FFmpeg: libavformat/mpeg.c Source File

00001 /*
00002  * MPEG1/2 demuxer
00003  * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 #include "avformat.h"
00023 #include "mpeg.h"
00024 
00025 //#define DEBUG_SEEK
00026 
00027 #undef NDEBUG
00028 #include <assert.h>
00029 
00030 /*********************************************/
00031 /* demux code */
00032 
00033 #define MAX_SYNC_SIZE 100000
00034 
00035 static int check_pes(uint8_t *p, uint8_t *end){
00036     int pes1;
00037     int pes2=      (p[3] & 0xC0) == 0x80
00038                 && (p[4] & 0xC0) != 0x40
00039                 &&((p[4] & 0xC0) == 0x00 || (p[4]&0xC0)>>2 == (p[6]&0xF0));
00040 
00041     for(p+=3; p<end && *p == 0xFF; p++);
00042     if((*p&0xC0) == 0x40) p+=2;
00043     if((*p&0xF0) == 0x20){
00044         pes1= p[0]&p[2]&p[4]&1;
00045         p+=5;
00046     }else if((*p&0xF0) == 0x30){
00047         pes1= p[0]&p[2]&p[4]&p[5]&p[7]&p[9]&1;
00048         p+=10;
00049     }else
00050         pes1 = *p == 0x0F;
00051 
00052     return pes1||pes2;
00053 }
00054 
00055 static int mpegps_probe(AVProbeData *p)
00056 {
00057     uint32_t code= -1;
00058     int sys=0, pspack=0, priv1=0, vid=0, audio=0, invalid=0;
00059     int i;
00060     int score=0;
00061 
00062     for(i=0; i<p->buf_size; i++){
00063         code = (code<<8) + p->buf[i];
00064         if ((code & 0xffffff00) == 0x100) {
00065             int pes= check_pes(p->buf+i, p->buf+p->buf_size);
00066 
00067             if(code == SYSTEM_HEADER_START_CODE) sys++;
00068             else if(code == PRIVATE_STREAM_1)    priv1++;
00069             else if(code == PACK_START_CODE)     pspack++;
00070             else if((code & 0xf0) == VIDEO_ID &&  pes) vid++;
00071             else if((code & 0xe0) == AUDIO_ID &&  pes) audio++;
00072 
00073             else if((code & 0xf0) == VIDEO_ID && !pes) invalid++;
00074             else if((code & 0xe0) == AUDIO_ID && !pes) invalid++;
00075         }
00076     }
00077 
00078     if(vid+audio > invalid)     /* invalid VDR files nd short PES streams */
00079         score= AVPROBE_SCORE_MAX/4;
00080 
00081 //av_log(NULL, AV_LOG_ERROR, "%d %d %d %d %d len:%d\n", sys, priv1, pspack,vid, audio, p->buf_size);
00082     if(sys>invalid && sys*9 <= pspack*10)
00083         return AVPROBE_SCORE_MAX/2+2; // +1 for .mpg
00084     if(priv1 + vid + audio > invalid && (priv1+vid+audio)*9 <= pspack*10)
00085         return AVPROBE_SCORE_MAX/2+2; // +1 for .mpg
00086     if((!!vid ^ !!audio) && (audio > 4 || vid > 1) && !sys && !pspack && p->buf_size>2048) /* PES stream */
00087         return AVPROBE_SCORE_MAX/2+2;
00088 
00089     //02-Penguin.flac has sys:0 priv1:0 pspack:0 vid:0 audio:1
00090     return score;
00091 }
00092 
00093 
00094 typedef struct MpegDemuxContext {
00095     int32_t header_state;
00096     unsigned char psm_es_type[256];
00097     int sofdec;
00098 } MpegDemuxContext;
00099 
00100 static int mpegps_read_header(AVFormatContext *s,
00101                               AVFormatParameters *ap)
00102 {
00103     MpegDemuxContext *m = s->priv_data;
00104     const char *sofdec = "Sofdec";
00105     int v, i = 0;
00106 
00107     m->header_state = 0xff;
00108     s->ctx_flags |= AVFMTCTX_NOHEADER;
00109 
00110     m->sofdec = -1;
00111     do {
00112         v = get_byte(s->pb);
00113         m->header_state = m->header_state << 8 | v;
00114         m->sofdec++;
00115     } while (v == sofdec[i] && i++ < 6);
00116 
00117     /* no need to do more */
00118     return 0;
00119 }
00120 
00121 static int64_t get_pts(ByteIOContext *pb, int c)
00122 {
00123     uint8_t buf[5];
00124 
00125     buf[0] = c<0 ? get_byte(pb) : c;
00126     get_buffer(pb, buf+1, 4);
00127 
00128     return ff_parse_pes_pts(buf);
00129 }
00130 
00131 static int find_next_start_code(ByteIOContext *pb, int *size_ptr,
00132                                 int32_t *header_state)
00133 {
00134     unsigned int state, v;
00135     int val, n;
00136 
00137     state = *header_state;
00138     n = *size_ptr;
00139     while (n > 0) {
00140         if (url_feof(pb))
00141             break;
00142         v = get_byte(pb);
00143         n--;
00144         if (state == 0x000001) {
00145             state = ((state << 8) | v) & 0xffffff;
00146             val = state;
00147             goto found;
00148         }
00149         state = ((state << 8) | v) & 0xffffff;
00150     }
00151     val = -1;
00152  found:
00153     *header_state = state;
00154     *size_ptr = n;
00155     return val;
00156 }
00157 
00158 #if 0 /* unused, remove? */
00159 /* XXX: optimize */
00160 static int find_prev_start_code(ByteIOContext *pb, int *size_ptr)
00161 {
00162     int64_t pos, pos_start;
00163     int max_size, start_code;
00164 
00165     max_size = *size_ptr;
00166     pos_start = url_ftell(pb);
00167 
00168     /* in order to go faster, we fill the buffer */
00169     pos = pos_start - 16386;
00170     if (pos < 0)
00171         pos = 0;
00172     url_fseek(pb, pos, SEEK_SET);
00173     get_byte(pb);
00174 
00175     pos = pos_start;
00176     for(;;) {
00177         pos--;
00178         if (pos < 0 || (pos_start - pos) >= max_size) {
00179             start_code = -1;
00180             goto the_end;
00181         }
00182         url_fseek(pb, pos, SEEK_SET);
00183         start_code = get_be32(pb);
00184         if ((start_code & 0xffffff00) == 0x100)
00185             break;
00186     }
00187  the_end:
00188     *size_ptr = pos_start - pos;
00189     return start_code;
00190 }
00191 #endif
00192 
00199 static long mpegps_psm_parse(MpegDemuxContext *m, ByteIOContext *pb)
00200 {
00201     int psm_length, ps_info_length, es_map_length;
00202 
00203     psm_length = get_be16(pb);
00204     get_byte(pb);
00205     get_byte(pb);
00206     ps_info_length = get_be16(pb);
00207 
00208     /* skip program_stream_info */
00209     url_fskip(pb, ps_info_length);
00210     es_map_length = get_be16(pb);
00211 
00212     /* at least one es available? */
00213     while (es_map_length >= 4){
00214         unsigned char type      = get_byte(pb);
00215         unsigned char es_id     = get_byte(pb);
00216         uint16_t es_info_length = get_be16(pb);
00217         /* remember mapping from stream id to stream type */
00218         m->psm_es_type[es_id] = type;
00219         /* skip program_stream_info */
00220         url_fskip(pb, es_info_length);
00221         es_map_length -= 4 + es_info_length;
00222     }
00223     get_be32(pb); /* crc32 */
00224     return 2 + psm_length;
00225 }
00226 
00227 /* read the next PES header. Return its position in ppos
00228    (if not NULL), and its start code, pts and dts.
00229  */
00230 static int mpegps_read_pes_header(AVFormatContext *s,
00231                                   int64_t *ppos, int *pstart_code,
00232                                   int64_t *ppts, int64_t *pdts)
00233 {
00234     MpegDemuxContext *m = s->priv_data;
00235     int len, size, startcode, c, flags, header_len;
00236     int pes_ext, ext2_len, id_ext, skip;
00237     int64_t pts, dts;
00238     int64_t last_sync= url_ftell(s->pb);
00239 
00240  error_redo:
00241         url_fseek(s->pb, last_sync, SEEK_SET);
00242  redo:
00243         /* next start code (should be immediately after) */
00244         m->header_state = 0xff;
00245         size = MAX_SYNC_SIZE;
00246         startcode = find_next_start_code(s->pb, &size, &m->header_state);
00247         last_sync = url_ftell(s->pb);
00248     //printf("startcode=%x pos=0x%"PRIx64"\n", startcode, url_ftell(s->pb));
00249     if (startcode < 0)
00250         return AVERROR(EIO);
00251     if (startcode == PACK_START_CODE)
00252         goto redo;
00253     if (startcode == SYSTEM_HEADER_START_CODE)
00254         goto redo;
00255     if (startcode == PADDING_STREAM) {
00256         url_fskip(s->pb, get_be16(s->pb));
00257         goto redo;
00258     }
00259     if (startcode == PRIVATE_STREAM_2) {
00260         len = get_be16(s->pb);
00261         if (!m->sofdec) {
00262             while (len-- >= 6) {
00263                 if (get_byte(s->pb) == 'S') {
00264                     uint8_t buf[5];
00265                     get_buffer(s->pb, buf, sizeof(buf));
00266                     m->sofdec = !memcmp(buf, "ofdec", 5);
00267                     len -= sizeof(buf);
00268                     break;
00269                 }
00270             }
00271             m->sofdec -= !m->sofdec;
00272         }
00273         url_fskip(s->pb, len);
00274         goto redo;
00275     }
00276     if (startcode == PROGRAM_STREAM_MAP) {
00277         mpegps_psm_parse(m, s->pb);
00278         goto redo;
00279     }
00280 
00281     /* find matching stream */
00282     if (!((startcode >= 0x1c0 && startcode <= 0x1df) ||
00283           (startcode >= 0x1e0 && startcode <= 0x1ef) ||
00284           (startcode == 0x1bd) || (startcode == 0x1fd)))
00285         goto redo;
00286     if (ppos) {
00287         *ppos = url_ftell(s->pb) - 4;
00288     }
00289     len = get_be16(s->pb);
00290     pts =
00291     dts = AV_NOPTS_VALUE;
00292     /* stuffing */
00293     for(;;) {
00294         if (len < 1)
00295             goto error_redo;
00296         c = get_byte(s->pb);
00297         len--;
00298         /* XXX: for mpeg1, should test only bit 7 */
00299         if (c != 0xff)
00300             break;
00301     }
00302     if ((c & 0xc0) == 0x40) {
00303         /* buffer scale & size */
00304         get_byte(s->pb);
00305         c = get_byte(s->pb);
00306         len -= 2;
00307     }
00308     if ((c & 0xe0) == 0x20) {
00309         dts = pts = get_pts(s->pb, c);
00310         len -= 4;
00311         if (c & 0x10){
00312             dts = get_pts(s->pb, -1);
00313             len -= 5;
00314         }
00315     } else if ((c & 0xc0) == 0x80) {
00316         /* mpeg 2 PES */
00317 #if 0 /* some streams have this field set for no apparent reason */
00318         if ((c & 0x30) != 0) {
00319             /* Encrypted multiplex not handled */
00320             goto redo;
00321         }
00322 #endif
00323         flags = get_byte(s->pb);
00324         header_len = get_byte(s->pb);
00325         len -= 2;
00326         if (header_len > len)
00327             goto error_redo;
00328         len -= header_len;
00329         if (flags & 0x80) {
00330             dts = pts = get_pts(s->pb, -1);
00331             header_len -= 5;
00332             if (flags & 0x40) {
00333                 dts = get_pts(s->pb, -1);
00334                 header_len -= 5;
00335             }
00336         }
00337         if (flags & 0x3f && header_len == 0){
00338             flags &= 0xC0;
00339             av_log(s, AV_LOG_WARNING, "Further flags set but no bytes left\n");
00340         }
00341         if (flags & 0x01) { /* PES extension */
00342             pes_ext = get_byte(s->pb);
00343             header_len--;
00344             /* Skip PES private data, program packet sequence counter and P-STD buffer */
00345             skip = (pes_ext >> 4) & 0xb;
00346             skip += skip & 0x9;
00347             if (pes_ext & 0x40 || skip > header_len){
00348                 av_log(s, AV_LOG_WARNING, "pes_ext %X is invalid\n", pes_ext);
00349                 pes_ext=skip=0;
00350             }
00351             url_fskip(s->pb, skip);
00352             header_len -= skip;
00353 
00354             if (pes_ext & 0x01) { /* PES extension 2 */
00355                 ext2_len = get_byte(s->pb);
00356                 header_len--;
00357                 if ((ext2_len & 0x7f) > 0) {
00358                     id_ext = get_byte(s->pb);
00359                     if ((id_ext & 0x80) == 0)
00360                         startcode = ((startcode & 0xff) << 8) | id_ext;
00361                     header_len--;
00362                 }
00363             }
00364         }
00365         if(header_len < 0)
00366             goto error_redo;
00367         url_fskip(s->pb, header_len);
00368     }
00369     else if( c!= 0xf )
00370         goto redo;
00371 
00372     if (startcode == PRIVATE_STREAM_1 && !m->psm_es_type[startcode & 0xff]) {
00373         startcode = get_byte(s->pb);
00374         len--;
00375         if (startcode >= 0x80 && startcode <= 0xcf) {
00376             /* audio: skip header */
00377             get_byte(s->pb);
00378             get_byte(s->pb);
00379             get_byte(s->pb);
00380             len -= 3;
00381             if (startcode >= 0xb0 && startcode <= 0xbf) {
00382                 /* MLP/TrueHD audio has a 4-byte header */
00383                 get_byte(s->pb);
00384                 len--;
00385             }
00386         }
00387     }
00388     if(len<0)
00389         goto error_redo;
00390     if(dts != AV_NOPTS_VALUE && ppos){
00391         int i;
00392         for(i=0; i<s->nb_streams; i++){
00393             if(startcode == s->streams[i]->id &&
00394                !url_is_streamed(s->pb) /* index useless on streams anyway */) {
00395                 ff_reduce_index(s, i);
00396                 av_add_index_entry(s->streams[i], *ppos, dts, 0, 0, AVINDEX_KEYFRAME /* FIXME keyframe? */);
00397             }
00398         }
00399     }
00400 
00401     *pstart_code = startcode;
00402     *ppts = pts;
00403     *pdts = dts;
00404     return len;
00405 }
00406 
00407 static int mpegps_read_packet(AVFormatContext *s,
00408                               AVPacket *pkt)
00409 {
00410     MpegDemuxContext *m = s->priv_data;
00411     AVStream *st;
00412     int len, startcode, i, es_type;
00413     enum CodecID codec_id = CODEC_ID_NONE;
00414     enum CodecType type;
00415     int64_t pts, dts, dummy_pos; //dummy_pos is needed for the index building to work
00416     uint8_t dvdaudio_substream_type;
00417 
00418  redo:
00419     len = mpegps_read_pes_header(s, &dummy_pos, &startcode, &pts, &dts);
00420     if (len < 0)
00421         return len;
00422 
00423     if(startcode == 0x1bd) {
00424         dvdaudio_substream_type = get_byte(s->pb);
00425         url_fskip(s->pb, 3);
00426         len -= 4;
00427     }
00428 
00429     /* now find stream */
00430     for(i=0;i<s->nb_streams;i++) {
00431         st = s->streams[i];
00432         if (st->id == startcode)
00433             goto found;
00434     }
00435 
00436     es_type = m->psm_es_type[startcode & 0xff];
00437     if(es_type > 0 && es_type != STREAM_TYPE_PRIVATE_DATA){
00438         if(es_type == STREAM_TYPE_VIDEO_MPEG1){
00439             codec_id = CODEC_ID_MPEG2VIDEO;
00440             type = CODEC_TYPE_VIDEO;
00441         } else if(es_type == STREAM_TYPE_VIDEO_MPEG2){
00442             codec_id = CODEC_ID_MPEG2VIDEO;
00443             type = CODEC_TYPE_VIDEO;
00444         } else if(es_type == STREAM_TYPE_AUDIO_MPEG1 ||
00445                   es_type == STREAM_TYPE_AUDIO_MPEG2){
00446             codec_id = CODEC_ID_MP3;
00447             type = CODEC_TYPE_AUDIO;
00448         } else if(es_type == STREAM_TYPE_AUDIO_AAC){
00449             codec_id = CODEC_ID_AAC;
00450             type = CODEC_TYPE_AUDIO;
00451         } else if(es_type == STREAM_TYPE_VIDEO_MPEG4){
00452             codec_id = CODEC_ID_MPEG4;
00453             type = CODEC_TYPE_VIDEO;
00454         } else if(es_type == STREAM_TYPE_VIDEO_H264){
00455             codec_id = CODEC_ID_H264;
00456             type = CODEC_TYPE_VIDEO;
00457         } else if(es_type == STREAM_TYPE_AUDIO_AC3){
00458             codec_id = CODEC_ID_AC3;
00459             type = CODEC_TYPE_AUDIO;
00460         } else {
00461             goto skip;
00462         }
00463     } else if (startcode >= 0x1e0 && startcode <= 0x1ef) {
00464         static const unsigned char avs_seqh[4] = { 0, 0, 1, 0xb0 };
00465         unsigned char buf[8];
00466         get_buffer(s->pb, buf, 8);
00467         url_fseek(s->pb, -8, SEEK_CUR);
00468         if(!memcmp(buf, avs_seqh, 4) && (buf[6] != 0 || buf[7] != 1))
00469             codec_id = CODEC_ID_CAVS;
00470         else
00471             codec_id = CODEC_ID_PROBE;
00472         type = CODEC_TYPE_VIDEO;
00473     } else if (startcode >= 0x1c0 && startcode <= 0x1df) {
00474         type = CODEC_TYPE_AUDIO;
00475         codec_id = m->sofdec > 0 ? CODEC_ID_ADPCM_ADX : CODEC_ID_MP2;
00476     } else if (startcode >= 0x80 && startcode <= 0x87) {
00477         type = CODEC_TYPE_AUDIO;
00478         codec_id = CODEC_ID_AC3;
00479     } else if (  ( startcode >= 0x88 && startcode <= 0x8f)
00480                ||( startcode >= 0x98 && startcode <= 0x9f)) {
00481         /* 0x90 - 0x97 is reserved for SDDS in DVD specs */
00482         type = CODEC_TYPE_AUDIO;
00483         codec_id = CODEC_ID_DTS;
00484     } else if (startcode >= 0xa0 && startcode <= 0xaf) {
00485         type = CODEC_TYPE_AUDIO;
00486         /* 16 bit form will be handled as CODEC_ID_PCM_S16BE */
00487         codec_id = CODEC_ID_PCM_DVD;
00488     } else if (startcode >= 0xb0 && startcode <= 0xbf) {
00489         type = CODEC_TYPE_AUDIO;
00490         codec_id = CODEC_ID_MLP;
00491     } else if (startcode >= 0xc0 && startcode <= 0xcf) {
00492         /* Used for both AC-3 and E-AC-3 in EVOB files */
00493         type = CODEC_TYPE_AUDIO;
00494         codec_id = CODEC_ID_AC3;
00495     } else if (startcode >= 0x20 && startcode <= 0x3f) {
00496         type = CODEC_TYPE_SUBTITLE;
00497         codec_id = CODEC_ID_DVD_SUBTITLE;
00498     } else if (startcode >= 0xfd55 && startcode <= 0xfd5f) {
00499         type = CODEC_TYPE_VIDEO;
00500         codec_id = CODEC_ID_VC1;
00501     } else if (startcode == 0x1bd) {
00502         // check dvd audio substream type
00503         type = CODEC_TYPE_AUDIO;
00504         switch(dvdaudio_substream_type & 0xe0) {
00505         case 0xa0:  codec_id = CODEC_ID_PCM_DVD;
00506                     break;
00507         case 0x80:  if((dvdaudio_substream_type & 0xf8) == 0x88)
00508                          codec_id = CODEC_ID_DTS;
00509                     else codec_id = CODEC_ID_AC3;
00510                     break;
00511         default:    av_log(s, AV_LOG_ERROR, "Unknown 0x1bd sub-stream\n");
00512                     goto skip;
00513         }
00514     } else {
00515     skip:
00516         /* skip packet */
00517         url_fskip(s->pb, len);
00518         goto redo;
00519     }
00520     /* no stream found: add a new stream */
00521     st = av_new_stream(s, startcode);
00522     if (!st)
00523         goto skip;
00524     st->codec->codec_type = type;
00525     st->codec->codec_id = codec_id;
00526     if (codec_id != CODEC_ID_PCM_S16BE)
00527         st->need_parsing = AVSTREAM_PARSE_FULL;
00528  found:
00529     if(st->discard >= AVDISCARD_ALL)
00530         goto skip;
00531     if ((startcode >= 0xa0 && startcode <= 0xaf) ||
00532         (startcode == 0x1bd && ((dvdaudio_substream_type & 0xe0) == 0xa0))) {
00533         int b1, freq;
00534 
00535         /* for LPCM, we just skip the header and consider it is raw
00536            audio data */
00537         if (len <= 3)
00538             goto skip;
00539         get_byte(s->pb); /* emphasis (1), muse(1), reserved(1), frame number(5) */
00540         b1 = get_byte(s->pb); /* quant (2), freq(2), reserved(1), channels(3) */
00541         get_byte(s->pb); /* dynamic range control (0x80 = off) */
00542         len -= 3;
00543         freq = (b1 >> 4) & 3;
00544         st->codec->sample_rate = lpcm_freq_tab[freq];
00545         st->codec->channels = 1 + (b1 & 7);
00546         st->codec->bits_per_coded_sample = 16 + ((b1 >> 6) & 3) * 4;
00547         st->codec->bit_rate = st->codec->channels *
00548                               st->codec->sample_rate *
00549                               st->codec->bits_per_coded_sample;
00550         if (st->codec->bits_per_coded_sample == 16)
00551             st->codec->codec_id = CODEC_ID_PCM_S16BE;
00552         else if (st->codec->bits_per_coded_sample == 28)
00553             return AVERROR(EINVAL);
00554     }
00555     av_new_packet(pkt, len);
00556     get_buffer(s->pb, pkt->data, pkt->size);
00557     pkt->pts = pts;
00558     pkt->dts = dts;
00559     pkt->stream_index = st->index;
00560 #if 0
00561     av_log(s, AV_LOG_DEBUG, "%d: pts=%0.3f dts=%0.3f size=%d\n",
00562            pkt->stream_index, pkt->pts / 90000.0, pkt->dts / 90000.0, pkt->size);
00563 #endif
00564 
00565     return 0;
00566 }
00567 
00568 static int64_t mpegps_read_dts(AVFormatContext *s, int stream_index,
00569                                int64_t *ppos, int64_t pos_limit)
00570 {
00571     int len, startcode;
00572     int64_t pos, pts, dts;
00573 
00574     pos = *ppos;
00575 #ifdef DEBUG_SEEK
00576     printf("read_dts: pos=0x%"PRIx64" next=%d -> ", pos, find_next);
00577 #endif
00578     if (url_fseek(s->pb, pos, SEEK_SET) < 0)
00579         return AV_NOPTS_VALUE;
00580 
00581     for(;;) {
00582         len = mpegps_read_pes_header(s, &pos, &startcode, &pts, &dts);
00583         if (len < 0) {
00584 #ifdef DEBUG_SEEK
00585             printf("none (ret=%d)\n", len);
00586 #endif
00587             return AV_NOPTS_VALUE;
00588         }
00589         if (startcode == s->streams[stream_index]->id &&
00590             dts != AV_NOPTS_VALUE) {
00591             break;
00592         }
00593         url_fskip(s->pb, len);
00594     }
00595 #ifdef DEBUG_SEEK
00596     printf("pos=0x%"PRIx64" dts=0x%"PRIx64" %0.3f\n", pos, dts, dts / 90000.0);
00597 #endif
00598     *ppos = pos;
00599     return dts;
00600 }
00601 
00602 AVInputFormat mpegps_demuxer = {
00603     "mpeg",
00604     NULL_IF_CONFIG_SMALL("MPEG-PS format"),
00605     sizeof(MpegDemuxContext),
00606     mpegps_probe,
00607     mpegps_read_header,
00608     mpegps_read_packet,
00609     NULL,
00610     NULL, //mpegps_read_seek,
00611     mpegps_read_dts,
00612     .flags = AVFMT_SHOW_IDS|AVFMT_TS_DISCONT,
00613 };