[FFmpeg-trac] #10258(undetermined:new): crop filter stops working after zmq change height when crop is the last filter

[FFmpeg]

#10258: crop filter stops working after zmq change height when crop is the last
filter
-------------------------------------+-------------------------------------
             Reporter:  Michael      |                     Type:  defect
  Enke                               |
               Status:  new          |                 Priority:  normal
            Component:               |                  Version:
  undetermined                       |  unspecified
             Keywords:  zmq crop     |               Blocked By:
  freeze                             |
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 Summary of the bug:
 How to reproduce:
 {{{
 % ffplay -f dshow -i video="Integrated Webcam" -vf
 hflip,zmq=b=tcp\\://127.0.0.1\\:13333,crop=w=in_w/2:h=in_h/2
 ffplay version 2023-03-05-git-912ac82a3c-full_build-www.gyan.dev
 }}}
 When sending now a message to crop filter to change h (Parsed_crop_2 h
 in_h), the video display freezes.
 Problem does not occur when
 - changing w
 - crop filter comes before zmq filter
 - behind crop filter, another filter is appended (e.g. vflip)

 As well, the zmq documentation is maybe wrong. It says: zmq must be
 inserted between two video filters
 But it works even zmq is the last or the first video filter.
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/10258>
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