void ff_interleave_add_packet(AVFormatContext *s, AVPacket *pkt,
                              int (*compare)(AVFormatContext *, AVPacket *, AVPacket *))
{
    AVPacketList **next_point, *this_pktl;

    this_pktl      = av_mallocz(sizeof(AVPacketList));
    this_pktl->pkt = *pkt;
#if FF_API_DESTRUCT_PACKET
FF_DISABLE_DEPRECATION_WARNINGS
    pkt->destruct  = NULL;           // do not free original but only the copy
FF_ENABLE_DEPRECATION_WARNINGS
#endif
    pkt->buf       = NULL;
    av_dup_packet(&this_pktl->pkt);  // duplicate the packet if it uses non-alloced memory

    if (s->streams[pkt->stream_index]->last_in_packet_buffer) {
        next_point = &(s->streams[pkt->stream_index]->last_in_packet_buffer->next);
    } else
        next_point = &s->packet_buffer;

    if (*next_point) {
        if (compare(s, &s->packet_buffer_end->pkt, pkt)) {
            while (!compare(s, &(*next_point)->pkt, pkt))
                next_point = &(*next_point)->next;
            goto next_non_null;
        } else {
            next_point = &(s->packet_buffer_end->next);
        }
    }
    assert(!*next_point);

    s->packet_buffer_end = this_pktl;
next_non_null:

    this_pktl->next = *next_point;

    s->streams[pkt->stream_index]->last_in_packet_buffer =
        *next_point                                      = this_pktl;
}