avcodec/dsputil: fix signedness in sizeof() comparissions

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
static void h263_v_loop_filter_c(uint8_t *src, int stride, int qscale){
    if(CONFIG_H263_DECODER || CONFIG_H263_ENCODER) {
    int x;
    const int strength= ff_h263_loop_filter_strength[qscale];

    for(x=0; x<8; x++){
        int d1, d2, ad1;
        int p0= src[x-2*stride];
        int p1= src[x-1*stride];
        int p2= src[x+0*stride];
        int p3= src[x+1*stride];
        int d = (p0 - p3 + 4*(p2 - p1)) / 8;

        if     (d<-2*strength) d1= 0;
        else if(d<-  strength) d1=-2*strength - d;
        else if(d<   strength) d1= d;
        else if(d< 2*strength) d1= 2*strength - d;
        else                   d1= 0;

        p1 += d1;
        p2 -= d1;
        if(p1&256) p1= ~(p1>>31);
        if(p2&256) p2= ~(p2>>31);

        src[x-1*stride] = p1;
        src[x+0*stride] = p2;

        ad1= FFABS(d1)>>1;

        d2= av_clip((p0-p3)/4, -ad1, ad1);

        src[x-2*stride] = p0 - d2;
        src[x+  stride] = p3 + d2;
    }
    }
}

static void h263_v_loop_filter_c(uint8_t *src, int stride, int qscale){
    if(CONFIG_H263_DECODER || CONFIG_H263_ENCODER) {
    int x;
    const int strength= ff_h263_loop_filter_strength[qscale];

    for(x=0; x<8; x++){
        int d1, d2, ad1;
        int p0= src[x-2*stride];
        int p1= src[x-1*stride];
        int p2= src[x+0*stride];
        int p3= src[x+1*stride];
        int d = (p0 - p3 + 4*(p2 - p1)) / 8;

        if     (d<-2*strength) d1= 0;
        else if(d<-  strength) d1=-2*strength - d;
        else if(d<   strength) d1= d;
        else if(d< 2*strength) d1= 2*strength - d;
        else                   d1= 0;

        p1 += d1;
        p2 -= d1;
        if(p1&256) p1= ~(p1>>31);
        if(p2&256) p2= ~(p2>>31);

        src[x-1*stride] = p1;
        src[x+0*stride] = p2;

        ad1= FFABS(d1)>>1;

        d2= av_clip((p0-p3)/4, -ad1, ad1);

        src[x-2*stride] = p0 - d2;
        src[x+  stride] = p3 + d2;
    }
    }
}
