[FFmpeg-devel] [PATCH 3/3] avfilter/vf_lenscorrection: get rid of floats i init code

Daniel Oberhoff danieloberhoff at gmail.com
Wed Aug 20 14:36:29 CEST 2014


---
 Daniel Oberhoff 
 daniel.oberhoff at gmail.com



On Aug 20, 2014, at 2:33 PM, Michael Niedermayer <michaelni at gmx.at> wrote:

> On Wed, Aug 20, 2014 at 02:23:10PM +0200, Daniel Oberhoff wrote:
>> So we prefer int64_t above float32?
> 
> well, its not exactly making me happy either but its just 2 32x32->64
> operations per pixel which  shouldnt be that bad when we need to do
> 16 multiplications for bicubic per sample
> also at the expense of a bit more space they could be precalculated
> as they dont change between frames
> 
> 
>> I assumed we stick with 32bits for calculations. Did you test this with very large resolutions?
> 
> just tried:
> ./ffplay -f lavfi -i testsrc=s=16385x8192  -vf lenscorrection=0.3:0.2:0.2:0.9,scale=640x48
> which seems working
> 
> 
>> I so congratulation :). I am glad I could push you to finish what I failed to do :).
>> 
>> As I would still like to have interpolation, I assume I shall refactor the interpolation out of perspective and rotation instead, right?

Ok, but by default I would only refactor so far as to support all use cases currently in perspective/rotate/lens_correction, and none more. Do you still think there should be a version/versions of the algorithm for packed formats?


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