./ffmpeg -f lavfi -i yuvtestsrc=duration=1:size=1200x1440 -sws_flags area \
                -s 1200x720 -f null -vframes 100 -pix_fmt $i -nostats \
                -cpuflags 0 -v error -

5.1x speedup:

yuyv422
  19339 UNITS in yuv2packed2,   16384 runs,      0 skips
   3718 UNITS in yuv2packed2,   16383 runs,      1 skips
yvyu422
  19438 UNITS in yuv2packed2,   16384 runs,      0 skips
   3800 UNITS in yuv2packed2,   16380 runs,      4 skips
uyvy422
  19128 UNITS in yuv2packed2,   16384 runs,      0 skips
   3721 UNITS in yuv2packed2,   16380 runs,      4 skips