!

Daniel