[FFmpeg-trac] #9201(undetermined:reopened): -c:v mpeg2video ignoring -qmin+qmax

[FFmpeg]

#9201: -c:v mpeg2video ignoring -qmin+qmax
-------------------------------------+-------------------------------------
             Reporter:  Warren       |                    Owner:  (none)
  Young                              |
                 Type:  defect       |                   Status:  reopened
             Priority:  normal       |                Component:
                                     |  undetermined
              Version:  unspecified  |               Resolution:
             Keywords:               |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
Comment (by IvanDSM):

 I'm having this issue with both FFmpeg 7.1.1-5 and the latest BtbN auto
 build as of writing (2025-09-04 14:22,
 ffmpeg-N-120970-g9ee7796c54-linux64-gpl.tar.xz from
 https://github.com/BtbN/FFmpeg-
 Builds/releases/tag/autobuild-2025-09-04-14-22).

 Here's my command line:

 {{{
 ffmpeg -threads 4 -i "Original/Petscop 11 [nXHUw2nw6aA].webm" -i
 "Original/Petscop 11 [nXHUw2nw6aA].en.idx" -vf
 scale=w=720:h=480:flags=lanczos+accurate_rnd+full_chroma_int,setsar=1,setdar=4/3,colorspace=iall=bt709:all=smpte170m:range=tv:format=yuv420p:dither=fsb
 -c:v mpeg2video -dc 10 -g 18 -trellis 2 -cmp rd -subcmp rd -mbcmp rd
 -precmp rd -mbd rd -b_strategy 2 -bidir_refine 4 -b:v 1024k -maxrate:v
 1575k -bufsize:v 921.6k -qsquish 1 -qmin 4 -dct faan -dia_size 4096
 -mpv_flags +mv0 -c:a ac3 -dsur_mode 0 -original 1 -dsurex_mode 0
 -dheadphone_mode 0 -b:a 160k -c:s dvdsub -pass 1 Encoded/pet11_1stpass.mkv
 }}}

 And the relevant output line:

 {{{
   Stream #0:0: Video: mpeg2video (Main) (mpg2 / 0x3267706D), yuv420p(tv,
 smpte170m, progressive), 720x480 [SAR 8:9 DAR 4:3], q=2-31, 1024 kb/s, 30
 fps, 1k tbn (default)
 }}}

 Changing {{{-qmin 4}}}'s position has no effect. Different {{{-qmin}}}
 values have no effect. {{{-qmax}}} also has no effect.

 Please let me know of anything I can do to help with this issue. I'm
 willing to test anything, and can do so relatively quickly.
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/9201#comment:4>
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