[FFmpeg-user] Seeking smart decomb filter

[Paul B Mahol]

On Thu, Jan 21, 2021 at 2:34 PM Mark Filipak (ffmpeg) <markfilipak at bog.us>
wrote:

> On 01/21/2021 07:54 AM, Paul B Mahol wrote:
> > On Thu, Jan 21, 2021 at 1:51 PM Mark Filipak (ffmpeg) <
> markfilipak at bog.us>
> > wrote:
> >
> >> On 01/21/2021 07:31 AM, Paul B Mahol wrote:
> >>> On Thu, Jan 21, 2021 at 12:51 PM Mark Filipak (ffmpeg) <
> >> markfilipak at bog.us>
> >>> wrote:
> >>>
> >>>> On 01/20/2021 04:50 PM, Paul B Mahol wrote:
> >>>>> On Wed, Jan 20, 2021 at 10:45 PM Mark Filipak (ffmpeg) <
> >>>> markfilipak at bog.us>
> >>>>> wrote:
> >>>>>> On 01/20/2021 06:17 AM, Paul B Mahol wrote:
> >>>>>>> Motion compensation does not work that way.
> >>>>>>
> >>>>>> Thank you, Paul. Yes, I knew that. I'm not seeking motion
> >> compensation.
> >>>>>> Kindly reread my filter
> >>>>>> features and suggest what comes closest. What I seek simply works on
> >>>>>> pixels. I'm relying on your
> >>>>>> experience (and perhaps the experiences of others here).
> >>>>>
> >>>>> Have you tried nnedi or estdif filters? Both are intra only
> >>>> deinterlacers.
> >>>>
> >>>> Thank you for the guidance. I'm trying estdif first because it seems
> >>>> simpler, but it doesn't do the
> >>>> good thing. It does decomb very effectively, but it does it by
> aligning
> >>>> (shifting) the edges in
> >>>> field'2' to the edges in field'1' (which are not shifted). Aligning
> with
> >>>> field'1' produces judder
> >>>> (or in my case, doesn't eliminate judder). What I want it to do is
> align
> >>>> both field'1' edges and
> >>>> field'2' edges to the median (i.e. half way between the input's
> edges).
> >> I
> >>>> do realize that such a
> >>>> method would introduce combing along the edges of the frame, but
> that's
> >>>> okay.
> >>>>
> >>>> Here's the command I used to transcode 24FPS to 60FPS:
> >>>> ffmpeg -i 24[1][2].mkv -map 0 -filter_complex "telecine=pattern=5,
> >>>> split[1][2],
> >>>> [1]select=not(eq(mod(n\,5)\,2))[3], [2]select=eq(mod(n\,5)\,2),
> >>>> estdif=mode=frame[4],
> >>>> [3][4]interleave" -codec:v libx265 -x265-params "crf=16:qcomp=0.60"
> >>>> -codec:a copy -codec:s copy
> >>>> 24[1][2]-to-60[1][1][estdif=mode=frame(1~2)][2][2].mkv
> >>>>
> >>>> I'll try nnedi. Perhaps I can figure it out.
> >>>>
> >>>
> >>> Do not even try.
> >>> Mentioned filters work only with interlaced frames, while your use case
> >> is
> >>> completely invalid and frowned upon.
> >>> I deeply regret replying to this thread.
> >>
> >> I did get nnedi to work but with similar results to estdif.
> >>
> >> Kindly educate me: What do you mean by "interlaced frames"? Aren't all
> >> frames that come out of the
> >> decoder and into the filter chain interlaced?
> >>
> >> Why do you say that my use case is invalid? telecine=pattern=5 works
> very
> >> well -- there's no judder
> >> at all! And if, for the combed frame, I use pp=linblenddeint, it's even
> >> better, far better than what
> >> either the NVIDIA GPU or the TV does when fed a 24FPS source and of
> course
> >> far, far better than
> >> telecine=pattern=23.
> >>
> >> Please educate me. Why are my stunning results invalid?
> >>
> >
> > Because you are trying to interpolate new frames using telecine filter.
>
> I am? I apologize for not being clear...
>
> The source is 24FPS. 'telecine=pattern=5' makes a 60FPS target with frames
> 0 & 1 == source frame 0,
> and frames 3 & 4 == source frame 1. Target frame 2 (i.e. the target frame
> in the middle) is combed
> of course. What I'm trying to do is decomb it. How is that interpolating
> new frames? Educate me. And
> if it is interpolating new frames, what's wrong with that? -- It looks
> stunning on a 60Hz TV whereas
> 24FPS fed to a 60Hz TV has serious judder.
>

You want to decomb telecined frames. But telecine already used existing
frames to create combed frames.
So you actually seek frame that is between these two fields in combed
frame, you cant create it by some nonsense tricks.


>
> >> Regards,
> >> Mark.
> >>
> >>>> Thanks again,
> >>>> Mark.
> >>>>
> >>>>>> Regards,
> >>>>>> Mark.
> >>>>>>
> >>>>>>> On Wed, Jan 20, 2021 at 2:45 AM Mark Filipak (ffmpeg) <
> >>>>>> markfilipak at bog.us>
> >>>>>>> wrote:
> >>>>>>>
> >>>>>>>> Hello All,
> >>>>>>>>
> >>>>>>>> I seek a decomb filter that operates on H/2 number of line pairs:
> >>>> lines
> >>>>>> i
> >>>>>>>> & i+1 (where i=0..H/2-1),
> >>>>>>>> by aligning edges in the two lines at x = delta-x(edge)/2 (i.e.
> the
> >>>>>>>> median). The ideal filter would
> >>>>>>>> differentiate overall motion due to panning versus local motion
> due
> >> to
> >>>>>>>> local object motion.
> >>>>>>>>
> >>>>>>>> Pan-combing on the left & right edges is acceptable but it would
> be
> >> a
> >>>>>>>> great bonus if the filter
> >>>>>>>> performed blend on those edges with the blending radius equal to
> >>>>>> one-half
> >>>>>>>> the pan-comb.
> >>>>>>>>
> >>>>>>>> Vertical, line-pair-to-line-pair processing is not needed or
> >> desired.
> >>>>>>>>
> >>>>>>>> Frame-to-frame processing is not needed or desired.
> >>>>>>>>
> >>>>>>>> I have been trying a great number of filters based on their names
> >> and
> >>>>>> what
> >>>>>>>> is in the documentation.
> >>>>>>>> The best I've found so far is pp=linblenddeint but it obviously
> >>>> doesn't
> >>>>>>>> align edges via the edge
> >>>>>>>> median and it obviously isn't aware of pan-combing versus
> >>>>>>>> object-motion-combing.
> >>>>>>>>
> >>>>>>>> Any suggestions are very welcome. If I find this filter I will
> post
> >> a
> >>>>>> link
> >>>>>>>> to a 60FPS telecined
> >>>>>>>> video that will amaze everyone -- better than anything that Cuda
> can
> >>>> do.
> >>>>>>>>
> >>>>>>>> -Mark.
>
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