maintainer-feedback requested: [Bug 262368] multimedia/ffmpeg: enable SVTAV1 on amd64 by default

Bugzilla Automation <bugzilla@FreeBSD.org> has asked freebsd-multimedia
(Nobody) <multimedia@FreeBSD.org> for maintainer-feedback:
Bug 262368: multimedia/ffmpeg: enable SVTAV1 on amd64 by default
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=262368



--- Description ---
SVT-AV1 is a mature implementation of a fast AV1 encoder. It makes heavy use of
threads and SIMD assembly thus better suited for live streaming (realtime
encoding).

$ ffmpeg -hide_banner -h encoder=libsvtav1
Encoder libsvtav1 [SVT-AV1(Scalable Video Technology for AV1) encoder]:
    General capabilities: delay threads
    Threading capabilities: other
    Supported pixel formats: yuv420p yuv420p10le
libsvtav1 AVOptions:
  -hielevel	     <int>	  E..V....... Hierarchical prediction levels
setting (from 3 to 4) (default 4level)
     3level	     3		  E..V.......
     4level	     4		  E..V.......
  -la_depth	     <int>	  E..V....... Look ahead distance [0, 120]
(from -1 to 120) (default -1)
  -preset	     <int>	  E..V....... Encoding preset (from -1 to 13)
(default -1)
  -tier 	     <int>	  E..V....... Set operating point tier (from 0
to 1) (default main)
     main	     0		  E..V.......
     high	     1		  E..V.......
  -crf		     <int>	  E..V....... Constant Rate Factor value (from
0 to 63) (default 0)
  -qp		     <int>	  E..V....... Initial Quantizer level value
(from 0 to 63) (default 0)
  -sc_detection      <boolean>	  E..V....... Scene change detection (default
false)
  -tile_columns      <int>	  E..V....... Log2 of number of tile columns to
use (from 0 to 4) (default 0)
  -tile_rows	     <int>	  E..V....... Log2 of number of tile rows to
use (from 0 to 6) (default 0)
  -svtav1-params     <dictionary> E..V....... Set the SVT-AV1 configuration
using a :-separated list of key=value parameters

$ fetch https://media.xiph.org/video/derf/y4m/pedestrian_area_1080p25.y4m

$ ffmpeg -hide_banner -benchmark -i pedestrian_area_1080p25.y4m -c:v libsvtav1
-crf 20 -y test.libsvtav1.mp4
[...]
bench: utime=20.564s stime=0.948s rtime=3.545s
bench: maxrss=1032284kB

$ ffmpeg -hide_banner -benchmark -i pedestrian_area_1080p25.y4m -c:v libaom-av1
-cpu-used 8 -usage realtime -crf 20 -y test.libaom-av1.mp4
[...]
bench: utime=49.713s stime=0.230s rtime=16.220s
bench: maxrss=206744kB