static int split_field_copy(Picture *dest, Picture *src, int parity, int id_add)
{
    int match = !!(src->reference & parity);

    if (match) {
        COPY_PICTURE(dest, src);
        if (parity != PICT_FRAME) {
            pic_as_field(dest, parity);
            dest->pic_id *= 2;
            dest->pic_id += id_add;
        }
    }

    return match;
}