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_period;
  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_period;
  56     int pat_packet_count;
  57     int pat_packet_period;
  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     int first_pts_check; ///< first pts check needed
 177     int64_t payload_pts;
 178     int64_t payload_dts;
 179     uint8_t payload[DEFAULT_PES_PAYLOAD_SIZE];
 180 } MpegTSWriteStream;
 181
 182 static void mpegts_write_pat(AVFormatContext *s)
 183 {
 184     MpegTSWrite *ts = s->priv_data;
 185     MpegTSService *service;
 186     uint8_t data[1012], *q;
 187     int i;
 188
 189     q = data;
 190     for(i = 0; i < ts->nb_services; i++) {
 191         service = ts->services[i];
 192         put16(&q, service->sid);
 193         put16(&q, 0xe000 | service->pmt.pid);
 194     }
 195     mpegts_write_section1(&ts->pat, PAT_TID, ts->tsid, 0, 0, 0,
 196                           data, q - data);
 197 }
 198
 199 static void mpegts_write_pmt(AVFormatContext *s, MpegTSService *service)
 200 {
 201     //    MpegTSWrite *ts = s->priv_data;
 202     uint8_t data[1012], *q, *desc_length_ptr, *program_info_length_ptr;
 203     int val, stream_type, i;
 204
 205     q = data;
 206     put16(&q, 0xe000 | service->pcr_pid);
 207
 208     program_info_length_ptr = q;
 209     q += 2; /* patched after */
 210
 211     /* put program info here */
 212
 213     val = 0xf000 | (q - program_info_length_ptr - 2);
 214     program_info_length_ptr[0] = val >> 8;
 215     program_info_length_ptr[1] = val;
 216
 217     for(i = 0; i < s->nb_streams; i++) {
 218         AVStream *st = s->streams[i];
 219         MpegTSWriteStream *ts_st = st->priv_data;
 220         AVMetadataTag *lang = av_metadata_get(st->metadata, "language", NULL,0);
 221         switch(st->codec->codec_id) {
 222         case CODEC_ID_MPEG1VIDEO:
 223         case CODEC_ID_MPEG2VIDEO:
 224             stream_type = STREAM_TYPE_VIDEO_MPEG2;
 225             break;
 226         case CODEC_ID_MPEG4:
 227             stream_type = STREAM_TYPE_VIDEO_MPEG4;
 228             break;
 229         case CODEC_ID_H264:
 230             stream_type = STREAM_TYPE_VIDEO_H264;
 231             break;
 232         case CODEC_ID_DIRAC:
 233             stream_type = STREAM_TYPE_VIDEO_DIRAC;
 234             break;
 235         case CODEC_ID_MP2:
 236         case CODEC_ID_MP3:
 237             stream_type = STREAM_TYPE_AUDIO_MPEG1;
 238             break;
 239         case CODEC_ID_AAC:
 240             stream_type = STREAM_TYPE_AUDIO_AAC;
 241             break;
 242         case CODEC_ID_AC3:
 243             stream_type = STREAM_TYPE_AUDIO_AC3;
 244             break;
 245         default:
 246             stream_type = STREAM_TYPE_PRIVATE_DATA;
 247             break;
 248         }
 249         *q++ = stream_type;
 250         put16(&q, 0xe000 | ts_st->pid);
 251         desc_length_ptr = q;
 252         q += 2; /* patched after */
 253
 254         /* write optional descriptors here */
 255         switch(st->codec->codec_type) {
 256         case CODEC_TYPE_AUDIO:
 257             if (lang && strlen(lang->value) == 3) {
 258                 *q++ = 0x0a; /* ISO 639 language descriptor */
 259                 *q++ = 4;
 260                 *q++ = lang->value[0];
 261                 *q++ = lang->value[1];
 262                 *q++ = lang->value[2];
 263                 *q++ = 0; /* undefined type */
 264             }
 265             break;
 266         case CODEC_TYPE_SUBTITLE:
 267             {
 268                 const char *language;
 269                 language = lang && strlen(lang->value)==3 ? lang->value : "eng";
 270                 *q++ = 0x59;
 271                 *q++ = 8;
 272                 *q++ = language[0];
 273                 *q++ = language[1];
 274                 *q++ = language[2];
 275                 *q++ = 0x10; /* normal subtitles (0x20 = if hearing pb) */
 276                 put16(&q, 1); /* page id */
 277                 put16(&q, 1); /* ancillary page id */
 278             }
 279             break;
 280         case CODEC_TYPE_VIDEO:
 281             if (stream_type == STREAM_TYPE_VIDEO_DIRAC) {
 282                 *q++ = 0x05; /*MPEG-2 registration descriptor*/
 283                 *q++ = 4;
 284                 *q++ = 'd';
 285                 *q++ = 'r';
 286                 *q++ = 'a';
 287                 *q++ = 'c';
 288             }
 289             break;
 290         }
 291
 292         val = 0xf000 | (q - desc_length_ptr - 2);
 293         desc_length_ptr[0] = val >> 8;
 294         desc_length_ptr[1] = val;
 295     }
 296     mpegts_write_section1(&service->pmt, PMT_TID, service->sid, 0, 0, 0,
 297                           data, q - data);
 298 }
 299
 300 /* NOTE: str == NULL is accepted for an empty string */
 301 static void putstr8(uint8_t **q_ptr, const char *str)
 302 {
 303     uint8_t *q;
 304     int len;
 305
 306     q = *q_ptr;
 307     if (!str)
 308         len = 0;
 309     else
 310         len = strlen(str);
 311     *q++ = len;
 312     memcpy(q, str, len);
 313     q += len;
 314     *q_ptr = q;
 315 }
 316
 317 static void mpegts_write_sdt(AVFormatContext *s)
 318 {
 319     MpegTSWrite *ts = s->priv_data;
 320     MpegTSService *service;
 321     uint8_t data[1012], *q, *desc_list_len_ptr, *desc_len_ptr;
 322     int i, running_status, free_ca_mode, val;
 323
 324     q = data;
 325     put16(&q, ts->onid);
 326     *q++ = 0xff;
 327     for(i = 0; i < ts->nb_services; i++) {
 328         service = ts->services[i];
 329         put16(&q, service->sid);
 330         *q++ = 0xfc | 0x00; /* currently no EIT info */
 331         desc_list_len_ptr = q;
 332         q += 2;
 333         running_status = 4; /* running */
 334         free_ca_mode = 0;
 335
 336         /* write only one descriptor for the service name and provider */
 337         *q++ = 0x48;
 338         desc_len_ptr = q;
 339         q++;
 340         *q++ = 0x01; /* digital television service */
 341         putstr8(&q, service->provider_name);
 342         putstr8(&q, service->name);
 343         desc_len_ptr[0] = q - desc_len_ptr - 1;
 344
 345         /* fill descriptor length */
 346         val = (running_status << 13) | (free_ca_mode << 12) |
 347             (q - desc_list_len_ptr - 2);
 348         desc_list_len_ptr[0] = val >> 8;
 349         desc_list_len_ptr[1] = val;
 350     }
 351     mpegts_write_section1(&ts->sdt, SDT_TID, ts->tsid, 0, 0, 0,
 352                           data, q - data);
 353 }
 354
 355 static MpegTSService *mpegts_add_service(MpegTSWrite *ts,
 356                                          int sid,
 357                                          const char *provider_name,
 358                                          const char *name)
 359 {
 360     MpegTSService *service;
 361
 362     service = av_mallocz(sizeof(MpegTSService));
 363     if (!service)
 364         return NULL;
 365     service->pmt.pid = DEFAULT_PMT_START_PID + ts->nb_services - 1;
 366     service->sid = sid;
 367     service->provider_name = av_strdup(provider_name);
 368     service->name = av_strdup(name);
 369     service->pcr_pid = 0x1fff;
 370     dynarray_add(&ts->services, &ts->nb_services, service);
 371     return service;
 372 }
 373
 374 static void section_write_packet(MpegTSSection *s, const uint8_t *packet)
 375 {
 376     AVFormatContext *ctx = s->opaque;
 377     put_buffer(ctx->pb, packet, TS_PACKET_SIZE);
 378 }
 379
 380 static int mpegts_write_header(AVFormatContext *s)
 381 {
 382     MpegTSWrite *ts = s->priv_data;
 383     MpegTSWriteStream *ts_st;
 384     MpegTSService *service;
 385     AVStream *st;
 386     AVMetadataTag *title;
 387     int i, total_bit_rate;
 388     const char *service_name;
 389     uint64_t sdt_size, pat_pmt_size, pos;
 390
 391     ts->tsid = DEFAULT_TSID;
 392     ts->onid = DEFAULT_ONID;
 393     /* allocate a single DVB service */
 394     title = av_metadata_get(s->metadata, "title", NULL, 0);
 395     service_name = title ? title->value : DEFAULT_SERVICE_NAME;
 396     service = mpegts_add_service(ts, DEFAULT_SID,
 397                                  DEFAULT_PROVIDER_NAME, service_name);
 398     service->pmt.write_packet = section_write_packet;
 399     service->pmt.opaque = s;
 400
 401     ts->pat.pid = PAT_PID;
 402     ts->pat.cc = 0;
 403     ts->pat.write_packet = section_write_packet;
 404     ts->pat.opaque = s;
 405
 406     ts->sdt.pid = SDT_PID;
 407     ts->sdt.cc = 0;
 408     ts->sdt.write_packet = section_write_packet;
 409     ts->sdt.opaque = s;
 410
 411     /* assign pids to each stream */
 412     total_bit_rate = 0;
 413     for(i = 0;i < s->nb_streams; i++) {
 414         st = s->streams[i];
 415         ts_st = av_mallocz(sizeof(MpegTSWriteStream));
 416         if (!ts_st)
 417             goto fail;
 418         st->priv_data = ts_st;
 419         ts_st->service = service;
 420         ts_st->pid = DEFAULT_START_PID + i;
 421         ts_st->payload_pts = AV_NOPTS_VALUE;
 422         ts_st->payload_dts = AV_NOPTS_VALUE;
 423         ts_st->first_pts_check = 1;
 424         /* update PCR pid by using the first video stream */
 425         if (st->codec->codec_type == CODEC_TYPE_VIDEO &&
 426             service->pcr_pid == 0x1fff)
 427             service->pcr_pid = ts_st->pid;
 428         total_bit_rate += st->codec->bit_rate;
 429         /* PES header size */
 430         if (st->codec->codec_type == CODEC_TYPE_VIDEO ||
 431             st->codec->codec_type == CODEC_TYPE_SUBTITLE)
 432             total_bit_rate += 25 * 8 / av_q2d(st->codec->time_base);
 433         else
 434             total_bit_rate += total_bit_rate * 25 / DEFAULT_PES_PAYLOAD_SIZE;
 435     }
 436
 437     /* if no video stream, use the first stream as PCR */
 438     if (service->pcr_pid == 0x1fff && s->nb_streams > 0) {
 439         ts_st = s->streams[0]->priv_data;
 440         service->pcr_pid = ts_st->pid;
 441     }
 442
 443     if (total_bit_rate <= 8 * 1024)
 444         total_bit_rate = 8 * 1024;
 445     service->pcr_packet_period = (total_bit_rate * PCR_RETRANS_TIME) /
 446         (TS_PACKET_SIZE * 8 * 1000);
 447     ts->sdt_packet_period = (total_bit_rate * SDT_RETRANS_TIME) /
 448         (TS_PACKET_SIZE * 8 * 1000);
 449     ts->pat_packet_period = (total_bit_rate * PAT_RETRANS_TIME) /
 450         (TS_PACKET_SIZE * 8 * 1000);
 451
 452     ts->mux_rate = 1; // avoid div by 0
 453
 454     /* write info at the start of the file, so that it will be fast to
 455        find them */
 456     pos = url_ftell(s->pb);
 457     mpegts_write_sdt(s);
 458     sdt_size = url_ftell(s->pb) - pos;
 459     pos = url_ftell(s->pb);
 460     mpegts_write_pat(s);
 461     for(i = 0; i < ts->nb_services; i++) {
 462         mpegts_write_pmt(s, ts->services[i]);
 463     }
 464     pat_pmt_size = url_ftell(s->pb) - pos;
 465
 466     total_bit_rate +=
 467         total_bit_rate *  4 / TS_PACKET_SIZE           + /* TS  header size */
 468         SDT_RETRANS_TIME * 8 * sdt_size     / 1000     + /* SDT size */
 469         PAT_RETRANS_TIME * 8 * pat_pmt_size / 1000     + /* PAT+PMT size */
 470         PCR_RETRANS_TIME * 8 * 8            / 1000;      /* PCR size */
 471
 472     av_log(s, AV_LOG_DEBUG, "muxrate %d freq sdt %d pat %d\n",
 473            total_bit_rate, ts->sdt_packet_period, ts->pat_packet_period);
 474
 475     if (s->mux_rate)
 476         ts->mux_rate = s->mux_rate;
 477     else
 478         ts->mux_rate = total_bit_rate;
 479
 480     // adjust pcr
 481     ts->cur_pcr /= ts->mux_rate;
 482
 483     put_flush_packet(s->pb);
 484
 485     return 0;
 486
 487  fail:
 488     for(i = 0;i < s->nb_streams; i++) {
 489         st = s->streams[i];
 490         av_free(st->priv_data);
 491     }
 492     return -1;
 493 }
 494
 495 /* send SDT, PAT and PMT tables regulary */
 496 static void retransmit_si_info(AVFormatContext *s)
 497 {
 498     MpegTSWrite *ts = s->priv_data;
 499     int i;
 500
 501     if (++ts->sdt_packet_count == ts->sdt_packet_period) {
 502         ts->sdt_packet_count = 0;
 503         mpegts_write_sdt(s);
 504     }
 505     if (++ts->pat_packet_count == ts->pat_packet_period) {
 506         ts->pat_packet_count = 0;
 507         mpegts_write_pat(s);
 508         for(i = 0; i < ts->nb_services; i++) {
 509             mpegts_write_pmt(s, ts->services[i]);
 510         }
 511     }
 512 }
 513
 514 static void write_pts(uint8_t *q, int fourbits, int64_t pts)
 515 {
 516     int val;
 517
 518     val = fourbits << 4 | (((pts >> 30) & 0x07) << 1) | 1;
 519     *q++ = val;
 520     val = (((pts >> 15) & 0x7fff) << 1) | 1;
 521     *q++ = val >> 8;
 522     *q++ = val;
 523     val = (((pts) & 0x7fff) << 1) | 1;
 524     *q++ = val >> 8;
 525     *q++ = val;
 526 }
 527
 528 /* NOTE: pes_data contains all the PES packet */
 529 static void mpegts_write_pes(AVFormatContext *s, AVStream *st,
 530                              const uint8_t *payload, int payload_size,
 531                              int64_t pts, int64_t dts)
 532 {
 533     MpegTSWriteStream *ts_st = st->priv_data;
 534     MpegTSWrite *ts = s->priv_data;
 535     uint8_t buf[TS_PACKET_SIZE];
 536     uint8_t *q;
 537     int val, is_start, len, header_len, write_pcr, private_code, flags;
 538     int afc_len, stuffing_len;
 539     int64_t pcr = -1; /* avoid warning */
 540
 541     is_start = 1;
 542     while (payload_size > 0) {
 543         retransmit_si_info(s);
 544
 545         write_pcr = 0;
 546         if (ts_st->pid == ts_st->service->pcr_pid) {
 547             ts_st->service->pcr_packet_count++;
 548             if (ts_st->service->pcr_packet_count >=
 549                 ts_st->service->pcr_packet_period) {
 550                 ts_st->service->pcr_packet_count = 0;
 551                 write_pcr = 1;
 552             }
 553         }
 554
 555         /* prepare packet header */
 556         q = buf;
 557         *q++ = 0x47;
 558         val = (ts_st->pid >> 8);
 559         if (is_start)
 560             val |= 0x40;
 561         *q++ = val;
 562         *q++ = ts_st->pid;
 563         *q++ = 0x10 | ts_st->cc | (write_pcr ? 0x20 : 0);
 564         ts_st->cc = (ts_st->cc + 1) & 0xf;
 565         if (write_pcr) {
 566             // add 11, pcr references the last byte of program clock reference base
 567             pcr = ts->cur_pcr + (4+7)*8*90000LL / ts->mux_rate;
 568             if (dts != AV_NOPTS_VALUE && dts < pcr)
 569                 av_log(s, AV_LOG_WARNING, "dts < pcr, TS is invalid\n");
 570             *q++ = 7; /* AFC length */
 571             *q++ = 0x10; /* flags: PCR present */
 572             *q++ = pcr >> 25;
 573             *q++ = pcr >> 17;
 574             *q++ = pcr >> 9;
 575             *q++ = pcr >> 1;
 576             *q++ = (pcr & 1) << 7;
 577             *q++ = 0;
 578         }
 579         if (is_start) {
 580             int pes_extension = 0;
 581             /* write PES header */
 582             *q++ = 0x00;
 583             *q++ = 0x00;
 584             *q++ = 0x01;
 585             private_code = 0;
 586             if (st->codec->codec_type == CODEC_TYPE_VIDEO) {
 587                 if (st->codec->codec_id == CODEC_ID_DIRAC) {
 588                     *q++ = 0xfd;
 589                 } else
 590                     *q++ = 0xe0;
 591             } else if (st->codec->codec_type == CODEC_TYPE_AUDIO &&
 592                        (st->codec->codec_id == CODEC_ID_MP2 ||
 593                         st->codec->codec_id == CODEC_ID_MP3)) {
 594                 *q++ = 0xc0;
 595             } else {
 596                 *q++ = 0xbd;
 597                 if (st->codec->codec_type == CODEC_TYPE_SUBTITLE) {
 598                     private_code = 0x20;
 599                 }
 600             }
 601             header_len = 0;
 602             flags = 0;
 603             if (pts != AV_NOPTS_VALUE) {
 604                 header_len += 5;
 605                 flags |= 0x80;
 606             }
 607             if (dts != AV_NOPTS_VALUE && pts != AV_NOPTS_VALUE && dts != pts) {
 608                 header_len += 5;
 609                 flags |= 0x40;
 610             }
 611             if (st->codec->codec_type == CODEC_TYPE_VIDEO &&
 612                 st->codec->codec_id == CODEC_ID_DIRAC) {
 613                 /* set PES_extension_flag */
 614                 pes_extension = 1;
 615                 flags |= 0x01;
 616
 617                 /*
 618                 * One byte for PES2 extension flag +
 619                 * one byte for extension length +
 620                 * one byte for extension id
 621                 */
 622                 header_len += 3;
 623             }
 624             len = payload_size + header_len + 3;
 625             if (private_code != 0)
 626                 len++;
 627             if (len > 0xffff)
 628                 len = 0;
 629             *q++ = len >> 8;
 630             *q++ = len;
 631             val = 0x80;
 632             /* data alignment indicator is required for subtitle data */
 633             if (st->codec->codec_type == CODEC_TYPE_SUBTITLE)
 634                 val |= 0x04;
 635             *q++ = val;
 636             *q++ = flags;
 637             *q++ = header_len;
 638             if (pts != AV_NOPTS_VALUE) {
 639                 write_pts(q, flags >> 6, pts);
 640                 q += 5;
 641             }
 642             if (dts != AV_NOPTS_VALUE && pts != AV_NOPTS_VALUE && dts != pts) {
 643                 write_pts(q, 1, dts);
 644                 q += 5;
 645             }
 646             if (pes_extension && st->codec->codec_id == CODEC_ID_DIRAC) {
 647                 flags = 0x01;  /* set PES_extension_flag_2 */
 648                 *q++ = flags;
 649                 *q++ = 0x80 | 0x01;  /* marker bit + extension length */
 650                 /*
 651                 * Set the stream id extension flag bit to 0 and
 652                 * write the extended stream id
 653                 */
 654                 *q++ = 0x00 | 0x60;
 655             }
 656             if (private_code != 0)
 657                 *q++ = private_code;
 658             is_start = 0;
 659         }
 660         /* header size */
 661         header_len = q - buf;
 662         /* data len */
 663         len = TS_PACKET_SIZE - header_len;
 664         if (len > payload_size)
 665             len = payload_size;
 666         stuffing_len = TS_PACKET_SIZE - header_len - len;
 667         if (stuffing_len > 0) {
 668             /* add stuffing with AFC */
 669             if (buf[3] & 0x20) {
 670                 /* stuffing already present: increase its size */
 671                 afc_len = buf[4] + 1;
 672                 memmove(buf + 4 + afc_len + stuffing_len,
 673                         buf + 4 + afc_len,
 674                         header_len - (4 + afc_len));
 675                 buf[4] += stuffing_len;
 676                 memset(buf + 4 + afc_len, 0xff, stuffing_len);
 677             } else {
 678                 /* add stuffing */
 679                 memmove(buf + 4 + stuffing_len, buf + 4, header_len - 4);
 680                 buf[3] |= 0x20;
 681                 buf[4] = stuffing_len - 1;
 682                 if (stuffing_len >= 2) {
 683                     buf[5] = 0x00;
 684                     memset(buf + 6, 0xff, stuffing_len - 2);
 685                 }
 686             }
 687         }
 688         memcpy(buf + TS_PACKET_SIZE - len, payload, len);
 689         payload += len;
 690         payload_size -= len;
 691         put_buffer(s->pb, buf, TS_PACKET_SIZE);
 692         ts->cur_pcr += TS_PACKET_SIZE*8*90000LL/ts->mux_rate;
 693     }
 694     put_flush_packet(s->pb);
 695 }
 696
 697 static int mpegts_write_packet(AVFormatContext *s, AVPacket *pkt)
 698 {
 699     AVStream *st = s->streams[pkt->stream_index];
 700     int len, size = pkt->size;
 701     uint8_t *buf= pkt->data;
 702     uint8_t *data= NULL;
 703     MpegTSWriteStream *ts_st = st->priv_data;
 704     const uint64_t delay = av_rescale(s->max_delay, 90000, AV_TIME_BASE);
 705     int64_t dts = AV_NOPTS_VALUE, pts = AV_NOPTS_VALUE;
 706
 707     if (pkt->pts != AV_NOPTS_VALUE)
 708         pts = pkt->pts + delay;
 709     if (pkt->dts != AV_NOPTS_VALUE)
 710         dts = pkt->dts + delay;
 711
 712     if (ts_st->first_pts_check && pts == AV_NOPTS_VALUE) {
 713         av_log(s, AV_LOG_ERROR, "first pts value must set\n");
 714         return -1;
 715     }
 716     ts_st->first_pts_check = 0;
 717
 718     if (st->codec->codec_id == CODEC_ID_H264) {
 719         if (pkt->size < 5 || AV_RB32(pkt->data) != 0x0000001) {
 720             av_log(s, AV_LOG_ERROR, "h264 bitstream malformated\n");
 721             return -1;
 722         }
 723         if (pkt->data[4] != 0x09) { // AUD NAL
 724             data = av_malloc(pkt->size+6);
 725             if (!data)
 726                 return -1;
 727             memcpy(data+6, pkt->data, pkt->size);
 728             AV_WB32(data, 0x00000001);
 729             data[4] = 0x09;
 730             data[5] = 0xe0; // any slice type
 731             buf  = data;
 732             size = pkt->size+6;
 733         }
 734     }
 735
 736     if (st->codec->codec_type == CODEC_TYPE_SUBTITLE ||
 737         st->codec->codec_type == CODEC_TYPE_VIDEO) {
 738         // for video and subtitle, write a single pes packet
 739         mpegts_write_pes(s, st, buf, size, pts, dts);
 740         av_free(data);
 741         return 0;
 742     }
 743
 744     if (ts_st->payload_pts == AV_NOPTS_VALUE) {
 745         ts_st->payload_dts = dts;
 746         ts_st->payload_pts = pts;
 747     }
 748
 749     // audio
 750     while (size > 0) {
 751         len = DEFAULT_PES_PAYLOAD_SIZE - ts_st->payload_index;
 752         if (len > size)
 753             len = size;
 754         memcpy(ts_st->payload + ts_st->payload_index, buf, len);
 755         buf += len;
 756         size -= len;
 757         ts_st->payload_index += len;
 758         if (ts_st->payload_index >= DEFAULT_PES_PAYLOAD_SIZE) {
 759             mpegts_write_pes(s, st, ts_st->payload, ts_st->payload_index,
 760                              ts_st->payload_pts, ts_st->payload_dts);
 761             ts_st->payload_pts = AV_NOPTS_VALUE;
 762             ts_st->payload_dts = AV_NOPTS_VALUE;
 763             ts_st->payload_index = 0;
 764         }
 765     }
 766
 767     return 0;
 768 }
 769
 770 static int mpegts_write_end(AVFormatContext *s)
 771 {
 772     MpegTSWrite *ts = s->priv_data;
 773     MpegTSWriteStream *ts_st;
 774     MpegTSService *service;
 775     AVStream *st;
 776     int i;
 777
 778     /* flush current packets */
 779     for(i = 0; i < s->nb_streams; i++) {
 780         st = s->streams[i];
 781         ts_st = st->priv_data;
 782         if (ts_st->payload_index > 0) {
 783             mpegts_write_pes(s, st, ts_st->payload, ts_st->payload_index,
 784                              ts_st->payload_pts, ts_st->payload_dts);
 785         }
 786     }
 787     put_flush_packet(s->pb);
 788
 789     for(i = 0; i < ts->nb_services; i++) {
 790         service = ts->services[i];
 791         av_freep(&service->provider_name);
 792         av_freep(&service->name);
 793         av_free(service);
 794     }
 795     av_free(ts->services);
 796
 797     return 0;
 798 }
 799
 800 AVOutputFormat mpegts_muxer = {
 801     "mpegts",
 802     NULL_IF_CONFIG_SMALL("MPEG-2 transport stream format"),
 803     "video/x-mpegts",
 804     "ts,m2t",
 805     sizeof(MpegTSWrite),
 806     CODEC_ID_MP2,
 807     CODEC_ID_MPEG2VIDEO,
 808     mpegts_write_header,
 809     mpegts_write_packet,
 810     mpegts_write_end,
 811 };