nut->curr_frame_start = url_ftell(bc); nut->curr_frame_size = get_v(bc); nut->last_frame_size = get_v(bc); dprintf("Packet: fwd: %d bwd: %d\n", nut->curr_frame_size, nut->last_frame_size);  return 0;
int64_t start, size, last_size; start= url_ftell(bc) - prefix_length;  if(start != nut->packet_start + nut->written_packet_size){ av_log(nut->avf, AV_LOG_ERROR, "get_packetheader called at weird position\n"); return -1; }  size= get_v(bc); last_size= get_v(bc); if(nut->written_packet_size != last_size){ av_log(nut->avf, AV_LOG_ERROR, "packet size missmatch %d != %lld at %lld\n", nut->written_packet_size, last_size, start); return -1; }  nut->last_packet_start = nut->packet_start; nut->packet_start = start; nut->written_packet_size= size;  return size;
static int get_packetheader(NUTContext *nut, ByteIOContext *bc){    nut->curr_frame_start = url_ftell(bc);    nut->curr_frame_size = get_v(bc);    nut->last_frame_size = get_v(bc);    dprintf("Packet: fwd: %d bwd: %d\n",	nut->curr_frame_size, nut->last_frame_size);        return 0;}