[FFmpeg-devel] [PATCH] mpegts: identify and demux DSMCC-B/MHEG streams
Scott Theisen
scott.the.elm at gmail.com
Mon Nov 28 22:08:16 EET 2022
Ping for review.
Thanks in advance,
Scott Theisen
On 11/13/22 18:19, Scott Theisen wrote:
> Ping for review.
>
> On 9/17/22 13:08, Scott Theisen wrote:
>> These changes are from MythTV.
>> ---
>>
>> The `AV_CODEC_ID`s are probably in the wrong place since these are
>> data codecs, but that is where they are In MythTV.
>>
>> There was also a related change to libavformat/demux.c's
>> avformat_find_stream_info() trying to optimize it for MHEG streams,
>> but it is unnecessary and was causing FATE to fail.
>>
>> libavcodec/codec_desc.c | 12 +++
>> libavcodec/codec_id.h | 6 ++
>> libavformat/avformat.h | 5 +
>> libavformat/mpegts.c | 199 +++++++++++++++++++++++++++++++++++++++-
>> libavformat/mpegts.h | 17 ++++
>> 5 files changed, 237 insertions(+), 2 deletions(-)
>>
>> diff --git a/libavcodec/codec_desc.c b/libavcodec/codec_desc.c
>> index 648c518b3c..0e54087863 100644
>> --- a/libavcodec/codec_desc.c
>> +++ b/libavcodec/codec_desc.c
>> @@ -3488,6 +3488,18 @@ static const AVCodecDescriptor
>> codec_descriptors[] = {
>> .props = AV_CODEC_PROP_TEXT_SUB,
>> .profiles = NULL_IF_CONFIG_SMALL(ff_arib_caption_profiles),
>> },
>> + {
>> + .id = AV_CODEC_ID_DVB_VBI,
>> + .type = AVMEDIA_TYPE_DATA,
>> + .name = "dvb_vbi",
>> + .long_name = NULL_IF_CONFIG_SMALL("dvb teletext"),
>> + },
>> + {
>> + .id = AV_CODEC_ID_DSMCC_B,
>> + .type = AVMEDIA_TYPE_DATA,
>> + .name = "dsmcc_b",
>> + .long_name = NULL_IF_CONFIG_SMALL("DSMCC B"),
>> + },
>> /* other kind of codecs and pseudo-codecs */
>> {
>> diff --git a/libavcodec/codec_id.h b/libavcodec/codec_id.h
>> index bc8226ff07..7e2198a800 100644
>> --- a/libavcodec/codec_id.h
>> +++ b/libavcodec/codec_id.h
>> @@ -559,6 +559,12 @@ enum AVCodecID {
>> AV_CODEC_ID_TTML,
>> AV_CODEC_ID_ARIB_CAPTION,
>> + /* teletext codecs */
>> + AV_CODEC_ID_DVB_VBI,
>> +
>> + /* DSMCC codec */
>> + AV_CODEC_ID_DSMCC_B,
>> +
>> /* other specific kind of codecs (generally used for
>> attachments) */
>> AV_CODEC_ID_FIRST_UNKNOWN = 0x18000, ///< A dummy ID
>> pointing at the start of various fake codecs.
>> AV_CODEC_ID_TTF = 0x18000,
>> diff --git a/libavformat/avformat.h b/libavformat/avformat.h
>> index 9d46875cce..664a1afa61 100644
>> --- a/libavformat/avformat.h
>> +++ b/libavformat/avformat.h
>> @@ -1117,6 +1117,11 @@ typedef struct AVStream {
>> *
>> */
>> int pts_wrap_bits;
>> +
>> + /* MHEG support */
>> + int component_tag; ///< Component tag given in PMT
>> + int carousel_id;
>> + int data_id;
>> } AVStream;
>> struct AVCodecParserContext *av_stream_get_parser(const AVStream
>> *s);
>> diff --git a/libavformat/mpegts.c b/libavformat/mpegts.c
>> index 8a3436f2be..be8edd9e62 100644
>> --- a/libavformat/mpegts.c
>> +++ b/libavformat/mpegts.c
>> @@ -46,6 +46,15 @@
>> #include <iconv.h>
>> #endif
>> +typedef struct SectionContext {
>> + int pid;
>> + int stream_type;
>> + int new_packet;
>> + MpegTSContext *ts;
>> + AVFormatContext *stream;
>> + AVStream *st;
>> +} SectionContext;
>> +
>> /* maximum size in which we look for synchronization if
>> * synchronization is lost */
>> #define MAX_RESYNC_SIZE 65536
>> @@ -412,6 +421,8 @@ static int discard_pid(MpegTSContext *ts,
>> unsigned int pid)
>> return !used && discarded;
>> }
>> +static void mpegts_push_section(MpegTSFilter *filter, const
>> uint8_t *section, int section_len);
>> +
>> /**
>> * Assemble PES packets out of TS packets, and then call the
>> "section_cb"
>> * function when they are complete.
>> @@ -438,6 +449,11 @@ static void write_section_data(MpegTSContext
>> *ts, MpegTSFilter *tss1,
>> tss->section_index += len;
>> }
>> + if (tss->section_cb == mpegts_push_section) {
>> + SectionContext *sect = tss->opaque;
>> + sect->new_packet = 1;
>> + }
>> +
>> offset = 0;
>> cur_section_buf = tss->section_buf;
>> while (cur_section_buf - tss->section_buf < MAX_SECTION_SIZE &&
>> cur_section_buf[0] != 0xff) {
>> @@ -798,6 +814,7 @@ static const StreamType ISO_types[] = {
>> { 0x02, AVMEDIA_TYPE_VIDEO, AV_CODEC_ID_MPEG2VIDEO },
>> { 0x03, AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_MP3 },
>> { 0x04, AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_MP3 },
>> + { 0x0b, AVMEDIA_TYPE_DATA, AV_CODEC_ID_DSMCC_B }, /*
>> DVB_CAROUSEL_ID */
>> { 0x0f, AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_AAC },
>> { 0x10, AVMEDIA_TYPE_VIDEO, AV_CODEC_ID_MPEG4 },
>> /* Makito encoder sets stream type 0x11 for AAC,
>> @@ -882,11 +899,20 @@ static const StreamType DESC_types[] = {
>> { 0x6a, AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_AC3 }, /*
>> AC-3 descriptor */
>> { 0x7a, AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_EAC3 }, /*
>> E-AC-3 descriptor */
>> { 0x7b, AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_DTS },
>> + { 0x13, AVMEDIA_TYPE_DATA, AV_CODEC_ID_DSMCC_B }, /*
>> DVB_CAROUSEL_ID */
>> + { 0x45, AVMEDIA_TYPE_DATA, AV_CODEC_ID_DVB_VBI }, /*
>> DVB_VBI_DATA_ID */
>> + { 0x46, AVMEDIA_TYPE_DATA, AV_CODEC_ID_DVB_VBI }, /*
>> DVB_VBI_TELETEXT_ID */ //FixMe type subtilte
>> { 0x56, AVMEDIA_TYPE_SUBTITLE, AV_CODEC_ID_DVB_TELETEXT },
>> { 0x59, AVMEDIA_TYPE_SUBTITLE, AV_CODEC_ID_DVB_SUBTITLE }, /*
>> subtitling descriptor */
>> { 0 },
>> };
>> +/* component tags */
>> +static const StreamType COMPONENT_TAG_types[] = {
>> + { 0x0a, AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_MP3 },
>> + { 0x52, AVMEDIA_TYPE_VIDEO, AV_CODEC_ID_MPEG2VIDEO },
>> +};
>> +
>> static void mpegts_find_stream_type(AVStream *st,
>> uint32_t stream_type,
>> const StreamType *types)
>> @@ -1979,7 +2005,13 @@ int ff_parse_mpeg2_descriptor(AVFormatContext
>> *fc, AVStream *st, int stream_type
>> memcpy(extradata, *pp, 4); /*
>> composition_page_id and ancillary_page_id */
>> extradata += 5;
>> - *pp += 4;
>> + {
>> + int comp_page = get16(pp, desc_end);
>> + int anc_page = get16(pp, desc_end);
>> + int sub_id = (anc_page << 16) | comp_page;
>> + if (sub_id && (st->codecpar->codec_id ==
>> AV_CODEC_ID_DVB_SUBTITLE))
>> + st->carousel_id = sub_id;
>> + }
>> }
>> language[i * 4 - 1] = 0;
>> @@ -2023,8 +2055,45 @@ int ff_parse_mpeg2_descriptor(AVFormatContext
>> *fc, AVStream *st, int stream_type
>> sti->request_probe = 50;
>> }
>> break;
>> + case DVB_BROADCAST_ID:
>> + st->data_id = get16(pp, desc_end);
>> + break;
>> + case DVB_CAROUSEL_ID:
>> + {
>> + int carId = 0;
>> + carId = get8(pp, desc_end);
>> + carId = (carId << 8) | get8(pp, desc_end);
>> + carId = (carId << 8) | get8(pp, desc_end);
>> + carId = (carId << 8) | get8(pp, desc_end);
>> + st->carousel_id = carId;
>> + }
>> + break;
>> case 0x52: /* stream identifier descriptor */
>> sti->stream_identifier = 1 + get8(pp, desc_end);
>> + st->component_tag = sti->stream_identifier - 1;
>> + // DVB_DATA_STREAM:
>> + /* Audio and video are sometimes encoded in private streams
>> labelled with
>> + * a component tag. */
>> +#if 0
>> + if (st->codecpar->codec_id == AV_CODEC_ID_NONE &&
>> + desc_count == 1 &&
>> + stream_type == STREAM_TYPE_PRIVATE_DATA)
>> + mpegts_find_stream_type(st, st->component_tag,
>> + COMPONENT_TAG_types);
>> +#endif
>> + break;
>> + case DVB_VBI_TELETEXT_ID:
>> + language[0] = get8(pp, desc_end);
>> + language[1] = get8(pp, desc_end);
>> + language[2] = get8(pp, desc_end);
>> + language[3] = 0;
>> +
>> + /* dvbci->txt_type = */ i = (get8(pp, desc_end)) >> 3; //
>> not exported, defeat compiler -Wunused-value
>> + if (language[0])
>> + av_dict_set(&st->metadata, "language", language, 0);
>> + break;
>> + case DVB_VBI_DATA_ID:
>> + // dvbci->vbi_data = 1; //not parsing the data service
>> descriptors
>> break;
>> case METADATA_DESCRIPTOR:
>> if (get16(pp, desc_end) == 0xFFFF)
>> @@ -2307,6 +2376,34 @@ static int is_pes_stream(int stream_type,
>> uint32_t prog_reg_desc)
>> (stream_type == 0x86 && prog_reg_desc ==
>> AV_RL32("CUEI")) );
>> }
>> +static SectionContext *add_section_stream(MpegTSContext *ts, int
>> pid, int stream_type)
>> +{
>> + MpegTSFilter *tss = ts->pids[pid];
>> + SectionContext *sect = 0;
>> + if (tss) { /* filter already exists */
>> + /* kill it, and start a new stream */
>> + mpegts_close_filter(ts, tss);
>> + }
>> +
>> + /* create a SECTION context */
>> + if (!(sect=av_mallocz(sizeof(SectionContext)))) {
>> + av_log(ts, AV_LOG_ERROR, "Error: av_mallocz() failed in
>> add_section_stream");
>> + return 0;
>> + }
>> + sect->ts = ts;
>> + sect->stream = ts->stream;
>> + sect->pid = pid;
>> + sect->stream_type = stream_type;
>> + tss = mpegts_open_section_filter(ts, pid, mpegts_push_section,
>> sect, 1);
>> + if (!tss) {
>> + av_free(sect);
>> + av_log(ts, AV_LOG_ERROR, "Error: unable to open mpegts
>> Section filter in add_section_stream");
>> + return 0;
>> + }
>> +
>> + return sect;
>> +}
>> +
>> static void pmt_cb(MpegTSFilter *filter, const uint8_t *section,
>> int section_len)
>> {
>> MpegTSContext *ts = filter->u.section_filter.opaque;
>> @@ -2425,7 +2522,56 @@ static void pmt_cb(MpegTSFilter *filter, const
>> uint8_t *section, int section_len
>> stream_identifier = parse_stream_identifier_desc(p, p_end)
>> + 1;
>> /* now create stream */
>> - if (ts->pids[pid] && ts->pids[pid]->type == MPEGTS_PES) {
>> + if (stream_type == STREAM_TYPE_DSMCC_B)
>> + {
>> + SectionContext *sect = NULL;
>> + int idx = -1;
>> +
>> + if (ts->pids[pid] && ts->pids[pid]->type ==
>> MPEGTS_SECTION &&
>> + ts->pids[pid]->u.section_filter.section_cb == mpegts_push_section) {
>> + // u.section_filter.opaque may be the MpegTSContext,
>> so test the section_cb
>> + sect = (SectionContext*)
>> ts->pids[pid]->u.section_filter.opaque;
>> + }
>> + if (!sect) {
>> + sect = add_section_stream(ts, pid, stream_type);
>> + }
>> + if (!sect)
>> + {
>> + av_log(ts, AV_LOG_ERROR, "mpegts_add_stream: "
>> + "error creating Section context for pid 0x%x
>> with type %i\n",
>> + pid, stream_type);
>> + goto out;
>> + }
>> +
>> + idx = ff_find_stream_index(ts->stream, pid);
>> + if (idx >= 0) {
>> + st = ts->stream->streams[idx];
>> + av_log(ts, AV_LOG_DEBUG, "mpegts_add_stream: "
>> + "reusing stream #%d, has id 0x%x and codec %s,
>> type %s at 0x%p\n",
>> + st->index, st->id,
>> avcodec_get_name(st->codecpar->codec_id),
>> + av_get_media_type_string(st->codecpar->codec_type), st);
>> + }
>> + if (!st) {
>> + st = avformat_new_stream(sect->stream, NULL);
>> + }
>> + if (!st) {
>> + goto out;
>> + }
>> + sect->st = st;
>> + sect->st->id = sect->pid;
>> +
>> + avpriv_set_pts_info(sect->st, 33, 1, 90000);
>> +
>> + sect->st->codecpar->codec_type = AVMEDIA_TYPE_DATA;
>> + sect->st->codecpar->codec_id = AV_CODEC_ID_DSMCC_B;
>> + sect->st->priv_data = sect;
>> + ffstream(sect->st)->need_parsing = AVSTREAM_PARSE_NONE;
>> +
>> + av_log(ts, AV_LOG_DEBUG, "mpegts_add_stream: "
>> + "stream #%d, has id 0x%x and codec %s, type %s at
>> 0x%p\n",
>> + st->index, st->id,
>> avcodec_get_name(st->codecpar->codec_id),
>> + av_get_media_type_string(st->codecpar->codec_type), st);
>> + } else if (ts->pids[pid] && ts->pids[pid]->type ==
>> MPEGTS_PES) {
>> pes = ts->pids[pid]->u.pes_filter.opaque;
>> if (ts->merge_pmt_versions && !pes->st) {
>> st = find_matching_stream(ts, pid, h->id,
>> stream_identifier, i, &old_program);
>> @@ -2527,6 +2673,55 @@ out:
>> av_free(mp4_descr[i].dec_config_descr);
>> }
>> +/* mpegts_push_section: return one or more tables. The tables may
>> not completely fill
>> + the packet and there may be stuffing bytes at the end.
>> + This is complicated because a single TS packet may result in
>> several tables being
>> + produced. We may have a "start" bit indicating, in effect, the
>> end of a table but
>> + the rest of the TS packet after the start may be filled with one
>> or more small tables.
>> +*/
>> +static void mpegts_push_section(MpegTSFilter *filter, const uint8_t
>> *section, int section_len)
>> +{
>> + SectionContext *sect = filter->u.section_filter.opaque;
>> + MpegTSContext *ts = sect->ts;
>> + SectionHeader header;
>> + AVPacket *pkt = ts->pkt;
>> + const uint8_t *p = section, *p_end = section + section_len - 4;
>> +
>> + if (parse_section_header(&header, &p, p_end) < 0)
>> + {
>> + av_log(ts, AV_LOG_DEBUG, "Unable to parse header\n");
>> + return;
>> + }
>> +
>> + if (sect->new_packet && pkt && sect->st && pkt->size == -1) {
>> + int pktLen = section_len + 184; /* Add enough for a complete
>> TS payload. */
>> + sect->new_packet = 0;
>> + av_packet_unref(pkt);
>> + if (av_new_packet(pkt, pktLen) == 0) {
>> + memcpy(pkt->data, section, section_len);
>> + memset(pkt->data+section_len, 0xff, pktLen-section_len);
>> + pkt->stream_index = sect->st->index;
>> + ts->stop_parse = 1;
>> + }
>> + } else if (pkt->data) { /* We've already added at least one
>> table. */
>> + uint8_t *data = pkt->data;
>> + int space = pkt->size;
>> + int table_size = 0;
>> + while (space > 3 + table_size) {
>> + table_size = (((data[1] & 0xf) << 8) | data[2]) + 3;
>> + if (table_size < space) {
>> + space -= table_size;
>> + data += table_size;
>> + } /* Otherwise we've got filler. */
>> + }
>> + if (space < section_len) {
>> + av_log(ts, AV_LOG_DEBUG, "Insufficient space for
>> additional packet\n");
>> + return;
>> + }
>> + memcpy(data, section, section_len);
>> + }
>> +}
>> +
>> static void pat_cb(MpegTSFilter *filter, const uint8_t *section,
>> int section_len)
>> {
>> MpegTSContext *ts = filter->u.section_filter.opaque;
>> diff --git a/libavformat/mpegts.h b/libavformat/mpegts.h
>> index a48f14e768..6f57af7786 100644
>> --- a/libavformat/mpegts.h
>> +++ b/libavformat/mpegts.h
>> @@ -122,6 +122,7 @@
>> #define STREAM_TYPE_AUDIO_MPEG2 0x04
>> #define STREAM_TYPE_PRIVATE_SECTION 0x05
>> #define STREAM_TYPE_PRIVATE_DATA 0x06
>> +#define STREAM_TYPE_DSMCC_B 0x0b
>> #define STREAM_TYPE_AUDIO_AAC 0x0f
>> #define STREAM_TYPE_AUDIO_AAC_LATM 0x11
>> #define STREAM_TYPE_VIDEO_MPEG4 0x10
>> @@ -139,6 +140,22 @@
>> #define STREAM_TYPE_AUDIO_TRUEHD 0x83
>> #define STREAM_TYPE_AUDIO_EAC3 0x87
>> +#define STREAM_TYPE_AUDIO_MISC_DTS 0x8a
>> +#define STREAM_TYPE_AUDIO_HDMV_AC3_PLUS 0x84
>> +#define STREAM_TYPE_AUDIO_HDMV_DTS_HD 0x85
>> +#define STREAM_TYPE_AUDIO_HDMV_DTS_HD_MASTER 0x86
>> +
>> +#define STREAM_TYPE_SUBTITLE_DVB 0x100
>> +#define STREAM_TYPE_VBI_DVB 0x101
>> +
>> +#define DVB_CAROUSEL_ID 0x13
>> +#define DVB_VBI_DATA_ID 0x45
>> +#define DVB_VBI_TELETEXT_ID 0x46
>> +#define DVB_TELETEXT_ID 0x56
>> +#define DVB_SUBT_DESCID 0x59
>> +#define DVB_BROADCAST_ID 0x66
>> +#define DVB_DATA_STREAM 0x52
>> +
>> /* ISO/IEC 13818-1 Table 2-22 */
>> #define STREAM_ID_PROGRAM_STREAM_MAP 0xbc
>> #define STREAM_ID_PRIVATE_STREAM_1 0xbd
>
More information about the ffmpeg-devel
mailing list