static void FUNCC(pred4x4_top_dc)(uint8_t *_src, const uint8_t *topright, int _stride){
    pixel *src = (pixel*)_src;
    int stride = _stride/sizeof(pixel);
    const int dc= (  src[-stride] + src[1-stride] + src[2-stride] + src[3-stride] + 2) >>2;
    const pixel4 a = PIXEL_SPLAT_X4(dc);

    AV_WN4PA(src+0*stride, a);
    AV_WN4PA(src+1*stride, a);
    AV_WN4PA(src+2*stride, a);
    AV_WN4PA(src+3*stride, a);
}