2 * MPEG2 transport stream (aka DVB) muxer
3 * Copyright (c) 2003 Fabrice Bellard.
5 * This file is part of FFmpeg.
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.
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.
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
22 #include "libavutil/bswap.h"
23 #include "libavutil/crc.h"
24 #include "libavcodec/mpegvideo.h"
28 /* write DVB SI sections */
30 /*********************************************/
31 /* mpegts section writer */
33 typedef struct MpegTSSection {
36 void (*write_packet)(struct MpegTSSection *s, const uint8_t *packet);
40 typedef struct MpegTSService {
41 MpegTSSection pmt; /* MPEG2 pmt table context */
42 int sid; /* service ID */
50 typedef struct MpegTSWrite {
51 MpegTSSection pat; /* MPEG2 pat table */
52 MpegTSSection sdt; /* MPEG2 sdt table context */
53 MpegTSService **services;
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)
68 MpegTSWrite *ts = ((AVFormatContext*)s->opaque)->priv_data;
70 unsigned char packet[TS_PACKET_SIZE];
71 const unsigned char *buf_ptr;
73 int first, b, len1, left;
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;
81 /* send each packet */
84 first = (buf == buf_ptr);
93 s->cc = (s->cc + 1) & 0xf;
95 *q++ = 0; /* 0 offset */
96 len1 = TS_PACKET_SIZE - (q - packet);
99 memcpy(q, buf_ptr, len1);
101 /* add known padding data */
102 left = TS_PACKET_SIZE - (q - packet);
104 memset(q, 0xff, left);
106 s->write_packet(s, packet);
111 ts->cur_pcr += TS_PACKET_SIZE*8*90000LL/ts->mux_rate;
115 static inline void put16(uint8_t **q_ptr, int val)
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)
128 uint8_t section[1024], *q;
129 unsigned int tot_len;
131 tot_len = 3 + 5 + len + 4;
132 /* check if not too big */
138 put16(&q, 0xb000 | (len + 5 + 4)); /* 5 byte header + 4 byte CRC */
140 *q++ = 0xc1 | (version << 1); /* current_next_indicator = 1 */
145 mpegts_write_section(s, section, tot_len);
149 /*********************************************/
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"
157 /* default network id, transport stream and service identifiers */
158 #define DEFAULT_ONID 0x0001
159 #define DEFAULT_TSID 0x0001
160 #define DEFAULT_SID 0x0001
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)
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
171 typedef struct MpegTSWriteStream {
172 struct MpegTSService *service;
173 int pid; /* stream associated pid */
178 uint8_t payload[DEFAULT_PES_PAYLOAD_SIZE];
181 static void mpegts_write_pat(AVFormatContext *s)
183 MpegTSWrite *ts = s->priv_data;
184 MpegTSService *service;
185 uint8_t data[1012], *q;
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);
194 mpegts_write_section1(&ts->pat, PAT_TID, ts->tsid, 0, 0, 0,
198 static void mpegts_write_pmt(AVFormatContext *s, MpegTSService *service)
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;
205 put16(&q, 0xe000 | service->pcr_pid);
207 program_info_length_ptr = q;
208 q += 2; /* patched after */
210 /* put program info here */
212 val = 0xf000 | (q - program_info_length_ptr - 2);
213 program_info_length_ptr[0] = val >> 8;
214 program_info_length_ptr[1] = val;
216 for(i = 0; i < s->nb_streams; i++) {
217 AVStream *st = s->streams[i];
218 MpegTSWriteStream *ts_st = st->priv_data;
219 switch(st->codec->codec_id) {
220 case CODEC_ID_MPEG1VIDEO:
221 case CODEC_ID_MPEG2VIDEO:
222 stream_type = STREAM_TYPE_VIDEO_MPEG2;
225 stream_type = STREAM_TYPE_VIDEO_MPEG4;
228 stream_type = STREAM_TYPE_VIDEO_H264;
231 stream_type = STREAM_TYPE_VIDEO_DIRAC;
235 stream_type = STREAM_TYPE_AUDIO_MPEG1;
238 stream_type = STREAM_TYPE_AUDIO_AAC;
241 stream_type = STREAM_TYPE_AUDIO_AC3;
244 stream_type = STREAM_TYPE_PRIVATE_DATA;
248 put16(&q, 0xe000 | ts_st->pid);
250 q += 2; /* patched after */
252 /* write optional descriptors here */
253 switch(st->codec->codec_type) {
254 case CODEC_TYPE_AUDIO:
255 if (strlen(st->language) == 3) {
256 *q++ = 0x0a; /* ISO 639 language descriptor */
258 *q++ = st->language[0];
259 *q++ = st->language[1];
260 *q++ = st->language[2];
261 *q++ = 0; /* undefined type */
264 case CODEC_TYPE_SUBTITLE:
266 const char *language;
267 language = st->language;
268 if (strlen(language) != 3)
275 *q++ = 0x10; /* normal subtitles (0x20 = if hearing pb) */
276 put16(&q, 1); /* page id */
277 put16(&q, 1); /* ancillary page id */
280 case CODEC_TYPE_VIDEO:
281 if (stream_type == STREAM_TYPE_VIDEO_DIRAC) {
282 *q++ = 0x05; /*MPEG-2 registration descriptor*/
292 val = 0xf000 | (q - desc_length_ptr - 2);
293 desc_length_ptr[0] = val >> 8;
294 desc_length_ptr[1] = val;
296 mpegts_write_section1(&service->pmt, PMT_TID, service->sid, 0, 0, 0,
300 /* NOTE: str == NULL is accepted for an empty string */
301 static void putstr8(uint8_t **q_ptr, const char *str)
317 static void mpegts_write_sdt(AVFormatContext *s)
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;
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;
333 running_status = 4; /* running */
336 /* write only one descriptor for the service name and provider */
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;
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;
351 mpegts_write_section1(&ts->sdt, SDT_TID, ts->tsid, 0, 0, 0,
355 static MpegTSService *mpegts_add_service(MpegTSWrite *ts,
357 const char *provider_name,
360 MpegTSService *service;
362 service = av_mallocz(sizeof(MpegTSService));
365 service->pmt.pid = DEFAULT_PMT_START_PID + ts->nb_services - 1;
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);
374 static void section_write_packet(MpegTSSection *s, const uint8_t *packet)
376 AVFormatContext *ctx = s->opaque;
377 put_buffer(ctx->pb, packet, TS_PACKET_SIZE);
380 static int mpegts_write_header(AVFormatContext *s)
382 MpegTSWrite *ts = s->priv_data;
383 MpegTSWriteStream *ts_st;
384 MpegTSService *service;
386 int i, total_bit_rate;
387 const char *service_name;
389 ts->tsid = DEFAULT_TSID;
390 ts->onid = DEFAULT_ONID;
391 /* allocate a single DVB service */
392 service_name = s->title;
393 if (service_name[0] == '\0')
394 service_name = 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;
400 ts->pat.pid = PAT_PID;
402 ts->pat.write_packet = section_write_packet;
405 ts->sdt.pid = SDT_PID;
407 ts->sdt.write_packet = section_write_packet;
410 /* assign pids to each stream */
412 for(i = 0;i < s->nb_streams; i++) {
414 ts_st = av_mallocz(sizeof(MpegTSWriteStream));
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;
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;
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);
445 total_bit_rate, ts->sdt_packet_freq, ts->pat_packet_freq);
448 ts->mux_rate = total_bit_rate;
450 /* write info at the start of the file, so that it will be fast to
454 for(i = 0; i < ts->nb_services; i++) {
455 mpegts_write_pmt(s, ts->services[i]);
457 put_flush_packet(s->pb);
462 for(i = 0;i < s->nb_streams; i++) {
464 av_free(st->priv_data);
469 /* send SDT, PAT and PMT tables regulary */
470 static void retransmit_si_info(AVFormatContext *s)
472 MpegTSWrite *ts = s->priv_data;
475 if (++ts->sdt_packet_count == ts->sdt_packet_freq) {
476 ts->sdt_packet_count = 0;
479 if (++ts->pat_packet_count == ts->pat_packet_freq) {
480 ts->pat_packet_count = 0;
482 for(i = 0; i < ts->nb_services; i++) {
483 mpegts_write_pmt(s, ts->services[i]);
488 static void write_pts(uint8_t *q, int fourbits, int64_t pts)
492 val = fourbits << 4 | (((pts >> 30) & 0x07) << 1) | 1;
494 val = (((pts >> 15) & 0x7fff) << 1) | 1;
497 val = (((pts) & 0x7fff) << 1) | 1;
502 /* NOTE: pes_data contains all the PES packet */
503 static void mpegts_write_pes(AVFormatContext *s, AVStream *st,
504 const uint8_t *payload, int payload_size,
505 int64_t pts, int64_t dts)
507 MpegTSWriteStream *ts_st = st->priv_data;
508 MpegTSWrite *ts = s->priv_data;
509 uint8_t buf[TS_PACKET_SIZE];
511 int val, is_start, len, header_len, write_pcr, private_code, flags;
512 int afc_len, stuffing_len;
513 int64_t pcr = -1; /* avoid warning */
516 while (payload_size > 0) {
517 retransmit_si_info(s);
520 if (ts_st->pid == ts_st->service->pcr_pid) {
521 ts_st->service->pcr_packet_count++;
522 if (ts_st->service->pcr_packet_count >=
523 ts_st->service->pcr_packet_freq) {
524 ts_st->service->pcr_packet_count = 0;
529 /* prepare packet header */
532 val = (ts_st->pid >> 8);
537 *q++ = 0x10 | ts_st->cc | (write_pcr ? 0x20 : 0);
538 ts_st->cc = (ts_st->cc + 1) & 0xf;
540 // add 11, pcr references the last byte of program clock reference base
541 pcr = ts->cur_pcr + (4+7)*8*90000LL / ts->mux_rate;
542 *q++ = 7; /* AFC length */
543 *q++ = 0x10; /* flags: PCR present */
548 *q++ = (pcr & 1) << 7;
552 int pes_extension = 0;
553 /* write PES header */
558 if (st->codec->codec_type == CODEC_TYPE_VIDEO) {
559 if (st->codec->codec_id == CODEC_ID_DIRAC) {
563 } else if (st->codec->codec_type == CODEC_TYPE_AUDIO &&
564 (st->codec->codec_id == CODEC_ID_MP2 ||
565 st->codec->codec_id == CODEC_ID_MP3)) {
569 if (st->codec->codec_type == CODEC_TYPE_SUBTITLE) {
575 if (pts != AV_NOPTS_VALUE) {
579 if (dts != AV_NOPTS_VALUE && dts != pts) {
583 if (st->codec->codec_type == CODEC_TYPE_VIDEO &&
584 st->codec->codec_id == CODEC_ID_DIRAC) {
585 /* set PES_extension_flag */
590 * One byte for PES2 extension flag +
591 * one byte for extension length +
592 * one byte for extension id
596 len = payload_size + header_len + 3;
597 if (private_code != 0)
602 /* data alignment indicator is required for subtitle data */
603 if (st->codec->codec_type == CODEC_TYPE_SUBTITLE)
608 if (pts != AV_NOPTS_VALUE) {
609 write_pts(q, flags >> 6, pts);
612 if (dts != AV_NOPTS_VALUE && dts != pts) {
613 write_pts(q, 1, dts);
616 if (pes_extension && st->codec->codec_id == CODEC_ID_DIRAC) {
617 flags = 0x01; /* set PES_extension_flag_2 */
619 *q++ = 0x80 | 0x01; /* marker bit + extension length */
621 * Set the stream id extension flag bit to 0 and
622 * write the extended stream id
626 if (private_code != 0)
631 header_len = q - buf;
633 len = TS_PACKET_SIZE - header_len;
634 if (len > payload_size)
636 stuffing_len = TS_PACKET_SIZE - header_len - len;
637 if (stuffing_len > 0) {
638 /* add stuffing with AFC */
640 /* stuffing already present: increase its size */
641 afc_len = buf[4] + 1;
642 memmove(buf + 4 + afc_len + stuffing_len,
644 header_len - (4 + afc_len));
645 buf[4] += stuffing_len;
646 memset(buf + 4 + afc_len, 0xff, stuffing_len);
649 memmove(buf + 4 + stuffing_len, buf + 4, header_len - 4);
651 buf[4] = stuffing_len - 1;
652 if (stuffing_len >= 2) {
654 memset(buf + 6, 0xff, stuffing_len - 2);
658 memcpy(buf + TS_PACKET_SIZE - len, payload, len);
661 put_buffer(s->pb, buf, TS_PACKET_SIZE);
662 ts->cur_pcr += TS_PACKET_SIZE*8*90000LL/ts->mux_rate;
664 put_flush_packet(s->pb);
667 static int mpegts_write_packet(AVFormatContext *s, AVPacket *pkt)
669 AVStream *st = s->streams[pkt->stream_index];
671 uint8_t *buf= pkt->data;
672 MpegTSWriteStream *ts_st = st->priv_data;
673 int len, max_payload_size;
674 const uint8_t *access_unit_index = NULL;
675 const uint64_t delay = av_rescale(s->max_delay, 90000, AV_TIME_BASE);
677 if (st->codec->codec_type == CODEC_TYPE_SUBTITLE) {
678 /* for subtitle, a single PES packet must be generated */
679 mpegts_write_pes(s, st, buf, size, pkt->pts, AV_NOPTS_VALUE);
683 if (st->codec->codec_id == CODEC_ID_DIRAC) {
684 /* for Dirac, a single PES packet must be generated */
685 mpegts_write_pes(s, st, buf, size, pkt->pts, pkt->dts);
688 max_payload_size = DEFAULT_PES_PAYLOAD_SIZE;
689 if (st->codec->codec_id == CODEC_ID_MPEG2VIDEO ||
690 st->codec->codec_id == CODEC_ID_MPEG1VIDEO) {
691 const uint8_t *p = pkt->data;
692 const uint8_t *end = pkt->data+pkt->size;
695 p = ff_find_start_code(p, end, &state);
696 if (state == PICTURE_START_CODE) {
697 access_unit_index = p - 4;
701 } else if (st->codec->codec_type == CODEC_TYPE_AUDIO) {
702 access_unit_index = pkt->data;
705 if (!access_unit_index) {
706 av_log(s, AV_LOG_ERROR, "error, could not find access unit start\n");
711 len = max_payload_size - ts_st->payload_index;
714 memcpy(ts_st->payload + ts_st->payload_index, buf, len);
717 ts_st->payload_index += len;
718 if (access_unit_index && access_unit_index < buf &&
719 ts_st->payload_pts == AV_NOPTS_VALUE &&
720 ts_st->payload_dts == AV_NOPTS_VALUE) {
721 ts_st->payload_dts = pkt->dts + delay;
722 ts_st->payload_pts = pkt->pts + delay;
724 if (ts_st->payload_index >= max_payload_size) {
725 mpegts_write_pes(s, st, ts_st->payload, ts_st->payload_index,
726 ts_st->payload_pts, ts_st->payload_dts);
727 ts_st->payload_pts = AV_NOPTS_VALUE;
728 ts_st->payload_dts = AV_NOPTS_VALUE;
729 ts_st->payload_index = 0;
730 access_unit_index = NULL; // unset access unit to avoid setting pts/dts again
736 static int mpegts_write_end(AVFormatContext *s)
738 MpegTSWrite *ts = s->priv_data;
739 MpegTSWriteStream *ts_st;
740 MpegTSService *service;
744 /* flush current packets */
745 for(i = 0; i < s->nb_streams; i++) {
747 ts_st = st->priv_data;
748 if (ts_st->payload_index > 0) {
749 mpegts_write_pes(s, st, ts_st->payload, ts_st->payload_index,
750 ts_st->payload_pts, ts_st->payload_dts);
753 put_flush_packet(s->pb);
755 for(i = 0; i < ts->nb_services; i++) {
756 service = ts->services[i];
757 av_freep(&service->provider_name);
758 av_freep(&service->name);
761 av_free(ts->services);
766 AVOutputFormat mpegts_muxer = {
768 NULL_IF_CONFIG_SMALL("MPEG-2 transport stream format"),