loop:   
    movd        mm0, [esi]
    punpcklbw   mm0, mm7   
    movd        mm2, [esi + ebx]
    punpcklbw   mm2, mm7 
    paddusw     mm4, mm2  
    psubusw     mm4, mm0  
    movq        mm6, mm4  
    psrlw       mm6, mm3  
    packuswb    mm6, mm7   
    movd        [edi], mm6   
    paddusw     mm4, mm2  
    psubusw     mm4, mm0  
    add         edi, eax     
    add         esi, 4  
    sub         ecx, 1 
    jnz         loop