static int decode_frame(NUTContext *nut, AVPacket *pkt, int frame_code){
AVFormatContext *s= nut->avf;
ByteIOContext *bc = &s->pb;
static int decode_frame(NUTContext *nut, AVPacket *pkt, int frame_code){
AVFormatContext *s= nut->avf;
ByteIOContext *bc = &s->pb;