[FFmpeg-trac] #4785(avfilter:closed): Decimate filter doesn't work when used directly with fieldmatch

[FFmpeg]

#4785: Decimate filter doesn't work when used directly with fieldmatch
-------------------------------------+-------------------------------------
             Reporter:  Detergent    |                    Owner:
                 Type:  defect       |                   Status:  closed
             Priority:  normal       |                Component:  avfilter
              Version:  git-master   |               Resolution:  invalid
             Keywords:  fieldmatch   |               Blocked By:
  decimate pullup                    |  Reproduced by developer:  0
             Blocking:               |
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------

Comment (by cehoyos):

 {{{fieldmatch}}} does not work the way you expect it to work, it never
 duplicates frames. You can use the following filterchain to do what you
 want, unfortunately, {{{decimate}}} sometimes drops the wrong frame:
 {{{-vf fps=30000/1001,fieldmatch,decimate}}}
 It works fine for a clean, bright sample like the one you uploaded afaict.

--
Ticket URL: <https://trac.ffmpeg.org/ticket/4785#comment:13>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker