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

15.3x speedup:

yuyv422
  14513 UNITS in yuv2packed1,   32768 runs,      0 skips
    949 UNITS in yuv2packed1,   32767 runs,      1 skips
yvyu422
  14516 UNITS in yuv2packed1,   32767 runs,      1 skips
    943 UNITS in yuv2packed1,   32767 runs,      1 skips
uyvy422
  14530 UNITS in yuv2packed1,   32767 runs,      1 skips
    941 UNITS in yuv2packed1,   32766 runs,      2 skips