| 
							- /*
 -  * "NUT" Container Format muxer and demuxer (DRAFT-200403??)
 -  * Copyright (c) 2003 Alex Beregszaszi
 -  * Copyright (c) 2004 Michael Niedermayer
 -  *
 -  * This file is part of FFmpeg.
 -  *
 -  * FFmpeg is free software; you can redistribute it and/or
 -  * modify it under the terms of the GNU Lesser General Public
 -  * License as published by the Free Software Foundation; either
 -  * version 2.1 of the License, or (at your option) any later version.
 -  *
 -  * FFmpeg is distributed in the hope that it will be useful,
 -  * but WITHOUT ANY WARRANTY; without even the implied warranty of
 -  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 -  * Lesser General Public License for more details.
 -  *
 -  * You should have received a copy of the GNU Lesser General Public
 -  * License along with FFmpeg; if not, write to the Free Software
 -  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 -  *
 -  *
 -  * Visit the official site at http://www.nut.hu/
 -  *
 -  */
 - 
 - /*
 -  * TODO:
 -  * - index writing
 -  * - index packet reading support
 - */
 - 
 - //#define DEBUG 1
 - 
 - #include <limits.h>
 - #include "avformat.h"
 - #include "mpegaudio.h"
 - #include "riff.h"
 - #include "adler32.h"
 - 
 - #undef NDEBUG
 - #include <assert.h>
 - 
 - //#define TRACE
 - 
 - //from /dev/random
 - 
 - #define     MAIN_STARTCODE (0x7A561F5F04ADULL + (((uint64_t)('N'<<8) + 'M')<<48))
 - #define   STREAM_STARTCODE (0x11405BF2F9DBULL + (((uint64_t)('N'<<8) + 'S')<<48))
 - #define KEYFRAME_STARTCODE (0xE4ADEECA4569ULL + (((uint64_t)('N'<<8) + 'K')<<48))
 - #define    INDEX_STARTCODE (0xDD672F23E64EULL + (((uint64_t)('N'<<8) + 'X')<<48))
 - #define     INFO_STARTCODE (0xAB68B596BA78ULL + (((uint64_t)('N'<<8) + 'I')<<48))
 - 
 - #define ID_STRING "nut/multimedia container\0"
 - 
 - #define MAX_DISTANCE (1024*16-1)
 - #define MAX_SHORT_DISTANCE (1024*4-1)
 - 
 - #define FLAG_DATA_SIZE       1
 - #define FLAG_KEY_FRAME       2
 - #define FLAG_INVALID         4
 - 
 - typedef struct {
 -     uint8_t flags;
 -     uint8_t stream_id_plus1;
 -     uint16_t size_mul;
 -     uint16_t size_lsb;
 -     int16_t timestamp_delta;
 -     uint8_t reserved_count;
 - } FrameCode;
 - 
 - typedef struct {
 -     int last_key_frame;
 -     int msb_timestamp_shift;
 -     int rate_num;
 -     int rate_den;
 -     int64_t last_pts;
 -     int64_t last_sync_pos;                    ///<pos of last 1/2 type frame
 -     int decode_delay;
 - } StreamContext;
 - 
 - typedef struct {
 -     AVFormatContext *avf;
 -     int written_packet_size;
 -     int64_t packet_start[3]; //0-> startcode less, 1-> short startcode 2-> long startcodes
 -     FrameCode frame_code[256];
 -     unsigned int stream_count;
 -     uint64_t next_startcode;     ///< stores the next startcode if it has alraedy been parsed but the stream isnt seekable
 -     StreamContext *stream;
 -     int max_distance;
 -     int max_short_distance;
 -     int rate_num;
 -     int rate_den;
 -     int short_startcode;
 - } NUTContext;
 - 
 - static char *info_table[][2]={
 -         {NULL                   ,  NULL }, // end
 -         {NULL                   ,  NULL },
 -         {NULL                   , "UTF8"},
 -         {NULL                   , "v"},
 -         {NULL                   , "s"},
 -         {"StreamId"             , "v"},
 -         {"SegmentId"            , "v"},
 -         {"StartTimestamp"       , "v"},
 -         {"EndTimestamp"         , "v"},
 -         {"Author"               , "UTF8"},
 -         {"Title"                , "UTF8"},
 -         {"Description"          , "UTF8"},
 -         {"Copyright"            , "UTF8"},
 -         {"Encoder"              , "UTF8"},
 -         {"Keyword"              , "UTF8"},
 -         {"Cover"                , "JPEG"},
 -         {"Cover"                , "PNG"},
 - };
 - 
 - static void update(NUTContext *nut, int stream_index, int64_t frame_start, int frame_type, int frame_code, int key_frame, int size, int64_t pts){
 -     StreamContext *stream= &nut->stream[stream_index];
 - 
 -     stream->last_key_frame= key_frame;
 -     nut->packet_start[ frame_type ]= frame_start;
 -     stream->last_pts= pts;
 - }
 - 
 - static void reset(AVFormatContext *s, int64_t global_ts){
 -     NUTContext *nut = s->priv_data;
 -     int i;
 - 
 -     for(i=0; i<s->nb_streams; i++){
 -         StreamContext *stream= &nut->stream[i];
 - 
 -         stream->last_key_frame= 1;
 - 
 -         stream->last_pts= av_rescale(global_ts, stream->rate_num*(int64_t)nut->rate_den, stream->rate_den*(int64_t)nut->rate_num);
 -     }
 - }
 - 
 - static void build_frame_code(AVFormatContext *s){
 -     NUTContext *nut = s->priv_data;
 -     int key_frame, index, pred, stream_id;
 -     int start=0;
 -     int end= 255;
 -     int keyframe_0_esc= s->nb_streams > 2;
 -     int pred_table[10];
 - 
 -     if(keyframe_0_esc){
 -         /* keyframe = 0 escape */
 -         FrameCode *ft= &nut->frame_code[start];
 -         ft->flags= FLAG_DATA_SIZE;
 -         ft->stream_id_plus1= 0;
 -         ft->size_mul=1;
 -         ft->timestamp_delta=0;
 -         start++;
 -     }
 - 
 -     for(stream_id= 0; stream_id<s->nb_streams; stream_id++){
 -         int start2= start + (end-start)*stream_id / s->nb_streams;
 -         int end2  = start + (end-start)*(stream_id+1) / s->nb_streams;
 -         AVCodecContext *codec = s->streams[stream_id]->codec;
 -         int is_audio= codec->codec_type == CODEC_TYPE_AUDIO;
 -         int intra_only= /*codec->intra_only || */is_audio;
 -         int pred_count;
 - 
 -         for(key_frame=0; key_frame<2; key_frame++){
 -             if(intra_only && keyframe_0_esc && key_frame==0)
 -                 continue;
 - 
 -             {
 -                 FrameCode *ft= &nut->frame_code[start2];
 -                 ft->flags= FLAG_KEY_FRAME*key_frame;
 -                 ft->flags|= FLAG_DATA_SIZE;
 -                 ft->stream_id_plus1= stream_id + 1;
 -                 ft->size_mul=1;
 -                 ft->timestamp_delta=0;
 -                 start2++;
 -             }
 -         }
 - 
 -         key_frame= intra_only;
 - #if 1
 -         if(is_audio){
 -             int frame_bytes= codec->frame_size*(int64_t)codec->bit_rate / (8*codec->sample_rate);
 -             int pts;
 -             for(pts=0; pts<2; pts++){
 -                 for(pred=0; pred<2; pred++){
 -                     FrameCode *ft= &nut->frame_code[start2];
 -                     ft->flags= FLAG_KEY_FRAME*key_frame;
 -                     ft->stream_id_plus1= stream_id + 1;
 -                     ft->size_mul=frame_bytes + 2;
 -                     ft->size_lsb=frame_bytes + pred;
 -                     ft->timestamp_delta=pts;
 -                     start2++;
 -                 }
 -             }
 -         }else{
 -             FrameCode *ft= &nut->frame_code[start2];
 -             ft->flags= FLAG_KEY_FRAME | FLAG_DATA_SIZE;
 -             ft->stream_id_plus1= stream_id + 1;
 -             ft->size_mul=1;
 -             ft->timestamp_delta=1;
 -             start2++;
 -         }
 - #endif
 - 
 -         if(codec->has_b_frames){
 -             pred_count=5;
 -             pred_table[0]=-2;
 -             pred_table[1]=-1;
 -             pred_table[2]=1;
 -             pred_table[3]=3;
 -             pred_table[4]=4;
 -         }else if(codec->codec_id == CODEC_ID_VORBIS){
 -             pred_count=3;
 -             pred_table[0]=2;
 -             pred_table[1]=9;
 -             pred_table[2]=16;
 -         }else{
 -             pred_count=1;
 -             pred_table[0]=1;
 -         }
 - 
 -         for(pred=0; pred<pred_count; pred++){
 -             int start3= start2 + (end2-start2)*pred / pred_count;
 -             int end3  = start2 + (end2-start2)*(pred+1) / pred_count;
 - 
 -             for(index=start3; index<end3; index++){
 -                 FrameCode *ft= &nut->frame_code[index];
 -                 ft->flags= FLAG_KEY_FRAME*key_frame;
 -                 ft->flags|= FLAG_DATA_SIZE;
 -                 ft->stream_id_plus1= stream_id + 1;
 - //FIXME use single byte size and pred from last
 -                 ft->size_mul= end3-start3;
 -                 ft->size_lsb= index - start3;
 -                 ft->timestamp_delta= pred_table[pred];
 -             }
 -         }
 -     }
 -     memmove(&nut->frame_code['N'+1], &nut->frame_code['N'], sizeof(FrameCode)*(255-'N'));
 -     nut->frame_code['N'].flags= FLAG_INVALID;
 - }
 - 
 - static uint64_t get_v(ByteIOContext *bc)
 - {
 -     uint64_t val = 0;
 - 
 -     for(;;)
 -     {
 -         int tmp = get_byte(bc);
 - 
 -         if (tmp&0x80)
 -             val= (val<<7) + tmp - 0x80;
 -         else{
 - //av_log(NULL, AV_LOG_DEBUG, "get_v()= %"PRId64"\n", (val<<7) + tmp);
 -             return (val<<7) + tmp;
 -         }
 -     }
 -     return -1;
 - }
 - 
 - static int get_str(ByteIOContext *bc, char *string, unsigned int maxlen){
 -     unsigned int len= get_v(bc);
 - 
 -     if(len && maxlen)
 -         get_buffer(bc, string, FFMIN(len, maxlen));
 -     while(len > maxlen){
 -         get_byte(bc);
 -         len--;
 -     }
 - 
 -     if(maxlen)
 -         string[FFMIN(len, maxlen-1)]= 0;
 - 
 -     if(maxlen == len)
 -         return -1;
 -     else
 -         return 0;
 - }
 - 
 - static int64_t get_s(ByteIOContext *bc){
 -     int64_t v = get_v(bc) + 1;
 - 
 -     if (v&1) return -(v>>1);
 -     else     return  (v>>1);
 - }
 - 
 - static uint64_t get_vb(ByteIOContext *bc){
 -     uint64_t val=0;
 -     unsigned int i= get_v(bc);
 - 
 -     if(i>8)
 -         return UINT64_MAX;
 - 
 -     while(i--)
 -         val = (val<<8) + get_byte(bc);
 - 
 - //av_log(NULL, AV_LOG_DEBUG, "get_vb()= %"PRId64"\n", val);
 -     return val;
 - }
 - 
 - #ifdef TRACE
 - static inline uint64_t get_v_trace(ByteIOContext *bc, char *file, char *func, int line){
 -     uint64_t v= get_v(bc);
 - 
 -     printf("get_v %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
 -     return v;
 - }
 - 
 - static inline int64_t get_s_trace(ByteIOContext *bc, char *file, char *func, int line){
 -     int64_t v= get_s(bc);
 - 
 -     printf("get_s %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
 -     return v;
 - }
 - 
 - static inline uint64_t get_vb_trace(ByteIOContext *bc, char *file, char *func, int line){
 -     uint64_t v= get_vb(bc);
 - 
 -     printf("get_vb %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
 -     return v;
 - }
 - #define get_v(bc)  get_v_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 - #define get_s(bc)  get_s_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 - #define get_vb(bc)  get_vb_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 - #endif
 - 
 - 
 - static int get_packetheader(NUTContext *nut, ByteIOContext *bc, int calculate_checksum)
 - {
 -     int64_t start, size;
 -     start= url_ftell(bc) - 8;
 - 
 -     size= get_v(bc);
 - 
 -     init_checksum(bc, calculate_checksum ? av_adler32_update : NULL, 1);
 - 
 -     nut->packet_start[2] = start;
 -     nut->written_packet_size= size;
 - 
 -     return size;
 - }
 - 
 - static int check_checksum(ByteIOContext *bc){
 -     unsigned long checksum= get_checksum(bc);
 -     return checksum != get_be32(bc);
 - }
 - 
 - /**
 -  *
 -  */
 - static int get_length(uint64_t val){
 -     int i;
 - 
 -     for (i=7; val>>i; i+=7);
 - 
 -     return i;
 - }
 - 
 - static uint64_t find_any_startcode(ByteIOContext *bc, int64_t pos){
 -     uint64_t state=0;
 - 
 -     if(pos >= 0)
 -         url_fseek(bc, pos, SEEK_SET); //note, this may fail if the stream isnt seekable, but that shouldnt matter, as in this case we simply start where we are currently
 - 
 -     while(!url_feof(bc)){
 -         state= (state<<8) | get_byte(bc);
 -         if((state>>56) != 'N')
 -             continue;
 -         switch(state){
 -         case MAIN_STARTCODE:
 -         case STREAM_STARTCODE:
 -         case KEYFRAME_STARTCODE:
 -         case INFO_STARTCODE:
 -         case INDEX_STARTCODE:
 -             return state;
 -         }
 -     }
 - 
 -     return 0;
 - }
 - 
 - /**
 -  * find the given startcode.
 -  * @param code the startcode
 -  * @param pos the start position of the search, or -1 if the current position
 -  * @returns the position of the startcode or -1 if not found
 -  */
 - static int64_t find_startcode(ByteIOContext *bc, uint64_t code, int64_t pos){
 -     for(;;){
 -         uint64_t startcode= find_any_startcode(bc, pos);
 -         if(startcode == code)
 -             return url_ftell(bc) - 8;
 -         else if(startcode == 0)
 -             return -1;
 -         pos=-1;
 -     }
 - }
 - 
 - static int64_t lsb2full(StreamContext *stream, int64_t lsb){
 -     int64_t mask = (1<<stream->msb_timestamp_shift)-1;
 -     int64_t delta= stream->last_pts - mask/2;
 -     return  ((lsb - delta)&mask) + delta;
 - }
 - 
 - #ifdef CONFIG_MUXERS
 - 
 - static void put_v(ByteIOContext *bc, uint64_t val)
 - {
 -     int i;
 - 
 - //av_log(NULL, AV_LOG_DEBUG, "put_v()= %"PRId64"\n", val);
 -     val &= 0x7FFFFFFFFFFFFFFFULL; // FIXME can only encode upto 63 bits currently
 -     i= get_length(val);
 - 
 -     for (i-=7; i>0; i-=7){
 -         put_byte(bc, 0x80 | (val>>i));
 -     }
 - 
 -     put_byte(bc, val&0x7f);
 - }
 - 
 - /**
 -  * stores a string as vb.
 -  */
 - static void put_str(ByteIOContext *bc, const char *string){
 -     int len= strlen(string);
 - 
 -     put_v(bc, len);
 -     put_buffer(bc, string, len);
 - }
 - 
 - static void put_s(ByteIOContext *bc, int64_t val){
 -     if (val<=0) put_v(bc, -2*val  );
 -     else        put_v(bc,  2*val-1);
 - }
 - 
 - static void put_vb(ByteIOContext *bc, uint64_t val){
 -     int i;
 - 
 -     for (i=8; val>>i; i+=8);
 - 
 -     put_v(bc, i>>3);
 -     for(i-=8; i>=0; i-=8)
 -         put_byte(bc, (val>>i)&0xFF);
 - }
 - 
 - #ifdef TRACE
 - static inline void put_v_trace(ByteIOContext *bc, uint64_t v, char *file, char *func, int line){
 -     printf("get_v %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
 - 
 -     put_v(bc, v);
 - }
 - 
 - static inline void put_s_trace(ByteIOContext *bc, int64_t v, char *file, char *func, int line){
 -     printf("get_s %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
 - 
 -     put_s(bc, v);
 - }
 - 
 - static inline void put_vb_trace(ByteIOContext *bc, uint64_t v, char *file, char *func, int line){
 -     printf("get_vb %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
 - 
 -     put_vb(bc, v);
 - }
 - #define put_v(bc, v)  put_v_trace(bc, v, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 - #define put_s(bc, v)  put_s_trace(bc, v, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 - #define put_vb(bc, v)  put_vb_trace(bc, v, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 - #endif
 - 
 - static int put_packetheader(NUTContext *nut, ByteIOContext *bc, int max_size, int calculate_checksum)
 - {
 -     put_flush_packet(bc);
 -     nut->packet_start[2]= url_ftell(bc) - 8;
 -     nut->written_packet_size = max_size;
 - 
 -     /* packet header */
 -     put_v(bc, nut->written_packet_size); /* forward ptr */
 - 
 -     if(calculate_checksum)
 -         init_checksum(bc, av_adler32_update, 1);
 - 
 -     return 0;
 - }
 - 
 - /**
 -  *
 -  * must not be called more then once per packet
 -  */
 - static int update_packetheader(NUTContext *nut, ByteIOContext *bc, int additional_size, int calculate_checksum){
 -     int64_t start= nut->packet_start[2];
 -     int64_t cur= url_ftell(bc);
 -     int size= cur - start - get_length(nut->written_packet_size)/7 - 8;
 - 
 -     if(calculate_checksum)
 -         size += 4;
 - 
 -     if(size != nut->written_packet_size){
 -         int i;
 - 
 -         assert( size <= nut->written_packet_size );
 - 
 -         url_fseek(bc, start + 8, SEEK_SET);
 -         for(i=get_length(size); i < get_length(nut->written_packet_size); i+=7)
 -             put_byte(bc, 0x80);
 -         put_v(bc, size);
 - 
 -         url_fseek(bc, cur, SEEK_SET);
 -         nut->written_packet_size= size; //FIXME may fail if multiple updates with differing sizes, as get_length may differ
 - 
 -         if(calculate_checksum)
 -             put_be32(bc, get_checksum(bc));
 -     }
 - 
 -     return 0;
 - }
 - 
 - static int nut_write_header(AVFormatContext *s)
 - {
 -     NUTContext *nut = s->priv_data;
 -     ByteIOContext *bc = &s->pb;
 -     AVCodecContext *codec;
 -     int i, j, tmp_time, tmp_flags,tmp_stream, tmp_mul, tmp_size, tmp_fields;
 - 
 -     if (strcmp(s->filename, "./data/b-libav.nut")) {
 -         av_log(s, AV_LOG_ERROR, " libavformat NUT is non-compliant and disabled\n");
 -         return -1;
 -     }
 - 
 -     nut->avf= s;
 - 
 -     nut->stream =
 -         av_mallocz(sizeof(StreamContext)*s->nb_streams);
 - 
 - 
 -     put_buffer(bc, ID_STRING, strlen(ID_STRING));
 -     put_byte(bc, 0);
 -     nut->packet_start[2]= url_ftell(bc);
 - 
 -     /* main header */
 -     put_be64(bc, MAIN_STARTCODE);
 -     put_packetheader(nut, bc, 120+5*256, 1);
 -     put_v(bc, 2); /* version */
 -     put_v(bc, s->nb_streams);
 -     put_v(bc, MAX_DISTANCE);
 -     put_v(bc, MAX_SHORT_DISTANCE);
 - 
 -     put_v(bc, nut->rate_num=1);
 -     put_v(bc, nut->rate_den=2);
 -     put_v(bc, nut->short_startcode=0x4EFE79);
 - 
 -     build_frame_code(s);
 -     assert(nut->frame_code['N'].flags == FLAG_INVALID);
 - 
 -     tmp_time= tmp_flags= tmp_stream= tmp_mul= tmp_size= /*tmp_res=*/ INT_MAX;
 -     for(i=0; i<256;){
 -         tmp_fields=0;
 -         tmp_size= 0;
 -         if(tmp_time   != nut->frame_code[i].timestamp_delta) tmp_fields=1;
 -         if(tmp_mul    != nut->frame_code[i].size_mul       ) tmp_fields=2;
 -         if(tmp_stream != nut->frame_code[i].stream_id_plus1) tmp_fields=3;
 -         if(tmp_size   != nut->frame_code[i].size_lsb       ) tmp_fields=4;
 - //        if(tmp_res    != nut->frame_code[i].res            ) tmp_fields=5;
 - 
 -         tmp_time  = nut->frame_code[i].timestamp_delta;
 -         tmp_flags = nut->frame_code[i].flags;
 -         tmp_stream= nut->frame_code[i].stream_id_plus1;
 -         tmp_mul   = nut->frame_code[i].size_mul;
 -         tmp_size  = nut->frame_code[i].size_lsb;
 - //        tmp_res   = nut->frame_code[i].res;
 - 
 -         for(j=0; i<256; j++,i++){
 -             if(nut->frame_code[i].timestamp_delta != tmp_time  ) break;
 -             if(nut->frame_code[i].flags           != tmp_flags ) break;
 -             if(nut->frame_code[i].stream_id_plus1 != tmp_stream) break;
 -             if(nut->frame_code[i].size_mul        != tmp_mul   ) break;
 -             if(nut->frame_code[i].size_lsb        != tmp_size+j) break;
 - //            if(nut->frame_code[i].res             != tmp_res   ) break;
 -         }
 -         if(j != tmp_mul - tmp_size) tmp_fields=6;
 - 
 -         put_v(bc, tmp_flags);
 -         put_v(bc, tmp_fields);
 -         if(tmp_fields>0) put_s(bc, tmp_time);
 -         if(tmp_fields>1) put_v(bc, tmp_mul);
 -         if(tmp_fields>2) put_v(bc, tmp_stream);
 -         if(tmp_fields>3) put_v(bc, tmp_size);
 -         if(tmp_fields>4) put_v(bc, 0 /*tmp_res*/);
 -         if(tmp_fields>5) put_v(bc, j);
 -     }
 - 
 -     update_packetheader(nut, bc, 0, 1);
 - 
 -     /* stream headers */
 -     for (i = 0; i < s->nb_streams; i++)
 -     {
 -         int nom, denom, ssize;
 - 
 -         codec = s->streams[i]->codec;
 - 
 -         put_be64(bc, STREAM_STARTCODE);
 -         put_packetheader(nut, bc, 120 + codec->extradata_size, 1);
 -         put_v(bc, i /*s->streams[i]->index*/);
 -         switch(codec->codec_type){
 -         case CODEC_TYPE_VIDEO: put_v(bc, 0); break;
 -         case CODEC_TYPE_AUDIO: put_v(bc, 1); break;
 - //        case CODEC_TYPE_TEXT : put_v(bc, 2); break;
 -         case CODEC_TYPE_DATA : put_v(bc, 3); break;
 -         default: return -1;
 -         }
 -         if (codec->codec_tag)
 -             put_vb(bc, codec->codec_tag);
 -         else if (codec->codec_type == CODEC_TYPE_VIDEO)
 -         {
 -             put_vb(bc, codec_get_bmp_tag(codec->codec_id));
 -         }
 -         else if (codec->codec_type == CODEC_TYPE_AUDIO)
 -         {
 -             put_vb(bc, codec_get_wav_tag(codec->codec_id));
 -         }
 -         else
 -             put_vb(bc, 0);
 - 
 -         ff_parse_specific_params(codec, &nom, &ssize, &denom);
 - 
 -         nut->stream[i].rate_num= nom;
 -         nut->stream[i].rate_den= denom;
 -         av_set_pts_info(s->streams[i], 60, denom, nom);
 - 
 -         put_v(bc, codec->bit_rate);
 -         put_vb(bc, 0); /* no language code */
 -         put_v(bc, nom);
 -         put_v(bc, denom);
 -         if(nom / denom < 1000)
 -             nut->stream[i].msb_timestamp_shift = 7;
 -         else
 -             nut->stream[i].msb_timestamp_shift = 14;
 -         put_v(bc, nut->stream[i].msb_timestamp_shift);
 -         put_v(bc, codec->has_b_frames);
 -         put_byte(bc, 0); /* flags: 0x1 - fixed_fps, 0x2 - index_present */
 - 
 -         if(codec->extradata_size){
 -             put_v(bc, 1);
 -             put_v(bc, codec->extradata_size);
 -             put_buffer(bc, codec->extradata, codec->extradata_size);
 -         }
 -         put_v(bc, 0); /* end of codec specific headers */
 - 
 -         switch(codec->codec_type)
 -         {
 -             case CODEC_TYPE_AUDIO:
 -                 put_v(bc, codec->sample_rate);
 -                 put_v(bc, 1);
 -                 put_v(bc, codec->channels);
 -                 break;
 -             case CODEC_TYPE_VIDEO:
 -                 put_v(bc, codec->width);
 -                 put_v(bc, codec->height);
 -                 put_v(bc, codec->sample_aspect_ratio.num);
 -                 put_v(bc, codec->sample_aspect_ratio.den);
 -                 put_v(bc, 0); /* csp type -- unknown */
 -                 break;
 -             default:
 -                 break;
 -         }
 -         update_packetheader(nut, bc, 0, 1);
 -     }
 - 
 -     /* info header */
 -     put_be64(bc, INFO_STARTCODE);
 -     put_packetheader(nut, bc, 30+strlen(s->author)+strlen(s->title)+
 -         strlen(s->comment)+strlen(s->copyright)+strlen(LIBAVFORMAT_IDENT), 1);
 -     if (s->author[0])
 -     {
 -         put_v(bc, 9); /* type */
 -         put_str(bc, s->author);
 -     }
 -     if (s->title[0])
 -     {
 -         put_v(bc, 10); /* type */
 -         put_str(bc, s->title);
 -     }
 -     if (s->comment[0])
 -     {
 -         put_v(bc, 11); /* type */
 -         put_str(bc, s->comment);
 -     }
 -     if (s->copyright[0])
 -     {
 -         put_v(bc, 12); /* type */
 -         put_str(bc, s->copyright);
 -     }
 -     /* encoder */
 -     if(!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)){
 -         put_v(bc, 13); /* type */
 -         put_str(bc, LIBAVFORMAT_IDENT);
 -     }
 - 
 -     put_v(bc, 0); /* eof info */
 -     update_packetheader(nut, bc, 0, 1);
 - 
 -     put_flush_packet(bc);
 - 
 -     return 0;
 - }
 - 
 - static int nut_write_packet(AVFormatContext *s, AVPacket *pkt)
 - {
 -     NUTContext *nut = s->priv_data;
 -     StreamContext *stream= &nut->stream[pkt->stream_index];
 -     ByteIOContext *bc = &s->pb;
 -     int key_frame = 0, full_pts=0;
 -     AVCodecContext *enc;
 -     int64_t coded_pts;
 -     int frame_type, best_length, frame_code, flags, i, size_mul, size_lsb, time_delta;
 -     const int64_t frame_start= url_ftell(bc);
 -     int64_t pts= pkt->pts;
 -     int size= pkt->size;
 -     int stream_index= pkt->stream_index;
 - 
 -     enc = s->streams[stream_index]->codec;
 -     key_frame = !!(pkt->flags & PKT_FLAG_KEY);
 - 
 -     frame_type=0;
 -     if(frame_start + size + 20 - FFMAX(nut->packet_start[1], nut->packet_start[2]) > MAX_DISTANCE)
 -         frame_type=2;
 -     if(key_frame && !stream->last_key_frame)
 -         frame_type=2;
 - 
 -     if(frame_type>1){
 -         int64_t global_ts= av_rescale(pts, stream->rate_den*(int64_t)nut->rate_num, stream->rate_num*(int64_t)nut->rate_den);
 -         reset(s, global_ts);
 -         put_be64(bc, KEYFRAME_STARTCODE);
 -         put_v(bc, global_ts);
 -     }
 -     assert(stream->last_pts != AV_NOPTS_VALUE);
 -     coded_pts = pts & ((1<<stream->msb_timestamp_shift)-1);
 -     if(lsb2full(stream, coded_pts) != pts)
 -         full_pts=1;
 - 
 -     if(full_pts)
 -         coded_pts= pts + (1<<stream->msb_timestamp_shift);
 - 
 -     best_length=INT_MAX;
 -     frame_code= -1;
 -     for(i=0; i<256; i++){
 -         int stream_id_plus1= nut->frame_code[i].stream_id_plus1;
 -         int fc_key_frame;
 -         int length=0;
 -         size_mul= nut->frame_code[i].size_mul;
 -         size_lsb= nut->frame_code[i].size_lsb;
 -         time_delta= nut->frame_code[i].timestamp_delta;
 -         flags= nut->frame_code[i].flags;
 - 
 -         assert(size_mul > size_lsb);
 - 
 -         if(stream_id_plus1 == 0) length+= get_length(stream_index);
 -         else if(stream_id_plus1 - 1 != stream_index)
 -             continue;
 -         fc_key_frame= !!(flags & FLAG_KEY_FRAME);
 - 
 -         assert(key_frame==0 || key_frame==1);
 -         if(fc_key_frame != key_frame)
 -             continue;
 - 
 -         if(flags & FLAG_DATA_SIZE){
 -             if(size % size_mul != size_lsb)
 -                 continue;
 -             length += get_length(size / size_mul);
 -         }else if(size != size_lsb)
 -             continue;
 - 
 -         if(full_pts && time_delta)
 -             continue;
 - 
 -         if(!time_delta){
 -             length += get_length(coded_pts);
 -         }else{
 -             if(time_delta != pts - stream->last_pts)
 -                 continue;
 -         }
 - 
 -         if(length < best_length){
 -             best_length= length;
 -             frame_code=i;
 -         }
 - //    av_log(s, AV_LOG_DEBUG, "%d %d %d %d %d %d %d %d %d %d\n", key_frame, frame_type, full_pts, size, stream_index, flags, size_mul, size_lsb, stream_id_plus1, length);
 -     }
 - 
 -     assert(frame_code != -1);
 -     flags= nut->frame_code[frame_code].flags;
 -     size_mul= nut->frame_code[frame_code].size_mul;
 -     size_lsb= nut->frame_code[frame_code].size_lsb;
 -     time_delta= nut->frame_code[frame_code].timestamp_delta;
 - #ifdef TRACE
 -     best_length /= 7;
 -     best_length ++; //frame_code
 -     if(frame_type==2){
 -         best_length += 8; // startcode
 -     }
 -     av_log(s, AV_LOG_DEBUG, "kf:%d ft:%d pt:%d fc:%2X len:%2d size:%d stream:%d flag:%d mul:%d lsb:%d s+1:%d pts_delta:%d pts:%"PRId64" fs:%"PRId64"\n", key_frame, frame_type, full_pts ? 1 : 0, frame_code, best_length, size, stream_index, flags, size_mul, size_lsb, nut->frame_code[frame_code].stream_id_plus1,(int)(pts - stream->last_pts), pts, frame_start);
 - //    av_log(s, AV_LOG_DEBUG, "%d %d %d\n", stream->lru_pts_delta[0], stream->lru_pts_delta[1], stream->lru_pts_delta[2]);
 - #endif
 - 
 -     assert(frame_type != 1); //short startcode not implemented yet
 -     put_byte(bc, frame_code);
 - 
 -     if(nut->frame_code[frame_code].stream_id_plus1 == 0)
 -         put_v(bc, stream_index);
 -     if (!time_delta){
 -         put_v(bc, coded_pts);
 -     }
 -     if(flags & FLAG_DATA_SIZE)
 -         put_v(bc, size / size_mul);
 -     else
 -         assert(size == size_lsb);
 -     if(size > MAX_DISTANCE){
 -         assert(frame_type > 1);
 -     }
 - 
 -     put_buffer(bc, pkt->data, size);
 - 
 -     update(nut, stream_index, frame_start, frame_type, frame_code, key_frame, size, pts);
 - 
 -     return 0;
 - }
 - 
 - static int nut_write_trailer(AVFormatContext *s)
 - {
 -     NUTContext *nut = s->priv_data;
 -     ByteIOContext *bc = &s->pb;
 - 
 - #if 0
 -     int i;
 - 
 -     /* WRITE INDEX */
 - 
 -     for (i = 0; s->nb_streams; i++)
 -     {
 -         put_be64(bc, INDEX_STARTCODE);
 -         put_packetheader(nut, bc, 64, 1);
 -         put_v(bc, s->streams[i]->id);
 -         put_v(bc, ...);
 -         update_packetheader(nut, bc, 0, 1);
 -     }
 - #endif
 - 
 -     put_flush_packet(bc);
 - 
 -     av_freep(&nut->stream);
 - 
 -     return 0;
 - }
 - #endif //CONFIG_MUXERS
 - 
 - static int nut_probe(AVProbeData *p)
 - {
 -     int i;
 -     uint64_t code= 0xff;
 - 
 -     for (i = 0; i < p->buf_size; i++) {
 -         code = (code << 8) | p->buf[i];
 -         if (code == MAIN_STARTCODE)
 -             return AVPROBE_SCORE_MAX;
 -     }
 -     return 0;
 - }
 - 
 - static int decode_main_header(NUTContext *nut){
 -     AVFormatContext *s= nut->avf;
 -     ByteIOContext *bc = &s->pb;
 -     uint64_t tmp;
 -     int i, j, tmp_stream, tmp_mul, tmp_time, tmp_size, count, tmp_res;
 - 
 -     get_packetheader(nut, bc, 1);
 - 
 -     tmp = get_v(bc);
 -     if (tmp != 2){
 -         av_log(s, AV_LOG_ERROR, "bad version (%"PRId64")\n", tmp);
 -         return -1;
 -     }
 - 
 -     nut->stream_count = get_v(bc);
 -     if(nut->stream_count > MAX_STREAMS){
 -         av_log(s, AV_LOG_ERROR, "too many streams\n");
 -         return -1;
 -     }
 -     nut->max_distance = get_v(bc);
 -     nut->max_short_distance = get_v(bc);
 -     nut->rate_num= get_v(bc);
 -     nut->rate_den= get_v(bc);
 -     nut->short_startcode= get_v(bc);
 -     if(nut->short_startcode>>16 != 'N'){
 -         av_log(s, AV_LOG_ERROR, "invalid short startcode %X\n", nut->short_startcode);
 -         return -1;
 -     }
 - 
 -     for(i=0; i<256;){
 -         int tmp_flags = get_v(bc);
 -         int tmp_fields= get_v(bc);
 -         if(tmp_fields>0) tmp_time  = get_s(bc);
 -         if(tmp_fields>1) tmp_mul   = get_v(bc);
 -         if(tmp_fields>2) tmp_stream= get_v(bc);
 -         if(tmp_fields>3) tmp_size  = get_v(bc);
 -         else             tmp_size  = 0;
 -         if(tmp_fields>4) tmp_res   = get_v(bc);
 -         else             tmp_res   = 0;
 -         if(tmp_fields>5) count     = get_v(bc);
 -         else             count     = tmp_mul - tmp_size;
 - 
 -         while(tmp_fields-- > 6)
 -            get_v(bc);
 - 
 -         if(count == 0 || i+count > 256){
 -             av_log(s, AV_LOG_ERROR, "illegal count %d at %d\n", count, i);
 -             return -1;
 -         }
 -         if(tmp_stream > nut->stream_count + 1){
 -             av_log(s, AV_LOG_ERROR, "illegal stream number\n");
 -             return -1;
 -         }
 - 
 -         for(j=0; j<count; j++,i++){
 -             nut->frame_code[i].flags           = tmp_flags ;
 -             nut->frame_code[i].timestamp_delta = tmp_time  ;
 -             nut->frame_code[i].stream_id_plus1 = tmp_stream;
 -             nut->frame_code[i].size_mul        = tmp_mul   ;
 -             nut->frame_code[i].size_lsb        = tmp_size+j;
 -             nut->frame_code[i].reserved_count  = tmp_res   ;
 -         }
 -     }
 -     if(nut->frame_code['N'].flags != FLAG_INVALID){
 -         av_log(s, AV_LOG_ERROR, "illegal frame_code table\n");
 -         return -1;
 -     }
 - 
 -     if(check_checksum(bc)){
 -         av_log(s, AV_LOG_ERROR, "Main header checksum mismatch\n");
 -         return -1;
 -     }
 - 
 -     return 0;
 - }
 - 
 - static int decode_stream_header(NUTContext *nut){
 -     AVFormatContext *s= nut->avf;
 -     ByteIOContext *bc = &s->pb;
 -     int class, nom, denom, stream_id;
 -     uint64_t tmp;
 -     AVStream *st;
 - 
 -     get_packetheader(nut, bc, 1);
 -     stream_id= get_v(bc);
 -     if(stream_id >= nut->stream_count || s->streams[stream_id])
 -         return -1;
 - 
 -     st = av_new_stream(s, stream_id);
 -     if (!st)
 -         return AVERROR_NOMEM;
 - 
 -     class = get_v(bc);
 -     tmp = get_vb(bc);
 -     st->codec->codec_tag= tmp;
 -     switch(class)
 -     {
 -         case 0:
 -             st->codec->codec_type = CODEC_TYPE_VIDEO;
 -             st->codec->codec_id = codec_get_bmp_id(tmp);
 -             if (st->codec->codec_id == CODEC_ID_NONE)
 -                 av_log(s, AV_LOG_ERROR, "Unknown codec?!\n");
 -             break;
 -         case 1:
 -         case 32: //compatibility
 -             st->codec->codec_type = CODEC_TYPE_AUDIO;
 -             st->codec->codec_id = codec_get_wav_id(tmp);
 -             if (st->codec->codec_id == CODEC_ID_NONE)
 -                 av_log(s, AV_LOG_ERROR, "Unknown codec?!\n");
 -             break;
 -         case 2:
 - //            st->codec->codec_type = CODEC_TYPE_TEXT;
 - //            break;
 -         case 3:
 -             st->codec->codec_type = CODEC_TYPE_DATA;
 -             break;
 -         default:
 -             av_log(s, AV_LOG_ERROR, "Unknown stream class (%d)\n", class);
 -             return -1;
 -     }
 -     s->bit_rate += get_v(bc);
 -     get_vb(bc); /* language code */
 -     nom = get_v(bc);
 -     denom = get_v(bc);
 -     nut->stream[stream_id].msb_timestamp_shift = get_v(bc);
 -     st->codec->has_b_frames=
 -     nut->stream[stream_id].decode_delay= get_v(bc);
 -     get_byte(bc); /* flags */
 - 
 -     /* codec specific data headers */
 -     while(get_v(bc) != 0){
 -         st->codec->extradata_size= get_v(bc);
 -         if((unsigned)st->codec->extradata_size > (1<<30))
 -             return -1;
 -         st->codec->extradata= av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
 -         get_buffer(bc, st->codec->extradata, st->codec->extradata_size);
 - //            url_fskip(bc, get_v(bc));
 -     }
 - 
 -     if (st->codec->codec_type == CODEC_TYPE_VIDEO) /* VIDEO */
 -     {
 -         st->codec->width = get_v(bc);
 -         st->codec->height = get_v(bc);
 -         st->codec->sample_aspect_ratio.num= get_v(bc);
 -         st->codec->sample_aspect_ratio.den= get_v(bc);
 -         get_v(bc); /* csp type */
 -     }
 -     if (st->codec->codec_type == CODEC_TYPE_AUDIO) /* AUDIO */
 -     {
 -         st->codec->sample_rate = get_v(bc);
 -         get_v(bc); // samplerate_den
 -         st->codec->channels = get_v(bc);
 -     }
 -     if(check_checksum(bc)){
 -         av_log(s, AV_LOG_ERROR, "Stream header %d checksum mismatch\n", stream_id);
 -         return -1;
 -     }
 -     av_set_pts_info(s->streams[stream_id], 60, denom, nom);
 -     nut->stream[stream_id].rate_num= nom;
 -     nut->stream[stream_id].rate_den= denom;
 -     return 0;
 - }
 - 
 - static int decode_info_header(NUTContext *nut){
 -     AVFormatContext *s= nut->avf;
 -     ByteIOContext *bc = &s->pb;
 - 
 -     get_packetheader(nut, bc, 1);
 - 
 -     for(;;){
 -         int id= get_v(bc);
 -         char *name, *type, custom_name[256], custom_type[256];
 - 
 -         if(!id)
 -             break;
 -         else if(id >= sizeof(info_table)/sizeof(info_table[0])){
 -             av_log(s, AV_LOG_ERROR, "info id is too large %d %zd\n", id, sizeof(info_table)/sizeof(info_table[0]));
 -             return -1;
 -         }
 - 
 -         type= info_table[id][1];
 -         name= info_table[id][0];
 - //av_log(s, AV_LOG_DEBUG, "%d %s %s\n", id, type, name);
 - 
 -         if(!type){
 -             get_str(bc, custom_type, sizeof(custom_type));
 -             type= custom_type;
 -         }
 -         if(!name){
 -             get_str(bc, custom_name, sizeof(custom_name));
 -             name= custom_name;
 -         }
 - 
 -         if(!strcmp(type, "v")){
 -             get_v(bc);
 -         }else{
 -             if(!strcmp(name, "Author"))
 -                 get_str(bc, s->author, sizeof(s->author));
 -             else if(!strcmp(name, "Title"))
 -                 get_str(bc, s->title, sizeof(s->title));
 -             else if(!strcmp(name, "Copyright"))
 -                 get_str(bc, s->copyright, sizeof(s->copyright));
 -             else if(!strcmp(name, "Description"))
 -                 get_str(bc, s->comment, sizeof(s->comment));
 -             else
 -                 get_str(bc, NULL, 0);
 -         }
 -     }
 -     if(check_checksum(bc)){
 -         av_log(s, AV_LOG_ERROR, "Info header checksum mismatch\n");
 -         return -1;
 -     }
 -     return 0;
 - }
 - 
 - static int nut_read_header(AVFormatContext *s, AVFormatParameters *ap)
 - {
 -     NUTContext *nut = s->priv_data;
 -     ByteIOContext *bc = &s->pb;
 -     int64_t pos;
 -     int inited_stream_count;
 - 
 -     nut->avf= s;
 - 
 -     /* main header */
 -     pos=0;
 -     for(;;){
 -         pos= find_startcode(bc, MAIN_STARTCODE, pos)+1;
 -         if (pos<0){
 -             av_log(s, AV_LOG_ERROR, "no main startcode found\n");
 -             return -1;
 -         }
 -         if(decode_main_header(nut) >= 0)
 -             break;
 -     }
 - 
 - 
 -     s->bit_rate = 0;
 - 
 -     nut->stream = av_malloc(sizeof(StreamContext)*nut->stream_count);
 - 
 -     /* stream headers */
 -     pos=0;
 -     for(inited_stream_count=0; inited_stream_count < nut->stream_count;){
 -         pos= find_startcode(bc, STREAM_STARTCODE, pos)+1;
 -         if (pos<0+1){
 -             av_log(s, AV_LOG_ERROR, "not all stream headers found\n");
 -             return -1;
 -         }
 -         if(decode_stream_header(nut) >= 0)
 -             inited_stream_count++;
 -     }
 - 
 -     /* info headers */
 -     pos=0;
 -     for(;;){
 -         uint64_t startcode= find_any_startcode(bc, pos);
 -         pos= url_ftell(bc);
 - 
 -         if(startcode==0){
 -             av_log(s, AV_LOG_ERROR, "EOF before video frames\n");
 -             return -1;
 -         }else if(startcode == KEYFRAME_STARTCODE){
 -             nut->next_startcode= startcode;
 -             break;
 -         }else if(startcode != INFO_STARTCODE){
 -             continue;
 -         }
 - 
 -         decode_info_header(nut);
 -     }
 - 
 -     return 0;
 - }
 - 
 - static int decode_frame_header(NUTContext *nut, int *key_frame_ret, int64_t *pts_ret, int *stream_id_ret, int frame_code, int frame_type, int64_t frame_start){
 -     AVFormatContext *s= nut->avf;
 -     StreamContext *stream;
 -     ByteIOContext *bc = &s->pb;
 -     int size, flags, size_mul, size_lsb, stream_id, time_delta;
 -     int64_t pts = 0;
 - 
 -     if(frame_type < 2 && frame_start - nut->packet_start[2] > nut->max_distance){
 -         av_log(s, AV_LOG_ERROR, "last frame must have been damaged\n");
 -         return -1;
 -     }
 - 
 -     if(frame_type)
 -         nut->packet_start[ frame_type ]= frame_start; //otherwise 1 goto 1 may happen
 - 
 -     flags= nut->frame_code[frame_code].flags;
 -     size_mul= nut->frame_code[frame_code].size_mul;
 -     size_lsb= nut->frame_code[frame_code].size_lsb;
 -     stream_id= nut->frame_code[frame_code].stream_id_plus1 - 1;
 -     time_delta= nut->frame_code[frame_code].timestamp_delta;
 - 
 -     if(stream_id==-1)
 -         stream_id= get_v(bc);
 -     if(stream_id >= s->nb_streams){
 -         av_log(s, AV_LOG_ERROR, "illegal stream_id\n");
 -         return -1;
 -     }
 -     stream= &nut->stream[stream_id];
 - 
 - //    av_log(s, AV_LOG_DEBUG, "ft:%d ppts:%d %d %d\n", frame_type, stream->lru_pts_delta[0], stream->lru_pts_delta[1], stream->lru_pts_delta[2]);
 - 
 -     *key_frame_ret= !!(flags & FLAG_KEY_FRAME);
 - 
 -     if(!time_delta){
 -         int64_t mask = (1<<stream->msb_timestamp_shift)-1;
 -         pts= get_v(bc);
 -         if(pts > mask){
 -             pts -= mask+1;
 -         }else{
 -             if(stream->last_pts == AV_NOPTS_VALUE){
 -                 av_log(s, AV_LOG_ERROR, "no reference pts available\n");
 -                 return -1;
 -             }
 -             pts= lsb2full(stream, pts);
 -         }
 -     }else{
 -         if(stream->last_pts == AV_NOPTS_VALUE){
 -             av_log(s, AV_LOG_ERROR, "no reference pts available\n");
 -             return -1;
 -         }
 -         pts= stream->last_pts + time_delta;
 -     }
 - 
 -     if(*key_frame_ret){
 - //        av_log(s, AV_LOG_DEBUG, "stream:%d start:%"PRId64" pts:%"PRId64" length:%"PRId64"\n",stream_id, frame_start, av_pts, frame_start - nut->stream[stream_id].last_sync_pos);
 -         av_add_index_entry(
 -             s->streams[stream_id],
 -             frame_start,
 -             pts,
 -             0,
 -             frame_start - nut->stream[stream_id].last_sync_pos,
 -             AVINDEX_KEYFRAME);
 -         nut->stream[stream_id].last_sync_pos= frame_start;
 - //                assert(nut->packet_start == frame_start);
 -     }
 - 
 -     assert(size_mul > size_lsb);
 -     size= size_lsb;
 -     if(flags & FLAG_DATA_SIZE)
 -         size+= size_mul*get_v(bc);
 - 
 - #ifdef TRACE
 - av_log(s, AV_LOG_DEBUG, "fs:%"PRId64" fc:%d ft:%d kf:%d pts:%"PRId64" size:%d mul:%d lsb:%d flags:%d delta:%d\n", frame_start, frame_code, frame_type, *key_frame_ret, pts, size, size_mul, size_lsb, flags, time_delta);
 - #endif
 - 
 -     if(frame_type==0 && url_ftell(bc) - nut->packet_start[2] + size > nut->max_distance){
 -         av_log(s, AV_LOG_ERROR, "frame size too large\n");
 -         return -1;
 -     }
 - 
 -     *stream_id_ret = stream_id;
 -     *pts_ret = pts;
 - 
 -     update(nut, stream_id, frame_start, frame_type, frame_code, *key_frame_ret, size, pts);
 - 
 -     return size;
 - }
 - 
 - static int decode_frame(NUTContext *nut, AVPacket *pkt, int frame_code, int frame_type, int64_t frame_start){
 -     AVFormatContext *s= nut->avf;
 -     ByteIOContext *bc = &s->pb;
 -     int size, stream_id, key_frame, discard;
 -     int64_t pts, last_IP_pts;
 - 
 -     size= decode_frame_header(nut, &key_frame, &pts, &stream_id, frame_code, frame_type, frame_start);
 -     if(size < 0)
 -         return -1;
 - 
 -     discard= s->streams[ stream_id ]->discard;
 -     last_IP_pts= s->streams[ stream_id ]->last_IP_pts;
 -     if(  (discard >= AVDISCARD_NONKEY && !key_frame)
 -        ||(discard >= AVDISCARD_BIDIR && last_IP_pts != AV_NOPTS_VALUE && last_IP_pts > pts)
 -        || discard >= AVDISCARD_ALL){
 -         url_fskip(bc, size);
 -         return 1;
 -     }
 - 
 -     av_get_packet(bc, pkt, size);
 -     pkt->stream_index = stream_id;
 -     if (key_frame)
 -         pkt->flags |= PKT_FLAG_KEY;
 -     pkt->pts = pts;
 - 
 -     return 0;
 - }
 - 
 - static int nut_read_packet(AVFormatContext *s, AVPacket *pkt)
 - {
 -     NUTContext *nut = s->priv_data;
 -     ByteIOContext *bc = &s->pb;
 -     int i, frame_code=0, ret;
 - 
 -     for(;;){
 -         int64_t pos= url_ftell(bc);
 -         int frame_type= 0;
 -         uint64_t tmp= nut->next_startcode;
 -         nut->next_startcode=0;
 - 
 -         if (url_feof(bc))
 -             return -1;
 - 
 -         if(tmp){
 -             pos-=8;
 -         }else{
 -             frame_code = get_byte(bc);
 -             if(frame_code == 'N'){
 -                 tmp= frame_code;
 -                 for(i=1; i<8; i++)
 -                     tmp = (tmp<<8) + get_byte(bc);
 -             }
 -         }
 -         switch(tmp){
 -         case MAIN_STARTCODE:
 -         case STREAM_STARTCODE:
 -         case INDEX_STARTCODE:
 -             get_packetheader(nut, bc, 0);
 -             assert(nut->packet_start[2] == pos);
 -             url_fseek(bc, nut->written_packet_size, SEEK_CUR);
 -             break;
 -         case INFO_STARTCODE:
 -             if(decode_info_header(nut)<0)
 -                 goto resync;
 -             break;
 -         case KEYFRAME_STARTCODE:
 -             frame_type = 2;
 -             reset(s, get_v(bc));
 -             frame_code = get_byte(bc);
 -         case 0:
 -             ret= decode_frame(nut, pkt, frame_code, frame_type, pos);
 -             if(ret==0)
 -                 return 0;
 -             else if(ret==1) //ok but discard packet
 -                 break;
 -         default:
 - resync:
 - av_log(s, AV_LOG_DEBUG, "syncing from %"PRId64"\n", nut->packet_start[2]+1);
 -             tmp= find_any_startcode(bc, nut->packet_start[2]+1);
 -             if(tmp==0)
 -                 return -1;
 - av_log(s, AV_LOG_DEBUG, "sync\n");
 -             nut->next_startcode= tmp;
 -         }
 -     }
 - }
 - 
 - static int64_t nut_read_timestamp(AVFormatContext *s, int stream_index, int64_t *pos_arg, int64_t pos_limit){
 -     NUTContext *nut = s->priv_data;
 -     StreamContext *stream;
 -     ByteIOContext *bc = &s->pb;
 -     int64_t pos, pts;
 -     uint64_t code;
 -     int frame_code,step, stream_id, i,size, key_frame;
 - av_log(s, AV_LOG_DEBUG, "read_timestamp(X,%d,%"PRId64",%"PRId64")\n", stream_index, *pos_arg, pos_limit);
 - 
 -     if(*pos_arg < 0)
 -         return AV_NOPTS_VALUE;
 - 
 -     pos= *pos_arg;
 -     step= FFMIN(16*1024, pos);
 -     do{
 -         pos-= step;
 -         code= find_any_startcode(bc, pos);
 - 
 -         if(code && url_ftell(bc) - 8 <= *pos_arg)
 -             break;
 -         step= FFMIN(2*step, pos);
 -     }while(step);
 - 
 -     if(!code) //nothing found, not even after pos_arg
 -         return AV_NOPTS_VALUE;
 - 
 -     url_fseek(bc, -8, SEEK_CUR);
 -     for(i=0; i<s->nb_streams; i++)
 -         nut->stream[i].last_sync_pos= url_ftell(bc);
 - 
 -     for(;;){
 -         int frame_type=0;
 -         int64_t pos= url_ftell(bc);
 -         uint64_t tmp=0;
 - 
 -         if(pos > pos_limit || url_feof(bc))
 -             return AV_NOPTS_VALUE;
 - 
 -         frame_code = get_byte(bc);
 -         if(frame_code == 'N'){
 -             tmp= frame_code;
 -             for(i=1; i<8; i++)
 -                 tmp = (tmp<<8) + get_byte(bc);
 -         }
 - //av_log(s, AV_LOG_DEBUG, "before switch %"PRIX64" at=%"PRId64"\n", tmp, pos);
 - 
 -         switch(tmp){
 -         case MAIN_STARTCODE:
 -         case STREAM_STARTCODE:
 -         case INDEX_STARTCODE:
 -         case INFO_STARTCODE:
 -             get_packetheader(nut, bc, 0);
 -             assert(nut->packet_start[2]==pos);
 -             url_fseek(bc, nut->written_packet_size, SEEK_CUR);
 -             break;
 -         case KEYFRAME_STARTCODE:
 -             frame_type=2;
 -             reset(s, get_v(bc));
 -             frame_code = get_byte(bc);
 -         case 0:
 -             size= decode_frame_header(nut, &key_frame, &pts, &stream_id, frame_code, frame_type, pos);
 -             if(size < 0)
 -                 goto resync;
 - 
 -             stream= &nut->stream[stream_id];
 -             if(stream_id != stream_index || !key_frame || pos < *pos_arg){
 -                 url_fseek(bc, size, SEEK_CUR);
 -                 break;
 -             }
 - 
 -             *pos_arg= pos;
 -             return pts;
 -         default:
 - resync:
 - av_log(s, AV_LOG_DEBUG, "syncing from %"PRId64"\n", nut->packet_start[2]+1);
 -             if(!find_any_startcode(bc, nut->packet_start[2]+1))
 -                 return AV_NOPTS_VALUE;
 - 
 -             url_fseek(bc, -8, SEEK_CUR);
 -         }
 -     }
 -     return AV_NOPTS_VALUE;
 - }
 - 
 - static int nut_read_seek(AVFormatContext *s, int stream_index, int64_t target_ts, int flags){
 - //    NUTContext *nut = s->priv_data;
 -     int64_t pos;
 - 
 -     if(av_seek_frame_binary(s, stream_index, target_ts, flags) < 0)
 -         return -1;
 - 
 -     pos= url_ftell(&s->pb);
 -     nut_read_timestamp(s, stream_index, &pos, pos-1);
 - 
 -     return 0;
 - }
 - 
 - static int nut_read_close(AVFormatContext *s)
 - {
 -     NUTContext *nut = s->priv_data;
 - 
 -     av_freep(&nut->stream);
 - 
 -     return 0;
 - }
 - 
 - #ifdef CONFIG_NUT_DEMUXER
 - AVInputFormat nut_demuxer = {
 -     "nut",
 -     "nut format",
 -     sizeof(NUTContext),
 -     nut_probe,
 -     nut_read_header,
 -     nut_read_packet,
 -     nut_read_close,
 -     nut_read_seek,
 -     nut_read_timestamp,
 -     .extensions = "nut",
 - };
 - #endif
 - #ifdef CONFIG_NUT_MUXER
 - AVOutputFormat nut_muxer = {
 -     "nut",
 -     "nut format",
 -     "video/x-nut",
 -     "nut",
 -     sizeof(NUTContext),
 - #ifdef CONFIG_LIBVORBIS
 -     CODEC_ID_VORBIS,
 - #elif defined(CONFIG_LIBMP3LAME)
 -     CODEC_ID_MP3,
 - #else
 -     CODEC_ID_MP2, /* AC3 needs liba52 decoder */
 - #endif
 -     CODEC_ID_MPEG4,
 -     nut_write_header,
 -     nut_write_packet,
 -     nut_write_trailer,
 -     .flags = AVFMT_GLOBALHEADER,
 - };
 - #endif
 
 
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