[FFmpeg-trac] #10279(undetermined:new): "width not divisible by 2" error with force_original_aspect_ratio=reduce

[FFmpeg]

#10279: "width not divisible by 2" error with force_original_aspect_ratio=reduce
-------------------------------------+-------------------------------------
             Reporter:  php4fan      |                     Type:  defect
               Status:  new          |                 Priority:  normal
            Component:               |                  Version:
  undetermined                       |  unspecified
             Keywords:               |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 Summary of the bug:
 How to reproduce:

 I have a file with a resolution of 480x848.

 I try to convert it with:
 {{{
 ffmpeg -i "input.mp4" -vcodec libx264 -acodec aac -strict -2 -vf
 "scale='min(800,iw)':'min(800,ih)':force_original_aspect_ratio=decrease"
 "output.mp4"
 }}}

 I get the stupid error:
 {{{
 width not divisible by 2 (453x800)
 }}}

 This is stupid, because I'm not giving you an exact width. I'm asking you
 to force the aspect ratio, and 453 is the result of computing a width to
 force the aspect ratio.
 Given that you are computing the width, it's up to you to round it to the
 nearest multiple of 2 if needed. Just like you don't complain about the
 computed width not being an integer, but you silently round to the nearest
 integer, in pretty much the same way you should round it to the nearest
 multiple of 2 (or 4 or whatever the requirement is) if the codec so
 requires.

 According to https://trac.ffmpeg.org/wiki/Scaling:

 > Some codecs require the size of width and height to be
 > a multiple of n. You can achieve this by setting
 > the width or height to -n:
 >   ffmpeg -i input.jpg -vf scale=320:-2 output_320.png

 but I don't see how that would be applicable here.
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/10279>
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