FFMPEG An Intermediate Guide/cmp

-cmp <string or int> : Full pel motion estimation compare function.

   sad ( 0 ) : Sum of absolute differences, fast ( default ).
   sse ( 1 ) : Sum of squared errors.
   satd ( 2 ) : Sum of absolute Hadamard transformed differences.
   dct ( 3 ) : Sum of absolute DCT transformed differences.
   psnr ( 4 ) : Sum of squared quantization errors ( avoid, low quality ).
   bit ( 5 ) : Number of bits needed for the block.
   rd ( 6 ) : Rate distortion optimal, slow.
   zero ( 7 ) : 0.
   vsad ( 8 ) : Sum of absolute vertical differences.
   vsse ( 9 ) : Sum of squared vertical differences.
   nsse ( 10 ) : Noise preserving sum of squared differences.
   w53 ( 11 ) : 5/3 wavelet ( only used in Snow ).
   w97 ( 12 ) : 9/7 wavelet ( only used in Snow ).
   dctmax ( 13 )
   chroma ( 14 )