On Thu, Aug 21, 2014 at 10:41:57AM +0200, Daniel Oberhoff wrote: > > --- > Daniel Oberhoff > daniel.oberh...@gmail.com > > > > On Aug 20, 2014, at 4:20 PM, Michael Niedermayer <michae...@gmx.at> wrote: > > > On Wed, Aug 20, 2014 at 03:48:39PM +0200, Daniel Oberhoff wrote: > >> > >> --- > >> Daniel Oberhoff > >> daniel.oberh...@gmail.com > >> > >> > >> > >> On Aug 20, 2014, at 3:11 PM, Michael Niedermayer <michae...@gmx.at> wrote: > >> > >>> On Wed, Aug 20, 2014 at 02:58:50PM +0200, Daniel Oberhoff wrote: > >>>> > >>>> --- > >>>> Daniel Oberhoff > >>>> daniel.oberh...@gmail.com > >>>> > >>>> > >>>> > >>>> On Aug 20, 2014, at 2:55 PM, Michael Niedermayer <michae...@gmx.at> > >>>> wrote: > >>>> > >>>>> On Wed, Aug 20, 2014 at 02:36:29PM +0200, Daniel Oberhoff wrote: > >>>>>> > >>>>>> --- > >>>>>> Daniel Oberhoff > >>>>>> daniel.oberh...@gmail.com > >>>>>> > >>>>>> > >>>>>> > >>>>>> On Aug 20, 2014, at 2:33 PM, Michael Niedermayer <michae...@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. > >>>>> > >>>>> sure > >>>>> > >>>>> > >>>>>> Do you still think there should be a version/versions of the algorithm > >>>>>> for packed formats? > >>>>> > >>>>> i think if we want to add gamma correct interpolation then yes > >>>>> otherwise its probably not worth the work > >>>> > >>>> to be honest: I have no idea about that, do you have pointers for that? > >>>> I.e. what it is, how it works, when it is needed, how it correlates with > >>>> the image representation (i.e. yuv vs rgb, compressed vs full, etc)? > >>> > >>> its very simple > >>> normal every day 8bit per sample rgb and yuv are not "linear", in the > >>> sense that twice the number of photons does not equal twice the > >>> integer value for , lets say red or y > >>> > >>> but interpolation, be that bilinear or bicubic assumes that it is so > >>> so it would be needed to first get linear rgb (which needs more than > >>> 8bits per sample to look good) then interpolate in that and then > >>> to convert back to everyday gamma corrected 8bit per sample rgb > >>> > >>> in principle these correction steps could be done by seperate filters > >>> and RGB48 could be used in vf_lenscorrection then vf_lenscorrection > >>> would not need to know about any of that > >> > >> Right, so by supporting rgb48 that would be effectively supported. Sounds > >> ok to me for the time being as workaround for high quality operation. > > > > yes, theoretically > > in practice we might need something to make it convenient to be used > > requiring the user the manually insert some kind of gamma correction > > filter before and afterwards is a bit inconvenient > > Hey, are you going to push this? Could then start a new resampling patch > tomorrow.
pushed, sorry you didnt say clearly they are ok and you are maitainer so i would have waited a day or 2 before pushing Thanks [...] -- Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB Why not whip the teacher when the pupil misbehaves? -- Diogenes of Sinope
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