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FFmpeg/libavformat/mpegtsenc.c
Anton Khirnov 9200514ad8 lavf: replace AVStream.codec with AVStream.codecpar 
Currently, AVStream contains an embedded AVCodecContext instance, which
is used by demuxers to export stream parameters to the caller and by
muxers to receive stream parameters from the caller. It is also used
internally as the codec context that is passed to parsers.

In addition, it is also widely used by the callers as the decoding (when
demuxer) or encoding (when muxing) context, though this has been
officially discouraged since Libav 11.

There are multiple important problems with this approach:
    - the fields in AVCodecContext are in general one of
        * stream parameters
        * codec options
        * codec state
      However, it's not clear which ones are which. It is consequently
      unclear which fields are a demuxer allowed to set or a muxer allowed to
      read. This leads to erratic behaviour depending on whether decoding or
      encoding is being performed or not (and whether it uses the AVStream
      embedded codec context).
    - various synchronization issues arising from the fact that the same
      context is used by several different APIs (muxers/demuxers,
      parsers, bitstream filters and encoders/decoders) simultaneously, with
      there being no clear rules for who can modify what and the different
      processes being typically delayed with respect to each other.
    - avformat_find_stream_info() making it necessary to support opening
      and closing a single codec context multiple times, thus
      complicating the semantics of freeing various allocated objects in the
      codec context.

Those problems are resolved by replacing the AVStream embedded codec
context with a newly added AVCodecParameters instance, which stores only
the stream parameters exported by the demuxers or read by the muxers.
2016-02-23 17:01:58 +01:00

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/*
* MPEG2 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 */
/*********************************************/
/* 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; /* MPEG2 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; /* MPEG2 pat table */
MpegTSSection sdt; /* MPEG2 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 regulary */
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 = 0x0001 }, 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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