I also would like to use zscale which does not require manual passing of
colorspace options such as
|-pix_fmt|, |-color_range|, |-colorspace|, |-color_primaries|, and
|-color_trc|
Default scaling does not account for the above flags, producing in some
cases washed out colors, see e.g.:
https://video.stackexchange.com/questions/28889/ffmpeg-does-not-preserve-colors-after-resizing/
https://video.stackexchange.com/questions/32383/ffmpeg-vf-scale-shifts-colors-to-washed-out
Presently libzimg2 is packaged in debian repositories, so it can be linked.
