assert(acc>=0);
static inline int sse(MpegEncContext *s, uint8_t *src1, uint8_t *src2, int w, int h, int stride){    uint32_t *sq = squareTbl + 256;    int acc=0;    int x,y;        if(w==16 && h==16)         return s->dsp.pix_norm(src1, src2, stride);        for(y=0; y<h; y++){        for(x=0; x<w; x++){            acc+= sq[src1[x + y*stride] - src2[x + y*stride]];        }     }    return acc;}