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avformat/mpegtsenc: add NIT support

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With some minor changes by Marton Balint:
 - removed trailing whitespace
 - fixed network_descriptors_length
 - fixed reserved_future_use flag in the start of the section
 - removed unused program variable
 - emit first NIT after PAT
 - some other cosmetics

Signed-off-by: Ubaldo Porcheddu <ubaldo@eja.it>
Signed-off-by: Marton Balint <cus@passwd.hu>
This commit is contained in:
Ubaldo Porcheddu 2021-05-18 13:56:00 +02:00 • committed by Marton Balint
parent f597041d57
commit 36b16a30db
3 changed files with 104 additions and 9 deletions
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7
doc/muxers.texi
View file

@ -1876,6 +1876,8 @@ Reemit PAT and PMT at each video frame.
Conform to System B (DVB) instead of System A (ATSC).
@item initial_discontinuity
Mark the initial packet of each stream as discontinuity.
@item nit
Emit NIT table.
@end table
@item mpegts_copyts @var{boolean}
@ -1897,8 +1899,11 @@ Maximum time in seconds between PAT/PMT tables. Default is @code{0.1}.
@item sdt_period @var{duration}
Maximum time in seconds between SDT tables. Default is @code{0.5}.
@item nit_period @var{duration}
Maximum time in seconds between NIT tables. Default is @code{0.5}.
@item tables_version @var{integer}
Set PAT, PMT and SDT version (default @code{0}, valid values are from 0 to 31, inclusively).
Set PAT, PMT, SDT and NIT version (default @code{0}, valid values are from 0 to 31, inclusively).
This option allows updating stream structure so that standard consumer may
detect the change. To do so, reopen output @code{AVFormatContext} (in case of API
usage) or restart @command{ffmpeg} instance, cyclically changing

104
libavformat/mpegtsenc.c
View file

@ -76,10 +76,12 @@ typedef struct MpegTSWrite {
const AVClass *av_class;
MpegTSSection pat; /* MPEG-2 PAT table */
MpegTSSection sdt; /* MPEG-2 SDT table context */
MpegTSSection nit; /* MPEG-2 NIT table context */
MpegTSService **services;
AVPacket *pkt;
int64_t sdt_period; /* SDT period in PCR time base */
int64_t pat_period; /* PAT/PMT period in PCR time base */
int64_t nit_period; /* NIT period in PCR time base */
int nb_services;
int64_t first_pcr;
int first_dts_checked;
@ -107,13 +109,18 @@ typedef struct MpegTSWrite {
#define MPEGTS_FLAG_PAT_PMT_AT_FRAMES 0x04
#define MPEGTS_FLAG_SYSTEM_B 0x08
#define MPEGTS_FLAG_DISCONT 0x10
#define MPEGTS_FLAG_NIT 0x20
int flags;
int copyts;
int tables_version;
int64_t pat_period_us;
int64_t sdt_period_us;
int64_t nit_period_us;
int64_t last_pat_ts;
int64_t last_sdt_ts;
int64_t last_nit_ts;
uint8_t provider_name[256];
int omit_video_pes_length;
} MpegTSWrite;
@ -196,8 +203,8 @@ static int mpegts_write_section1(MpegTSSection *s, int tid, int id,
{
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;
/* reserved_future_use field must be set to 1 for SDT and NIT */
unsigned int flags = (tid == SDT_TID || tid == NIT_TID) ? 0xf000 : 0xb000;
tot_len = 3 + 5 + len + 4;
/* check if not too big */
@ -227,6 +234,7 @@ static int mpegts_write_section1(MpegTSSection *s, int tid, int id,
#define SDT_RETRANS_TIME 500
#define PAT_RETRANS_TIME 100
#define PCR_RETRANS_TIME 20
#define NIT_RETRANS_TIME 500
typedef struct MpegTSWriteStream {
int pid; /* stream associated pid */
@ -260,6 +268,10 @@ static void mpegts_write_pat(AVFormatContext *s)
int i;
q = data;
if (ts->flags & MPEGTS_FLAG_NIT) {
put16(&q, 0x0000);
put16(&q, NIT_PID);
}
for (i = 0; i < ts->nb_services; i++) {
service = ts->services[i];
put16(&q, service->sid);
@ -796,6 +808,47 @@ static void mpegts_write_sdt(AVFormatContext *s)
data, q - data);
}
static void mpegts_write_nit(AVFormatContext *s)
{
MpegTSWrite *ts = s->priv_data;
uint8_t data[SECTION_LENGTH], *q, *desc_len_ptr, *loop_len_ptr;
q = data;
//network_descriptors_length
put16(&q, 0xf000 | (ts->provider_name[0] + 2));
//network_name_descriptor
*q++ = 0x40;
putbuf(&q, ts->provider_name, ts->provider_name[0] + 1);
//transport_stream_loop_length
loop_len_ptr = q;
q += 2;
put16(&q, ts->transport_stream_id);
put16(&q, ts->original_network_id);
//transport_descriptors_length
desc_len_ptr = q;
q += 2;
//service_list_descriptor
*q++ = 0x41;
*q++ = 3 * ts->nb_services;
for (int i = 0; i < ts->nb_services; i++) {
put16(&q, ts->services[i]->sid);
*q++ = ts->service_type;
}
//calculate lengths
put16(&desc_len_ptr, 0xf000 | q - (desc_len_ptr + 2));
put16(&loop_len_ptr, 0xf000 | q - (loop_len_ptr + 2));
mpegts_write_section1(&ts->nit, NIT_TID, ts->original_network_id, ts->tables_version, 0, 0,
data, q - data);
}
/* This stores a string in buf with the correct encoding and also sets the
* first byte as the length. !str is accepted for an empty string.
* If the string is already encoded, invalid UTF-8 or has no multibyte sequence
@ -966,6 +1019,8 @@ static void select_pcr_streams(AVFormatContext *s)
static int mpegts_init(AVFormatContext *s)
{
MpegTSWrite *ts = s->priv_data;
AVDictionaryEntry *provider;
const char *provider_name;
int i, j;
int ret;
@ -1022,6 +1077,12 @@ static int mpegts_init(AVFormatContext *s)
ts->sdt.write_packet = section_write_packet;
ts->sdt.opaque = s;
ts->nit.pid = NIT_PID;
ts->nit.cc = 15;
ts->nit.discontinuity= ts->flags & MPEGTS_FLAG_DISCONT;
ts->nit.write_packet = section_write_packet;
ts->nit.opaque = s;
ts->pkt = av_packet_alloc();
if (!ts->pkt)
return AVERROR(ENOMEM);
@ -1143,23 +1204,36 @@ static int mpegts_init(AVFormatContext *s)
ts->last_pat_ts = AV_NOPTS_VALUE;
ts->last_sdt_ts = AV_NOPTS_VALUE;
ts->last_nit_ts = AV_NOPTS_VALUE;
ts->pat_period = av_rescale(ts->pat_period_us, PCR_TIME_BASE, AV_TIME_BASE);
ts->sdt_period = av_rescale(ts->sdt_period_us, PCR_TIME_BASE, AV_TIME_BASE);
ts->nit_period = av_rescale(ts->nit_period_us, PCR_TIME_BASE, AV_TIME_BASE);
/* assign provider name */
provider = av_dict_get(s->metadata, "service_provider", NULL, 0);
provider_name = provider ? provider->value : DEFAULT_PROVIDER_NAME;
if (encode_str8(ts->provider_name, provider_name) < 0) {
av_log(s, AV_LOG_ERROR, "Too long provider name\n");
return AVERROR(EINVAL);
}
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,
"sdt every %"PRId64" ms, pat/pmt every %"PRId64" ms\n",
"sdt every %"PRId64" ms, pat/pmt every %"PRId64" ms",
av_rescale(ts->sdt_period, 1000, PCR_TIME_BASE),
av_rescale(ts->pat_period, 1000, PCR_TIME_BASE));
if (ts->flags & MPEGTS_FLAG_NIT)
av_log(s, AV_LOG_VERBOSE, ", nit every %"PRId64" ms", av_rescale(ts->nit_period, 1000, PCR_TIME_BASE));
av_log(s, AV_LOG_VERBOSE, "\n");
return 0;
}
/* send SDT, PAT and PMT tables regularly */
static void retransmit_si_info(AVFormatContext *s, int force_pat, int force_sdt, int64_t pcr)
/* send SDT, NIT, PAT and PMT tables regularly */
static void retransmit_si_info(AVFormatContext *s, int force_pat, int force_sdt, int force_nit, int64_t pcr)
{
MpegTSWrite *ts = s->priv_data;
int i;
@ -1181,6 +1255,15 @@ static void retransmit_si_info(AVFormatContext *s, int force_pat, int force_sdt,
for (i = 0; i < ts->nb_services; i++)
mpegts_write_pmt(s, ts->services[i]);
}
if ((pcr != AV_NOPTS_VALUE && ts->last_nit_ts == AV_NOPTS_VALUE) ||
(pcr != AV_NOPTS_VALUE && pcr - ts->last_nit_ts >= ts->nit_period) ||
force_nit
) {
if (pcr != AV_NOPTS_VALUE)
ts->last_nit_ts = FFMAX(pcr, ts->last_nit_ts);
if (ts->flags & MPEGTS_FLAG_NIT)
mpegts_write_nit(s);
}
}
static int write_pcr_bits(uint8_t *buf, int64_t pcr)
@ -1337,6 +1420,7 @@ static void mpegts_write_pes(AVFormatContext *s, AVStream *st,
int64_t delay = av_rescale(s->max_delay, 90000, AV_TIME_BASE);
int force_pat = st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO && key && !ts_st->prev_payload_key;
int force_sdt = 0;
int force_nit = 0;
av_assert0(ts_st->payload != buf || st->codecpar->codec_type != AVMEDIA_TYPE_VIDEO);
if (ts->flags & MPEGTS_FLAG_PAT_PMT_AT_FRAMES && st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
@ -1346,6 +1430,7 @@ static void mpegts_write_pes(AVFormatContext *s, AVStream *st,
if (ts->flags & MPEGTS_FLAG_REEMIT_PAT_PMT) {
force_pat = 1;
force_sdt = 1;
force_nit = 1;
ts->flags &= ~MPEGTS_FLAG_REEMIT_PAT_PMT;
}
@ -1357,9 +1442,10 @@ static void mpegts_write_pes(AVFormatContext *s, AVStream *st,
else if (dts != AV_NOPTS_VALUE)
pcr = (dts - delay) * 300;
retransmit_si_info(s, force_pat, force_sdt, pcr);
retransmit_si_info(s, force_pat, force_sdt, force_nit, pcr);
force_pat = 0;
force_sdt = 0;
force_nit = 0;
write_pcr = 0;
if (ts->mux_rate > 1) {
@ -2132,8 +2218,10 @@ static const AVOption options[] = {
0, AV_OPT_TYPE_CONST, { .i64 = MPEGTS_FLAG_SYSTEM_B }, 0, INT_MAX, ENC, "mpegts_flags" },
{ "initial_discontinuity", "Mark initial packets as discontinuous",
0, AV_OPT_TYPE_CONST, { .i64 = MPEGTS_FLAG_DISCONT }, 0, INT_MAX, ENC, "mpegts_flags" },
{ "nit", "Enable NIT transmission",
0, AV_OPT_TYPE_CONST, { .i64 = MPEGTS_FLAG_NIT}, 0, INT_MAX, ENC, "mpegts_flags" },
{ "mpegts_copyts", "don't offset dts/pts", OFFSET(copyts), AV_OPT_TYPE_BOOL, { .i64 = -1 }, -1, 1, ENC },
{ "tables_version", "set PAT, PMT and SDT version", OFFSET(tables_version), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 31, ENC },
{ "tables_version", "set PAT, PMT, SDT and NIT version", OFFSET(tables_version), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 31, ENC },
{ "omit_video_pes_length", "Omit the PES packet length for video packets",
OFFSET(omit_video_pes_length), AV_OPT_TYPE_BOOL, { .i64 = 1 }, 0, 1, ENC },
{ "pcr_period", "PCR retransmission time in milliseconds",
@ -2142,6 +2230,8 @@ static const AVOption options[] = {
OFFSET(pat_period_us), AV_OPT_TYPE_DURATION, { .i64 = PAT_RETRANS_TIME * 1000LL }, 0, INT64_MAX, ENC },
{ "sdt_period", "SDT retransmission time limit in seconds",
OFFSET(sdt_period_us), AV_OPT_TYPE_DURATION, { .i64 = SDT_RETRANS_TIME * 1000LL }, 0, INT64_MAX, ENC },
{ "nit_period", "NIT retransmission time limit in seconds",
OFFSET(nit_period_us), AV_OPT_TYPE_DURATION, { .i64 = NIT_RETRANS_TIME * 1000LL }, 0, INT64_MAX, ENC },
{ NULL },
};

2
libavformat/version.h
View file

@ -33,7 +33,7 @@
// Also please add any ticket numbers that you believe might be affected here
#define LIBAVFORMAT_VERSION_MAJOR 59
#define LIBAVFORMAT_VERSION_MINOR 2
#define LIBAVFORMAT_VERSION_MICRO 100
#define LIBAVFORMAT_VERSION_MICRO 101
#define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
LIBAVFORMAT_VERSION_MINOR, \