static void conv411(uint8_t *dst, int dst_wrap, uint8_t *src, int src_wrap, int width, int height) { int w, c; uint8_t *s1, *s2, *d; for(;height > 0; height--) { s1 = src; s2 = src + src_wrap; d = dst; for(w = width;w > 0; w--) { c = (s1[0] + s2[0]) >> 1; d[0] = c; d[1] = c; s1++; s2++; d += 2; } src += src_wrap * 2; dst += dst_wrap; } }