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ffmpeg/libavformat/mpegtsenc.c

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/*
* MPEG-2 transport stream (aka DVB) muxer
* Copyright (c) 2003 Fabrice Bellard
*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Libav is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavutil/bswap.h"
#include "libavutil/crc.h"
#include "libavutil/dict.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/mathematics.h"
#include "libavutil/opt.h"
#include "libavcodec/internal.h"
#include "avformat.h"
#include "avio_internal.h"
#include "internal.h"
#include "mpegts.h"
#define PCR_TIME_BASE 27000000
/* write DVB SI sections */
#define DVB_PRIVATE_NETWORK_START 0xff01
/*********************************************/
/* mpegts section writer */
typedef struct MpegTSSection {
int pid;
int cc;
void (*write_packet)(struct MpegTSSection *s, const uint8_t *packet);
void *opaque;
} MpegTSSection;
typedef struct MpegTSService {
MpegTSSection pmt; /* MPEG-2 PMT table context */
int sid; /* service ID */
char *name;
char *provider_name;
int pcr_pid;
int pcr_packet_count;
int pcr_packet_period;
} MpegTSService;
typedef struct MpegTSWrite {
const AVClass *av_class;
MpegTSSection pat; /* MPEG-2 PAT table */
MpegTSSection sdt; /* MPEG-2 SDT table context */
MpegTSService **services;
int sdt_packet_count;
int sdt_packet_period;
int pat_packet_count;
int pat_packet_period;
int nb_services;
int onid;
int tsid;
int64_t first_pcr;
int mux_rate; ///< set to 1 when VBR
int pes_payload_size;
int transport_stream_id;
int original_network_id;
int service_id;
int pmt_start_pid;
int start_pid;
int m2ts_mode;
int reemit_pat_pmt; // backward compatibility
int pcr_period;
#define MPEGTS_FLAG_REEMIT_PAT_PMT 0x01
#define MPEGTS_FLAG_AAC_LATM 0x02
#define MPEGTS_FLAG_SYSTEM_B 0x04
int flags;
} MpegTSWrite;
/* a PES packet header is generated every DEFAULT_PES_HEADER_FREQ packets */
#define DEFAULT_PES_HEADER_FREQ 16
#define DEFAULT_PES_PAYLOAD_SIZE ((DEFAULT_PES_HEADER_FREQ - 1) * 184 + 170)
/* The section length is 12 bits. The first 2 are set to 0, the remaining
* 10 bits should not exceed 1021. */
#define SECTION_LENGTH 1020
/* NOTE: 4 bytes must be left at the end for the crc32 */
static void mpegts_write_section(MpegTSSection *s, uint8_t *buf, int len)
{
unsigned int crc;
unsigned char packet[TS_PACKET_SIZE];
const unsigned char *buf_ptr;
unsigned char *q;
int first, b, len1, left;
crc = av_bswap32(av_crc(av_crc_get_table(AV_CRC_32_IEEE),
-1, buf, len - 4));
buf[len - 4] = (crc >> 24) & 0xff;
buf[len - 3] = (crc >> 16) & 0xff;
buf[len - 2] = (crc >> 8) & 0xff;
buf[len - 1] = crc & 0xff;
/* send each packet */
buf_ptr = buf;
while (len > 0) {
first = buf == buf_ptr;
q = packet;
*q++ = 0x47;
b = s->pid >> 8;
if (first)
b |= 0x40;
*q++ = b;
*q++ = s->pid;
s->cc = s->cc + 1 & 0xf;
*q++ = 0x10 | s->cc;
if (first)
*q++ = 0; /* 0 offset */
len1 = TS_PACKET_SIZE - (q - packet);
if (len1 > len)
len1 = len;
memcpy(q, buf_ptr, len1);
q += len1;
/* add known padding data */
left = TS_PACKET_SIZE - (q - packet);
if (left > 0)
memset(q, 0xff, left);
s->write_packet(s, packet);
buf_ptr += len1;
len -= len1;
}
}
static inline void put16(uint8_t **q_ptr, int val)
{
uint8_t *q;
q = *q_ptr;
*q++ = val >> 8;
*q++ = val;
*q_ptr = q;
}
static int mpegts_write_section1(MpegTSSection *s, int tid, int id,
int version, int sec_num, int last_sec_num,
uint8_t *buf, int len)
{
uint8_t section[1024], *q;
unsigned int tot_len;
/* reserved_future_use field must be set to 1 for SDT */
unsigned int flags = tid == SDT_TID ? 0xf000 : 0xb000;
tot_len = 3 + 5 + len + 4;
/* check if not too big */
if (tot_len > 1024)
return AVERROR_INVALIDDATA;
q = section;
*q++ = tid;
put16(&q, flags | (len + 5 + 4)); /* 5 byte header + 4 byte CRC */
put16(&q, id);
*q++ = 0xc1 | (version << 1); /* current_next_indicator = 1 */
*q++ = sec_num;
*q++ = last_sec_num;
memcpy(q, buf, len);
mpegts_write_section(s, section, tot_len);
return 0;
}
/*********************************************/
/* mpegts writer */
#define DEFAULT_PROVIDER_NAME "Libav"
#define DEFAULT_SERVICE_NAME "Service01"
/* we retransmit the SI info at this rate */
#define SDT_RETRANS_TIME 500
#define PAT_RETRANS_TIME 100
#define PCR_RETRANS_TIME 20
typedef struct MpegTSWriteStream {
struct MpegTSService *service;
int pid; /* stream associated pid */
int cc;
int payload_size;
int first_pts_check; ///< first pts check needed
int64_t payload_pts;
int64_t payload_dts;
int payload_flags;
uint8_t *payload;
AVFormatContext *amux;
AVRational user_tb;
} MpegTSWriteStream;
static void mpegts_write_pat(AVFormatContext *s)
{
MpegTSWrite *ts = s->priv_data;
MpegTSService *service;
uint8_t data[SECTION_LENGTH], *q;
int i;
q = data;
for (i = 0; i < ts->nb_services; i++) {
service = ts->services[i];
put16(&q, service->sid);
put16(&q, 0xe000 | service->pmt.pid);
}
mpegts_write_section1(&ts->pat, PAT_TID, ts->tsid, 0, 0, 0,
data, q - data);
}
static void mpegts_write_pmt(AVFormatContext *s, MpegTSService *service)
{
MpegTSWrite *ts = s->priv_data;
uint8_t data[SECTION_LENGTH], *q, *desc_length_ptr, *program_info_length_ptr;
int val, stream_type, i, err = 0;
q = data;
put16(&q, 0xe000 | service->pcr_pid);
program_info_length_ptr = q;
q += 2; /* patched after */
/* put program info here */
val = 0xf000 | (q - program_info_length_ptr - 2);
program_info_length_ptr[0] = val >> 8;
program_info_length_ptr[1] = val;
for (i = 0; i < s->nb_streams; i++) {
AVStream *st = s->streams[i];
MpegTSWriteStream *ts_st = st->priv_data;
AVDictionaryEntry *lang = av_dict_get(st->metadata, "language", NULL, 0);
if (q - data > SECTION_LENGTH - 3 - 2 - 6) {
err = 1;
break;
}
switch (st->codecpar->codec_id) {
case AV_CODEC_ID_MPEG1VIDEO:
case AV_CODEC_ID_MPEG2VIDEO:
stream_type = STREAM_TYPE_VIDEO_MPEG2;
break;
case AV_CODEC_ID_MPEG4:
stream_type = STREAM_TYPE_VIDEO_MPEG4;
break;
case AV_CODEC_ID_H264:
stream_type = STREAM_TYPE_VIDEO_H264;
break;
case AV_CODEC_ID_HEVC:
stream_type = STREAM_TYPE_VIDEO_HEVC;
break;
case AV_CODEC_ID_CAVS:
stream_type = STREAM_TYPE_VIDEO_CAVS;
break;
case AV_CODEC_ID_DIRAC:
stream_type = STREAM_TYPE_VIDEO_DIRAC;
break;
case AV_CODEC_ID_MP2:
case AV_CODEC_ID_MP3:
stream_type = STREAM_TYPE_AUDIO_MPEG1;
break;
case AV_CODEC_ID_AAC:
stream_type = (ts->flags & MPEGTS_FLAG_AAC_LATM)
? STREAM_TYPE_AUDIO_AAC_LATM
: STREAM_TYPE_AUDIO_AAC;
break;
case AV_CODEC_ID_AAC_LATM:
stream_type = STREAM_TYPE_AUDIO_AAC_LATM;
break;
case AV_CODEC_ID_AC3:
stream_type = (ts->flags & MPEGTS_FLAG_SYSTEM_B)
? STREAM_TYPE_PRIVATE_DATA
: STREAM_TYPE_AUDIO_AC3;
break;
default:
stream_type = STREAM_TYPE_PRIVATE_DATA;
break;
}
*q++ = stream_type;
put16(&q, 0xe000 | ts_st->pid);
desc_length_ptr = q;
q += 2; /* patched after */
/* write optional descriptors here */
switch (st->codecpar->codec_type) {
case AVMEDIA_TYPE_AUDIO:
if (st->codecpar->codec_id == AV_CODEC_ID_AC3 && (ts->flags & MPEGTS_FLAG_SYSTEM_B)) {
*q++ = 0x6a; /* ETSI EN 300 468 AC-3 descriptor */
*q++ = 1;
*q++ = 0x00;
}
if (lang) {
char *p;
char *next = lang->value;
uint8_t *len_ptr;
*q++ = 0x0a; /* ISO 639 language descriptor */
len_ptr = q++;
*len_ptr = 0;
for (p = lang->value; next && *len_ptr < 255 / 4 * 4; p = next + 1) {
if (q - data > SECTION_LENGTH - 4) {
err = 1;
break;
}
next = strchr(p, ',');
if (strlen(p) != 3 && (!next || next != p + 3))
continue; /* not a 3-letter code */
*q++ = *p++;
*q++ = *p++;
*q++ = *p++;
if (st->disposition & AV_DISPOSITION_CLEAN_EFFECTS)
*q++ = 0x01;
else if (st->disposition & AV_DISPOSITION_HEARING_IMPAIRED)
*q++ = 0x02;
else if (st->disposition & AV_DISPOSITION_VISUAL_IMPAIRED)
*q++ = 0x03;
else
*q++ = 0; /* undefined type */
*len_ptr += 4;
}
if (*len_ptr == 0)
q -= 2; /* no language codes were written */
}
break;
case AVMEDIA_TYPE_SUBTITLE:
{
const char *language;
language = lang && strlen(lang->value) == 3 ? lang->value : "eng";
*q++ = 0x59;
*q++ = 8;
*q++ = language[0];
*q++ = language[1];
*q++ = language[2];
*q++ = 0x10; /* normal subtitles (0x20 = if hearing pb) */
if (q - data > SECTION_LENGTH - 4) {
err = 1;
break;
}
if (st->codecpar->extradata_size == 4) {
memcpy(q, st->codecpar->extradata, 4);
q += 4;
} else {
put16(&q, 1); /* page id */
put16(&q, 1); /* ancillary page id */
}
}
break;
case AVMEDIA_TYPE_VIDEO:
if (stream_type == STREAM_TYPE_VIDEO_DIRAC) {
*q++ = 0x05; /*MPEG-2 registration descriptor*/
*q++ = 4;
*q++ = 'd';
*q++ = 'r';
*q++ = 'a';
*q++ = 'c';
}
break;
}
val = 0xf000 | (q - desc_length_ptr - 2);
desc_length_ptr[0] = val >> 8;
desc_length_ptr[1] = val;
}
if (err)
av_log(s, AV_LOG_ERROR,
"The PMT section cannot fit stream %d and all following streams.\n"
"Try reducing the number of languages in the audio streams "
"or the total number of streams.\n", i);
mpegts_write_section1(&service->pmt, PMT_TID, service->sid, 0, 0, 0,
data, q - data);
}
/* NOTE: str == NULL is accepted for an empty string */
static void putstr8(uint8_t **q_ptr, const char *str)
{
uint8_t *q;
int len;
q = *q_ptr;
if (!str)
len = 0;
else
len = strlen(str);
*q++ = len;
memcpy(q, str, len);
q += len;
*q_ptr = q;
}
static void mpegts_write_sdt(AVFormatContext *s)
{
MpegTSWrite *ts = s->priv_data;
MpegTSService *service;
uint8_t data[SECTION_LENGTH], *q, *desc_list_len_ptr, *desc_len_ptr;
int i, running_status, free_ca_mode, val;
q = data;
put16(&q, ts->onid);
*q++ = 0xff;
for (i = 0; i < ts->nb_services; i++) {
service = ts->services[i];
put16(&q, service->sid);
*q++ = 0xfc | 0x00; /* currently no EIT info */
desc_list_len_ptr = q;
q += 2;
running_status = 4; /* running */
free_ca_mode = 0;
/* write only one descriptor for the service name and provider */
*q++ = 0x48;
desc_len_ptr = q;
q++;
*q++ = 0x01; /* digital television service */
putstr8(&q, service->provider_name);
putstr8(&q, service->name);
desc_len_ptr[0] = q - desc_len_ptr - 1;
/* fill descriptor length */
val = (running_status << 13) | (free_ca_mode << 12) |
(q - desc_list_len_ptr - 2);
desc_list_len_ptr[0] = val >> 8;
desc_list_len_ptr[1] = val;
}
mpegts_write_section1(&ts->sdt, SDT_TID, ts->tsid, 0, 0, 0,
data, q - data);
}
static MpegTSService *mpegts_add_service(MpegTSWrite *ts, int sid,
const char *provider_name,
const char *name)
{
MpegTSService *service;
service = av_mallocz(sizeof(MpegTSService));
if (!service)
return NULL;
service->pmt.pid = ts->pmt_start_pid + ts->nb_services;
service->sid = sid;
service->pcr_pid = 0x1fff;
service->provider_name = av_strdup(provider_name);
service->name = av_strdup(name);
if (!service->provider_name || !service->name) {
av_free(service->provider_name);
av_free(service->name);
av_free(service);
return NULL;
}
dynarray_add(&ts->services, &ts->nb_services, service);
return service;
}
static int64_t get_pcr(const MpegTSWrite *ts, AVIOContext *pb)
{
return av_rescale(avio_tell(pb) + 11, 8 * PCR_TIME_BASE, ts->mux_rate) +
ts->first_pcr;
}
static void mpegts_prefix_m2ts_header(AVFormatContext *s)
{
MpegTSWrite *ts = s->priv_data;
if (ts->m2ts_mode) {
int64_t pcr = get_pcr(s->priv_data, s->pb);
uint32_t tp_extra_header = pcr % 0x3fffffff;
tp_extra_header = AV_RB32(&tp_extra_header);
avio_write(s->pb, (unsigned char *) &tp_extra_header,
sizeof(tp_extra_header));
}
}
static void section_write_packet(MpegTSSection *s, const uint8_t *packet)
{
AVFormatContext *ctx = s->opaque;
mpegts_prefix_m2ts_header(ctx);
avio_write(ctx->pb, packet, TS_PACKET_SIZE);
}
static int mpegts_write_header(AVFormatContext *s)
{
MpegTSWrite *ts = s->priv_data;
MpegTSWriteStream *ts_st;
MpegTSService *service;
AVStream *st, *pcr_st = NULL;
AVDictionaryEntry *title, *provider;
int i, j;
const char *service_name;
const char *provider_name;
int *pids;
int ret;
if (s->max_delay < 0) /* Not set by the caller */
s->max_delay = 0;
// round up to a whole number of TS packets
ts->pes_payload_size = (ts->pes_payload_size + 14 + 183) / 184 * 184 - 14;
ts->tsid = ts->transport_stream_id;
ts->onid = ts->original_network_id;
/* allocate a single DVB service */
title = av_dict_get(s->metadata, "service_name", NULL, 0);
if (!title)
title = av_dict_get(s->metadata, "title", NULL, 0);
service_name = title ? title->value : DEFAULT_SERVICE_NAME;
provider = av_dict_get(s->metadata, "service_provider", NULL, 0);
provider_name = provider ? provider->value : DEFAULT_PROVIDER_NAME;
service = mpegts_add_service(ts, ts->service_id,
provider_name, service_name);
if (!service)
return AVERROR(ENOMEM);
service->pmt.write_packet = section_write_packet;
service->pmt.opaque = s;
service->pmt.cc = 15;
ts->pat.pid = PAT_PID;
/* Initialize at 15 so that it wraps and is equal to 0 for the
* first packet we write. */
ts->pat.cc = 15;
ts->pat.write_packet = section_write_packet;
ts->pat.opaque = s;
ts->sdt.pid = SDT_PID;
ts->sdt.cc = 15;
ts->sdt.write_packet = section_write_packet;
ts->sdt.opaque = s;
pids = av_malloc(s->nb_streams * sizeof(*pids));
if (!pids) {
av_free(service);
return AVERROR(ENOMEM);
}
/* assign pids to each stream */
for (i = 0; i < s->nb_streams; i++) {
st = s->streams[i];
ts_st = av_mallocz(sizeof(MpegTSWriteStream));
if (!ts_st) {
ret = AVERROR(ENOMEM);
goto fail;
}
st->priv_data = ts_st;
ts_st->user_tb = st->time_base;
avpriv_set_pts_info(st, 33, 1, 90000);
ts_st->payload = av_mallocz(ts->pes_payload_size);
if (!ts_st->payload) {
ret = AVERROR(ENOMEM);
goto fail;
}
ts_st->service = service;
/* MPEG pid values < 16 are reserved. Applications which set st->id in
* this range are assigned a calculated pid. */
if (st->id < 16) {
ts_st->pid = ts->start_pid + i;
} else if (st->id < 0x1FFF) {
ts_st->pid = st->id;
} else {
av_log(s, AV_LOG_ERROR,
"Invalid stream id %d, must be less than 8191\n", st->id);
ret = AVERROR(EINVAL);
goto fail;
}
if (ts_st->pid == service->pmt.pid) {
av_log(s, AV_LOG_ERROR, "Duplicate stream id %d\n", ts_st->pid);
ret = AVERROR(EINVAL);
goto fail;
}
for (j = 0; j < i; j++) {
if (pids[j] == ts_st->pid) {
av_log(s, AV_LOG_ERROR, "Duplicate stream id %d\n", ts_st->pid);
ret = AVERROR(EINVAL);
goto fail;
}
}
pids[i] = ts_st->pid;
ts_st->payload_pts = AV_NOPTS_VALUE;
ts_st->payload_dts = AV_NOPTS_VALUE;
ts_st->first_pts_check = 1;
ts_st->cc = 15;
/* update PCR pid by using the first video stream */
if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO &&
service->pcr_pid == 0x1fff) {
service->pcr_pid = ts_st->pid;
pcr_st = st;
}
if (st->codecpar->codec_id == AV_CODEC_ID_AAC &&
st->codecpar->extradata_size > 0) {
AVStream *ast;
ts_st->amux = avformat_alloc_context();
if (!ts_st->amux) {
ret = AVERROR(ENOMEM);
goto fail;
}
ts_st->amux->oformat =
av_guess_format((ts->flags & MPEGTS_FLAG_AAC_LATM) ? "latm" : "adts",
NULL, NULL);
if (!ts_st->amux->oformat) {
ret = AVERROR(EINVAL);
goto fail;
}
if (!(ast = avformat_new_stream(ts_st->amux, NULL))) {
ret = AVERROR(ENOMEM);
goto fail;
}
ret = avcodec_parameters_copy(ast->codecpar, st->codecpar);
if (ret != 0)
goto fail;
ast->time_base = st->time_base;
ret = avformat_write_header(ts_st->amux, NULL);
if (ret < 0)
goto fail;
}
}
av_free(pids);
/* if no video stream, use the first stream as PCR */
if (service->pcr_pid == 0x1fff && s->nb_streams > 0) {
pcr_st = s->streams[0];
ts_st = pcr_st->priv_data;
service->pcr_pid = ts_st->pid;
} else
ts_st = pcr_st->priv_data;
if (ts->mux_rate > 1) {
service->pcr_packet_period = (ts->mux_rate * ts->pcr_period) /
(TS_PACKET_SIZE * 8 * 1000);
ts->sdt_packet_period = (ts->mux_rate * SDT_RETRANS_TIME) /
(TS_PACKET_SIZE * 8 * 1000);
ts->pat_packet_period = (ts->mux_rate * PAT_RETRANS_TIME) /
(TS_PACKET_SIZE * 8 * 1000);
ts->first_pcr = av_rescale(s->max_delay, PCR_TIME_BASE, AV_TIME_BASE);
} else {
/* Arbitrary values, PAT/PMT could be written on key frames */
ts->sdt_packet_period = 200;
ts->pat_packet_period = 40;
if (pcr_st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO) {
int frame_size = av_get_audio_frame_duration2(pcr_st->codecpar, 0);
if (!frame_size) {
av_log(s, AV_LOG_WARNING, "frame size not set\n");
service->pcr_packet_period =
pcr_st->codecpar->sample_rate / (10 * 512);
} else {
service->pcr_packet_period =
pcr_st->codecpar->sample_rate / (10 * frame_size);
}
} else {
// max delta PCR 0.1s
// TODO: should be avg_frame_rate
service->pcr_packet_period =
ts_st->user_tb.den / (10 * ts_st->user_tb.num);
}
}
// output a PCR as soon as possible
service->pcr_packet_count = service->pcr_packet_period;
ts->pat_packet_count = ts->pat_packet_period - 1;
ts->sdt_packet_count = ts->sdt_packet_period - 1;
if (ts->mux_rate == 1)
av_log(s, AV_LOG_VERBOSE, "muxrate VBR, ");
else
av_log(s, AV_LOG_VERBOSE, "muxrate %d, ", ts->mux_rate);
av_log(s, AV_LOG_VERBOSE,
"pcr every %d pkts, sdt every %d, pat/pmt every %d pkts\n",
service->pcr_packet_period,
ts->sdt_packet_period, ts->pat_packet_period);
if (ts->m2ts_mode == -1) {
if (av_match_ext(s->filename, "m2ts")) {
ts->m2ts_mode = 1;
} else {
ts->m2ts_mode = 0;
}
}
avio_flush(s->pb);
return 0;
fail:
av_free(service);
av_free(pids);
for (i = 0; i < s->nb_streams; i++) {
st = s->streams[i];
ts_st = st->priv_data;
if (ts_st) {
av_freep(&ts_st->payload);
if (ts_st->amux) {
avformat_free_context(ts_st->amux);
ts_st->amux = NULL;
}
}
av_freep(&st->priv_data);
}
return ret;
}
/* send SDT, PAT and PMT tables regularly */
static void retransmit_si_info(AVFormatContext *s)
{
MpegTSWrite *ts = s->priv_data;
int i;
if (++ts->sdt_packet_count == ts->sdt_packet_period) {
ts->sdt_packet_count = 0;
mpegts_write_sdt(s);
}
if (++ts->pat_packet_count == ts->pat_packet_period) {
ts->pat_packet_count = 0;
mpegts_write_pat(s);
for (i = 0; i < ts->nb_services; i++)
mpegts_write_pmt(s, ts->services[i]);
}
}
static int write_pcr_bits(uint8_t *buf, int64_t pcr)
{
int64_t pcr_low = pcr % 300, pcr_high = pcr / 300;
*buf++ = pcr_high >> 25;
*buf++ = pcr_high >> 17;
*buf++ = pcr_high >> 9;
*buf++ = pcr_high >> 1;
*buf++ = pcr_high << 7 | pcr_low >> 8 | 0x7e;
*buf++ = pcr_low;
return 6;
}
/* Write a single null transport stream packet */
static void mpegts_insert_null_packet(AVFormatContext *s)
{
uint8_t *q;
uint8_t buf[TS_PACKET_SIZE];
q = buf;
*q++ = 0x47;
*q++ = 0x00 | 0x1f;
*q++ = 0xff;
*q++ = 0x10;
memset(q, 0x0FF, TS_PACKET_SIZE - (q - buf));
mpegts_prefix_m2ts_header(s);
avio_write(s->pb, buf, TS_PACKET_SIZE);
}
/* Write a single transport stream packet with a PCR and no payload */
static void mpegts_insert_pcr_only(AVFormatContext *s, AVStream *st)
{
MpegTSWrite *ts = s->priv_data;
MpegTSWriteStream *ts_st = st->priv_data;
uint8_t *q;
uint8_t buf[TS_PACKET_SIZE];
q = buf;
*q++ = 0x47;
*q++ = ts_st->pid >> 8;
*q++ = ts_st->pid;
*q++ = 0x20 | ts_st->cc; /* Adaptation only */
/* Continuity Count field does not increment (see 13818-1 section 2.4.3.3) */
*q++ = TS_PACKET_SIZE - 5; /* Adaptation Field Length */
*q++ = 0x10; /* Adaptation flags: PCR present */
/* PCR coded into 6 bytes */
q += write_pcr_bits(q, get_pcr(ts, s->pb));
/* stuffing bytes */
memset(q, 0xFF, TS_PACKET_SIZE - (q - buf));
mpegts_prefix_m2ts_header(s);
avio_write(s->pb, buf, TS_PACKET_SIZE);
}
static void write_pts(uint8_t *q, int fourbits, int64_t pts)
{
int val;
val = fourbits << 4 | (((pts >> 30) & 0x07) << 1) | 1;
*q++ = val;
val = (((pts >> 15) & 0x7fff) << 1) | 1;
*q++ = val >> 8;
*q++ = val;
val = (((pts) & 0x7fff) << 1) | 1;
*q++ = val >> 8;
*q++ = val;
}
/* Set an adaptation field flag in an MPEG-TS packet*/
static void set_af_flag(uint8_t *pkt, int flag)
{
// expect at least one flag to set
assert(flag);
if ((pkt[3] & 0x20) == 0) {
// no AF yet, set adaptation field flag
pkt[3] |= 0x20;
// 1 byte length, no flags
pkt[4] = 1;
pkt[5] = 0;
}
pkt[5] |= flag;
}
/* Extend the adaptation field by size bytes */
static void extend_af(uint8_t *pkt, int size)
{
// expect already existing adaptation field
assert(pkt[3] & 0x20);
pkt[4] += size;
}
/* Get a pointer to MPEG-TS payload (right after TS packet header) */
static uint8_t *get_ts_payload_start(uint8_t *pkt)
{
if (pkt[3] & 0x20)
return pkt + 5 + pkt[4];
else
return pkt + 4;
}
/* Add a PES header to the front of the payload, and segment into an integer
* number of TS packets. The final TS packet is padded using an oversized
* adaptation header to exactly fill the last TS packet.
* NOTE: 'payload' contains a complete PES payload. */
static void mpegts_write_pes(AVFormatContext *s, AVStream *st,
const uint8_t *payload, int payload_size,
int64_t pts, int64_t dts, int key)
{
MpegTSWriteStream *ts_st = st->priv_data;
MpegTSWrite *ts = s->priv_data;
uint8_t buf[TS_PACKET_SIZE];
uint8_t *q;
int val, is_start, len, header_len, write_pcr, private_code, flags;
int afc_len, stuffing_len;
int64_t pcr = -1; /* avoid warning */
int64_t delay = av_rescale(s->max_delay, 90000, AV_TIME_BASE);
is_start = 1;
while (payload_size > 0) {
retransmit_si_info(s);
write_pcr = 0;
if (ts_st->pid == ts_st->service->pcr_pid) {
if (ts->mux_rate > 1 || is_start) // VBR pcr period is based on frames
ts_st->service->pcr_packet_count++;
if (ts_st->service->pcr_packet_count >=
ts_st->service->pcr_packet_period) {
ts_st->service->pcr_packet_count = 0;
write_pcr = 1;
}
}
if (ts->mux_rate > 1 && dts != AV_NOPTS_VALUE &&
(dts - get_pcr(ts, s->pb) / 300) > delay) {
/* pcr insert gets priority over null packet insert */
if (write_pcr)
mpegts_insert_pcr_only(s, st);
else
mpegts_insert_null_packet(s);
/* recalculate write_pcr and possibly retransmit si_info */
continue;
}
/* prepare packet header */
q = buf;
*q++ = 0x47;
val = ts_st->pid >> 8;
if (is_start)
val |= 0x40;
*q++ = val;
*q++ = ts_st->pid;
ts_st->cc = ts_st->cc + 1 & 0xf;
*q++ = 0x10 | ts_st->cc; // payload indicator + CC
if (key && is_start && pts != AV_NOPTS_VALUE) {
// set Random Access for key frames
if (ts_st->pid == ts_st->service->pcr_pid)
write_pcr = 1;
set_af_flag(buf, 0x40);
q = get_ts_payload_start(buf);
}
if (write_pcr) {
set_af_flag(buf, 0x10);
q = get_ts_payload_start(buf);
// add 11, pcr references the last byte of program clock reference base
if (ts->mux_rate > 1)
pcr = get_pcr(ts, s->pb);
else
pcr = (dts - delay) * 300;
if (dts != AV_NOPTS_VALUE && dts < pcr / 300)
av_log(s, AV_LOG_WARNING, "dts < pcr, TS is invalid\n");
extend_af(buf, write_pcr_bits(q, pcr));
q = get_ts_payload_start(buf);
}
if (is_start) {
int pes_extension = 0;
/* write PES header */
*q++ = 0x00;
*q++ = 0x00;
*q++ = 0x01;
private_code = 0;
if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
if (st->codecpar->codec_id == AV_CODEC_ID_DIRAC)
*q++ = 0xfd;
else
*q++ = 0xe0;
} else if (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO &&
(st->codecpar->codec_id == AV_CODEC_ID_MP2 ||
st->codecpar->codec_id == AV_CODEC_ID_MP3 ||
st->codecpar->codec_id == AV_CODEC_ID_AAC)) {
*q++ = 0xc0;
} else {
*q++ = 0xbd;
if (st->codecpar->codec_type == AVMEDIA_TYPE_SUBTITLE)
private_code = 0x20;
}
header_len = 0;
flags = 0;
if (pts != AV_NOPTS_VALUE) {
header_len += 5;
flags |= 0x80;
}
if (dts != AV_NOPTS_VALUE && pts != AV_NOPTS_VALUE && dts != pts) {
header_len += 5;
flags |= 0x40;
}
if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO &&
st->codecpar->codec_id == AV_CODEC_ID_DIRAC) {
/* set PES_extension_flag */
pes_extension = 1;
flags |= 0x01;
/* One byte for PES2 extension flag +
* one byte for extension length +
* one byte for extension id */
header_len += 3;
}
len = payload_size + header_len + 3;
if (private_code != 0)
len++;
if (len > 0xffff)
len = 0;
*q++ = len >> 8;
*q++ = len;
val = 0x80;
/* data alignment indicator is required for subtitle data */
if (st->codecpar->codec_type == AVMEDIA_TYPE_SUBTITLE)
val |= 0x04;
*q++ = val;
*q++ = flags;
*q++ = header_len;
if (pts != AV_NOPTS_VALUE) {
write_pts(q, flags >> 6, pts);
q += 5;
}
if (dts != AV_NOPTS_VALUE && pts != AV_NOPTS_VALUE && dts != pts) {
write_pts(q, 1, dts);
q += 5;
}
if (pes_extension && st->codecpar->codec_id == AV_CODEC_ID_DIRAC) {
flags = 0x01; /* set PES_extension_flag_2 */
*q++ = flags;
*q++ = 0x80 | 0x01; /* marker bit + extension length */
/* Set the stream ID extension flag bit to 0 and
* write the extended stream ID. */
*q++ = 0x00 | 0x60;
}
if (private_code != 0)
*q++ = private_code;
is_start = 0;
}
/* header size */
header_len = q - buf;
/* data len */
len = TS_PACKET_SIZE - header_len;
if (len > payload_size)
len = payload_size;
stuffing_len = TS_PACKET_SIZE - header_len - len;
if (stuffing_len > 0) {
/* add stuffing with AFC */
if (buf[3] & 0x20) {
/* stuffing already present: increase its size */
afc_len = buf[4] + 1;
memmove(buf + 4 + afc_len + stuffing_len,
buf + 4 + afc_len,
header_len - (4 + afc_len));
buf[4] += stuffing_len;
memset(buf + 4 + afc_len, 0xff, stuffing_len);
} else {
/* add stuffing */
memmove(buf + 4 + stuffing_len, buf + 4, header_len - 4);
buf[3] |= 0x20;
buf[4] = stuffing_len - 1;
if (stuffing_len >= 2) {
buf[5] = 0x00;
memset(buf + 6, 0xff, stuffing_len - 2);
}
}
}
memcpy(buf + TS_PACKET_SIZE - len, payload, len);
payload += len;
payload_size -= len;
mpegts_prefix_m2ts_header(s);
avio_write(s->pb, buf, TS_PACKET_SIZE);
}
avio_flush(s->pb);
}
static int mpegts_write_packet_internal(AVFormatContext *s, AVPacket *pkt)
{
AVStream *st = s->streams[pkt->stream_index];
int size = pkt->size;
uint8_t *buf = pkt->data;
uint8_t *data = NULL;
MpegTSWrite *ts = s->priv_data;
MpegTSWriteStream *ts_st = st->priv_data;
const uint64_t delay = av_rescale(s->max_delay, 90000, AV_TIME_BASE) * 2;
int64_t dts = AV_NOPTS_VALUE, pts = AV_NOPTS_VALUE;
if (ts->reemit_pat_pmt) {
av_log(s, AV_LOG_WARNING,
"resend_headers option is deprecated, use -mpegts_flags resend_headers\n");
ts->reemit_pat_pmt = 0;
ts->flags |= MPEGTS_FLAG_REEMIT_PAT_PMT;
}
if (ts->flags & MPEGTS_FLAG_REEMIT_PAT_PMT) {
ts->pat_packet_count = ts->pat_packet_period - 1;
ts->sdt_packet_count = ts->sdt_packet_period - 1;
ts->flags &= ~MPEGTS_FLAG_REEMIT_PAT_PMT;
}
if (pkt->pts != AV_NOPTS_VALUE)
pts = pkt->pts + delay;
if (pkt->dts != AV_NOPTS_VALUE)
dts = pkt->dts + delay;
if (ts_st->first_pts_check && pts == AV_NOPTS_VALUE) {
av_log(s, AV_LOG_ERROR, "first pts value must set\n");
return AVERROR_INVALIDDATA;
}
ts_st->first_pts_check = 0;
if (st->codecpar->codec_id == AV_CODEC_ID_H264) {
const uint8_t *p = buf, *buf_end = p + size;
uint32_t state = -1;
if (pkt->size < 5 || AV_RB32(pkt->data) != 0x0000001) {
av_log(s, AV_LOG_ERROR, "H.264 bitstream malformed, "
"no startcode found, use -bsf h264_mp4toannexb\n");
return AVERROR_INVALIDDATA;
}
do {
p = avpriv_find_start_code(p, buf_end, &state);
av_log(s, AV_LOG_TRACE, "nal %d\n", state & 0x1f);
} while (p < buf_end && (state & 0x1f) != 9 &&
(state & 0x1f) != 5 && (state & 0x1f) != 1);
if ((state & 0x1f) != 9) { // AUD NAL
data = av_malloc(pkt->size + 6);
if (!data)
return AVERROR(ENOMEM);
memcpy(data + 6, pkt->data, pkt->size);
AV_WB32(data, 0x00000001);
data[4] = 0x09;
data[5] = 0xf0; // any slice type (0xe) + rbsp stop one bit
buf = data;
size = pkt->size + 6;
}
} else if (st->codecpar->codec_id == AV_CODEC_ID_AAC) {
if (pkt->size < 2) {
av_log(s, AV_LOG_ERROR, "AAC packet too short\n");
return AVERROR_INVALIDDATA;
}
if ((AV_RB16(pkt->data) & 0xfff0) != 0xfff0) {
int ret;
AVPacket pkt2;
if (!ts_st->amux) {
av_log(s, AV_LOG_ERROR, "AAC bitstream not in ADTS format "
"and extradata missing\n");
return AVERROR_INVALIDDATA;
}
av_init_packet(&pkt2);
pkt2.data = pkt->data;
pkt2.size = pkt->size;
ret = avio_open_dyn_buf(&ts_st->amux->pb);
if (ret < 0)
return AVERROR(ENOMEM);
ret = av_write_frame(ts_st->amux, &pkt2);
if (ret < 0) {
ffio_free_dyn_buf(&ts_st->amux->pb);
return ret;
}
size = avio_close_dyn_buf(ts_st->amux->pb, &data);
ts_st->amux->pb = NULL;
buf = data;
}
}
if (st->codecpar->codec_type != AVMEDIA_TYPE_AUDIO) {
// for video and subtitle, write a single pes packet
mpegts_write_pes(s, st, buf, size, pts, dts,
pkt->flags & AV_PKT_FLAG_KEY);
av_free(data);
return 0;
}
if (ts_st->payload_size + size > ts->pes_payload_size ||
(dts != AV_NOPTS_VALUE && ts_st->payload_dts != AV_NOPTS_VALUE &&
av_compare_ts(dts - ts_st->payload_dts, st->time_base,
s->max_delay, AV_TIME_BASE_Q) >= 0)) {
if (ts_st->payload_size) {
mpegts_write_pes(s, st, ts_st->payload, ts_st->payload_size,
ts_st->payload_pts, ts_st->payload_dts,
ts_st->payload_flags & AV_PKT_FLAG_KEY);
ts_st->payload_size = 0;
}
if (size > ts->pes_payload_size) {
mpegts_write_pes(s, st, buf, size, pts, dts,
pkt->flags & AV_PKT_FLAG_KEY);
av_free(data);
return 0;
}
}
if (!ts_st->payload_size) {
ts_st->payload_pts = pts;
ts_st->payload_dts = dts;
ts_st->payload_flags = pkt->flags;
}
memcpy(ts_st->payload + ts_st->payload_size, buf, size);
ts_st->payload_size += size;
av_free(data);
return 0;
}
static void mpegts_write_flush(AVFormatContext *s)
{
int i;
/* flush current packets */
for (i = 0; i < s->nb_streams; i++) {
AVStream *st = s->streams[i];
MpegTSWriteStream *ts_st = st->priv_data;
if (ts_st->payload_size > 0) {
mpegts_write_pes(s, st, ts_st->payload, ts_st->payload_size,
ts_st->payload_pts, ts_st->payload_dts,
ts_st->payload_flags & AV_PKT_FLAG_KEY);
ts_st->payload_size = 0;
}
}
avio_flush(s->pb);
}
static int mpegts_write_packet(AVFormatContext *s, AVPacket *pkt)
{
if (!pkt) {
mpegts_write_flush(s);
return 1;
} else {
return mpegts_write_packet_internal(s, pkt);
}
}
static int mpegts_write_end(AVFormatContext *s)
{
MpegTSWrite *ts = s->priv_data;
MpegTSService *service;
int i;
if (s->pb)
mpegts_write_flush(s);
for (i = 0; i < s->nb_streams; i++) {
AVStream *st = s->streams[i];
MpegTSWriteStream *ts_st = st->priv_data;
av_freep(&ts_st->payload);
if (ts_st->amux) {
avformat_free_context(ts_st->amux);
ts_st->amux = NULL;
}
}
for (i = 0; i < ts->nb_services; i++) {
service = ts->services[i];
av_freep(&service->provider_name);
av_freep(&service->name);
av_free(service);
}
av_free(ts->services);
return 0;
}
static const AVOption options[] = {
{ "mpegts_transport_stream_id", "Set transport_stream_id field.",
offsetof(MpegTSWrite, transport_stream_id), AV_OPT_TYPE_INT,
{ .i64 = 0x0001 }, 0x0001, 0xffff, AV_OPT_FLAG_ENCODING_PARAM },
{ "mpegts_original_network_id", "Set original_network_id field.",
offsetof(MpegTSWrite, original_network_id), AV_OPT_TYPE_INT,
{ .i64 = DVB_PRIVATE_NETWORK_START }, 0x0001, 0xffff, AV_OPT_FLAG_ENCODING_PARAM },
{ "mpegts_service_id", "Set service_id field.",
offsetof(MpegTSWrite, service_id), AV_OPT_TYPE_INT,
{ .i64 = 0x0001 }, 0x0001, 0xffff, AV_OPT_FLAG_ENCODING_PARAM },
{ "mpegts_pmt_start_pid", "Set the first pid of the PMT.",
offsetof(MpegTSWrite, pmt_start_pid), AV_OPT_TYPE_INT,
{ .i64 = 0x1000 }, 0x1000, 0x1f00, AV_OPT_FLAG_ENCODING_PARAM },
{ "mpegts_start_pid", "Set the first pid.",
offsetof(MpegTSWrite, start_pid), AV_OPT_TYPE_INT,
{ .i64 = 0x0100 }, 0x0100, 0x0f00, AV_OPT_FLAG_ENCODING_PARAM },
{"mpegts_m2ts_mode", "Enable m2ts mode.",
offsetof(MpegTSWrite, m2ts_mode), AV_OPT_TYPE_INT,
{ .i64 = -1 }, -1, 1, AV_OPT_FLAG_ENCODING_PARAM},
{ "muxrate", NULL,
offsetof(MpegTSWrite, mux_rate), AV_OPT_TYPE_INT,
{ .i64 = 1 }, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
{ "pes_payload_size", "Minimum PES packet payload in bytes",
offsetof(MpegTSWrite, pes_payload_size), AV_OPT_TYPE_INT,
{ .i64 = DEFAULT_PES_PAYLOAD_SIZE }, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
{ "mpegts_flags", "MPEG-TS muxing flags",
offsetof(MpegTSWrite, flags), AV_OPT_TYPE_FLAGS, { .i64 = 0 }, 0, INT_MAX,
AV_OPT_FLAG_ENCODING_PARAM, "mpegts_flags" },
{ "resend_headers", "Reemit PAT/PMT before writing the next packet",
0, AV_OPT_TYPE_CONST, { .i64 = MPEGTS_FLAG_REEMIT_PAT_PMT }, 0, INT_MAX,
AV_OPT_FLAG_ENCODING_PARAM, "mpegts_flags" },
{ "latm", "Use LATM packetization for AAC",
0, AV_OPT_TYPE_CONST, { .i64 = MPEGTS_FLAG_AAC_LATM }, 0, INT_MAX,
AV_OPT_FLAG_ENCODING_PARAM, "mpegts_flags" },
{ "system_b", "Conform to System B (DVB) instead of System A (ATSC)",
0, AV_OPT_TYPE_CONST, { .i64 = MPEGTS_FLAG_SYSTEM_B }, 0, INT_MAX,
AV_OPT_FLAG_ENCODING_PARAM, "mpegts_flags" },
// backward compatibility
{ "resend_headers", "Reemit PAT/PMT before writing the next packet",
offsetof(MpegTSWrite, reemit_pat_pmt), AV_OPT_TYPE_INT,
{ .i64 = 0 }, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
{ "pcr_period", "PCR retransmission time",
offsetof(MpegTSWrite, pcr_period), AV_OPT_TYPE_INT,
{ .i64 = PCR_RETRANS_TIME }, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
{ NULL },
};
static const AVClass mpegts_muxer_class = {
.class_name = "MPEGTS muxer",
.item_name = av_default_item_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
AVOutputFormat ff_mpegts_muxer = {
.name = "mpegts",
.long_name = NULL_IF_CONFIG_SMALL("MPEG-TS (MPEG-2 Transport Stream)"),
.mime_type = "video/MP2T",
.extensions = "ts,m2t,m2ts,mts",
.priv_data_size = sizeof(MpegTSWrite),
.audio_codec = AV_CODEC_ID_MP2,
.video_codec = AV_CODEC_ID_MPEG2VIDEO,
.write_header = mpegts_write_header,
.write_packet = mpegts_write_packet,
.write_trailer = mpegts_write_end,
.flags = AVFMT_ALLOW_FLUSH | AVFMT_VARIABLE_FPS,
.priv_class = &mpegts_muxer_class,
};
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