public static extern long av_rescale_delta(AVRational in_tb, long in_ts, AVRational fs_tb, int duration, long* last, AVRational out_tb);
 public static extern void av_codec_set_pkt_timebase(AVCodecContext* avctx, AVRational val);
 public static extern long av_rescale_q_rnd(long a, AVRational bq, AVRational cq, AVRounding p3);
 public static extern int av_compare_ts(long ts_a, AVRational tb_a, long ts_b, AVRational tb_b);
 public static extern int av_find_nearest_q_idx(AVRational q, AVRational* q_list);
 public static extern long av_rescale_q(long a, AVRational bq, AVRational cq);
 public static extern int av_nearer_q(AVRational q, AVRational q1, AVRational q2);
 public static extern AVRational av_sub_q(AVRational b, AVRational c);
 public static extern AVRational av_add_q(AVRational b, AVRational c);
 public static extern AVRational av_div_q(AVRational b, AVRational c);
 public static extern AVRational av_mul_q(AVRational b, AVRational c);