MpegEncContext * const s = &h->s;
static void free_tables(H264Context *h){    MpegEncContext * const s = &h->s;    av_freep(&h->intra4x4_pred_mode);    av_freep(&h->non_zero_count);    av_freep(&h->slice_table_base);    h->slice_table= NULL;        av_freep(&h->mb2b_xy);    av_freep(&h->mb2b8_xy);}