[FFmpeg-trac] #8590(undetermined:closed): 'telecine=pattern' error for p24, soft telecined sources

[FFmpeg]

#8590: 'telecine=pattern' error for p24, soft telecined sources
-------------------------------------+-------------------------------------
             Reporter:  markfilipak  |                    Owner:
                 Type:  defect       |                   Status:  closed
             Priority:  normal       |                Component:
                                     |  undetermined
              Version:  unspecified  |               Resolution:  invalid
             Keywords:               |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------

Comment (by pdr0):

 Replying to [comment:25 markfilipak]:
 > I did this:
 > ffmpeg -i 23.976p.mp4 -vf "telecine=pattern=5" telecine=pattern=5.mkv
 >
 > When I play telecine=pattern=5.mkv via MPV, and I single-step, it is
 doing exactly what I expected and wanted.
 >
 > I did this:
 > ffmpeg -i 23.976p.mp4 -vf "telecine=pattern=5,bwdif=mode=send_frame"
 telecine=pattern=5,bwdif=mode=send_frame.mkv
 >
 > The problem with telecine=pattern=5,bwdif=mode=send_frame.mkv is that in
 each 1/6sec, all 10 frames are being decombed instead of just the 2 frames
 that actually are combed.
 > P P C P P P P C P P
 > Decombing a progressive picture shouldn't do anything, but apparently it
 is (very slight). But so what?
 >
 > So, this 5-5-5-5 DOES appear to be doing what I want.


 You would need a deinterlacer that either deinterlaces based on specific
 frames (e.g. every nth frame), or based on a combing threshold. The former
 can be problematic if there is a cadence break . The latter is adaptive
 but some types of content might be incorrectly deinterlaced, or some
 missed

 But the judder would be no different when 60fps is returned . If you
 single rate deinterlace , with top field first, in frames notation you
 would get AAABBCCCDD . BFF would return AABBBCCDDD . This is 3:2 frame
 repeats or 2:3 frame repeats. In terms of cadence, that's the same as 24pN
 displayed on a 60Hz display

--
Ticket URL: <https://trac.ffmpeg.org/ticket/8590#comment:26>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker