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
25 /* write DVB SI sections */
27 /*********************************************/
28 /* mpegts section writer */
30 typedef struct MpegTSSection {
33 void (*write_packet)(struct MpegTSSection *s, const uint8_t *packet);
37 /* NOTE: 4 bytes must be left at the end for the crc32 */
38 static void mpegts_write_section(MpegTSSection *s, uint8_t *buf, int len)
41 unsigned char packet[TS_PACKET_SIZE];
42 const unsigned char *buf_ptr;
44 int first, b, len1, left;
46 crc = bswap_32(av_crc(av_crc04C11DB7, -1, buf, len - 4));
47 buf[len - 4] = (crc >> 24) & 0xff;
48 buf[len - 3] = (crc >> 16) & 0xff;
49 buf[len - 2] = (crc >> 8) & 0xff;
50 buf[len - 1] = (crc) & 0xff;
52 /* send each packet */
55 first = (buf == buf_ptr);
63 s->cc = (s->cc + 1) & 0xf;
66 *q++ = 0; /* 0 offset */
67 len1 = TS_PACKET_SIZE - (q - packet);
70 memcpy(q, buf_ptr, len1);
72 /* add known padding data */
73 left = TS_PACKET_SIZE - (q - packet);
75 memset(q, 0xff, left);
77 s->write_packet(s, packet);
84 static inline void put16(uint8_t **q_ptr, int val)
93 static int mpegts_write_section1(MpegTSSection *s, int tid, int id,
94 int version, int sec_num, int last_sec_num,
95 uint8_t *buf, int len)
97 uint8_t section[1024], *q;
100 tot_len = 3 + 5 + len + 4;
101 /* check if not too big */
107 put16(&q, 0xb000 | (len + 5 + 4)); /* 5 byte header + 4 byte CRC */
109 *q++ = 0xc1 | (version << 1); /* current_next_indicator = 1 */
114 mpegts_write_section(s, section, tot_len);
118 /*********************************************/
121 #define DEFAULT_PMT_START_PID 0x1000
122 #define DEFAULT_START_PID 0x0100
123 #define DEFAULT_PROVIDER_NAME "FFmpeg"
124 #define DEFAULT_SERVICE_NAME "Service01"
126 /* default network id, transport stream and service identifiers */
127 #define DEFAULT_ONID 0x0001
128 #define DEFAULT_TSID 0x0001
129 #define DEFAULT_SID 0x0001
131 /* a PES packet header is generated every DEFAULT_PES_HEADER_FREQ packets */
132 #define DEFAULT_PES_HEADER_FREQ 16
133 #define DEFAULT_PES_PAYLOAD_SIZE ((DEFAULT_PES_HEADER_FREQ - 1) * 184 + 170)
135 /* we retransmit the SI info at this rate */
136 #define SDT_RETRANS_TIME 500
137 #define PAT_RETRANS_TIME 100
138 #define PCR_RETRANS_TIME 20
140 typedef struct MpegTSWriteStream {
141 struct MpegTSService *service;
142 int pid; /* stream associated pid */
147 uint8_t payload[DEFAULT_PES_PAYLOAD_SIZE];
150 typedef struct MpegTSService {
151 MpegTSSection pmt; /* MPEG2 pmt table context */
152 int sid; /* service ID */
156 int pcr_packet_count;
160 typedef struct MpegTSWrite {
161 MpegTSSection pat; /* MPEG2 pat table */
162 MpegTSSection sdt; /* MPEG2 sdt table context */
163 MpegTSService **services;
164 int sdt_packet_count;
166 int pat_packet_count;
173 static void mpegts_write_pat(AVFormatContext *s)
175 MpegTSWrite *ts = s->priv_data;
176 MpegTSService *service;
177 uint8_t data[1012], *q;
181 for(i = 0; i < ts->nb_services; i++) {
182 service = ts->services[i];
183 put16(&q, service->sid);
184 put16(&q, 0xe000 | service->pmt.pid);
186 mpegts_write_section1(&ts->pat, PAT_TID, ts->tsid, 0, 0, 0,
190 static void mpegts_write_pmt(AVFormatContext *s, MpegTSService *service)
192 // MpegTSWrite *ts = s->priv_data;
193 uint8_t data[1012], *q, *desc_length_ptr, *program_info_length_ptr;
194 int val, stream_type, i;
197 put16(&q, 0xe000 | service->pcr_pid);
199 program_info_length_ptr = q;
200 q += 2; /* patched after */
202 /* put program info here */
204 val = 0xf000 | (q - program_info_length_ptr - 2);
205 program_info_length_ptr[0] = val >> 8;
206 program_info_length_ptr[1] = val;
208 for(i = 0; i < s->nb_streams; i++) {
209 AVStream *st = s->streams[i];
210 MpegTSWriteStream *ts_st = st->priv_data;
211 switch(st->codec->codec_id) {
212 case CODEC_ID_MPEG1VIDEO:
213 case CODEC_ID_MPEG2VIDEO:
214 stream_type = STREAM_TYPE_VIDEO_MPEG2;
217 stream_type = STREAM_TYPE_VIDEO_MPEG4;
220 stream_type = STREAM_TYPE_VIDEO_H264;
224 stream_type = STREAM_TYPE_AUDIO_MPEG1;
227 stream_type = STREAM_TYPE_AUDIO_AAC;
230 stream_type = STREAM_TYPE_AUDIO_AC3;
233 stream_type = STREAM_TYPE_PRIVATE_DATA;
237 put16(&q, 0xe000 | ts_st->pid);
239 q += 2; /* patched after */
241 /* write optional descriptors here */
242 switch(st->codec->codec_type) {
243 case CODEC_TYPE_AUDIO:
244 if (strlen(st->language) == 3) {
245 *q++ = 0x0a; /* ISO 639 language descriptor */
247 *q++ = st->language[0];
248 *q++ = st->language[1];
249 *q++ = st->language[2];
250 *q++ = 0; /* undefined type */
253 case CODEC_TYPE_SUBTITLE:
255 const char *language;
256 language = st->language;
257 if (strlen(language) != 3)
264 *q++ = 0x10; /* normal subtitles (0x20 = if hearing pb) */
265 put16(&q, 1); /* page id */
266 put16(&q, 1); /* ancillary page id */
271 val = 0xf000 | (q - desc_length_ptr - 2);
272 desc_length_ptr[0] = val >> 8;
273 desc_length_ptr[1] = val;
275 mpegts_write_section1(&service->pmt, PMT_TID, service->sid, 0, 0, 0,
279 /* NOTE: str == NULL is accepted for an empty string */
280 static void putstr8(uint8_t **q_ptr, const char *str)
296 static void mpegts_write_sdt(AVFormatContext *s)
298 MpegTSWrite *ts = s->priv_data;
299 MpegTSService *service;
300 uint8_t data[1012], *q, *desc_list_len_ptr, *desc_len_ptr;
301 int i, running_status, free_ca_mode, val;
306 for(i = 0; i < ts->nb_services; i++) {
307 service = ts->services[i];
308 put16(&q, service->sid);
309 *q++ = 0xfc | 0x00; /* currently no EIT info */
310 desc_list_len_ptr = q;
312 running_status = 4; /* running */
315 /* write only one descriptor for the service name and provider */
319 *q++ = 0x01; /* digital television service */
320 putstr8(&q, service->provider_name);
321 putstr8(&q, service->name);
322 desc_len_ptr[0] = q - desc_len_ptr - 1;
324 /* fill descriptor length */
325 val = (running_status << 13) | (free_ca_mode << 12) |
326 (q - desc_list_len_ptr - 2);
327 desc_list_len_ptr[0] = val >> 8;
328 desc_list_len_ptr[1] = val;
330 mpegts_write_section1(&ts->sdt, SDT_TID, ts->tsid, 0, 0, 0,
334 static MpegTSService *mpegts_add_service(MpegTSWrite *ts,
336 const char *provider_name,
339 MpegTSService *service;
341 service = av_mallocz(sizeof(MpegTSService));
344 service->pmt.pid = DEFAULT_PMT_START_PID + ts->nb_services - 1;
346 service->provider_name = av_strdup(provider_name);
347 service->name = av_strdup(name);
348 service->pcr_pid = 0x1fff;
349 dynarray_add(&ts->services, &ts->nb_services, service);
353 static void section_write_packet(MpegTSSection *s, const uint8_t *packet)
355 AVFormatContext *ctx = s->opaque;
356 put_buffer(&ctx->pb, packet, TS_PACKET_SIZE);
359 static int mpegts_write_header(AVFormatContext *s)
361 MpegTSWrite *ts = s->priv_data;
362 MpegTSWriteStream *ts_st;
363 MpegTSService *service;
365 int i, total_bit_rate;
366 const char *service_name;
368 ts->tsid = DEFAULT_TSID;
369 ts->onid = DEFAULT_ONID;
370 /* allocate a single DVB service */
371 service_name = s->title;
372 if (service_name[0] == '\0')
373 service_name = DEFAULT_SERVICE_NAME;
374 service = mpegts_add_service(ts, DEFAULT_SID,
375 DEFAULT_PROVIDER_NAME, service_name);
376 service->pmt.write_packet = section_write_packet;
377 service->pmt.opaque = s;
379 ts->pat.pid = PAT_PID;
381 ts->pat.write_packet = section_write_packet;
384 ts->sdt.pid = SDT_PID;
386 ts->sdt.write_packet = section_write_packet;
389 /* assign pids to each stream */
391 for(i = 0;i < s->nb_streams; i++) {
393 ts_st = av_mallocz(sizeof(MpegTSWriteStream));
396 st->priv_data = ts_st;
397 ts_st->service = service;
398 ts_st->pid = DEFAULT_START_PID + i;
399 ts_st->payload_pts = AV_NOPTS_VALUE;
400 ts_st->payload_dts = AV_NOPTS_VALUE;
401 /* update PCR pid by using the first video stream */
402 if (st->codec->codec_type == CODEC_TYPE_VIDEO &&
403 service->pcr_pid == 0x1fff)
404 service->pcr_pid = ts_st->pid;
405 total_bit_rate += st->codec->bit_rate;
408 /* if no video stream, use the first stream as PCR */
409 if (service->pcr_pid == 0x1fff && s->nb_streams > 0) {
410 ts_st = s->streams[0]->priv_data;
411 service->pcr_pid = ts_st->pid;
414 if (total_bit_rate <= 8 * 1024)
415 total_bit_rate = 8 * 1024;
416 service->pcr_packet_freq = (total_bit_rate * PCR_RETRANS_TIME) /
417 (TS_PACKET_SIZE * 8 * 1000);
418 ts->sdt_packet_freq = (total_bit_rate * SDT_RETRANS_TIME) /
419 (TS_PACKET_SIZE * 8 * 1000);
420 ts->pat_packet_freq = (total_bit_rate * PAT_RETRANS_TIME) /
421 (TS_PACKET_SIZE * 8 * 1000);
424 total_bit_rate, ts->sdt_packet_freq, ts->pat_packet_freq);
427 /* write info at the start of the file, so that it will be fast to
431 for(i = 0; i < ts->nb_services; i++) {
432 mpegts_write_pmt(s, ts->services[i]);
434 put_flush_packet(&s->pb);
439 for(i = 0;i < s->nb_streams; i++) {
441 av_free(st->priv_data);
446 /* send SDT, PAT and PMT tables regulary */
447 static void retransmit_si_info(AVFormatContext *s)
449 MpegTSWrite *ts = s->priv_data;
452 if (++ts->sdt_packet_count == ts->sdt_packet_freq) {
453 ts->sdt_packet_count = 0;
456 if (++ts->pat_packet_count == ts->pat_packet_freq) {
457 ts->pat_packet_count = 0;
459 for(i = 0; i < ts->nb_services; i++) {
460 mpegts_write_pmt(s, ts->services[i]);
465 static void write_pts(uint8_t *q, int fourbits, int64_t pts)
469 val = fourbits << 4 | (((pts >> 30) & 0x07) << 1) | 1;
471 val = (((pts >> 15) & 0x7fff) << 1) | 1;
474 val = (((pts) & 0x7fff) << 1) | 1;
479 /* NOTE: pes_data contains all the PES packet */
480 static void mpegts_write_pes(AVFormatContext *s, AVStream *st,
481 const uint8_t *payload, int payload_size,
482 int64_t pts, int64_t dts)
484 MpegTSWriteStream *ts_st = st->priv_data;
485 uint8_t buf[TS_PACKET_SIZE];
487 int val, is_start, len, header_len, write_pcr, private_code, flags;
488 int afc_len, stuffing_len;
489 int64_t pcr = -1; /* avoid warning */
492 while (payload_size > 0) {
493 retransmit_si_info(s);
496 if (ts_st->pid == ts_st->service->pcr_pid) {
497 ts_st->service->pcr_packet_count++;
498 if (ts_st->service->pcr_packet_count >=
499 ts_st->service->pcr_packet_freq) {
500 ts_st->service->pcr_packet_count = 0;
502 /* XXX: this is incorrect, but at least we have a PCR
508 /* prepare packet header */
511 val = (ts_st->pid >> 8);
516 *q++ = 0x10 | ts_st->cc | (write_pcr ? 0x20 : 0);
517 ts_st->cc = (ts_st->cc + 1) & 0xf;
519 *q++ = 7; /* AFC length */
520 *q++ = 0x10; /* flags: PCR present */
525 *q++ = (pcr & 1) << 7;
529 /* write PES header */
534 if (st->codec->codec_type == CODEC_TYPE_VIDEO) {
536 } else if (st->codec->codec_type == CODEC_TYPE_AUDIO &&
537 (st->codec->codec_id == CODEC_ID_MP2 ||
538 st->codec->codec_id == CODEC_ID_MP3)) {
542 if (st->codec->codec_type == CODEC_TYPE_SUBTITLE) {
548 if (pts != AV_NOPTS_VALUE) {
552 if (dts != AV_NOPTS_VALUE) {
556 len = payload_size + header_len + 3;
557 if (private_code != 0)
562 /* data alignment indicator is required for subtitle data */
563 if (st->codec->codec_type == CODEC_TYPE_SUBTITLE)
568 if (pts != AV_NOPTS_VALUE) {
569 write_pts(q, flags >> 6, pts);
572 if (dts != AV_NOPTS_VALUE) {
573 write_pts(q, 1, dts);
576 if (private_code != 0)
581 header_len = q - buf;
583 len = TS_PACKET_SIZE - header_len;
584 if (len > payload_size)
586 stuffing_len = TS_PACKET_SIZE - header_len - len;
587 if (stuffing_len > 0) {
588 /* add stuffing with AFC */
590 /* stuffing already present: increase its size */
591 afc_len = buf[4] + 1;
592 memmove(buf + 4 + afc_len + stuffing_len,
594 header_len - (4 + afc_len));
595 buf[4] += stuffing_len;
596 memset(buf + 4 + afc_len, 0xff, stuffing_len);
599 memmove(buf + 4 + stuffing_len, buf + 4, header_len - 4);
601 buf[4] = stuffing_len - 1;
602 if (stuffing_len >= 2) {
604 memset(buf + 6, 0xff, stuffing_len - 2);
608 memcpy(buf + TS_PACKET_SIZE - len, payload, len);
611 put_buffer(&s->pb, buf, TS_PACKET_SIZE);
613 put_flush_packet(&s->pb);
616 static int mpegts_write_packet(AVFormatContext *s, AVPacket *pkt)
618 AVStream *st = s->streams[pkt->stream_index];
620 uint8_t *buf= pkt->data;
621 MpegTSWriteStream *ts_st = st->priv_data;
622 int len, max_payload_size;
624 if (st->codec->codec_type == CODEC_TYPE_SUBTITLE) {
625 /* for subtitle, a single PES packet must be generated */
626 mpegts_write_pes(s, st, buf, size, pkt->pts, AV_NOPTS_VALUE);
630 max_payload_size = DEFAULT_PES_PAYLOAD_SIZE;
632 len = max_payload_size - ts_st->payload_index;
635 memcpy(ts_st->payload + ts_st->payload_index, buf, len);
638 ts_st->payload_index += len;
639 if (ts_st->payload_pts == AV_NOPTS_VALUE)
640 ts_st->payload_pts = pkt->pts;
641 if (ts_st->payload_dts == AV_NOPTS_VALUE)
642 ts_st->payload_dts = pkt->dts;
643 if (ts_st->payload_index >= max_payload_size) {
644 mpegts_write_pes(s, st, ts_st->payload, ts_st->payload_index,
645 ts_st->payload_pts, ts_st->payload_dts);
646 ts_st->payload_pts = AV_NOPTS_VALUE;
647 ts_st->payload_dts = AV_NOPTS_VALUE;
648 ts_st->payload_index = 0;
654 static int mpegts_write_end(AVFormatContext *s)
656 MpegTSWrite *ts = s->priv_data;
657 MpegTSWriteStream *ts_st;
658 MpegTSService *service;
662 /* flush current packets */
663 for(i = 0; i < s->nb_streams; i++) {
665 ts_st = st->priv_data;
666 if (ts_st->payload_index > 0) {
667 mpegts_write_pes(s, st, ts_st->payload, ts_st->payload_index,
668 ts_st->payload_pts, ts_st->payload_dts);
671 put_flush_packet(&s->pb);
673 for(i = 0; i < ts->nb_services; i++) {
674 service = ts->services[i];
675 av_freep(&service->provider_name);
676 av_freep(&service->name);
679 av_free(ts->services);
684 AVOutputFormat mpegts_muxer = {
686 "MPEG2 transport stream format",