2 * MPEG2 transport stream (aka DVB) mux
3 * Copyright (c) 2003 Fabrice Bellard.
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 /* write DVB SI sections */
25 /*********************************************/
26 /* mpegts section writer */
28 typedef struct MpegTSSection {
31 void (*write_packet)(struct MpegTSSection *s, const uint8_t *packet);
35 /* NOTE: 4 bytes must be left at the end for the crc32 */
36 static void mpegts_write_section(MpegTSSection *s, uint8_t *buf, int len)
39 unsigned char packet[TS_PACKET_SIZE];
40 const unsigned char *buf_ptr;
42 int first, b, len1, left;
44 crc = bswap_32(av_crc(av_crc04C11DB7, -1, buf, len - 4));
45 buf[len - 4] = (crc >> 24) & 0xff;
46 buf[len - 3] = (crc >> 16) & 0xff;
47 buf[len - 2] = (crc >> 8) & 0xff;
48 buf[len - 1] = (crc) & 0xff;
50 /* send each packet */
53 first = (buf == buf_ptr);
61 s->cc = (s->cc + 1) & 0xf;
64 *q++ = 0; /* 0 offset */
65 len1 = TS_PACKET_SIZE - (q - packet);
68 memcpy(q, buf_ptr, len1);
70 /* add known padding data */
71 left = TS_PACKET_SIZE - (q - packet);
73 memset(q, 0xff, left);
75 s->write_packet(s, packet);
82 static inline void put16(uint8_t **q_ptr, int val)
91 static int mpegts_write_section1(MpegTSSection *s, int tid, int id,
92 int version, int sec_num, int last_sec_num,
93 uint8_t *buf, int len)
95 uint8_t section[1024], *q;
98 tot_len = 3 + 5 + len + 4;
99 /* check if not too big */
105 put16(&q, 0xb000 | (len + 5 + 4)); /* 5 byte header + 4 byte CRC */
107 *q++ = 0xc1 | (version << 1); /* current_next_indicator = 1 */
112 mpegts_write_section(s, section, tot_len);
116 /*********************************************/
119 #define DEFAULT_PMT_START_PID 0x1000
120 #define DEFAULT_START_PID 0x0100
121 #define DEFAULT_PROVIDER_NAME "FFmpeg"
122 #define DEFAULT_SERVICE_NAME "Service01"
124 /* default network id, transport stream and service identifiers */
125 #define DEFAULT_ONID 0x0001
126 #define DEFAULT_TSID 0x0001
127 #define DEFAULT_SID 0x0001
129 /* a PES packet header is generated every DEFAULT_PES_HEADER_FREQ packets */
130 #define DEFAULT_PES_HEADER_FREQ 16
131 #define DEFAULT_PES_PAYLOAD_SIZE ((DEFAULT_PES_HEADER_FREQ - 1) * 184 + 170)
133 /* we retransmit the SI info at this rate */
134 #define SDT_RETRANS_TIME 500
135 #define PAT_RETRANS_TIME 100
136 #define PCR_RETRANS_TIME 20
138 typedef struct MpegTSWriteStream {
139 struct MpegTSService *service;
140 int pid; /* stream associated pid */
144 uint8_t payload[DEFAULT_PES_PAYLOAD_SIZE];
147 typedef struct MpegTSService {
148 MpegTSSection pmt; /* MPEG2 pmt table context */
149 int sid; /* service ID */
153 int pcr_packet_count;
157 typedef struct MpegTSWrite {
158 MpegTSSection pat; /* MPEG2 pat table */
159 MpegTSSection sdt; /* MPEG2 sdt table context */
160 MpegTSService **services;
161 int sdt_packet_count;
163 int pat_packet_count;
170 static void mpegts_write_pat(AVFormatContext *s)
172 MpegTSWrite *ts = s->priv_data;
173 MpegTSService *service;
174 uint8_t data[1012], *q;
178 for(i = 0; i < ts->nb_services; i++) {
179 service = ts->services[i];
180 put16(&q, service->sid);
181 put16(&q, 0xe000 | service->pmt.pid);
183 mpegts_write_section1(&ts->pat, PAT_TID, ts->tsid, 0, 0, 0,
187 static void mpegts_write_pmt(AVFormatContext *s, MpegTSService *service)
189 // MpegTSWrite *ts = s->priv_data;
190 uint8_t data[1012], *q, *desc_length_ptr, *program_info_length_ptr;
191 int val, stream_type, i;
194 put16(&q, 0xe000 | service->pcr_pid);
196 program_info_length_ptr = q;
197 q += 2; /* patched after */
199 /* put program info here */
201 val = 0xf000 | (q - program_info_length_ptr - 2);
202 program_info_length_ptr[0] = val >> 8;
203 program_info_length_ptr[1] = val;
205 for(i = 0; i < s->nb_streams; i++) {
206 AVStream *st = s->streams[i];
207 MpegTSWriteStream *ts_st = st->priv_data;
208 switch(st->codec->codec_id) {
209 case CODEC_ID_MPEG1VIDEO:
210 case CODEC_ID_MPEG2VIDEO:
211 stream_type = STREAM_TYPE_VIDEO_MPEG2;
214 stream_type = STREAM_TYPE_VIDEO_MPEG4;
217 stream_type = STREAM_TYPE_VIDEO_H264;
221 stream_type = STREAM_TYPE_AUDIO_MPEG1;
224 stream_type = STREAM_TYPE_AUDIO_AAC;
227 stream_type = STREAM_TYPE_AUDIO_AC3;
230 stream_type = STREAM_TYPE_PRIVATE_DATA;
234 put16(&q, 0xe000 | ts_st->pid);
236 q += 2; /* patched after */
238 /* write optional descriptors here */
239 switch(st->codec->codec_type) {
240 case CODEC_TYPE_AUDIO:
241 if (strlen(st->language) == 3) {
242 *q++ = 0x0a; /* ISO 639 language descriptor */
244 *q++ = st->language[0];
245 *q++ = st->language[1];
246 *q++ = st->language[2];
247 *q++ = 0; /* undefined type */
250 case CODEC_TYPE_SUBTITLE:
252 const char *language;
253 language = st->language;
254 if (strlen(language) != 3)
261 *q++ = 0x10; /* normal subtitles (0x20 = if hearing pb) */
262 put16(&q, 1); /* page id */
263 put16(&q, 1); /* ancillary page id */
268 val = 0xf000 | (q - desc_length_ptr - 2);
269 desc_length_ptr[0] = val >> 8;
270 desc_length_ptr[1] = val;
272 mpegts_write_section1(&service->pmt, PMT_TID, service->sid, 0, 0, 0,
276 /* NOTE: str == NULL is accepted for an empty string */
277 static void putstr8(uint8_t **q_ptr, const char *str)
293 static void mpegts_write_sdt(AVFormatContext *s)
295 MpegTSWrite *ts = s->priv_data;
296 MpegTSService *service;
297 uint8_t data[1012], *q, *desc_list_len_ptr, *desc_len_ptr;
298 int i, running_status, free_ca_mode, val;
303 for(i = 0; i < ts->nb_services; i++) {
304 service = ts->services[i];
305 put16(&q, service->sid);
306 *q++ = 0xfc | 0x00; /* currently no EIT info */
307 desc_list_len_ptr = q;
309 running_status = 4; /* running */
312 /* write only one descriptor for the service name and provider */
316 *q++ = 0x01; /* digital television service */
317 putstr8(&q, service->provider_name);
318 putstr8(&q, service->name);
319 desc_len_ptr[0] = q - desc_len_ptr - 1;
321 /* fill descriptor length */
322 val = (running_status << 13) | (free_ca_mode << 12) |
323 (q - desc_list_len_ptr - 2);
324 desc_list_len_ptr[0] = val >> 8;
325 desc_list_len_ptr[1] = val;
327 mpegts_write_section1(&ts->sdt, SDT_TID, ts->tsid, 0, 0, 0,
331 static MpegTSService *mpegts_add_service(MpegTSWrite *ts,
333 const char *provider_name,
336 MpegTSService *service;
338 service = av_mallocz(sizeof(MpegTSService));
341 service->pmt.pid = DEFAULT_PMT_START_PID + ts->nb_services - 1;
343 service->provider_name = av_strdup(provider_name);
344 service->name = av_strdup(name);
345 service->pcr_pid = 0x1fff;
346 dynarray_add(&ts->services, &ts->nb_services, service);
350 static void section_write_packet(MpegTSSection *s, const uint8_t *packet)
352 AVFormatContext *ctx = s->opaque;
353 put_buffer(&ctx->pb, packet, TS_PACKET_SIZE);
356 static int mpegts_write_header(AVFormatContext *s)
358 MpegTSWrite *ts = s->priv_data;
359 MpegTSWriteStream *ts_st;
360 MpegTSService *service;
362 int i, total_bit_rate;
363 const char *service_name;
365 ts->tsid = DEFAULT_TSID;
366 ts->onid = DEFAULT_ONID;
367 /* allocate a single DVB service */
368 service_name = s->title;
369 if (service_name[0] == '\0')
370 service_name = DEFAULT_SERVICE_NAME;
371 service = mpegts_add_service(ts, DEFAULT_SID,
372 DEFAULT_PROVIDER_NAME, service_name);
373 service->pmt.write_packet = section_write_packet;
374 service->pmt.opaque = s;
376 ts->pat.pid = PAT_PID;
378 ts->pat.write_packet = section_write_packet;
381 ts->sdt.pid = SDT_PID;
383 ts->sdt.write_packet = section_write_packet;
386 /* assign pids to each stream */
388 for(i = 0;i < s->nb_streams; i++) {
390 ts_st = av_mallocz(sizeof(MpegTSWriteStream));
393 st->priv_data = ts_st;
394 ts_st->service = service;
395 ts_st->pid = DEFAULT_START_PID + i;
396 ts_st->payload_pts = AV_NOPTS_VALUE;
397 /* update PCR pid by using the first video stream */
398 if (st->codec->codec_type == CODEC_TYPE_VIDEO &&
399 service->pcr_pid == 0x1fff)
400 service->pcr_pid = ts_st->pid;
401 total_bit_rate += st->codec->bit_rate;
404 /* if no video stream, use the first stream as PCR */
405 if (service->pcr_pid == 0x1fff && s->nb_streams > 0) {
406 ts_st = s->streams[0]->priv_data;
407 service->pcr_pid = ts_st->pid;
410 if (total_bit_rate <= 8 * 1024)
411 total_bit_rate = 8 * 1024;
412 service->pcr_packet_freq = (total_bit_rate * PCR_RETRANS_TIME) /
413 (TS_PACKET_SIZE * 8 * 1000);
414 ts->sdt_packet_freq = (total_bit_rate * SDT_RETRANS_TIME) /
415 (TS_PACKET_SIZE * 8 * 1000);
416 ts->pat_packet_freq = (total_bit_rate * PAT_RETRANS_TIME) /
417 (TS_PACKET_SIZE * 8 * 1000);
420 total_bit_rate, ts->sdt_packet_freq, ts->pat_packet_freq);
423 /* write info at the start of the file, so that it will be fast to
427 for(i = 0; i < ts->nb_services; i++) {
428 mpegts_write_pmt(s, ts->services[i]);
430 put_flush_packet(&s->pb);
435 for(i = 0;i < s->nb_streams; i++) {
437 av_free(st->priv_data);
442 /* send SDT, PAT and PMT tables regulary */
443 static void retransmit_si_info(AVFormatContext *s)
445 MpegTSWrite *ts = s->priv_data;
448 if (++ts->sdt_packet_count == ts->sdt_packet_freq) {
449 ts->sdt_packet_count = 0;
452 if (++ts->pat_packet_count == ts->pat_packet_freq) {
453 ts->pat_packet_count = 0;
455 for(i = 0; i < ts->nb_services; i++) {
456 mpegts_write_pmt(s, ts->services[i]);
461 /* NOTE: pes_data contains all the PES packet */
462 static void mpegts_write_pes(AVFormatContext *s, AVStream *st,
463 const uint8_t *payload, int payload_size,
466 MpegTSWriteStream *ts_st = st->priv_data;
467 uint8_t buf[TS_PACKET_SIZE];
469 int val, is_start, len, header_len, write_pcr, private_code;
470 int afc_len, stuffing_len;
471 int64_t pcr = -1; /* avoid warning */
474 while (payload_size > 0) {
475 retransmit_si_info(s);
478 if (ts_st->pid == ts_st->service->pcr_pid) {
479 ts_st->service->pcr_packet_count++;
480 if (ts_st->service->pcr_packet_count >=
481 ts_st->service->pcr_packet_freq) {
482 ts_st->service->pcr_packet_count = 0;
484 /* XXX: this is incorrect, but at least we have a PCR
490 /* prepare packet header */
493 val = (ts_st->pid >> 8);
498 *q++ = 0x10 | ts_st->cc | (write_pcr ? 0x20 : 0);
499 ts_st->cc = (ts_st->cc + 1) & 0xf;
501 *q++ = 7; /* AFC length */
502 *q++ = 0x10; /* flags: PCR present */
507 *q++ = (pcr & 1) << 7;
511 /* write PES header */
516 if (st->codec->codec_type == CODEC_TYPE_VIDEO) {
518 } else if (st->codec->codec_type == CODEC_TYPE_AUDIO &&
519 (st->codec->codec_id == CODEC_ID_MP2 ||
520 st->codec->codec_id == CODEC_ID_MP3)) {
524 if (st->codec->codec_type == CODEC_TYPE_SUBTITLE) {
528 if (pts != AV_NOPTS_VALUE)
532 if (private_code != 0)
534 len = payload_size + header_len;
538 /* data alignment indicator is required for subtitle data */
539 if (st->codec->codec_type == CODEC_TYPE_SUBTITLE)
542 if (pts != AV_NOPTS_VALUE) {
543 *q++ = 0x80; /* PTS only */
544 *q++ = 0x05; /* header len */
546 (((pts >> 30) & 0x07) << 1) | 1;
548 val = (((pts >> 15) & 0x7fff) << 1) | 1;
551 val = (((pts) & 0x7fff) << 1) | 1;
558 if (private_code != 0)
563 header_len = q - buf;
565 len = TS_PACKET_SIZE - header_len;
566 if (len > payload_size)
568 stuffing_len = TS_PACKET_SIZE - header_len - len;
569 if (stuffing_len > 0) {
570 /* add stuffing with AFC */
572 /* stuffing already present: increase its size */
573 afc_len = buf[4] + 1;
574 memmove(buf + 4 + afc_len + stuffing_len,
576 header_len - (4 + afc_len));
577 buf[4] += stuffing_len;
578 memset(buf + 4 + afc_len, 0xff, stuffing_len);
581 memmove(buf + 4 + stuffing_len, buf + 4, header_len - 4);
583 buf[4] = stuffing_len - 1;
584 if (stuffing_len >= 2) {
586 memset(buf + 6, 0xff, stuffing_len - 2);
590 memcpy(buf + TS_PACKET_SIZE - len, payload, len);
593 put_buffer(&s->pb, buf, TS_PACKET_SIZE);
595 put_flush_packet(&s->pb);
598 static int mpegts_write_packet(AVFormatContext *s, AVPacket *pkt)
600 AVStream *st = s->streams[pkt->stream_index];
602 uint8_t *buf= pkt->data;
603 MpegTSWriteStream *ts_st = st->priv_data;
604 int len, max_payload_size;
606 if (st->codec->codec_type == CODEC_TYPE_SUBTITLE) {
607 /* for subtitle, a single PES packet must be generated */
608 mpegts_write_pes(s, st, buf, size, pkt->pts);
612 max_payload_size = DEFAULT_PES_PAYLOAD_SIZE;
614 len = max_payload_size - ts_st->payload_index;
617 memcpy(ts_st->payload + ts_st->payload_index, buf, len);
620 ts_st->payload_index += len;
621 if (ts_st->payload_pts == AV_NOPTS_VALUE)
622 ts_st->payload_pts = pkt->pts;
623 if (ts_st->payload_index >= max_payload_size) {
624 mpegts_write_pes(s, st, ts_st->payload, ts_st->payload_index,
626 ts_st->payload_pts = AV_NOPTS_VALUE;
627 ts_st->payload_index = 0;
633 static int mpegts_write_end(AVFormatContext *s)
635 MpegTSWrite *ts = s->priv_data;
636 MpegTSWriteStream *ts_st;
637 MpegTSService *service;
641 /* flush current packets */
642 for(i = 0; i < s->nb_streams; i++) {
644 ts_st = st->priv_data;
645 if (ts_st->payload_index > 0) {
646 mpegts_write_pes(s, st, ts_st->payload, ts_st->payload_index,
650 put_flush_packet(&s->pb);
652 for(i = 0; i < ts->nb_services; i++) {
653 service = ts->services[i];
654 av_freep(&service->provider_name);
655 av_freep(&service->name);
658 av_free(ts->services);
663 AVOutputFormat mpegts_muxer = {
665 "MPEG2 transport stream format",