On Fri, Jan 16, 2015 at 08:48:59PM -0800, Philip Langdale wrote: > On Fri, 16 Jan 2015 22:17:56 +0100 > Nicolas George <geo...@nsup.org> wrote: > > > Le septidi 27 nivôse, an CCXXIII, Philip Langdale a écrit : > > > Right. It is display aspect ratio, not sample aspect ratio. And then > > > you have the 45/44 problem, unless that's somehow just affecting me. > > > > IIRC, the tests you ran were not accurate enough to know for sure. I > > suggest the following test case: > > > > - start with a 832 × 448 input (testsrc=s=832x448 should do the > > trick); > > > > - force darWidth / darHeight = 19 / 17 (patching the source directly > > seems like the simplest way of doing it for this kind of tests); > > > > - encode to H.265 elementary stream; > > > > - check the output file with the ffmpeg summary AND ffprobe > > -show_stream AND ffmpeg -vf showinfo -f null -. > > > > The numbers are selected with unambiguous prime factors. > > > > I do not have access to nvidia hardware, so I can not run the tests. > > Ok. I did this test and it produces correct results - SAR 133:221 which > yields the correct final aspect ratio, but if I try and do a real world > case, like my PAL DVD, it goes wrong - and Timo's patch goes wrong too, > with this same weird 1.02 (45/44) scale factor. > > It's making my head hurt. > > So I feed in this input: > > Stream #0:0: Video: rawvideo (RGB[24] / 0x18424752), rgb24, 720x576 > [SAR 64:45 DAR 16:9], 25 tbr, 25 tbn, 25 tbc > > With libx264, I get the same SAR and DAR out. > > With nvenc, I get: > > sample_aspect_ratio=16:11 > display_aspect_ratio=20:11 > > which is everything off by ~1.02.
this leaves the explanation that "nvidias stuff is buggy" as the obvious explanation [...] -- Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB Democracy is the form of government in which you can choose your dictator
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