git.sesse.net Git - ffmpeg/blob - libavformat/nutdec.c

   1 /*
   2  * "NUT" Container Format demuxer
   3  * Copyright (c) 2004-2006 Michael Niedermayer
   4  * Copyright (c) 2003 Alex Beregszaszi
   5  *
   6  * This file is part of FFmpeg.
   7  *
   8  * FFmpeg is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * FFmpeg is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with FFmpeg; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #include <strings.h>
  24 #include "libavutil/avstring.h"
  25 #include "libavutil/bswap.h"
  26 #include "libavutil/tree.h"
  27 #include "nut.h"
  28
  29 #undef NDEBUG
  30 #include <assert.h>
  31
  32 static int get_str(ByteIOContext *bc, char *string, unsigned int maxlen){
  33     unsigned int len= ff_get_v(bc);
  34
  35     if(len && maxlen)
  36         get_buffer(bc, string, FFMIN(len, maxlen));
  37     while(len > maxlen){
  38         get_byte(bc);
  39         len--;
  40     }
  41
  42     if(maxlen)
  43         string[FFMIN(len, maxlen-1)]= 0;
  44
  45     if(maxlen == len)
  46         return -1;
  47     else
  48         return 0;
  49 }
  50
  51 static int64_t get_s(ByteIOContext *bc){
  52     int64_t v = ff_get_v(bc) + 1;
  53
  54     if (v&1) return -(v>>1);
  55     else     return  (v>>1);
  56 }
  57
  58 static uint64_t get_fourcc(ByteIOContext *bc){
  59     unsigned int len= ff_get_v(bc);
  60
  61     if     (len==2) return get_le16(bc);
  62     else if(len==4) return get_le32(bc);
  63     else            return -1;
  64 }
  65
  66 #ifdef TRACE
  67 static inline uint64_t get_v_trace(ByteIOContext *bc, char *file, char *func, int line){
  68     uint64_t v= ff_get_v(bc);
  69
  70     av_log(NULL, AV_LOG_DEBUG, "get_v %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
  71     return v;
  72 }
  73
  74 static inline int64_t get_s_trace(ByteIOContext *bc, char *file, char *func, int line){
  75     int64_t v= get_s(bc);
  76
  77     av_log(NULL, AV_LOG_DEBUG, "get_s %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
  78     return v;
  79 }
  80
  81 static inline uint64_t get_vb_trace(ByteIOContext *bc, char *file, char *func, int line){
  82     uint64_t v= get_vb(bc);
  83
  84     av_log(NULL, AV_LOG_DEBUG, "get_vb %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
  85     return v;
  86 }
  87 #define ff_get_v(bc)  get_v_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
  88 #define get_s(bc)  get_s_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
  89 #define get_vb(bc)  get_vb_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
  90 #endif
  91
  92 static int get_packetheader(NUTContext *nut, ByteIOContext *bc, int calculate_checksum, uint64_t startcode)
  93 {
  94     int64_t size;
  95 //    start= url_ftell(bc) - 8;
  96
  97     startcode= be2ne_64(startcode);
  98     startcode= ff_crc04C11DB7_update(0, (uint8_t*)&startcode, 8);
  99
 100     init_checksum(bc, ff_crc04C11DB7_update, startcode);
 101     size= ff_get_v(bc);
 102     if(size > 4096)
 103         get_be32(bc);
 104     if(get_checksum(bc) && size > 4096)
 105         return -1;
 106
 107     init_checksum(bc, calculate_checksum ? ff_crc04C11DB7_update : NULL, 0);
 108
 109     return size;
 110 }
 111
 112 static uint64_t find_any_startcode(ByteIOContext *bc, int64_t pos){
 113     uint64_t state=0;
 114
 115     if(pos >= 0)
 116         url_fseek(bc, pos, SEEK_SET); //note, this may fail if the stream is not seekable, but that should not matter, as in this case we simply start where we currently are
 117
 118     while(!url_feof(bc)){
 119         state= (state<<8) | get_byte(bc);
 120         if((state>>56) != 'N')
 121             continue;
 122         switch(state){
 123         case MAIN_STARTCODE:
 124         case STREAM_STARTCODE:
 125         case SYNCPOINT_STARTCODE:
 126         case INFO_STARTCODE:
 127         case INDEX_STARTCODE:
 128             return state;
 129         }
 130     }
 131
 132     return 0;
 133 }
 134
 135 /**
 136  * Find the given startcode.
 137  * @param code the startcode
 138  * @param pos the start position of the search, or -1 if the current position
 139  * @return the position of the startcode or -1 if not found
 140  */
 141 static int64_t find_startcode(ByteIOContext *bc, uint64_t code, int64_t pos){
 142     for(;;){
 143         uint64_t startcode= find_any_startcode(bc, pos);
 144         if(startcode == code)
 145             return url_ftell(bc) - 8;
 146         else if(startcode == 0)
 147             return -1;
 148         pos=-1;
 149     }
 150 }
 151
 152 static int nut_probe(AVProbeData *p){
 153     int i;
 154     uint64_t code= 0;
 155
 156     for (i = 0; i < p->buf_size; i++) {
 157         code = (code << 8) | p->buf[i];
 158         if (code == MAIN_STARTCODE)
 159             return AVPROBE_SCORE_MAX;
 160     }
 161     return 0;
 162 }
 163
 164 #define GET_V(dst, check) \
 165     tmp= ff_get_v(bc);\
 166     if(!(check)){\
 167         av_log(s, AV_LOG_ERROR, "Error " #dst " is (%"PRId64")\n", tmp);\
 168         return -1;\
 169     }\
 170     dst= tmp;
 171
 172 static int skip_reserved(ByteIOContext *bc, int64_t pos){
 173     pos -= url_ftell(bc);
 174     if(pos<0){
 175         url_fseek(bc, pos, SEEK_CUR);
 176         return -1;
 177     }else{
 178         while(pos--)
 179             get_byte(bc);
 180         return 0;
 181     }
 182 }
 183
 184 static int decode_main_header(NUTContext *nut){
 185     AVFormatContext *s= nut->avf;
 186     ByteIOContext *bc = s->pb;
 187     uint64_t tmp, end;
 188     unsigned int stream_count;
 189     int i, j, tmp_stream, tmp_mul, tmp_pts, tmp_size, count, tmp_res, tmp_head_idx;
 190     int64_t tmp_match;
 191
 192     end= get_packetheader(nut, bc, 1, MAIN_STARTCODE);
 193     end += url_ftell(bc);
 194
 195     GET_V(tmp              , tmp >=2 && tmp <= 3)
 196     GET_V(stream_count     , tmp > 0 && tmp <=MAX_STREAMS)
 197
 198     nut->max_distance = ff_get_v(bc);
 199     if(nut->max_distance > 65536){
 200         av_log(s, AV_LOG_DEBUG, "max_distance %d\n", nut->max_distance);
 201         nut->max_distance= 65536;
 202     }
 203
 204     GET_V(nut->time_base_count, tmp>0 && tmp<INT_MAX / sizeof(AVRational))
 205     nut->time_base= av_malloc(nut->time_base_count * sizeof(AVRational));
 206
 207     for(i=0; i<nut->time_base_count; i++){
 208         GET_V(nut->time_base[i].num, tmp>0 && tmp<(1ULL<<31))
 209         GET_V(nut->time_base[i].den, tmp>0 && tmp<(1ULL<<31))
 210         if(av_gcd(nut->time_base[i].num, nut->time_base[i].den) != 1){
 211             av_log(s, AV_LOG_ERROR, "time base invalid\n");
 212             return -1;
 213         }
 214     }
 215     tmp_pts=0;
 216     tmp_mul=1;
 217     tmp_stream=0;
 218     tmp_match= 1-(1LL<<62);
 219     tmp_head_idx= 0;
 220     for(i=0; i<256;){
 221         int tmp_flags = ff_get_v(bc);
 222         int tmp_fields= ff_get_v(bc);
 223         if(tmp_fields>0) tmp_pts   = get_s(bc);
 224         if(tmp_fields>1) tmp_mul   = ff_get_v(bc);
 225         if(tmp_fields>2) tmp_stream= ff_get_v(bc);
 226         if(tmp_fields>3) tmp_size  = ff_get_v(bc);
 227         else             tmp_size  = 0;
 228         if(tmp_fields>4) tmp_res   = ff_get_v(bc);
 229         else             tmp_res   = 0;
 230         if(tmp_fields>5) count     = ff_get_v(bc);
 231         else             count     = tmp_mul - tmp_size;
 232         if(tmp_fields>6) tmp_match = get_s(bc);
 233         if(tmp_fields>7) tmp_head_idx= ff_get_v(bc);
 234
 235         while(tmp_fields-- > 8)
 236            ff_get_v(bc);
 237
 238         if(count == 0 || i+count > 256){
 239             av_log(s, AV_LOG_ERROR, "illegal count %d at %d\n", count, i);
 240             return -1;
 241         }
 242         if(tmp_stream >= stream_count){
 243             av_log(s, AV_LOG_ERROR, "illegal stream number\n");
 244             return -1;
 245         }
 246
 247         for(j=0; j<count; j++,i++){
 248             if (i == 'N') {
 249                 nut->frame_code[i].flags= FLAG_INVALID;
 250                 j--;
 251                 continue;
 252             }
 253             nut->frame_code[i].flags           = tmp_flags ;
 254             nut->frame_code[i].pts_delta       = tmp_pts   ;
 255             nut->frame_code[i].stream_id       = tmp_stream;
 256             nut->frame_code[i].size_mul        = tmp_mul   ;
 257             nut->frame_code[i].size_lsb        = tmp_size+j;
 258             nut->frame_code[i].reserved_count  = tmp_res   ;
 259             nut->frame_code[i].header_idx      = tmp_head_idx;
 260         }
 261     }
 262     assert(nut->frame_code['N'].flags == FLAG_INVALID);
 263
 264     if(end > url_ftell(bc) + 4){
 265         int rem= 1024;
 266         GET_V(nut->header_count, tmp<128U)
 267         nut->header_count++;
 268         for(i=1; i<nut->header_count; i++){
 269             GET_V(nut->header_len[i], tmp>0 && tmp<256);
 270             rem -= nut->header_len[i];
 271             if(rem < 0){
 272                 av_log(s, AV_LOG_ERROR, "invalid elision header\n");
 273                 return -1;
 274             }
 275             nut->header[i]= av_malloc(nut->header_len[i]);
 276             get_buffer(bc, nut->header[i], nut->header_len[i]);
 277         }
 278         assert(nut->header_len[0]==0);
 279     }
 280
 281     if(skip_reserved(bc, end) || get_checksum(bc)){
 282         av_log(s, AV_LOG_ERROR, "main header checksum mismatch\n");
 283         return -1;
 284     }
 285
 286     nut->stream = av_mallocz(sizeof(StreamContext)*stream_count);
 287     for(i=0; i<stream_count; i++){
 288         av_new_stream(s, i);
 289     }
 290
 291     return 0;
 292 }
 293
 294 static int decode_stream_header(NUTContext *nut){
 295     AVFormatContext *s= nut->avf;
 296     ByteIOContext *bc = s->pb;
 297     StreamContext *stc;
 298     int class, stream_id;
 299     uint64_t tmp, end;
 300     AVStream *st;
 301
 302     end= get_packetheader(nut, bc, 1, STREAM_STARTCODE);
 303     end += url_ftell(bc);
 304
 305     GET_V(stream_id, tmp < s->nb_streams && !nut->stream[tmp].time_base);
 306     stc= &nut->stream[stream_id];
 307
 308     st = s->streams[stream_id];
 309     if (!st)
 310         return AVERROR(ENOMEM);
 311
 312     class = ff_get_v(bc);
 313     tmp = get_fourcc(bc);
 314     st->codec->codec_tag= tmp;
 315     switch(class)
 316     {
 317         case 0:
 318             st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
 319             st->codec->codec_id = av_codec_get_id(
 320                 (const AVCodecTag * const []) { ff_codec_bmp_tags, ff_nut_video_tags, 0 },
 321                 tmp);
 322             break;
 323         case 1:
 324             st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
 325             st->codec->codec_id = ff_codec_get_id(ff_codec_wav_tags, tmp);
 326             break;
 327         case 2:
 328             st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
 329             st->codec->codec_id = ff_codec_get_id(ff_nut_subtitle_tags, tmp);
 330             break;
 331         case 3:
 332             st->codec->codec_type = AVMEDIA_TYPE_DATA;
 333             break;
 334         default:
 335             av_log(s, AV_LOG_ERROR, "unknown stream class (%d)\n", class);
 336             return -1;
 337     }
 338     if(class<3 && st->codec->codec_id == CODEC_ID_NONE)
 339         av_log(s, AV_LOG_ERROR, "Unknown codec tag '0x%04x' for stream number %d\n",
 340                (unsigned int)tmp, stream_id);
 341
 342     GET_V(stc->time_base_id    , tmp < nut->time_base_count);
 343     GET_V(stc->msb_pts_shift   , tmp < 16);
 344     stc->max_pts_distance= ff_get_v(bc);
 345     GET_V(stc->decode_delay    , tmp < 1000); //sanity limit, raise this if Moore's law is true
 346     st->codec->has_b_frames= stc->decode_delay;
 347     ff_get_v(bc); //stream flags
 348
 349     GET_V(st->codec->extradata_size, tmp < (1<<30));
 350     if(st->codec->extradata_size){
 351         st->codec->extradata= av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
 352         get_buffer(bc, st->codec->extradata, st->codec->extradata_size);
 353     }
 354
 355     if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO){
 356         GET_V(st->codec->width , tmp > 0)
 357         GET_V(st->codec->height, tmp > 0)
 358         st->sample_aspect_ratio.num= ff_get_v(bc);
 359         st->sample_aspect_ratio.den= ff_get_v(bc);
 360         if((!st->sample_aspect_ratio.num) != (!st->sample_aspect_ratio.den)){
 361             av_log(s, AV_LOG_ERROR, "invalid aspect ratio %d/%d\n", st->sample_aspect_ratio.num, st->sample_aspect_ratio.den);
 362             return -1;
 363         }
 364         ff_get_v(bc); /* csp type */
 365     }else if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO){
 366         GET_V(st->codec->sample_rate , tmp > 0)
 367         ff_get_v(bc); // samplerate_den
 368         GET_V(st->codec->channels, tmp > 0)
 369     }
 370     if(skip_reserved(bc, end) || get_checksum(bc)){
 371         av_log(s, AV_LOG_ERROR, "stream header %d checksum mismatch\n", stream_id);
 372         return -1;
 373     }
 374     stc->time_base= &nut->time_base[stc->time_base_id];
 375     av_set_pts_info(s->streams[stream_id], 63, stc->time_base->num, stc->time_base->den);
 376     return 0;
 377 }
 378
 379 static void set_disposition_bits(AVFormatContext* avf, char* value, int stream_id){
 380     int flag = 0, i;
 381     for (i=0; ff_nut_dispositions[i].flag; ++i) {
 382         if (!strcmp(ff_nut_dispositions[i].str, value))
 383             flag = ff_nut_dispositions[i].flag;
 384     }
 385     if (!flag)
 386         av_log(avf, AV_LOG_INFO, "unknown disposition type '%s'\n", value);
 387     for (i = 0; i < avf->nb_streams; ++i)
 388         if (stream_id == i || stream_id == -1)
 389             avf->streams[i]->disposition |= flag;
 390 }
 391
 392 static int decode_info_header(NUTContext *nut){
 393     AVFormatContext *s= nut->avf;
 394     ByteIOContext *bc = s->pb;
 395     uint64_t tmp, chapter_start, chapter_len;
 396     unsigned int stream_id_plus1, count;
 397     int chapter_id, i;
 398     int64_t value, end;
 399     char name[256], str_value[1024], type_str[256];
 400     const char *type;
 401     AVChapter *chapter= NULL;
 402     AVStream *st= NULL;
 403
 404     end= get_packetheader(nut, bc, 1, INFO_STARTCODE);
 405     end += url_ftell(bc);
 406
 407     GET_V(stream_id_plus1, tmp <= s->nb_streams)
 408     chapter_id   = get_s(bc);
 409     chapter_start= ff_get_v(bc);
 410     chapter_len  = ff_get_v(bc);
 411     count        = ff_get_v(bc);
 412
 413     if(chapter_id && !stream_id_plus1){
 414         int64_t start= chapter_start / nut->time_base_count;
 415         chapter= ff_new_chapter(s, chapter_id,
 416                                 nut->time_base[chapter_start % nut->time_base_count],
 417                                 start, start + chapter_len, NULL);
 418     } else if(stream_id_plus1)
 419         st= s->streams[stream_id_plus1 - 1];
 420
 421     for(i=0; i<count; i++){
 422         get_str(bc, name, sizeof(name));
 423         value= get_s(bc);
 424         if(value == -1){
 425             type= "UTF-8";
 426             get_str(bc, str_value, sizeof(str_value));
 427         }else if(value == -2){
 428             get_str(bc, type_str, sizeof(type_str));
 429             type= type_str;
 430             get_str(bc, str_value, sizeof(str_value));
 431         }else if(value == -3){
 432             type= "s";
 433             value= get_s(bc);
 434         }else if(value == -4){
 435             type= "t";
 436             value= ff_get_v(bc);
 437         }else if(value < -4){
 438             type= "r";
 439             get_s(bc);
 440         }else{
 441             type= "v";
 442         }
 443
 444         if (stream_id_plus1 > s->nb_streams) {
 445             av_log(s, AV_LOG_ERROR, "invalid stream id for info packet\n");
 446             continue;
 447         }
 448
 449         if(!strcmp(type, "UTF-8")){
 450             AVMetadata **metadata = NULL;
 451             if(chapter_id==0 && !strcmp(name, "Disposition"))
 452                 set_disposition_bits(s, str_value, stream_id_plus1 - 1);
 453             else if(chapter)          metadata= &chapter->metadata;
 454             else if(stream_id_plus1)  metadata= &st->metadata;
 455             else                      metadata= &s->metadata;
 456             if(metadata && strcasecmp(name,"Uses")
 457                && strcasecmp(name,"Depends") && strcasecmp(name,"Replaces"))
 458                 av_metadata_set2(metadata, name, str_value, 0);
 459         }
 460     }
 461
 462     if(skip_reserved(bc, end) || get_checksum(bc)){
 463         av_log(s, AV_LOG_ERROR, "info header checksum mismatch\n");
 464         return -1;
 465     }
 466     return 0;
 467 }
 468
 469 static int decode_syncpoint(NUTContext *nut, int64_t *ts, int64_t *back_ptr){
 470     AVFormatContext *s= nut->avf;
 471     ByteIOContext *bc = s->pb;
 472     int64_t end, tmp;
 473
 474     nut->last_syncpoint_pos= url_ftell(bc)-8;
 475
 476     end= get_packetheader(nut, bc, 1, SYNCPOINT_STARTCODE);
 477     end += url_ftell(bc);
 478
 479     tmp= ff_get_v(bc);
 480     *back_ptr= nut->last_syncpoint_pos - 16*ff_get_v(bc);
 481     if(*back_ptr < 0)
 482         return -1;
 483
 484     ff_nut_reset_ts(nut, nut->time_base[tmp % nut->time_base_count], tmp / nut->time_base_count);
 485
 486     if(skip_reserved(bc, end) || get_checksum(bc)){
 487         av_log(s, AV_LOG_ERROR, "sync point checksum mismatch\n");
 488         return -1;
 489     }
 490
 491     *ts= tmp / s->nb_streams * av_q2d(nut->time_base[tmp % s->nb_streams])*AV_TIME_BASE;
 492     ff_nut_add_sp(nut, nut->last_syncpoint_pos, *back_ptr, *ts);
 493
 494     return 0;
 495 }
 496
 497 static int find_and_decode_index(NUTContext *nut){
 498     AVFormatContext *s= nut->avf;
 499     ByteIOContext *bc = s->pb;
 500     uint64_t tmp, end;
 501     int i, j, syncpoint_count;
 502     int64_t filesize= url_fsize(bc);
 503     int64_t *syncpoints;
 504     int8_t *has_keyframe;
 505     int ret= -1;
 506
 507     url_fseek(bc, filesize-12, SEEK_SET);
 508     url_fseek(bc, filesize-get_be64(bc), SEEK_SET);
 509     if(get_be64(bc) != INDEX_STARTCODE){
 510         av_log(s, AV_LOG_ERROR, "no index at the end\n");
 511         return -1;
 512     }
 513
 514     end= get_packetheader(nut, bc, 1, INDEX_STARTCODE);
 515     end += url_ftell(bc);
 516
 517     ff_get_v(bc); //max_pts
 518     GET_V(syncpoint_count, tmp < INT_MAX/8 && tmp > 0)
 519     syncpoints= av_malloc(sizeof(int64_t)*syncpoint_count);
 520     has_keyframe= av_malloc(sizeof(int8_t)*(syncpoint_count+1));
 521     for(i=0; i<syncpoint_count; i++){
 522         syncpoints[i] = ff_get_v(bc);
 523         if(syncpoints[i] <= 0)
 524             goto fail;
 525         if(i)
 526             syncpoints[i] += syncpoints[i-1];
 527     }
 528
 529     for(i=0; i<s->nb_streams; i++){
 530         int64_t last_pts= -1;
 531         for(j=0; j<syncpoint_count;){
 532             uint64_t x= ff_get_v(bc);
 533             int type= x&1;
 534             int n= j;
 535             x>>=1;
 536             if(type){
 537                 int flag= x&1;
 538                 x>>=1;
 539                 if(n+x >= syncpoint_count + 1){
 540                     av_log(s, AV_LOG_ERROR, "index overflow A\n");
 541                     goto fail;
 542                 }
 543                 while(x--)
 544                     has_keyframe[n++]= flag;
 545                 has_keyframe[n++]= !flag;
 546             }else{
 547                 while(x != 1){
 548                     if(n>=syncpoint_count + 1){
 549                         av_log(s, AV_LOG_ERROR, "index overflow B\n");
 550                         goto fail;
 551                     }
 552                     has_keyframe[n++]= x&1;
 553                     x>>=1;
 554                 }
 555             }
 556             if(has_keyframe[0]){
 557                 av_log(s, AV_LOG_ERROR, "keyframe before first syncpoint in index\n");
 558                 goto fail;
 559             }
 560             assert(n<=syncpoint_count+1);
 561             for(; j<n && j<syncpoint_count; j++){
 562                 if(has_keyframe[j]){
 563                     uint64_t B, A= ff_get_v(bc);
 564                     if(!A){
 565                         A= ff_get_v(bc);
 566                         B= ff_get_v(bc);
 567                         //eor_pts[j][i] = last_pts + A + B
 568                     }else
 569                         B= 0;
 570                     av_add_index_entry(
 571                         s->streams[i],
 572                         16*syncpoints[j-1],
 573                         last_pts + A,
 574                         0,
 575                         0,
 576                         AVINDEX_KEYFRAME);
 577                     last_pts += A + B;
 578                 }
 579             }
 580         }
 581     }
 582
 583     if(skip_reserved(bc, end) || get_checksum(bc)){
 584         av_log(s, AV_LOG_ERROR, "index checksum mismatch\n");
 585         goto fail;
 586     }
 587     ret= 0;
 588 fail:
 589     av_free(syncpoints);
 590     av_free(has_keyframe);
 591     return ret;
 592 }
 593
 594 static int nut_read_header(AVFormatContext *s, AVFormatParameters *ap)
 595 {
 596     NUTContext *nut = s->priv_data;
 597     ByteIOContext *bc = s->pb;
 598     int64_t pos;
 599     int initialized_stream_count;
 600
 601     nut->avf= s;
 602
 603     /* main header */
 604     pos=0;
 605     do{
 606         pos= find_startcode(bc, MAIN_STARTCODE, pos)+1;
 607         if (pos<0+1){
 608             av_log(s, AV_LOG_ERROR, "No main startcode found.\n");
 609             return -1;
 610         }
 611     }while(decode_main_header(nut) < 0);
 612
 613     /* stream headers */
 614     pos=0;
 615     for(initialized_stream_count=0; initialized_stream_count < s->nb_streams;){
 616         pos= find_startcode(bc, STREAM_STARTCODE, pos)+1;
 617         if (pos<0+1){
 618             av_log(s, AV_LOG_ERROR, "Not all stream headers found.\n");
 619             return -1;
 620         }
 621         if(decode_stream_header(nut) >= 0)
 622             initialized_stream_count++;
 623     }
 624
 625     /* info headers */
 626     pos=0;
 627     for(;;){
 628         uint64_t startcode= find_any_startcode(bc, pos);
 629         pos= url_ftell(bc);
 630
 631         if(startcode==0){
 632             av_log(s, AV_LOG_ERROR, "EOF before video frames\n");
 633             return -1;
 634         }else if(startcode == SYNCPOINT_STARTCODE){
 635             nut->next_startcode= startcode;
 636             break;
 637         }else if(startcode != INFO_STARTCODE){
 638             continue;
 639         }
 640
 641         decode_info_header(nut);
 642     }
 643
 644     s->data_offset= pos-8;
 645
 646     if(!url_is_streamed(bc)){
 647         int64_t orig_pos= url_ftell(bc);
 648         find_and_decode_index(nut);
 649         url_fseek(bc, orig_pos, SEEK_SET);
 650     }
 651     assert(nut->next_startcode == SYNCPOINT_STARTCODE);
 652
 653     return 0;
 654 }
 655
 656 static int decode_frame_header(NUTContext *nut, int64_t *pts, int *stream_id, uint8_t *header_idx, int frame_code){
 657     AVFormatContext *s= nut->avf;
 658     ByteIOContext *bc = s->pb;
 659     StreamContext *stc;
 660     int size, flags, size_mul, pts_delta, i, reserved_count;
 661     uint64_t tmp;
 662
 663     if(url_ftell(bc) > nut->last_syncpoint_pos + nut->max_distance){
 664         av_log(s, AV_LOG_ERROR, "Last frame must have been damaged %"PRId64" > %"PRId64" + %d\n", url_ftell(bc), nut->last_syncpoint_pos, nut->max_distance);
 665         return -1;
 666     }
 667
 668     flags          = nut->frame_code[frame_code].flags;
 669     size_mul       = nut->frame_code[frame_code].size_mul;
 670     size           = nut->frame_code[frame_code].size_lsb;
 671     *stream_id     = nut->frame_code[frame_code].stream_id;
 672     pts_delta      = nut->frame_code[frame_code].pts_delta;
 673     reserved_count = nut->frame_code[frame_code].reserved_count;
 674     *header_idx    = nut->frame_code[frame_code].header_idx;
 675
 676     if(flags & FLAG_INVALID)
 677         return -1;
 678     if(flags & FLAG_CODED)
 679         flags ^= ff_get_v(bc);
 680     if(flags & FLAG_STREAM_ID){
 681         GET_V(*stream_id, tmp < s->nb_streams)
 682     }
 683     stc= &nut->stream[*stream_id];
 684     if(flags&FLAG_CODED_PTS){
 685         int coded_pts= ff_get_v(bc);
 686 //FIXME check last_pts validity?
 687         if(coded_pts < (1<<stc->msb_pts_shift)){
 688             *pts=ff_lsb2full(stc, coded_pts);
 689         }else
 690             *pts=coded_pts - (1<<stc->msb_pts_shift);
 691     }else
 692         *pts= stc->last_pts + pts_delta;
 693     if(flags&FLAG_SIZE_MSB){
 694         size += size_mul*ff_get_v(bc);
 695     }
 696     if(flags&FLAG_MATCH_TIME)
 697         get_s(bc);
 698     if(flags&FLAG_HEADER_IDX)
 699         *header_idx= ff_get_v(bc);
 700     if(flags&FLAG_RESERVED)
 701         reserved_count= ff_get_v(bc);
 702     for(i=0; i<reserved_count; i++)
 703         ff_get_v(bc);
 704
 705     if(*header_idx >= (unsigned)nut->header_count){
 706         av_log(s, AV_LOG_ERROR, "header_idx invalid\n");
 707         return -1;
 708     }
 709     if(size > 4096)
 710         *header_idx=0;
 711     size -= nut->header_len[*header_idx];
 712
 713     if(flags&FLAG_CHECKSUM){
 714         get_be32(bc); //FIXME check this
 715     }else if(size > 2*nut->max_distance || FFABS(stc->last_pts - *pts) > stc->max_pts_distance){
 716         av_log(s, AV_LOG_ERROR, "frame size > 2max_distance and no checksum\n");
 717         return -1;
 718     }
 719
 720     stc->last_pts= *pts;
 721     stc->last_flags= flags;
 722
 723     return size;
 724 }
 725
 726 static int decode_frame(NUTContext *nut, AVPacket *pkt, int frame_code){
 727     AVFormatContext *s= nut->avf;
 728     ByteIOContext *bc = s->pb;
 729     int size, stream_id, discard;
 730     int64_t pts, last_IP_pts;
 731     StreamContext *stc;
 732     uint8_t header_idx;
 733
 734     size= decode_frame_header(nut, &pts, &stream_id, &header_idx, frame_code);
 735     if(size < 0)
 736         return -1;
 737
 738     stc= &nut->stream[stream_id];
 739
 740     if (stc->last_flags & FLAG_KEY)
 741         stc->skip_until_key_frame=0;
 742
 743     discard= s->streams[ stream_id ]->discard;
 744     last_IP_pts= s->streams[ stream_id ]->last_IP_pts;
 745     if(  (discard >= AVDISCARD_NONKEY && !(stc->last_flags & FLAG_KEY))
 746        ||(discard >= AVDISCARD_BIDIR && last_IP_pts != AV_NOPTS_VALUE && last_IP_pts > pts)
 747        || discard >= AVDISCARD_ALL
 748        || stc->skip_until_key_frame){
 749         url_fskip(bc, size);
 750         return 1;
 751     }
 752
 753     av_new_packet(pkt, size + nut->header_len[header_idx]);
 754     memcpy(pkt->data, nut->header[header_idx], nut->header_len[header_idx]);
 755     pkt->pos= url_ftell(bc); //FIXME
 756     get_buffer(bc, pkt->data + nut->header_len[header_idx], size);
 757
 758     pkt->stream_index = stream_id;
 759     if (stc->last_flags & FLAG_KEY)
 760         pkt->flags |= AV_PKT_FLAG_KEY;
 761     pkt->pts = pts;
 762
 763     return 0;
 764 }
 765
 766 static int nut_read_packet(AVFormatContext *s, AVPacket *pkt)
 767 {
 768     NUTContext *nut = s->priv_data;
 769     ByteIOContext *bc = s->pb;
 770     int i, frame_code=0, ret, skip;
 771     int64_t ts, back_ptr;
 772
 773     for(;;){
 774         int64_t pos= url_ftell(bc);
 775         uint64_t tmp= nut->next_startcode;
 776         nut->next_startcode=0;
 777
 778         if(tmp){
 779             pos-=8;
 780         }else{
 781             frame_code = get_byte(bc);
 782             if(url_feof(bc))
 783                 return -1;
 784             if(frame_code == 'N'){
 785                 tmp= frame_code;
 786                 for(i=1; i<8; i++)
 787                     tmp = (tmp<<8) + get_byte(bc);
 788             }
 789         }
 790         switch(tmp){
 791         case MAIN_STARTCODE:
 792         case STREAM_STARTCODE:
 793         case INDEX_STARTCODE:
 794             skip= get_packetheader(nut, bc, 0, tmp);
 795             url_fseek(bc, skip, SEEK_CUR);
 796             break;
 797         case INFO_STARTCODE:
 798             if(decode_info_header(nut)<0)
 799                 goto resync;
 800             break;
 801         case SYNCPOINT_STARTCODE:
 802             if(decode_syncpoint(nut, &ts, &back_ptr)<0)
 803                 goto resync;
 804             frame_code = get_byte(bc);
 805         case 0:
 806             ret= decode_frame(nut, pkt, frame_code);
 807             if(ret==0)
 808                 return 0;
 809             else if(ret==1) //ok but discard packet
 810                 break;
 811         default:
 812 resync:
 813 av_log(s, AV_LOG_DEBUG, "syncing from %"PRId64"\n", pos);
 814             tmp= find_any_startcode(bc, nut->last_syncpoint_pos+1);
 815             if(tmp==0)
 816                 return -1;
 817 av_log(s, AV_LOG_DEBUG, "sync\n");
 818             nut->next_startcode= tmp;
 819         }
 820     }
 821 }
 822
 823 static int64_t nut_read_timestamp(AVFormatContext *s, int stream_index, int64_t *pos_arg, int64_t pos_limit){
 824     NUTContext *nut = s->priv_data;
 825     ByteIOContext *bc = s->pb;
 826     int64_t pos, pts, back_ptr;
 827 av_log(s, AV_LOG_DEBUG, "read_timestamp(X,%d,%"PRId64",%"PRId64")\n", stream_index, *pos_arg, pos_limit);
 828
 829     pos= *pos_arg;
 830     do{
 831         pos= find_startcode(bc, SYNCPOINT_STARTCODE, pos)+1;
 832         if(pos < 1){
 833             assert(nut->next_startcode == 0);
 834             av_log(s, AV_LOG_ERROR, "read_timestamp failed.\n");
 835             return AV_NOPTS_VALUE;
 836         }
 837     }while(decode_syncpoint(nut, &pts, &back_ptr) < 0);
 838     *pos_arg = pos-1;
 839     assert(nut->last_syncpoint_pos == *pos_arg);
 840
 841     av_log(s, AV_LOG_DEBUG, "return %"PRId64" %"PRId64"\n", pts,back_ptr );
 842     if     (stream_index == -1) return pts;
 843     else if(stream_index == -2) return back_ptr;
 844
 845 assert(0);
 846 }
 847
 848 static int read_seek(AVFormatContext *s, int stream_index, int64_t pts, int flags){
 849     NUTContext *nut = s->priv_data;
 850     AVStream *st= s->streams[stream_index];
 851     Syncpoint dummy={.ts= pts*av_q2d(st->time_base)*AV_TIME_BASE};
 852     Syncpoint nopts_sp= {.ts= AV_NOPTS_VALUE, .back_ptr= AV_NOPTS_VALUE};
 853     Syncpoint *sp, *next_node[2]= {&nopts_sp, &nopts_sp};
 854     int64_t pos, pos2, ts;
 855     int i;
 856
 857     if(st->index_entries){
 858         int index= av_index_search_timestamp(st, pts, flags);
 859         if(index<0)
 860             return -1;
 861
 862         pos2= st->index_entries[index].pos;
 863         ts  = st->index_entries[index].timestamp;
 864     }else{
 865         av_tree_find(nut->syncpoints, &dummy, (void *) ff_nut_sp_pts_cmp,
 866                      (void **) next_node);
 867         av_log(s, AV_LOG_DEBUG, "%"PRIu64"-%"PRIu64" %"PRId64"-%"PRId64"\n", next_node[0]->pos, next_node[1]->pos,
 868                                                     next_node[0]->ts , next_node[1]->ts);
 869         pos= av_gen_search(s, -1, dummy.ts, next_node[0]->pos, next_node[1]->pos, next_node[1]->pos,
 870                                             next_node[0]->ts , next_node[1]->ts, AVSEEK_FLAG_BACKWARD, &ts, nut_read_timestamp);
 871
 872         if(!(flags & AVSEEK_FLAG_BACKWARD)){
 873             dummy.pos= pos+16;
 874             next_node[1]= &nopts_sp;
 875             av_tree_find(nut->syncpoints, &dummy, (void *) ff_nut_sp_pos_cmp,
 876                          (void **) next_node);
 877             pos2= av_gen_search(s, -2, dummy.pos, next_node[0]->pos     , next_node[1]->pos, next_node[1]->pos,
 878                                                 next_node[0]->back_ptr, next_node[1]->back_ptr, flags, &ts, nut_read_timestamp);
 879             if(pos2>=0)
 880                 pos= pos2;
 881             //FIXME dir but I think it does not matter
 882         }
 883         dummy.pos= pos;
 884         sp= av_tree_find(nut->syncpoints, &dummy, (void *) ff_nut_sp_pos_cmp,
 885                          NULL);
 886
 887         assert(sp);
 888         pos2= sp->back_ptr  - 15;
 889     }
 890     av_log(NULL, AV_LOG_DEBUG, "SEEKTO: %"PRId64"\n", pos2);
 891     pos= find_startcode(s->pb, SYNCPOINT_STARTCODE, pos2);
 892     url_fseek(s->pb, pos, SEEK_SET);
 893     av_log(NULL, AV_LOG_DEBUG, "SP: %"PRId64"\n", pos);
 894     if(pos2 > pos || pos2 + 15 < pos){
 895         av_log(NULL, AV_LOG_ERROR, "no syncpoint at backptr pos\n");
 896     }
 897     for(i=0; i<s->nb_streams; i++)
 898         nut->stream[i].skip_until_key_frame=1;
 899
 900     return 0;
 901 }
 902
 903 static int nut_read_close(AVFormatContext *s)
 904 {
 905     NUTContext *nut = s->priv_data;
 906     int i;
 907
 908     av_freep(&nut->time_base);
 909     av_freep(&nut->stream);
 910     ff_nut_free_sp(nut);
 911     for(i = 1; i < nut->header_count; i++)
 912         av_freep(&nut->header[i]);
 913
 914     return 0;
 915 }
 916
 917 #if CONFIG_NUT_DEMUXER
 918 AVInputFormat nut_demuxer = {
 919     "nut",
 920     NULL_IF_CONFIG_SMALL("NUT format"),
 921     sizeof(NUTContext),
 922     nut_probe,
 923     nut_read_header,
 924     nut_read_packet,
 925     nut_read_close,
 926     read_seek,
 927     .extensions = "nut",
 928     .metadata_conv = ff_nut_metadata_conv,
 929     .codec_tag = (const AVCodecTag * const []) { ff_codec_bmp_tags, ff_nut_video_tags, ff_codec_wav_tags, ff_nut_subtitle_tags, 0 },
 930 };
 931 #endif