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libavformat/nutdec.c

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00001 /*
00002  * "NUT" Container Format demuxer
00003  * Copyright (c) 2004-2006 Michael Niedermayer
00004  * Copyright (c) 2003 Alex Beregszaszi
00005  *
00006  * This file is part of Libav.
00007  *
00008  * Libav is free software; you can redistribute it and/or
00009  * modify it under the terms of the GNU Lesser General Public
00010  * License as published by the Free Software Foundation; either
00011  * version 2.1 of the License, or (at your option) any later version.
00012  *
00013  * Libav is distributed in the hope that it will be useful,
00014  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00015  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00016  * Lesser General Public License for more details.
00017  *
00018  * You should have received a copy of the GNU Lesser General Public
00019  * License along with Libav; if not, write to the Free Software
00020  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00021  */
00022 
00023 #include "libavutil/avstring.h"
00024 #include "libavutil/bswap.h"
00025 #include "libavutil/dict.h"
00026 #include "libavutil/mathematics.h"
00027 #include "libavutil/tree.h"
00028 #include "avio_internal.h"
00029 #include "nut.h"
00030 
00031 #undef NDEBUG
00032 #include <assert.h>
00033 
00034 #define NUT_MAX_STREAMS 256    /* arbitrary sanity check value */
00035 
00036 static int get_str(AVIOContext *bc, char *string, unsigned int maxlen){
00037     unsigned int len= ffio_read_varlen(bc);
00038 
00039     if(len && maxlen)
00040         avio_read(bc, string, FFMIN(len, maxlen));
00041     while(len > maxlen){
00042         avio_r8(bc);
00043         len--;
00044     }
00045 
00046     if(maxlen)
00047         string[FFMIN(len, maxlen-1)]= 0;
00048 
00049     if(maxlen == len)
00050         return -1;
00051     else
00052         return 0;
00053 }
00054 
00055 static int64_t get_s(AVIOContext *bc){
00056     int64_t v = ffio_read_varlen(bc) + 1;
00057 
00058     if (v&1) return -(v>>1);
00059     else     return  (v>>1);
00060 }
00061 
00062 static uint64_t get_fourcc(AVIOContext *bc){
00063     unsigned int len= ffio_read_varlen(bc);
00064 
00065     if     (len==2) return avio_rl16(bc);
00066     else if(len==4) return avio_rl32(bc);
00067     else            return -1;
00068 }
00069 
00070 #ifdef TRACE
00071 static inline uint64_t get_v_trace(AVIOContext *bc, char *file, char *func, int line){
00072     uint64_t v= ffio_read_varlen(bc);
00073 
00074     av_log(NULL, AV_LOG_DEBUG, "get_v %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
00075     return v;
00076 }
00077 
00078 static inline int64_t get_s_trace(AVIOContext *bc, char *file, char *func, int line){
00079     int64_t v= get_s(bc);
00080 
00081     av_log(NULL, AV_LOG_DEBUG, "get_s %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
00082     return v;
00083 }
00084 
00085 static inline uint64_t get_vb_trace(AVIOContext *bc, char *file, char *func, int line){
00086     uint64_t v= get_vb(bc);
00087 
00088     av_log(NULL, AV_LOG_DEBUG, "get_vb %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
00089     return v;
00090 }
00091 #define ffio_read_varlen(bc)  get_v_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
00092 #define get_s(bc)  get_s_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
00093 #define get_vb(bc)  get_vb_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
00094 #endif
00095 
00096 static int get_packetheader(NUTContext *nut, AVIOContext *bc, int calculate_checksum, uint64_t startcode)
00097 {
00098     int64_t size;
00099 //    start= avio_tell(bc) - 8;
00100 
00101     startcode= av_be2ne64(startcode);
00102     startcode= ff_crc04C11DB7_update(0, (uint8_t*)&startcode, 8);
00103 
00104     ffio_init_checksum(bc, ff_crc04C11DB7_update, startcode);
00105     size= ffio_read_varlen(bc);
00106     if(size > 4096)
00107         avio_rb32(bc);
00108     if(ffio_get_checksum(bc) && size > 4096)
00109         return -1;
00110 
00111     ffio_init_checksum(bc, calculate_checksum ? ff_crc04C11DB7_update : NULL, 0);
00112 
00113     return size;
00114 }
00115 
00116 static uint64_t find_any_startcode(AVIOContext *bc, int64_t pos){
00117     uint64_t state=0;
00118 
00119     if(pos >= 0)
00120         avio_seek(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
00121 
00122     while(!bc->eof_reached){
00123         state= (state<<8) | avio_r8(bc);
00124         if((state>>56) != 'N')
00125             continue;
00126         switch(state){
00127         case MAIN_STARTCODE:
00128         case STREAM_STARTCODE:
00129         case SYNCPOINT_STARTCODE:
00130         case INFO_STARTCODE:
00131         case INDEX_STARTCODE:
00132             return state;
00133         }
00134     }
00135 
00136     return 0;
00137 }
00138 
00145 static int64_t find_startcode(AVIOContext *bc, uint64_t code, int64_t pos){
00146     for(;;){
00147         uint64_t startcode= find_any_startcode(bc, pos);
00148         if(startcode == code)
00149             return avio_tell(bc) - 8;
00150         else if(startcode == 0)
00151             return -1;
00152         pos=-1;
00153     }
00154 }
00155 
00156 static int nut_probe(AVProbeData *p){
00157     int i;
00158     uint64_t code= 0;
00159 
00160     for (i = 0; i < p->buf_size; i++) {
00161         code = (code << 8) | p->buf[i];
00162         if (code == MAIN_STARTCODE)
00163             return AVPROBE_SCORE_MAX;
00164     }
00165     return 0;
00166 }
00167 
00168 #define GET_V(dst, check) \
00169     tmp= ffio_read_varlen(bc);\
00170     if(!(check)){\
00171         av_log(s, AV_LOG_ERROR, "Error " #dst " is (%"PRId64")\n", tmp);\
00172         return -1;\
00173     }\
00174     dst= tmp;
00175 
00176 static int skip_reserved(AVIOContext *bc, int64_t pos){
00177     pos -= avio_tell(bc);
00178     if(pos<0){
00179         avio_seek(bc, pos, SEEK_CUR);
00180         return -1;
00181     }else{
00182         while(pos--)
00183             avio_r8(bc);
00184         return 0;
00185     }
00186 }
00187 
00188 static int decode_main_header(NUTContext *nut){
00189     AVFormatContext *s= nut->avf;
00190     AVIOContext *bc = s->pb;
00191     uint64_t tmp, end;
00192     unsigned int stream_count;
00193     int i, j, tmp_stream, tmp_mul, tmp_pts, tmp_size, count, tmp_res, tmp_head_idx;
00194 
00195     end= get_packetheader(nut, bc, 1, MAIN_STARTCODE);
00196     end += avio_tell(bc);
00197 
00198     GET_V(tmp              , tmp >=2 && tmp <= 3)
00199     GET_V(stream_count     , tmp > 0 && tmp <= NUT_MAX_STREAMS)
00200 
00201     nut->max_distance = ffio_read_varlen(bc);
00202     if(nut->max_distance > 65536){
00203         av_log(s, AV_LOG_DEBUG, "max_distance %d\n", nut->max_distance);
00204         nut->max_distance= 65536;
00205     }
00206 
00207     GET_V(nut->time_base_count, tmp>0 && tmp<INT_MAX / sizeof(AVRational))
00208     nut->time_base= av_malloc(nut->time_base_count * sizeof(AVRational));
00209 
00210     for(i=0; i<nut->time_base_count; i++){
00211         GET_V(nut->time_base[i].num, tmp>0 && tmp<(1ULL<<31))
00212         GET_V(nut->time_base[i].den, tmp>0 && tmp<(1ULL<<31))
00213         if(av_gcd(nut->time_base[i].num, nut->time_base[i].den) != 1){
00214             av_log(s, AV_LOG_ERROR, "time base invalid\n");
00215             return AVERROR_INVALIDDATA;
00216         }
00217     }
00218     tmp_pts=0;
00219     tmp_mul=1;
00220     tmp_stream=0;
00221     tmp_head_idx= 0;
00222     for(i=0; i<256;){
00223         int tmp_flags = ffio_read_varlen(bc);
00224         int tmp_fields= ffio_read_varlen(bc);
00225         if(tmp_fields>0) tmp_pts   = get_s(bc);
00226         if(tmp_fields>1) tmp_mul   = ffio_read_varlen(bc);
00227         if(tmp_fields>2) tmp_stream= ffio_read_varlen(bc);
00228         if(tmp_fields>3) tmp_size  = ffio_read_varlen(bc);
00229         else             tmp_size  = 0;
00230         if(tmp_fields>4) tmp_res   = ffio_read_varlen(bc);
00231         else             tmp_res   = 0;
00232         if(tmp_fields>5) count     = ffio_read_varlen(bc);
00233         else             count     = tmp_mul - tmp_size;
00234         if(tmp_fields>6) get_s(bc);
00235         if(tmp_fields>7) tmp_head_idx= ffio_read_varlen(bc);
00236 
00237         while(tmp_fields-- > 8)
00238            ffio_read_varlen(bc);
00239 
00240         if(count == 0 || i+count > 256){
00241             av_log(s, AV_LOG_ERROR, "illegal count %d at %d\n", count, i);
00242             return AVERROR_INVALIDDATA;
00243         }
00244         if(tmp_stream >= stream_count){
00245             av_log(s, AV_LOG_ERROR, "illegal stream number\n");
00246             return AVERROR_INVALIDDATA;
00247         }
00248 
00249         for(j=0; j<count; j++,i++){
00250             if (i == 'N') {
00251                 nut->frame_code[i].flags= FLAG_INVALID;
00252                 j--;
00253                 continue;
00254             }
00255             nut->frame_code[i].flags           = tmp_flags ;
00256             nut->frame_code[i].pts_delta       = tmp_pts   ;
00257             nut->frame_code[i].stream_id       = tmp_stream;
00258             nut->frame_code[i].size_mul        = tmp_mul   ;
00259             nut->frame_code[i].size_lsb        = tmp_size+j;
00260             nut->frame_code[i].reserved_count  = tmp_res   ;
00261             nut->frame_code[i].header_idx      = tmp_head_idx;
00262         }
00263     }
00264     assert(nut->frame_code['N'].flags == FLAG_INVALID);
00265 
00266     if(end > avio_tell(bc) + 4){
00267         int rem= 1024;
00268         GET_V(nut->header_count, tmp<128U)
00269         nut->header_count++;
00270         for(i=1; i<nut->header_count; i++){
00271             GET_V(nut->header_len[i], tmp>0 && tmp<256);
00272             rem -= nut->header_len[i];
00273             if(rem < 0){
00274                 av_log(s, AV_LOG_ERROR, "invalid elision header\n");
00275                 return AVERROR_INVALIDDATA;
00276             }
00277             nut->header[i]= av_malloc(nut->header_len[i]);
00278             avio_read(bc, nut->header[i], nut->header_len[i]);
00279         }
00280         assert(nut->header_len[0]==0);
00281     }
00282 
00283     if(skip_reserved(bc, end) || ffio_get_checksum(bc)){
00284         av_log(s, AV_LOG_ERROR, "main header checksum mismatch\n");
00285         return AVERROR_INVALIDDATA;
00286     }
00287 
00288     nut->stream = av_mallocz(sizeof(StreamContext)*stream_count);
00289     for(i=0; i<stream_count; i++){
00290         avformat_new_stream(s, NULL);
00291     }
00292 
00293     return 0;
00294 }
00295 
00296 static int decode_stream_header(NUTContext *nut){
00297     AVFormatContext *s= nut->avf;
00298     AVIOContext *bc = s->pb;
00299     StreamContext *stc;
00300     int class, stream_id;
00301     uint64_t tmp, end;
00302     AVStream *st;
00303 
00304     end= get_packetheader(nut, bc, 1, STREAM_STARTCODE);
00305     end += avio_tell(bc);
00306 
00307     GET_V(stream_id, tmp < s->nb_streams && !nut->stream[tmp].time_base);
00308     stc= &nut->stream[stream_id];
00309 
00310     st = s->streams[stream_id];
00311     if (!st)
00312         return AVERROR(ENOMEM);
00313 
00314     class = ffio_read_varlen(bc);
00315     tmp = get_fourcc(bc);
00316     st->codec->codec_tag= tmp;
00317     switch(class)
00318     {
00319         case 0:
00320             st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00321             st->codec->codec_id = av_codec_get_id(
00322                 (const AVCodecTag * const []) { ff_codec_bmp_tags, ff_nut_video_tags, 0 },
00323                 tmp);
00324             break;
00325         case 1:
00326             st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00327             st->codec->codec_id = ff_codec_get_id(ff_codec_wav_tags, tmp);
00328             break;
00329         case 2:
00330             st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
00331             st->codec->codec_id = ff_codec_get_id(ff_nut_subtitle_tags, tmp);
00332             break;
00333         case 3:
00334             st->codec->codec_type = AVMEDIA_TYPE_DATA;
00335             break;
00336         default:
00337             av_log(s, AV_LOG_ERROR, "unknown stream class (%d)\n", class);
00338             return -1;
00339     }
00340     if(class<3 && st->codec->codec_id == CODEC_ID_NONE)
00341         av_log(s, AV_LOG_ERROR, "Unknown codec tag '0x%04x' for stream number %d\n",
00342                (unsigned int)tmp, stream_id);
00343 
00344     GET_V(stc->time_base_id    , tmp < nut->time_base_count);
00345     GET_V(stc->msb_pts_shift   , tmp < 16);
00346     stc->max_pts_distance= ffio_read_varlen(bc);
00347     GET_V(stc->decode_delay    , tmp < 1000); //sanity limit, raise this if Moore's law is true
00348     st->codec->has_b_frames= stc->decode_delay;
00349     ffio_read_varlen(bc); //stream flags
00350 
00351     GET_V(st->codec->extradata_size, tmp < (1<<30));
00352     if(st->codec->extradata_size){
00353         st->codec->extradata= av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
00354         avio_read(bc, st->codec->extradata, st->codec->extradata_size);
00355     }
00356 
00357     if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO){
00358         GET_V(st->codec->width , tmp > 0)
00359         GET_V(st->codec->height, tmp > 0)
00360         st->sample_aspect_ratio.num= ffio_read_varlen(bc);
00361         st->sample_aspect_ratio.den= ffio_read_varlen(bc);
00362         if((!st->sample_aspect_ratio.num) != (!st->sample_aspect_ratio.den)){
00363             av_log(s, AV_LOG_ERROR, "invalid aspect ratio %d/%d\n", st->sample_aspect_ratio.num, st->sample_aspect_ratio.den);
00364             return -1;
00365         }
00366         ffio_read_varlen(bc); /* csp type */
00367     }else if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO){
00368         GET_V(st->codec->sample_rate , tmp > 0)
00369         ffio_read_varlen(bc); // samplerate_den
00370         GET_V(st->codec->channels, tmp > 0)
00371     }
00372     if(skip_reserved(bc, end) || ffio_get_checksum(bc)){
00373         av_log(s, AV_LOG_ERROR, "stream header %d checksum mismatch\n", stream_id);
00374         return -1;
00375     }
00376     stc->time_base= &nut->time_base[stc->time_base_id];
00377     avpriv_set_pts_info(s->streams[stream_id], 63, stc->time_base->num, stc->time_base->den);
00378     return 0;
00379 }
00380 
00381 static void set_disposition_bits(AVFormatContext* avf, char* value, int stream_id){
00382     int flag = 0, i;
00383     for (i=0; ff_nut_dispositions[i].flag; ++i) {
00384         if (!strcmp(ff_nut_dispositions[i].str, value))
00385             flag = ff_nut_dispositions[i].flag;
00386     }
00387     if (!flag)
00388         av_log(avf, AV_LOG_INFO, "unknown disposition type '%s'\n", value);
00389     for (i = 0; i < avf->nb_streams; ++i)
00390         if (stream_id == i || stream_id == -1)
00391             avf->streams[i]->disposition |= flag;
00392 }
00393 
00394 static int decode_info_header(NUTContext *nut){
00395     AVFormatContext *s= nut->avf;
00396     AVIOContext *bc = s->pb;
00397     uint64_t tmp, chapter_start, chapter_len;
00398     unsigned int stream_id_plus1, count;
00399     int chapter_id, i;
00400     int64_t value, end;
00401     char name[256], str_value[1024], type_str[256];
00402     const char *type;
00403     AVChapter *chapter= NULL;
00404     AVStream *st= NULL;
00405     AVDictionary **metadata = NULL;
00406 
00407     end= get_packetheader(nut, bc, 1, INFO_STARTCODE);
00408     end += avio_tell(bc);
00409 
00410     GET_V(stream_id_plus1, tmp <= s->nb_streams)
00411     chapter_id   = get_s(bc);
00412     chapter_start= ffio_read_varlen(bc);
00413     chapter_len  = ffio_read_varlen(bc);
00414     count        = ffio_read_varlen(bc);
00415 
00416     if(chapter_id && !stream_id_plus1){
00417         int64_t start= chapter_start / nut->time_base_count;
00418         chapter= avpriv_new_chapter(s, chapter_id,
00419                                 nut->time_base[chapter_start % nut->time_base_count],
00420                                 start, start + chapter_len, NULL);
00421         metadata = &chapter->metadata;
00422     } else if(stream_id_plus1) {
00423         st= s->streams[stream_id_plus1 - 1];
00424         metadata = &st->metadata;
00425     } else
00426         metadata = &s->metadata;
00427 
00428     for(i=0; i<count; i++){
00429         get_str(bc, name, sizeof(name));
00430         value= get_s(bc);
00431         if(value == -1){
00432             type= "UTF-8";
00433             get_str(bc, str_value, sizeof(str_value));
00434         }else if(value == -2){
00435             get_str(bc, type_str, sizeof(type_str));
00436             type= type_str;
00437             get_str(bc, str_value, sizeof(str_value));
00438         }else if(value == -3){
00439             type= "s";
00440             value= get_s(bc);
00441         }else if(value == -4){
00442             type= "t";
00443             value= ffio_read_varlen(bc);
00444         }else if(value < -4){
00445             type= "r";
00446             get_s(bc);
00447         }else{
00448             type= "v";
00449         }
00450 
00451         if (stream_id_plus1 > s->nb_streams) {
00452             av_log(s, AV_LOG_ERROR, "invalid stream id for info packet\n");
00453             continue;
00454         }
00455 
00456         if(!strcmp(type, "UTF-8")){
00457             if(chapter_id==0 && !strcmp(name, "Disposition")) {
00458                 set_disposition_bits(s, str_value, stream_id_plus1 - 1);
00459                 continue;
00460             }
00461             if(metadata && av_strcasecmp(name,"Uses")
00462                && av_strcasecmp(name,"Depends") && av_strcasecmp(name,"Replaces"))
00463                 av_dict_set(metadata, name, str_value, 0);
00464         }
00465     }
00466 
00467     if(skip_reserved(bc, end) || ffio_get_checksum(bc)){
00468         av_log(s, AV_LOG_ERROR, "info header checksum mismatch\n");
00469         return -1;
00470     }
00471     return 0;
00472 }
00473 
00474 static int decode_syncpoint(NUTContext *nut, int64_t *ts, int64_t *back_ptr){
00475     AVFormatContext *s= nut->avf;
00476     AVIOContext *bc = s->pb;
00477     int64_t end, tmp;
00478 
00479     nut->last_syncpoint_pos= avio_tell(bc)-8;
00480 
00481     end= get_packetheader(nut, bc, 1, SYNCPOINT_STARTCODE);
00482     end += avio_tell(bc);
00483 
00484     tmp= ffio_read_varlen(bc);
00485     *back_ptr= nut->last_syncpoint_pos - 16*ffio_read_varlen(bc);
00486     if(*back_ptr < 0)
00487         return -1;
00488 
00489     ff_nut_reset_ts(nut, nut->time_base[tmp % nut->time_base_count], tmp / nut->time_base_count);
00490 
00491     if(skip_reserved(bc, end) || ffio_get_checksum(bc)){
00492         av_log(s, AV_LOG_ERROR, "sync point checksum mismatch\n");
00493         return -1;
00494     }
00495 
00496     *ts= tmp / s->nb_streams * av_q2d(nut->time_base[tmp % s->nb_streams])*AV_TIME_BASE;
00497     ff_nut_add_sp(nut, nut->last_syncpoint_pos, *back_ptr, *ts);
00498 
00499     return 0;
00500 }
00501 
00502 static int find_and_decode_index(NUTContext *nut){
00503     AVFormatContext *s= nut->avf;
00504     AVIOContext *bc = s->pb;
00505     uint64_t tmp, end;
00506     int i, j, syncpoint_count;
00507     int64_t filesize= avio_size(bc);
00508     int64_t *syncpoints;
00509     int8_t *has_keyframe;
00510     int ret= -1;
00511 
00512     avio_seek(bc, filesize-12, SEEK_SET);
00513     avio_seek(bc, filesize-avio_rb64(bc), SEEK_SET);
00514     if(avio_rb64(bc) != INDEX_STARTCODE){
00515         av_log(s, AV_LOG_ERROR, "no index at the end\n");
00516         return -1;
00517     }
00518 
00519     end= get_packetheader(nut, bc, 1, INDEX_STARTCODE);
00520     end += avio_tell(bc);
00521 
00522     ffio_read_varlen(bc); //max_pts
00523     GET_V(syncpoint_count, tmp < INT_MAX/8 && tmp > 0)
00524     syncpoints= av_malloc(sizeof(int64_t)*syncpoint_count);
00525     has_keyframe= av_malloc(sizeof(int8_t)*(syncpoint_count+1));
00526     for(i=0; i<syncpoint_count; i++){
00527         syncpoints[i] = ffio_read_varlen(bc);
00528         if(syncpoints[i] <= 0)
00529             goto fail;
00530         if(i)
00531             syncpoints[i] += syncpoints[i-1];
00532     }
00533 
00534     for(i=0; i<s->nb_streams; i++){
00535         int64_t last_pts= -1;
00536         for(j=0; j<syncpoint_count;){
00537             uint64_t x= ffio_read_varlen(bc);
00538             int type= x&1;
00539             int n= j;
00540             x>>=1;
00541             if(type){
00542                 int flag= x&1;
00543                 x>>=1;
00544                 if(n+x >= syncpoint_count + 1){
00545                     av_log(s, AV_LOG_ERROR, "index overflow A\n");
00546                     goto fail;
00547                 }
00548                 while(x--)
00549                     has_keyframe[n++]= flag;
00550                 has_keyframe[n++]= !flag;
00551             }else{
00552                 while(x != 1){
00553                     if(n>=syncpoint_count + 1){
00554                         av_log(s, AV_LOG_ERROR, "index overflow B\n");
00555                         goto fail;
00556                     }
00557                     has_keyframe[n++]= x&1;
00558                     x>>=1;
00559                 }
00560             }
00561             if(has_keyframe[0]){
00562                 av_log(s, AV_LOG_ERROR, "keyframe before first syncpoint in index\n");
00563                 goto fail;
00564             }
00565             assert(n<=syncpoint_count+1);
00566             for(; j<n && j<syncpoint_count; j++){
00567                 if(has_keyframe[j]){
00568                     uint64_t B, A= ffio_read_varlen(bc);
00569                     if(!A){
00570                         A= ffio_read_varlen(bc);
00571                         B= ffio_read_varlen(bc);
00572                         //eor_pts[j][i] = last_pts + A + B
00573                     }else
00574                         B= 0;
00575                     av_add_index_entry(
00576                         s->streams[i],
00577                         16*syncpoints[j-1],
00578                         last_pts + A,
00579                         0,
00580                         0,
00581                         AVINDEX_KEYFRAME);
00582                     last_pts += A + B;
00583                 }
00584             }
00585         }
00586     }
00587 
00588     if(skip_reserved(bc, end) || ffio_get_checksum(bc)){
00589         av_log(s, AV_LOG_ERROR, "index checksum mismatch\n");
00590         goto fail;
00591     }
00592     ret= 0;
00593 fail:
00594     av_free(syncpoints);
00595     av_free(has_keyframe);
00596     return ret;
00597 }
00598 
00599 static int nut_read_header(AVFormatContext *s, AVFormatParameters *ap)
00600 {
00601     NUTContext *nut = s->priv_data;
00602     AVIOContext *bc = s->pb;
00603     int64_t pos;
00604     int initialized_stream_count;
00605 
00606     nut->avf= s;
00607 
00608     /* main header */
00609     pos=0;
00610     do{
00611         pos= find_startcode(bc, MAIN_STARTCODE, pos)+1;
00612         if (pos<0+1){
00613             av_log(s, AV_LOG_ERROR, "No main startcode found.\n");
00614             return AVERROR_INVALIDDATA;
00615         }
00616     }while(decode_main_header(nut) < 0);
00617 
00618     /* stream headers */
00619     pos=0;
00620     for(initialized_stream_count=0; initialized_stream_count < s->nb_streams;){
00621         pos= find_startcode(bc, STREAM_STARTCODE, pos)+1;
00622         if (pos<0+1){
00623             av_log(s, AV_LOG_ERROR, "Not all stream headers found.\n");
00624             return AVERROR_INVALIDDATA;
00625         }
00626         if(decode_stream_header(nut) >= 0)
00627             initialized_stream_count++;
00628     }
00629 
00630     /* info headers */
00631     pos=0;
00632     for(;;){
00633         uint64_t startcode= find_any_startcode(bc, pos);
00634         pos= avio_tell(bc);
00635 
00636         if(startcode==0){
00637             av_log(s, AV_LOG_ERROR, "EOF before video frames\n");
00638             return AVERROR_INVALIDDATA;
00639         }else if(startcode == SYNCPOINT_STARTCODE){
00640             nut->next_startcode= startcode;
00641             break;
00642         }else if(startcode != INFO_STARTCODE){
00643             continue;
00644         }
00645 
00646         decode_info_header(nut);
00647     }
00648 
00649     s->data_offset= pos-8;
00650 
00651     if(bc->seekable){
00652         int64_t orig_pos= avio_tell(bc);
00653         find_and_decode_index(nut);
00654         avio_seek(bc, orig_pos, SEEK_SET);
00655     }
00656     assert(nut->next_startcode == SYNCPOINT_STARTCODE);
00657 
00658     ff_metadata_conv_ctx(s, NULL, ff_nut_metadata_conv);
00659 
00660     return 0;
00661 }
00662 
00663 static int decode_frame_header(NUTContext *nut, int64_t *pts, int *stream_id, uint8_t *header_idx, int frame_code){
00664     AVFormatContext *s= nut->avf;
00665     AVIOContext *bc = s->pb;
00666     StreamContext *stc;
00667     int size, flags, size_mul, pts_delta, i, reserved_count;
00668     uint64_t tmp;
00669 
00670     if(avio_tell(bc) > nut->last_syncpoint_pos + nut->max_distance){
00671         av_log(s, AV_LOG_ERROR, "Last frame must have been damaged %"PRId64" > %"PRId64" + %d\n", avio_tell(bc), nut->last_syncpoint_pos, nut->max_distance);
00672         return AVERROR_INVALIDDATA;
00673     }
00674 
00675     flags          = nut->frame_code[frame_code].flags;
00676     size_mul       = nut->frame_code[frame_code].size_mul;
00677     size           = nut->frame_code[frame_code].size_lsb;
00678     *stream_id     = nut->frame_code[frame_code].stream_id;
00679     pts_delta      = nut->frame_code[frame_code].pts_delta;
00680     reserved_count = nut->frame_code[frame_code].reserved_count;
00681     *header_idx    = nut->frame_code[frame_code].header_idx;
00682 
00683     if(flags & FLAG_INVALID)
00684         return AVERROR_INVALIDDATA;
00685     if(flags & FLAG_CODED)
00686         flags ^= ffio_read_varlen(bc);
00687     if(flags & FLAG_STREAM_ID){
00688         GET_V(*stream_id, tmp < s->nb_streams)
00689     }
00690     stc= &nut->stream[*stream_id];
00691     if(flags&FLAG_CODED_PTS){
00692         int coded_pts= ffio_read_varlen(bc);
00693 //FIXME check last_pts validity?
00694         if(coded_pts < (1<<stc->msb_pts_shift)){
00695             *pts=ff_lsb2full(stc, coded_pts);
00696         }else
00697             *pts=coded_pts - (1<<stc->msb_pts_shift);
00698     }else
00699         *pts= stc->last_pts + pts_delta;
00700     if(flags&FLAG_SIZE_MSB){
00701         size += size_mul*ffio_read_varlen(bc);
00702     }
00703     if(flags&FLAG_MATCH_TIME)
00704         get_s(bc);
00705     if(flags&FLAG_HEADER_IDX)
00706         *header_idx= ffio_read_varlen(bc);
00707     if(flags&FLAG_RESERVED)
00708         reserved_count= ffio_read_varlen(bc);
00709     for(i=0; i<reserved_count; i++)
00710         ffio_read_varlen(bc);
00711 
00712     if(*header_idx >= (unsigned)nut->header_count){
00713         av_log(s, AV_LOG_ERROR, "header_idx invalid\n");
00714         return AVERROR_INVALIDDATA;
00715     }
00716     if(size > 4096)
00717         *header_idx=0;
00718     size -= nut->header_len[*header_idx];
00719 
00720     if(flags&FLAG_CHECKSUM){
00721         avio_rb32(bc); //FIXME check this
00722     }else if(size > 2*nut->max_distance || FFABS(stc->last_pts - *pts) > stc->max_pts_distance){
00723         av_log(s, AV_LOG_ERROR, "frame size > 2max_distance and no checksum\n");
00724         return AVERROR_INVALIDDATA;
00725     }
00726 
00727     stc->last_pts= *pts;
00728     stc->last_flags= flags;
00729 
00730     return size;
00731 }
00732 
00733 static int decode_frame(NUTContext *nut, AVPacket *pkt, int frame_code){
00734     AVFormatContext *s= nut->avf;
00735     AVIOContext *bc = s->pb;
00736     int size, stream_id, discard;
00737     int64_t pts, last_IP_pts;
00738     StreamContext *stc;
00739     uint8_t header_idx;
00740 
00741     size= decode_frame_header(nut, &pts, &stream_id, &header_idx, frame_code);
00742     if(size < 0)
00743         return size;
00744 
00745     stc= &nut->stream[stream_id];
00746 
00747     if (stc->last_flags & FLAG_KEY)
00748         stc->skip_until_key_frame=0;
00749 
00750     discard= s->streams[ stream_id ]->discard;
00751     last_IP_pts= s->streams[ stream_id ]->last_IP_pts;
00752     if(  (discard >= AVDISCARD_NONKEY && !(stc->last_flags & FLAG_KEY))
00753        ||(discard >= AVDISCARD_BIDIR && last_IP_pts != AV_NOPTS_VALUE && last_IP_pts > pts)
00754        || discard >= AVDISCARD_ALL
00755        || stc->skip_until_key_frame){
00756         avio_skip(bc, size);
00757         return 1;
00758     }
00759 
00760     av_new_packet(pkt, size + nut->header_len[header_idx]);
00761     memcpy(pkt->data, nut->header[header_idx], nut->header_len[header_idx]);
00762     pkt->pos= avio_tell(bc); //FIXME
00763     avio_read(bc, pkt->data + nut->header_len[header_idx], size);
00764 
00765     pkt->stream_index = stream_id;
00766     if (stc->last_flags & FLAG_KEY)
00767         pkt->flags |= AV_PKT_FLAG_KEY;
00768     pkt->pts = pts;
00769 
00770     return 0;
00771 }
00772 
00773 static int nut_read_packet(AVFormatContext *s, AVPacket *pkt)
00774 {
00775     NUTContext *nut = s->priv_data;
00776     AVIOContext *bc = s->pb;
00777     int i, frame_code=0, ret, skip;
00778     int64_t ts, back_ptr;
00779 
00780     for(;;){
00781         int64_t pos= avio_tell(bc);
00782         uint64_t tmp= nut->next_startcode;
00783         nut->next_startcode=0;
00784 
00785         if(tmp){
00786             pos-=8;
00787         }else{
00788             frame_code = avio_r8(bc);
00789             if(bc->eof_reached)
00790                 return -1;
00791             if(frame_code == 'N'){
00792                 tmp= frame_code;
00793                 for(i=1; i<8; i++)
00794                     tmp = (tmp<<8) + avio_r8(bc);
00795             }
00796         }
00797         switch(tmp){
00798         case MAIN_STARTCODE:
00799         case STREAM_STARTCODE:
00800         case INDEX_STARTCODE:
00801             skip= get_packetheader(nut, bc, 0, tmp);
00802             avio_skip(bc, skip);
00803             break;
00804         case INFO_STARTCODE:
00805             if(decode_info_header(nut)<0)
00806                 goto resync;
00807             break;
00808         case SYNCPOINT_STARTCODE:
00809             if(decode_syncpoint(nut, &ts, &back_ptr)<0)
00810                 goto resync;
00811             frame_code = avio_r8(bc);
00812         case 0:
00813             ret= decode_frame(nut, pkt, frame_code);
00814             if(ret==0)
00815                 return 0;
00816             else if(ret==1) //ok but discard packet
00817                 break;
00818         default:
00819 resync:
00820 av_log(s, AV_LOG_DEBUG, "syncing from %"PRId64"\n", pos);
00821             tmp= find_any_startcode(bc, nut->last_syncpoint_pos+1);
00822             if(tmp==0)
00823                 return AVERROR_INVALIDDATA;
00824 av_log(s, AV_LOG_DEBUG, "sync\n");
00825             nut->next_startcode= tmp;
00826         }
00827     }
00828 }
00829 
00830 static int64_t nut_read_timestamp(AVFormatContext *s, int stream_index, int64_t *pos_arg, int64_t pos_limit){
00831     NUTContext *nut = s->priv_data;
00832     AVIOContext *bc = s->pb;
00833     int64_t pos, pts, back_ptr;
00834 av_log(s, AV_LOG_DEBUG, "read_timestamp(X,%d,%"PRId64",%"PRId64")\n", stream_index, *pos_arg, pos_limit);
00835 
00836     pos= *pos_arg;
00837     do{
00838         pos= find_startcode(bc, SYNCPOINT_STARTCODE, pos)+1;
00839         if(pos < 1){
00840             assert(nut->next_startcode == 0);
00841             av_log(s, AV_LOG_ERROR, "read_timestamp failed.\n");
00842             return AV_NOPTS_VALUE;
00843         }
00844     }while(decode_syncpoint(nut, &pts, &back_ptr) < 0);
00845     *pos_arg = pos-1;
00846     assert(nut->last_syncpoint_pos == *pos_arg);
00847 
00848     av_log(s, AV_LOG_DEBUG, "return %"PRId64" %"PRId64"\n", pts,back_ptr );
00849     if     (stream_index == -1) return pts;
00850     else if(stream_index == -2) return back_ptr;
00851 
00852 assert(0);
00853 }
00854 
00855 static int read_seek(AVFormatContext *s, int stream_index, int64_t pts, int flags){
00856     NUTContext *nut = s->priv_data;
00857     AVStream *st= s->streams[stream_index];
00858     Syncpoint dummy={.ts= pts*av_q2d(st->time_base)*AV_TIME_BASE};
00859     Syncpoint nopts_sp= {.ts= AV_NOPTS_VALUE, .back_ptr= AV_NOPTS_VALUE};
00860     Syncpoint *sp, *next_node[2]= {&nopts_sp, &nopts_sp};
00861     int64_t pos, pos2, ts;
00862     int i;
00863 
00864     if(st->index_entries){
00865         int index= av_index_search_timestamp(st, pts, flags);
00866         if(index<0)
00867             return -1;
00868 
00869         pos2= st->index_entries[index].pos;
00870         ts  = st->index_entries[index].timestamp;
00871     }else{
00872         av_tree_find(nut->syncpoints, &dummy, (void *) ff_nut_sp_pts_cmp,
00873                      (void **) next_node);
00874         av_log(s, AV_LOG_DEBUG, "%"PRIu64"-%"PRIu64" %"PRId64"-%"PRId64"\n", next_node[0]->pos, next_node[1]->pos,
00875                                                     next_node[0]->ts , next_node[1]->ts);
00876         pos = ff_gen_search(s, -1, dummy.ts, next_node[0]->pos, next_node[1]->pos, next_node[1]->pos,
00877                                              next_node[0]->ts , next_node[1]->ts, AVSEEK_FLAG_BACKWARD, &ts, nut_read_timestamp);
00878 
00879         if(!(flags & AVSEEK_FLAG_BACKWARD)){
00880             dummy.pos= pos+16;
00881             next_node[1]= &nopts_sp;
00882             av_tree_find(nut->syncpoints, &dummy, (void *) ff_nut_sp_pos_cmp,
00883                          (void **) next_node);
00884             pos2 = ff_gen_search(s, -2, dummy.pos, next_node[0]->pos     , next_node[1]->pos, next_node[1]->pos,
00885                                                    next_node[0]->back_ptr, next_node[1]->back_ptr, flags, &ts, nut_read_timestamp);
00886             if(pos2>=0)
00887                 pos= pos2;
00888             //FIXME dir but I think it does not matter
00889         }
00890         dummy.pos= pos;
00891         sp= av_tree_find(nut->syncpoints, &dummy, (void *) ff_nut_sp_pos_cmp,
00892                          NULL);
00893 
00894         assert(sp);
00895         pos2= sp->back_ptr  - 15;
00896     }
00897     av_log(NULL, AV_LOG_DEBUG, "SEEKTO: %"PRId64"\n", pos2);
00898     pos= find_startcode(s->pb, SYNCPOINT_STARTCODE, pos2);
00899     avio_seek(s->pb, pos, SEEK_SET);
00900     av_log(NULL, AV_LOG_DEBUG, "SP: %"PRId64"\n", pos);
00901     if(pos2 > pos || pos2 + 15 < pos){
00902         av_log(NULL, AV_LOG_ERROR, "no syncpoint at backptr pos\n");
00903     }
00904     for(i=0; i<s->nb_streams; i++)
00905         nut->stream[i].skip_until_key_frame=1;
00906 
00907     return 0;
00908 }
00909 
00910 static int nut_read_close(AVFormatContext *s)
00911 {
00912     NUTContext *nut = s->priv_data;
00913     int i;
00914 
00915     av_freep(&nut->time_base);
00916     av_freep(&nut->stream);
00917     ff_nut_free_sp(nut);
00918     for(i = 1; i < nut->header_count; i++)
00919         av_freep(&nut->header[i]);
00920 
00921     return 0;
00922 }
00923 
00924 #if CONFIG_NUT_DEMUXER
00925 AVInputFormat ff_nut_demuxer = {
00926     .name           = "nut",
00927     .long_name      = NULL_IF_CONFIG_SMALL("NUT format"),
00928     .priv_data_size = sizeof(NUTContext),
00929     .read_probe     = nut_probe,
00930     .read_header    = nut_read_header,
00931     .read_packet    = nut_read_packet,
00932     .read_close     = nut_read_close,
00933     .read_seek      = read_seek,
00934     .extensions = "nut",
00935     .codec_tag = (const AVCodecTag * const []) { ff_codec_bmp_tags, ff_nut_video_tags, ff_codec_wav_tags, ff_nut_subtitle_tags, 0 },
00936 };
00937 #endif
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