Script sort MP4 (and other) videos by orientation to portrait and landscape folders >>> IMPOSSIBLE?
You can use the test function provided by fish to compare the two dimensions:
#!/usr/local/bin/fish
for i in *.{mp4,MP4,mov,MOV,m4v,M4V}
  if test (mdls -raw -name kMDItemPixelHeight $i) -gt (mdls -raw -name kMDItemPixelWidth $i)
     mv $i portrait/
  else
     mv $i landscape/
  end
end

bash probably provides the same functionality, but I'm more familiar with fish.