./ffmpeg -f lavfi -i yuvtestsrc=duration=1:size=1200x1440 \
    -s 2400x720 -f rawvideo -y -vframes 5 -pix_fmt yuv420p16le -nostats test.raw

2.26 speedup (x86 SSE2 is 2.32):
  23772 UNITS in hscale,    4096 runs,      0 skips
  53862 UNITS in hscale,    4096 runs,      0 skips