From c75bc9c3d6dbacfafd6572c31d0861ffb54c20cc Mon Sep 17 00:00:00 2001 From: Randrianasulu Andrew Date: Thu, 5 May 2022 18:05:45 +0300 Subject: [PATCH 3/4] avformat/mpegtsenc: write SIT instead of SDT for m2ts --- doc/muxers.texi | 3 +- libavformat/mpegtsenc.c | 65 ++++++++++++++++++++++++++++++++++++++--- 2 files changed, 63 insertions(+), 5 deletions(-) diff --git a/doc/muxers.texi b/doc/muxers.texi index 1af603b..575841c 100644 --- a/doc/muxers.texi +++ b/doc/muxers.texi @@ -1924,7 +1924,8 @@ is less than 100 ms is used for VBR streams. 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}. +Maximum time in seconds between SDT tables. Default is @code{0.5}. Regardless +of this setting no SDT is written in m2ts mode. @item nit_period @var{duration} Maximum time in seconds between NIT tables. Default is @code{0.5}. diff --git a/libavformat/mpegtsenc.c b/libavformat/mpegtsenc.c index 30735fc..0af9bc0 100644 --- a/libavformat/mpegtsenc.c +++ b/libavformat/mpegtsenc.c @@ -29,6 +29,7 @@ #include "libavcodec/ac3_parser_internal.h" #include "libavcodec/startcode.h" +#include "libavcodec/put_bits.h" #include "avformat.h" #include "avio_internal.h" @@ -78,6 +79,7 @@ typedef struct MpegTSWrite { const AVClass *av_class; MpegTSSection pat; /* MPEG-2 PAT table */ MpegTSSection sdt; /* MPEG-2 SDT table context */ + MpegTSSection sit; /* MPEG-2 SIT table context */ MpegTSSection nit; /* MPEG-2 NIT table context */ MpegTSService **services; AVPacket *pkt; @@ -206,8 +208,9 @@ 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 and NIT */ - unsigned int flags = (tid == SDT_TID || tid == NIT_TID) ? 0xf000 : 0xb000; + /* reserved_future_use field must be set to 1 for SDT, SIT and NIT */ + unsigned int flags = (tid == SDT_TID || tid == NIT_TID || tid == SIT_TID) ? 0xf000 : 0xb000; + tot_len = 3 + 5 + len + 4; /* check if not too big */ @@ -235,6 +238,7 @@ static int mpegts_write_section1(MpegTSSection *s, int tid, int id, /* we retransmit the SI info at this rate */ #define SDT_RETRANS_TIME 500 +#define SIT_RETRANS_TIME 500 #define PAT_RETRANS_TIME 100 #define PCR_RETRANS_TIME 20 #define NIT_RETRANS_TIME 500 @@ -275,6 +279,10 @@ static void mpegts_write_pat(AVFormatContext *s) put16(&q, 0x0000); put16(&q, NIT_PID); } + if (ts->m2ts_mode) { + put16(&q, 0); + put16(&q, 0xe000 | SIT_PID); + } for (i = 0; i < ts->nb_services; i++) { service = ts->services[i]; put16(&q, service->sid); @@ -832,6 +840,44 @@ static int mpegts_write_pmt(AVFormatContext *s, MpegTSService *service) return 0; } +static void mpegts_write_sit(AVFormatContext *s) +{ + MpegTSWrite *ts = s->priv_data; + uint8_t data[SECTION_LENGTH]; + PutBitContext bs; + + init_put_bits(&bs, data, sizeof(data)); + + put_bits(&bs, 4, 0x0f); // DVB_reserved_for_future_use + + if (ts->m2ts_mode) { + put_bits(&bs, 12, 0x0a); // transmission_info_loop_length + put_bits(&bs, 8, 0x63); // descriptor_tag - partial_transport_stream_descriptor + put_bits(&bs, 8, 0x08); // descriptor_length + put_bits(&bs, 2, 0x03); // DVB_reserved_future_use + put_bits(&bs, 22, ts->mux_rate / 400); // peak_rate + put_bits(&bs, 2, 0x03); // DVB_reserved_future_use + put_bits(&bs, 22, 0x3fffff); // minimum_overall_smoothing_rate + put_bits(&bs, 2, 0x03); // DVB_reserved_future_use + put_bits(&bs, 14, 0x3fff); // maximum_overall_smoothing_buffer + } else { + put_bits(&bs, 12, 0); // transmission_info_loop_length + } + + for (int i = 0; i < ts->nb_services; i++) { + put_bits(&bs, 16, ts->services[i]->sid & 0xffff); // service_id (equivalent to program_number) + put_bits(&bs, 1, 1); // DVB_reserved_future_use + put_bits(&bs, 3, 0); // running_status + put_bits(&bs, 12, 0); // service_loop_length + } + + flush_put_bits(&bs); + + mpegts_write_section1(&ts->sit, SIT_TID, 0xffff, ts->tables_version, 0, 0, + data, put_bits_count(&bs) >> 3); +} + + static void mpegts_write_sdt(AVFormatContext *s) { MpegTSWrite *ts = s->priv_data; @@ -1115,6 +1161,8 @@ static int mpegts_init(AVFormatContext *s) } av_log(s, AV_LOG_INFO, "Muxrate is not set for m2ts mode, using %d bps\n", ts->mux_rate); } + // this is used for sit period in m2ts mode + ts->sdt_period_us = SIT_RETRANS_TIME * 1000LL; } if (s->max_delay < 0) /* Not set by the caller */ @@ -1149,6 +1197,12 @@ static int mpegts_init(AVFormatContext *s) ts->sdt.write_packet = section_write_packet; ts->sdt.opaque = s; + ts->sit.pid = SIT_PID; + ts->sit.cc = 15; + ts->sit.discontinuity= ts->flags & MPEGTS_FLAG_DISCONT; + ts->sit.write_packet = section_write_packet; + ts->sit.opaque = s; + ts->nit.pid = NIT_PID; ts->nit.cc = 15; ts->nit.discontinuity= ts->flags & MPEGTS_FLAG_DISCONT; @@ -1314,7 +1368,10 @@ static void retransmit_si_info(AVFormatContext *s, int force_pat, int force_sdt, ) { if (pcr != AV_NOPTS_VALUE) ts->last_sdt_ts = FFMAX(pcr, ts->last_sdt_ts); - mpegts_write_sdt(s); + if (!ts->m2ts_mode) + mpegts_write_sdt(s); + else + mpegts_write_sit(s); } if ((pcr != AV_NOPTS_VALUE && ts->last_pat_ts == AV_NOPTS_VALUE) || (pcr != AV_NOPTS_VALUE && pcr - ts->last_pat_ts >= ts->pat_period) || @@ -2300,7 +2357,7 @@ static const AVOption options[] = { { "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, SDT and NIT version", OFFSET(tables_version), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 31, ENC }, + { "tables_version", "set PAT, PMT, SDT, SIT 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", -- 2.35.1