[FFmpeg-trac] #10993(avfilter:new): "-sws_flags" ignored in "-lavfi" ("-filter_complex")

[FFmpeg]

#10993: "-sws_flags" ignored in "-lavfi" ("-filter_complex")
-------------------------------------+-------------------------------------
             Reporter:               |                    Owner:  (none)
  MasterQuestionable                 |
                 Type:  defect       |                   Status:  new
             Priority:  important    |                Component:  avfilter
              Version:  git-master   |               Resolution:
             Keywords:  sws_flags    |               Blocked By:
  lavfi filter_complex               |
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------

Old description:

> ͏    E.g.
> ("-lavfi" vs. "-vf")
> ͏    ffmpeg -v debug -hide_banner -nostdin -nostats -i
> "W020170309545700291313.jpg" -lavfi "scale=iw/2:-2" -sws_flags
> gauss+accurate_rnd+full_chroma_int -compression_level 1 -pred none
> "scale.lavfi.png"
> ͏    ffmpeg -v debug -hide_banner -nostdin -nostats -i
> "W020170309545700291313.jpg" -vf "scale=iw/2:-2" -sws_flags
> gauss+accurate_rnd+full_chroma_int -compression_level 1 -pred none
> "scale.vf.png"
>
> ͏
> https://web.archive.org/web/20230512231916/http://www.nlc.cn/newgtkj/tssc/mzyj/201703/W020170309545700291313.jpg
>
> ͏    See also:
> ͏    https://stackoverflow.com/questions/55193264#55193912
> ͏    https://trac.ffmpeg.org/wiki/Scaling

New description:

 ͏    E.g.
 ("-lavfi" vs. "-vf")
 ͏    ffmpeg -v debug -hide_banner -nostdin -nostats -i
 "W020170309545700291313.jpg" -lavfi "scale=iw/2:-2" -sws_flags
 gauss+accurate_rnd+print_info -compression_level 1 -pred none
 "scale.lavfi.png"
 ͏    ffmpeg -v debug -hide_banner -nostdin -nostats -i
 "W020170309545700291313.jpg" -vf "scale=iw/2:-2" -sws_flags
 gauss+accurate_rnd+print_info -compression_level 1 -pred none
 "scale.vf.png"

 ͏
 https://web.archive.org/web/20230512231916/http://www.nlc.cn/newgtkj/tssc/mzyj/201703/W020170309545700291313.jpg

 ͏    See also:
 ͏    https://stackoverflow.com/questions/55193264#55193912
 ͏    https://trac.ffmpeg.org/wiki/Scaling

--
Comment (by MasterQuestionable):

 ͏    Thanks for mentioning.

 ͏    ----

 ͏    Matters most:
 ͏    ffmpeg -v debug -hide_banner -nostdin -nostats -i
 "W020170309545700135684.jpg" -i "W020170309545700291313.jpg" -lavfi
 "hstack,format=rgb24" -sws_flags gauss+accurate_rnd+print_info -lossless 1
 -q 100 -compression_level 6 "gauss-full_chroma_int.webp"

 ͏    Per the doc "format" doesn't support "flags":
 ͏    https://ffmpeg.org/ffmpeg-filters.html#format

 ͏    Hacky workaround required:
 ͏    ffmpeg -v debug -hide_banner -nostdin -nostats -i
 "W020170309545700135684.jpg" -i "W020170309545700291313.jpg" -lavfi
 "sws_flags=gauss+accurate_rnd+print_info; hstack,format=rgb24" -lossless 1
 -q 100 -compression_level 6 "gauss-full_chroma_int.webp"
 ͏    (per [ https://ffmpeg.org/ffmpeg-filters.html#Filtergraph-syntax ])

 ͏    And there seems to be no solution for "-sws_dither": which may matter
 at times.
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/10993#comment:2>
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