libavformat/mpegtsenc.c

   1 /*
   2  * MPEG2 transport stream (aka DVB) muxer
   3  * Copyright (c) 2003 Fabrice Bellard
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include "libavutil/bswap.h"
  23 #include "libavutil/crc.h"
  24 #include "libavcodec/mpegvideo.h"
  25 #include "avformat.h"
  26 #include "mpegts.h"
  27
  28 /* write DVB SI sections */
  29
  30 /*********************************************/
  31 /* mpegts section writer */
  32
  33 typedef struct MpegTSSection {
  34     int pid;
  35     int cc;
  36     void (*write_packet)(struct MpegTSSection *s, const uint8_t *packet);
  37     void *opaque;
  38 } MpegTSSection;
  39
  40 typedef struct MpegTSService {
  41     MpegTSSection pmt; /* MPEG2 pmt table context */
  42     int sid;           /* service ID */
  43     char *name;
  44     char *provider_name;
  45     int pcr_pid;
  46     int pcr_packet_count;
  47     int pcr_packet_freq;
  48 } MpegTSService;
  49
  50 typedef struct MpegTSWrite {
  51     MpegTSSection pat; /* MPEG2 pat table */
  52     MpegTSSection sdt; /* MPEG2 sdt table context */
  53     MpegTSService **services;
  54     int sdt_packet_count;
  55     int sdt_packet_freq;
  56     int pat_packet_count;
  57     int pat_packet_freq;
  58     int nb_services;
  59     int onid;
  60     int tsid;
  61     uint64_t cur_pcr;
  62     int mux_rate;
  63 } MpegTSWrite;
  64
  65 /* NOTE: 4 bytes must be left at the end for the crc32 */
  66 static void mpegts_write_section(MpegTSSection *s, uint8_t *buf, int len)
  67 {
  68     MpegTSWrite *ts = ((AVFormatContext*)s->opaque)->priv_data;
  69     unsigned int crc;
  70     unsigned char packet[TS_PACKET_SIZE];
  71     const unsigned char *buf_ptr;
  72     unsigned char *q;
  73     int first, b, len1, left;
  74
  75     crc = bswap_32(av_crc(av_crc_get_table(AV_CRC_32_IEEE), -1, buf, len - 4));
  76     buf[len - 4] = (crc >> 24) & 0xff;
  77     buf[len - 3] = (crc >> 16) & 0xff;
  78     buf[len - 2] = (crc >> 8) & 0xff;
  79     buf[len - 1] = (crc) & 0xff;
  80
  81     /* send each packet */
  82     buf_ptr = buf;
  83     while (len > 0) {
  84         first = (buf == buf_ptr);
  85         q = packet;
  86         *q++ = 0x47;
  87         b = (s->pid >> 8);
  88         if (first)
  89             b |= 0x40;
  90         *q++ = b;
  91         *q++ = s->pid;
  92         *q++ = 0x10 | s->cc;
  93         s->cc = (s->cc + 1) & 0xf;
  94         if (first)
  95             *q++ = 0; /* 0 offset */
  96         len1 = TS_PACKET_SIZE - (q - packet);
  97         if (len1 > len)
  98             len1 = len;
  99         memcpy(q, buf_ptr, len1);
 100         q += len1;
 101         /* add known padding data */
 102         left = TS_PACKET_SIZE - (q - packet);
 103         if (left > 0)
 104             memset(q, 0xff, left);
 105
 106         s->write_packet(s, packet);
 107
 108         buf_ptr += len1;
 109         len -= len1;
 110
 111         ts->cur_pcr += TS_PACKET_SIZE*8*90000LL/ts->mux_rate;
 112     }
 113 }
 114
 115 static inline void put16(uint8_t **q_ptr, int val)
 116 {
 117     uint8_t *q;
 118     q = *q_ptr;
 119     *q++ = val >> 8;
 120     *q++ = val;
 121     *q_ptr = q;
 122 }
 123
 124 static int mpegts_write_section1(MpegTSSection *s, int tid, int id,
 125                           int version, int sec_num, int last_sec_num,
 126                           uint8_t *buf, int len)
 127 {
 128     uint8_t section[1024], *q;
 129     unsigned int tot_len;
 130
 131     tot_len = 3 + 5 + len + 4;
 132     /* check if not too big */
 133     if (tot_len > 1024)
 134         return -1;
 135
 136     q = section;
 137     *q++ = tid;
 138     put16(&q, 0xb000 | (len + 5 + 4)); /* 5 byte header + 4 byte CRC */
 139     put16(&q, id);
 140     *q++ = 0xc1 | (version << 1); /* current_next_indicator = 1 */
 141     *q++ = sec_num;
 142     *q++ = last_sec_num;
 143     memcpy(q, buf, len);
 144
 145     mpegts_write_section(s, section, tot_len);
 146     return 0;
 147 }
 148
 149 /*********************************************/
 150 /* mpegts writer */
 151
 152 #define DEFAULT_PMT_START_PID   0x1000
 153 #define DEFAULT_START_PID       0x0100
 154 #define DEFAULT_PROVIDER_NAME   "FFmpeg"
 155 #define DEFAULT_SERVICE_NAME    "Service01"
 156
 157 /* default network id, transport stream and service identifiers */
 158 #define DEFAULT_ONID            0x0001
 159 #define DEFAULT_TSID            0x0001
 160 #define DEFAULT_SID             0x0001
 161
 162 /* a PES packet header is generated every DEFAULT_PES_HEADER_FREQ packets */
 163 #define DEFAULT_PES_HEADER_FREQ 16
 164 #define DEFAULT_PES_PAYLOAD_SIZE ((DEFAULT_PES_HEADER_FREQ - 1) * 184 + 170)
 165
 166 /* we retransmit the SI info at this rate */
 167 #define SDT_RETRANS_TIME 500
 168 #define PAT_RETRANS_TIME 100
 169 #define PCR_RETRANS_TIME 20
 170
 171 typedef struct MpegTSWriteStream {
 172     struct MpegTSService *service;
 173     int pid; /* stream associated pid */
 174     int cc;
 175     int payload_index;
 176     int64_t payload_pts;
 177     int64_t payload_dts;
 178     uint8_t payload[DEFAULT_PES_PAYLOAD_SIZE];
 179 } MpegTSWriteStream;
 180
 181 static void mpegts_write_pat(AVFormatContext *s)
 182 {
 183     MpegTSWrite *ts = s->priv_data;
 184     MpegTSService *service;
 185     uint8_t data[1012], *q;
 186     int i;
 187
 188     q = data;
 189     for(i = 0; i < ts->nb_services; i++) {
 190         service = ts->services[i];
 191         put16(&q, service->sid);
 192         put16(&q, 0xe000 | service->pmt.pid);
 193     }
 194     mpegts_write_section1(&ts->pat, PAT_TID, ts->tsid, 0, 0, 0,
 195                           data, q - data);
 196 }
 197
 198 static void mpegts_write_pmt(AVFormatContext *s, MpegTSService *service)
 199 {
 200     //    MpegTSWrite *ts = s->priv_data;
 201     uint8_t data[1012], *q, *desc_length_ptr, *program_info_length_ptr;
 202     int val, stream_type, i;
 203
 204     q = data;
 205     put16(&q, 0xe000 | service->pcr_pid);
 206
 207     program_info_length_ptr = q;
 208     q += 2; /* patched after */
 209
 210     /* put program info here */
 211
 212     val = 0xf000 | (q - program_info_length_ptr - 2);
 213     program_info_length_ptr[0] = val >> 8;
 214     program_info_length_ptr[1] = val;
 215
 216     for(i = 0; i < s->nb_streams; i++) {
 217         AVStream *st = s->streams[i];
 218         MpegTSWriteStream *ts_st = st->priv_data;
 219         AVMetadataTag *lang = av_metadata_get(st->metadata, "language", NULL,0);
 220         switch(st->codec->codec_id) {
 221         case CODEC_ID_MPEG1VIDEO:
 222         case CODEC_ID_MPEG2VIDEO:
 223             stream_type = STREAM_TYPE_VIDEO_MPEG2;
 224             break;
 225         case CODEC_ID_MPEG4:
 226             stream_type = STREAM_TYPE_VIDEO_MPEG4;
 227             break;
 228         case CODEC_ID_H264:
 229             stream_type = STREAM_TYPE_VIDEO_H264;
 230             break;
 231         case CODEC_ID_DIRAC:
 232             stream_type = STREAM_TYPE_VIDEO_DIRAC;
 233             break;
 234         case CODEC_ID_MP2:
 235         case CODEC_ID_MP3:
 236             stream_type = STREAM_TYPE_AUDIO_MPEG1;
 237             break;
 238         case CODEC_ID_AAC:
 239             stream_type = STREAM_TYPE_AUDIO_AAC;
 240             break;
 241         case CODEC_ID_AC3:
 242             stream_type = STREAM_TYPE_AUDIO_AC3;
 243             break;
 244         default:
 245             stream_type = STREAM_TYPE_PRIVATE_DATA;
 246             break;
 247         }
 248         *q++ = stream_type;
 249         put16(&q, 0xe000 | ts_st->pid);
 250         desc_length_ptr = q;
 251         q += 2; /* patched after */
 252
 253         /* write optional descriptors here */
 254         switch(st->codec->codec_type) {
 255         case CODEC_TYPE_AUDIO:
 256             if (lang && strlen(lang->value) == 3) {
 257                 *q++ = 0x0a; /* ISO 639 language descriptor */
 258                 *q++ = 4;
 259                 *q++ = lang->value[0];
 260                 *q++ = lang->value[1];
 261                 *q++ = lang->value[2];
 262                 *q++ = 0; /* undefined type */
 263             }
 264             break;
 265         case CODEC_TYPE_SUBTITLE:
 266             {
 267                 const char *language;
 268                 language = lang && strlen(lang->value)==3 ? lang->value : "eng";
 269                 *q++ = 0x59;
 270                 *q++ = 8;
 271                 *q++ = language[0];
 272                 *q++ = language[1];
 273                 *q++ = language[2];
 274                 *q++ = 0x10; /* normal subtitles (0x20 = if hearing pb) */
 275                 put16(&q, 1); /* page id */
 276                 put16(&q, 1); /* ancillary page id */
 277             }
 278             break;
 279         case CODEC_TYPE_VIDEO:
 280             if (stream_type == STREAM_TYPE_VIDEO_DIRAC) {
 281                 *q++ = 0x05; /*MPEG-2 registration descriptor*/
 282                 *q++ = 4;
 283                 *q++ = 'd';
 284                 *q++ = 'r';
 285                 *q++ = 'a';
 286                 *q++ = 'c';
 287             }
 288             break;
 289         }
 290
 291         val = 0xf000 | (q - desc_length_ptr - 2);
 292         desc_length_ptr[0] = val >> 8;
 293         desc_length_ptr[1] = val;
 294     }
 295     mpegts_write_section1(&service->pmt, PMT_TID, service->sid, 0, 0, 0,
 296                           data, q - data);
 297 }
 298
 299 /* NOTE: str == NULL is accepted for an empty string */
 300 static void putstr8(uint8_t **q_ptr, const char *str)
 301 {
 302     uint8_t *q;
 303     int len;
 304
 305     q = *q_ptr;
 306     if (!str)
 307         len = 0;
 308     else
 309         len = strlen(str);
 310     *q++ = len;
 311     memcpy(q, str, len);
 312     q += len;
 313     *q_ptr = q;
 314 }
 315
 316 static void mpegts_write_sdt(AVFormatContext *s)
 317 {
 318     MpegTSWrite *ts = s->priv_data;
 319     MpegTSService *service;
 320     uint8_t data[1012], *q, *desc_list_len_ptr, *desc_len_ptr;
 321     int i, running_status, free_ca_mode, val;
 322
 323     q = data;
 324     put16(&q, ts->onid);
 325     *q++ = 0xff;
 326     for(i = 0; i < ts->nb_services; i++) {
 327         service = ts->services[i];
 328         put16(&q, service->sid);
 329         *q++ = 0xfc | 0x00; /* currently no EIT info */
 330         desc_list_len_ptr = q;
 331         q += 2;
 332         running_status = 4; /* running */
 333         free_ca_mode = 0;
 334
 335         /* write only one descriptor for the service name and provider */
 336         *q++ = 0x48;
 337         desc_len_ptr = q;
 338         q++;
 339         *q++ = 0x01; /* digital television service */
 340         putstr8(&q, service->provider_name);
 341         putstr8(&q, service->name);
 342         desc_len_ptr[0] = q - desc_len_ptr - 1;
 343
 344         /* fill descriptor length */
 345         val = (running_status << 13) | (free_ca_mode << 12) |
 346             (q - desc_list_len_ptr - 2);
 347         desc_list_len_ptr[0] = val >> 8;
 348         desc_list_len_ptr[1] = val;
 349     }
 350     mpegts_write_section1(&ts->sdt, SDT_TID, ts->tsid, 0, 0, 0,
 351                           data, q - data);
 352 }
 353
 354 static MpegTSService *mpegts_add_service(MpegTSWrite *ts,
 355                                          int sid,
 356                                          const char *provider_name,
 357                                          const char *name)
 358 {
 359     MpegTSService *service;
 360
 361     service = av_mallocz(sizeof(MpegTSService));
 362     if (!service)
 363         return NULL;
 364     service->pmt.pid = DEFAULT_PMT_START_PID + ts->nb_services - 1;
 365     service->sid = sid;
 366     service->provider_name = av_strdup(provider_name);
 367     service->name = av_strdup(name);
 368     service->pcr_pid = 0x1fff;
 369     dynarray_add(&ts->services, &ts->nb_services, service);
 370     return service;
 371 }
 372
 373 static void section_write_packet(MpegTSSection *s, const uint8_t *packet)
 374 {
 375     AVFormatContext *ctx = s->opaque;
 376     put_buffer(ctx->pb, packet, TS_PACKET_SIZE);
 377 }
 378
 379 static int mpegts_write_header(AVFormatContext *s)
 380 {
 381     MpegTSWrite *ts = s->priv_data;
 382     MpegTSWriteStream *ts_st;
 383     MpegTSService *service;
 384     AVStream *st;
 385     AVMetadataTag *title;
 386     int i, total_bit_rate;
 387     const char *service_name;
 388     uint64_t sdt_size, pat_pmt_size, pos;
 389
 390     ts->tsid = DEFAULT_TSID;
 391     ts->onid = DEFAULT_ONID;
 392     /* allocate a single DVB service */
 393     title = av_metadata_get(s->metadata, "title", NULL, 0);
 394     service_name = title ? title->value : DEFAULT_SERVICE_NAME;
 395     service = mpegts_add_service(ts, DEFAULT_SID,
 396                                  DEFAULT_PROVIDER_NAME, service_name);
 397     service->pmt.write_packet = section_write_packet;
 398     service->pmt.opaque = s;
 399
 400     ts->pat.pid = PAT_PID;
 401     ts->pat.cc = 0;
 402     ts->pat.write_packet = section_write_packet;
 403     ts->pat.opaque = s;
 404
 405     ts->sdt.pid = SDT_PID;
 406     ts->sdt.cc = 0;
 407     ts->sdt.write_packet = section_write_packet;
 408     ts->sdt.opaque = s;
 409
 410     /* assign pids to each stream */
 411     total_bit_rate = 0;
 412     for(i = 0;i < s->nb_streams; i++) {
 413         st = s->streams[i];
 414         ts_st = av_mallocz(sizeof(MpegTSWriteStream));
 415         if (!ts_st)
 416             goto fail;
 417         st->priv_data = ts_st;
 418         ts_st->service = service;
 419         ts_st->pid = DEFAULT_START_PID + i;
 420         ts_st->payload_pts = AV_NOPTS_VALUE;
 421         ts_st->payload_dts = AV_NOPTS_VALUE;
 422         /* update PCR pid by using the first video stream */
 423         if (st->codec->codec_type == CODEC_TYPE_VIDEO &&
 424             service->pcr_pid == 0x1fff)
 425             service->pcr_pid = ts_st->pid;
 426         total_bit_rate += st->codec->bit_rate;
 427     }
 428
 429     /* if no video stream, use the first stream as PCR */
 430     if (service->pcr_pid == 0x1fff && s->nb_streams > 0) {
 431         ts_st = s->streams[0]->priv_data;
 432         service->pcr_pid = ts_st->pid;
 433     }
 434
 435     if (total_bit_rate <= 8 * 1024)
 436         total_bit_rate = 8 * 1024;
 437     service->pcr_packet_freq = (total_bit_rate * PCR_RETRANS_TIME) /
 438         (TS_PACKET_SIZE * 8 * 1000);
 439     ts->sdt_packet_freq = (total_bit_rate * SDT_RETRANS_TIME) /
 440         (TS_PACKET_SIZE * 8 * 1000);
 441     ts->pat_packet_freq = (total_bit_rate * PAT_RETRANS_TIME) /
 442         (TS_PACKET_SIZE * 8 * 1000);
 443
 444     ts->mux_rate = 1; // avoid div by 0
 445
 446     /* write info at the start of the file, so that it will be fast to
 447        find them */
 448     pos = url_ftell(s->pb);
 449     mpegts_write_sdt(s);
 450     sdt_size = url_ftell(s->pb) - pos;
 451     pos = url_ftell(s->pb);
 452     mpegts_write_pat(s);
 453     for(i = 0; i < ts->nb_services; i++) {
 454         mpegts_write_pmt(s, ts->services[i]);
 455     }
 456     pat_pmt_size = url_ftell(s->pb) - pos;
 457
 458     total_bit_rate +=
 459         total_bit_rate * 25 / (8 * DEFAULT_PES_PAYLOAD_SIZE) + /* PES header size */
 460         total_bit_rate * 4 / (8 * TS_PACKET_SIZE) +            /* TS  header size */
 461         SDT_RETRANS_TIME * sdt_size +                          /* SDT size */
 462         PAT_RETRANS_TIME * pat_pmt_size +                      /* PAT+PMT size */
 463         PCR_RETRANS_TIME * 8;                                  /* PCR size */
 464
 465     av_log(s, AV_LOG_DEBUG, "muxrate %d freq sdt %d pat %d\n",
 466            total_bit_rate, ts->sdt_packet_freq, ts->pat_packet_freq);
 467
 468     if (s->mux_rate)
 469         ts->mux_rate = s->mux_rate;
 470     else
 471         ts->mux_rate = total_bit_rate;
 472
 473     // adjust pcr
 474     ts->cur_pcr /= ts->mux_rate;
 475
 476     put_flush_packet(s->pb);
 477
 478     return 0;
 479
 480  fail:
 481     for(i = 0;i < s->nb_streams; i++) {
 482         st = s->streams[i];
 483         av_free(st->priv_data);
 484     }
 485     return -1;
 486 }
 487
 488 /* send SDT, PAT and PMT tables regulary */
 489 static void retransmit_si_info(AVFormatContext *s)
 490 {
 491     MpegTSWrite *ts = s->priv_data;
 492     int i;
 493
 494     if (++ts->sdt_packet_count == ts->sdt_packet_freq) {
 495         ts->sdt_packet_count = 0;
 496         mpegts_write_sdt(s);
 497     }
 498     if (++ts->pat_packet_count == ts->pat_packet_freq) {
 499         ts->pat_packet_count = 0;
 500         mpegts_write_pat(s);
 501         for(i = 0; i < ts->nb_services; i++) {
 502             mpegts_write_pmt(s, ts->services[i]);
 503         }
 504     }
 505 }
 506
 507 static void write_pts(uint8_t *q, int fourbits, int64_t pts)
 508 {
 509     int val;
 510
 511     val = fourbits << 4 | (((pts >> 30) & 0x07) << 1) | 1;
 512     *q++ = val;
 513     val = (((pts >> 15) & 0x7fff) << 1) | 1;
 514     *q++ = val >> 8;
 515     *q++ = val;
 516     val = (((pts) & 0x7fff) << 1) | 1;
 517     *q++ = val >> 8;
 518     *q++ = val;
 519 }
 520
 521 /* NOTE: pes_data contains all the PES packet */
 522 static void mpegts_write_pes(AVFormatContext *s, AVStream *st,
 523                              const uint8_t *payload, int payload_size,
 524                              int64_t pts, int64_t dts)
 525 {
 526     MpegTSWriteStream *ts_st = st->priv_data;
 527     MpegTSWrite *ts = s->priv_data;
 528     uint8_t buf[TS_PACKET_SIZE];
 529     uint8_t *q;
 530     int val, is_start, len, header_len, write_pcr, private_code, flags;
 531     int afc_len, stuffing_len;
 532     int64_t pcr = -1; /* avoid warning */
 533
 534     is_start = 1;
 535     while (payload_size > 0) {
 536         retransmit_si_info(s);
 537
 538         write_pcr = 0;
 539         if (ts_st->pid == ts_st->service->pcr_pid) {
 540             ts_st->service->pcr_packet_count++;
 541             if (ts_st->service->pcr_packet_count >=
 542                 ts_st->service->pcr_packet_freq) {
 543                 ts_st->service->pcr_packet_count = 0;
 544                 write_pcr = 1;
 545             }
 546         }
 547
 548         /* prepare packet header */
 549         q = buf;
 550         *q++ = 0x47;
 551         val = (ts_st->pid >> 8);
 552         if (is_start)
 553             val |= 0x40;
 554         *q++ = val;
 555         *q++ = ts_st->pid;
 556         *q++ = 0x10 | ts_st->cc | (write_pcr ? 0x20 : 0);
 557         ts_st->cc = (ts_st->cc + 1) & 0xf;
 558         if (write_pcr) {
 559             // add 11, pcr references the last byte of program clock reference base
 560             pcr = ts->cur_pcr + (4+7)*8*90000LL / ts->mux_rate;
 561             if (dts != AV_NOPTS_VALUE && dts < pcr)
 562                 av_log(s, AV_LOG_WARNING, "dts < pcr, TS is invalid\n");
 563             *q++ = 7; /* AFC length */
 564             *q++ = 0x10; /* flags: PCR present */
 565             *q++ = pcr >> 25;
 566             *q++ = pcr >> 17;
 567             *q++ = pcr >> 9;
 568             *q++ = pcr >> 1;
 569             *q++ = (pcr & 1) << 7;
 570             *q++ = 0;
 571         }
 572         if (is_start) {
 573             int pes_extension = 0;
 574             /* write PES header */
 575             *q++ = 0x00;
 576             *q++ = 0x00;
 577             *q++ = 0x01;
 578             private_code = 0;
 579             if (st->codec->codec_type == CODEC_TYPE_VIDEO) {
 580                 if (st->codec->codec_id == CODEC_ID_DIRAC) {
 581                     *q++ = 0xfd;
 582                 } else
 583                     *q++ = 0xe0;
 584             } else if (st->codec->codec_type == CODEC_TYPE_AUDIO &&
 585                        (st->codec->codec_id == CODEC_ID_MP2 ||
 586                         st->codec->codec_id == CODEC_ID_MP3)) {
 587                 *q++ = 0xc0;
 588             } else {
 589                 *q++ = 0xbd;
 590                 if (st->codec->codec_type == CODEC_TYPE_SUBTITLE) {
 591                     private_code = 0x20;
 592                 }
 593             }
 594             header_len = 0;
 595             flags = 0;
 596             if (pts != AV_NOPTS_VALUE) {
 597                 header_len += 5;
 598                 flags |= 0x80;
 599             }
 600             if (dts != AV_NOPTS_VALUE && dts != pts) {
 601                 header_len += 5;
 602                 flags |= 0x40;
 603             }
 604             if (st->codec->codec_type == CODEC_TYPE_VIDEO &&
 605                 st->codec->codec_id == CODEC_ID_DIRAC) {
 606                 /* set PES_extension_flag */
 607                 pes_extension = 1;
 608                 flags |= 0x01;
 609
 610                 /*
 611                 * One byte for PES2 extension flag +
 612                 * one byte for extension length +
 613                 * one byte for extension id
 614                 */
 615                 header_len += 3;
 616             }
 617             len = payload_size + header_len + 3;
 618             if (private_code != 0)
 619                 len++;
 620             *q++ = len >> 8;
 621             *q++ = len;
 622             val = 0x80;
 623             /* data alignment indicator is required for subtitle data */
 624             if (st->codec->codec_type == CODEC_TYPE_SUBTITLE)
 625                 val |= 0x04;
 626             *q++ = val;
 627             *q++ = flags;
 628             *q++ = header_len;
 629             if (pts != AV_NOPTS_VALUE) {
 630                 write_pts(q, flags >> 6, pts);
 631                 q += 5;
 632             }
 633             if (dts != AV_NOPTS_VALUE && dts != pts) {
 634                 write_pts(q, 1, dts);
 635                 q += 5;
 636             }
 637             if (pes_extension && st->codec->codec_id == CODEC_ID_DIRAC) {
 638                 flags = 0x01;  /* set PES_extension_flag_2 */
 639                 *q++ = flags;
 640                 *q++ = 0x80 | 0x01;  /* marker bit + extension length */
 641                 /*
 642                 * Set the stream id extension flag bit to 0 and
 643                 * write the extended stream id
 644                 */
 645                 *q++ = 0x00 | 0x60;
 646             }
 647             if (private_code != 0)
 648                 *q++ = private_code;
 649             is_start = 0;
 650         }
 651         /* header size */
 652         header_len = q - buf;
 653         /* data len */
 654         len = TS_PACKET_SIZE - header_len;
 655         if (len > payload_size)
 656             len = payload_size;
 657         stuffing_len = TS_PACKET_SIZE - header_len - len;
 658         if (stuffing_len > 0) {
 659             /* add stuffing with AFC */
 660             if (buf[3] & 0x20) {
 661                 /* stuffing already present: increase its size */
 662                 afc_len = buf[4] + 1;
 663                 memmove(buf + 4 + afc_len + stuffing_len,
 664                         buf + 4 + afc_len,
 665                         header_len - (4 + afc_len));
 666                 buf[4] += stuffing_len;
 667                 memset(buf + 4 + afc_len, 0xff, stuffing_len);
 668             } else {
 669                 /* add stuffing */
 670                 memmove(buf + 4 + stuffing_len, buf + 4, header_len - 4);
 671                 buf[3] |= 0x20;
 672                 buf[4] = stuffing_len - 1;
 673                 if (stuffing_len >= 2) {
 674                     buf[5] = 0x00;
 675                     memset(buf + 6, 0xff, stuffing_len - 2);
 676                 }
 677             }
 678         }
 679         memcpy(buf + TS_PACKET_SIZE - len, payload, len);
 680         payload += len;
 681         payload_size -= len;
 682         put_buffer(s->pb, buf, TS_PACKET_SIZE);
 683         ts->cur_pcr += TS_PACKET_SIZE*8*90000LL/ts->mux_rate;
 684     }
 685     put_flush_packet(s->pb);
 686 }
 687
 688 static int mpegts_write_packet(AVFormatContext *s, AVPacket *pkt)
 689 {
 690     AVStream *st = s->streams[pkt->stream_index];
 691     int size= pkt->size;
 692     uint8_t *buf= pkt->data;
 693     uint8_t *data= NULL;
 694     MpegTSWriteStream *ts_st = st->priv_data;
 695     int len, max_payload_size;
 696     const uint8_t *access_unit_index = NULL;
 697     const uint64_t delay = av_rescale(s->max_delay, 90000, AV_TIME_BASE);
 698     int64_t dts = AV_NOPTS_VALUE, pts = AV_NOPTS_VALUE;
 699
 700     if (pkt->pts != AV_NOPTS_VALUE)
 701         pts = pkt->pts + delay;
 702     if (pkt->dts != AV_NOPTS_VALUE)
 703         dts = pkt->dts + delay;
 704
 705     if (st->codec->codec_type == CODEC_TYPE_SUBTITLE) {
 706         /* for subtitle, a single PES packet must be generated */
 707         mpegts_write_pes(s, st, buf, size, pts, AV_NOPTS_VALUE);
 708         return 0;
 709     }
 710
 711     if (st->codec->codec_id == CODEC_ID_DIRAC) {
 712         /* for Dirac, a single PES packet must be generated */
 713         mpegts_write_pes(s, st, buf, size, pts, dts);
 714         return 0;
 715     }
 716     max_payload_size = DEFAULT_PES_PAYLOAD_SIZE;
 717     if (st->codec->codec_id == CODEC_ID_MPEG2VIDEO ||
 718         st->codec->codec_id == CODEC_ID_MPEG1VIDEO) {
 719         const uint8_t *p = pkt->data;
 720         const uint8_t *end = pkt->data+pkt->size;
 721         uint32_t state = -1;
 722         while (p < end) {
 723             p = ff_find_start_code(p, end, &state);
 724             if (state == PICTURE_START_CODE) {
 725                 access_unit_index = p - 4;
 726                 break;
 727             }
 728         }
 729     } if (st->codec->codec_id == CODEC_ID_H264) {
 730         if (pkt->size < 5 || AV_RB32(pkt->data) != 0x0000001) {
 731             av_log(s, AV_LOG_ERROR, "h264 bitstream malformated\n");
 732             return -1;
 733         }
 734         if (pkt->data[4] != 0x09) { // AUD NAL
 735             data = av_malloc(pkt->size+6);
 736             if (!data)
 737                 return -1;
 738             memcpy(data+6, pkt->data, pkt->size);
 739             AV_WB32(data, 0x00000001);
 740             data[4] = 0x09;
 741             data[5] = 0xe0; // any slice type
 742             buf  = data;
 743             size = pkt->size+6;
 744         }
 745         access_unit_index = buf;
 746     } else {
 747         access_unit_index = pkt->data;
 748     }
 749
 750     if (!access_unit_index) {
 751         av_log(s, AV_LOG_ERROR, "error, could not find access unit start\n");
 752         return -1;
 753     }
 754
 755     while (size > 0) {
 756         len = max_payload_size - ts_st->payload_index;
 757         if (len > size)
 758             len = size;
 759         memcpy(ts_st->payload + ts_st->payload_index, buf, len);
 760         buf += len;
 761         size -= len;
 762         ts_st->payload_index += len;
 763         if (access_unit_index && access_unit_index < buf &&
 764             ts_st->payload_pts == AV_NOPTS_VALUE &&
 765             ts_st->payload_dts == AV_NOPTS_VALUE) {
 766             ts_st->payload_dts = dts;
 767             ts_st->payload_pts = pts;
 768         }
 769         if (ts_st->payload_index >= max_payload_size) {
 770             mpegts_write_pes(s, st, ts_st->payload, ts_st->payload_index,
 771                              ts_st->payload_pts, ts_st->payload_dts);
 772             ts_st->payload_pts = AV_NOPTS_VALUE;
 773             ts_st->payload_dts = AV_NOPTS_VALUE;
 774             ts_st->payload_index = 0;
 775             access_unit_index = NULL; // unset access unit to avoid setting pts/dts again
 776         }
 777     }
 778
 779     av_free(data);
 780
 781     return 0;
 782 }
 783
 784 static int mpegts_write_end(AVFormatContext *s)
 785 {
 786     MpegTSWrite *ts = s->priv_data;
 787     MpegTSWriteStream *ts_st;
 788     MpegTSService *service;
 789     AVStream *st;
 790     int i;
 791
 792     /* flush current packets */
 793     for(i = 0; i < s->nb_streams; i++) {
 794         st = s->streams[i];
 795         ts_st = st->priv_data;
 796         if (ts_st->payload_index > 0) {
 797             mpegts_write_pes(s, st, ts_st->payload, ts_st->payload_index,
 798                              ts_st->payload_pts, ts_st->payload_dts);
 799         }
 800     }
 801     put_flush_packet(s->pb);
 802
 803     for(i = 0; i < ts->nb_services; i++) {
 804         service = ts->services[i];
 805         av_freep(&service->provider_name);
 806         av_freep(&service->name);
 807         av_free(service);
 808     }
 809     av_free(ts->services);
 810
 811     return 0;
 812 }
 813
 814 AVOutputFormat mpegts_muxer = {
 815     "mpegts",
 816     NULL_IF_CONFIG_SMALL("MPEG-2 transport stream format"),
 817     "video/x-mpegts",
 818     "ts,m2t",
 819     sizeof(MpegTSWrite),
 820     CODEC_ID_MP2,
 821     CODEC_ID_MPEG2VIDEO,
 822     mpegts_write_header,
 823     mpegts_write_packet,
 824     mpegts_write_end,
 825 };