diff options
| -rw-r--r-- | libavformat/mpegts.c | 372 | ||||
| -rw-r--r-- | libavformat/mpegts.h | 7 |
2 files changed, 302 insertions, 77 deletions
diff --git a/libavformat/mpegts.c b/libavformat/mpegts.c index bd6b64da90..6c4f1a16a0 100644 --- a/libavformat/mpegts.c +++ b/libavformat/mpegts.c @@ -29,7 +29,7 @@ synchronisation is lost */ #define MAX_RESYNC_SIZE 4096 -static int add_pes_stream(AVFormatContext *s, int pid); +static int add_pes_stream(MpegTSContext *ts, int pid); enum MpegTSFilterType { MPEGTS_PES, @@ -74,13 +74,20 @@ typedef struct MpegTSService { char *name; } MpegTSService; -typedef struct MpegTSContext { +struct MpegTSContext { /* user data */ AVFormatContext *stream; int raw_packet_size; /* raw packet size, including FEC if present */ int auto_guess; /* if true, all pids are analized to find streams */ int set_service_ret; + int mpeg2ts_raw; /* force raw MPEG2 transport stream output, if possible */ + int mpeg2ts_compute_pcr; /* compute exact PCR for each transport stream packet */ + + /* used to estimate the exact PCR */ + int64_t cur_pcr; + int pcr_incr; + /* data needed to handle file based ts */ int stop_parse; /* stop parsing loop */ AVPacket *pkt; /* packet containing av data */ @@ -100,7 +107,7 @@ typedef struct MpegTSContext { int req_sid; MpegTSFilter *pids[NB_PID_MAX]; -} MpegTSContext; +}; static void write_section_data(AVFormatContext *s, MpegTSFilter *tss1, const uint8_t *buf, int buf_size, int is_start) @@ -151,7 +158,10 @@ MpegTSFilter *mpegts_open_section_filter(MpegTSContext *ts, unsigned int pid, { MpegTSFilter *filter; MpegTSSectionFilter *sec; - + +#ifdef DEBUG_SI + printf("Filter: pid=0x%x\n", pid); +#endif if (pid >= NB_PID_MAX || ts->pids[pid]) return NULL; filter = av_mallocz(sizeof(MpegTSFilter)); @@ -391,7 +401,7 @@ static void pmt_cb(void *opaque, const uint8_t *section, int section_len) case STREAM_TYPE_VIDEO_MPEG1: case STREAM_TYPE_VIDEO_MPEG2: case STREAM_TYPE_AUDIO_AC3: - add_pes_stream(ts->stream, pid); + add_pes_stream(ts, pid); break; default: /* we ignore the other streams */ @@ -619,6 +629,7 @@ enum MpegTSState { typedef struct PESContext { int pid; + MpegTSContext *ts; AVFormatContext *stream; AVStream *st; enum MpegTSState state; @@ -648,7 +659,7 @@ static void mpegts_push_data(void *opaque, const uint8_t *buf, int buf_size, int is_start) { PESContext *pes = opaque; - MpegTSContext *ts = pes->stream->priv_data; + MpegTSContext *ts = pes->ts; AVStream *st; const uint8_t *p; int len, code, codec_type, codec_id; @@ -779,9 +790,8 @@ static void mpegts_push_data(void *opaque, } } -static int add_pes_stream(AVFormatContext *s, int pid) +static int add_pes_stream(MpegTSContext *ts, int pid) { - MpegTSContext *ts = s->priv_data; MpegTSFilter *tss; PESContext *pes; @@ -789,7 +799,8 @@ static int add_pes_stream(AVFormatContext *s, int pid) pes = av_mallocz(sizeof(PESContext)); if (!pes) return -1; - pes->stream = s; + pes->ts = ts; + pes->stream = ts->stream; pes->pid = pid; tss = mpegts_open_pes_filter(ts, pid, mpegts_push_data, pes); if (!tss) { @@ -800,9 +811,9 @@ static int add_pes_stream(AVFormatContext *s, int pid) } /* handle one TS packet */ -static void handle_packet(AVFormatContext *s, uint8_t *packet) +static void handle_packet(MpegTSContext *ts, const uint8_t *packet) { - MpegTSContext *ts = s->priv_data; + AVFormatContext *s = ts->stream; MpegTSFilter *tss; int len, pid, cc, cc_ok, afc, is_start; const uint8_t *p, *p_end; @@ -811,7 +822,7 @@ static void handle_packet(AVFormatContext *s, uint8_t *packet) is_start = packet[1] & 0x40; tss = ts->pids[pid]; if (ts->auto_guess && tss == NULL && is_start) { - add_pes_stream(s, pid); + add_pes_stream(ts, pid); tss = ts->pids[pid]; } if (!tss) @@ -868,9 +879,8 @@ static void handle_packet(AVFormatContext *s, uint8_t *packet) /* XXX: try to find a better synchro over several packets (use get_packet_size() ?) */ -static int mpegts_resync(AVFormatContext *s) +static int mpegts_resync(ByteIOContext *pb) { - ByteIOContext *pb = &s->pb; int c, i; for(i = 0;i < MAX_RESYNC_SIZE; i++) { @@ -886,13 +896,39 @@ static int mpegts_resync(AVFormatContext *s) return -1; } -static int handle_packets(AVFormatContext *s, int nb_packets) +/* return -1 if error or EOF. Return 0 if OK. */ +static int read_packet(ByteIOContext *pb, uint8_t *buf, int raw_packet_size) { - MpegTSContext *ts = s->priv_data; + int skip, len; + + for(;;) { + len = get_buffer(pb, buf, TS_PACKET_SIZE); + if (len != TS_PACKET_SIZE) + return AVERROR_IO; + /* check paquet sync byte */ + if (buf[0] != 0x47) { + /* find a new packet start */ + url_fseek(pb, -TS_PACKET_SIZE, SEEK_CUR); + if (mpegts_resync(pb) < 0) + return AVERROR_INVALIDDATA; + else + continue; + } else { + skip = raw_packet_size - TS_PACKET_SIZE; + if (skip > 0) + url_fskip(pb, skip); + break; + } + } + return 0; +} + +static int handle_packets(MpegTSContext *ts, int nb_packets) +{ + AVFormatContext *s = ts->stream; ByteIOContext *pb = &s->pb; - uint8_t packet[TS_FEC_PACKET_SIZE]; - int packet_num, len; - int64_t pos; + uint8_t packet[TS_PACKET_SIZE]; + int packet_num, ret; ts->stop_parse = 0; packet_num = 0; @@ -902,20 +938,10 @@ static int handle_packets(AVFormatContext *s, int nb_packets) packet_num++; if (nb_packets != 0 && packet_num >= nb_packets) break; - pos = url_ftell(pb); - len = get_buffer(pb, packet, ts->raw_packet_size); - if (len != ts->raw_packet_size) - return AVERROR_IO; - /* check paquet sync byte */ - if (packet[0] != 0x47) { - /* find a new packet start */ - url_fseek(pb, -ts->raw_packet_size, SEEK_CUR); - if (mpegts_resync(s) < 0) - return AVERROR_INVALIDDATA; - else - continue; - } - handle_packet(s, packet); + ret = read_packet(pb, packet, ts->raw_packet_size); + if (ret != 0) + return ret; + handle_packet(ts, packet); } return 0; } @@ -944,6 +970,35 @@ void set_service_cb(void *opaque, int ret) ts->stop_parse = 1; } +/* return the 90 kHz PCR and the extension for the 27 MHz PCR. return + (-1) if not available */ +static int parse_pcr(int64_t *ppcr_high, int *ppcr_low, + const uint8_t *packet) +{ + int afc, len, flags; + const uint8_t *p; + unsigned int v; + + afc = (packet[3] >> 4) & 3; + if (afc <= 1) + return -1; + p = packet + 4; + len = p[0]; + p++; + if (len == 0) + return -1; + flags = *p++; + len--; + if (!(flags & 0x10)) + return -1; + if (len < 6) + return -1; + v = (p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3]; + *ppcr_high = ((int64_t)v << 1) | (p[4] >> 7); + *ppcr_low = ((p[4] & 1) << 8) | p[5]; + return 0; +} + static int mpegts_read_header(AVFormatContext *s, AVFormatParameters *ap) { @@ -954,6 +1009,11 @@ static int mpegts_read_header(AVFormatContext *s, int64_t pos; MpegTSService *service; + if (ap) { + ts->mpeg2ts_raw = ap->mpeg2ts_raw; + ts->mpeg2ts_compute_pcr = ap->mpeg2ts_compute_pcr; + } + /* read the first 1024 bytes to get packet size */ pos = url_ftell(pb); len = get_buffer(pb, buf, sizeof(buf)); @@ -962,57 +1022,112 @@ static int mpegts_read_header(AVFormatContext *s, ts->raw_packet_size = get_packet_size(buf, sizeof(buf)); if (ts->raw_packet_size <= 0) goto fail; + ts->stream = s; ts->auto_guess = 0; - - if (!ts->auto_guess) { - ts->set_service_ret = -1; - /* first do a scaning to get all the services */ - url_fseek(pb, pos, SEEK_SET); - mpegts_scan_sdt(ts); + if (!ts->mpeg2ts_raw) { + /* normal demux */ - handle_packets(s, MAX_SCAN_PACKETS); + if (!ts->auto_guess) { + ts->set_service_ret = -1; - if (ts->nb_services <= 0) { - /* no SDT found, we try to look at the PAT */ - - /* First remove the SDT filters from each PID */ - int i; - for (i=0; i < NB_PID_MAX; i++) { - if (ts->pids[i]) - mpegts_close_filter(ts, ts->pids[i]); - } + /* first do a scaning to get all the services */ url_fseek(pb, pos, SEEK_SET); - mpegts_scan_pat(ts); + mpegts_scan_sdt(ts); - handle_packets(s, MAX_SCAN_PACKETS); - } - - if (ts->nb_services <= 0) - return -1; - - /* tune to first service found */ - service = ts->services[0]; - sid = service->sid; + handle_packets(ts, MAX_SCAN_PACKETS); + + if (ts->nb_services <= 0) { + /* no SDT found, we try to look at the PAT */ + + /* First remove the SDT filters from each PID */ + int i; + for (i=0; i < NB_PID_MAX; i++) { + if (ts->pids[i]) + mpegts_close_filter(ts, ts->pids[i]); + } + url_fseek(pb, pos, SEEK_SET); + mpegts_scan_pat(ts); + + handle_packets(ts, MAX_SCAN_PACKETS); + } + + if (ts->nb_services <= 0) + return -1; + + /* tune to first service found */ + service = ts->services[0]; + sid = service->sid; #ifdef DEBUG_SI - printf("tuning to '%s'\n", service->name); + printf("tuning to '%s'\n", service->name); #endif + + /* now find the info for the first service if we found any, + otherwise try to filter all PATs */ + + url_fseek(pb, pos, SEEK_SET); + mpegts_set_service(ts, sid, set_service_cb, ts); + + handle_packets(ts, MAX_SCAN_PACKETS); + + /* if could not find service, exit */ + if (ts->set_service_ret != 0) + return -1; + +#ifdef DEBUG_SI + printf("tuning done\n"); +#endif + } + s->ctx_flags |= AVFMTCTX_NOHEADER; + } else { + AVStream *st; + int pcr_pid, pid, nb_packets, nb_pcrs, ret, pcr_l; + int64_t pcrs[2], pcr_h; + int packet_count[2]; + uint8_t packet[TS_PACKET_SIZE]; + + /* only read packets */ - /* now find the info for the first service if we found any, - otherwise try to filter all PATs */ - - url_fseek(pb, pos, SEEK_SET); - ts->stream = s; - mpegts_set_service(ts, sid, set_service_cb, ts); - - handle_packets(s, MAX_SCAN_PACKETS); - - /* if could not find service, exit */ - if (ts->set_service_ret != 0) - return -1; + s->pts_num = 1; + s->pts_den = 27000000; + + st = av_new_stream(s, 0); + if (!st) + goto fail; + st->codec.codec_type = CODEC_TYPE_DATA; + st->codec.codec_id = CODEC_ID_MPEG2TS; + + /* we iterate until we find two PCRs to estimate the bitrate */ + pcr_pid = -1; + nb_pcrs = 0; + nb_packets = 0; + for(;;) { + ret = read_packet(&s->pb, packet, ts->raw_packet_size); + if (ret < 0) + return -1; + pid = ((packet[1] & 0x1f) << 8) | packet[2]; + if ((pcr_pid == -1 || pcr_pid == pid) && + parse_pcr(&pcr_h, &pcr_l, packet) == 0) { + pcr_pid = pid; + packet_count[nb_pcrs] = nb_packets; + pcrs[nb_pcrs] = pcr_h * 300 + pcr_l; + nb_pcrs++; + if (nb_pcrs >= 2) + break; + } + nb_packets++; + } -#ifdef DEBUG_SI - printf("tuning done\n"); + /* NOTE1: the bitrate is computed without the FEC */ + /* NOTE2: it is only the bitrate of the start of the stream */ + ts->pcr_incr = (pcrs[1] - pcrs[0]) / (packet_count[1] - packet_count[0]); + ts->cur_pcr = pcrs[0] - ts->pcr_incr * packet_count[0]; + s->bit_rate = (TS_PACKET_SIZE * 8) * 27e6 / ts->pcr_incr; + st->codec.bit_rate = s->bit_rate; + st->start_time = ts->cur_pcr * 1000000.0 / 27.0e6; +#if 0 + printf("start=%0.3f pcr=%0.3f incr=%d\n", + st->start_time / 1000000.0, pcrs[0] / 27e6, ts->pcr_incr); #endif } @@ -1022,12 +1137,62 @@ static int mpegts_read_header(AVFormatContext *s, return -1; } +#define MAX_PACKET_READAHEAD ((128 * 1024) / 188) + +static int mpegts_raw_read_packet(AVFormatContext *s, + AVPacket *pkt) +{ + MpegTSContext *ts = s->priv_data; + int ret, i; + int64_t pcr_h, next_pcr_h, pos; + int pcr_l, next_pcr_l; + uint8_t pcr_buf[12]; + + if (av_new_packet(pkt, TS_PACKET_SIZE) < 0) + return -ENOMEM; + ret = read_packet(&s->pb, pkt->data, ts->raw_packet_size); + if (ret < 0) { + av_free_packet(pkt); + return ret; + } + if (ts->mpeg2ts_compute_pcr) { + /* compute exact PCR for each packet */ + if (parse_pcr(&pcr_h, &pcr_l, pkt->data) == 0) { + /* we read the next PCR (XXX: optimize it by using a bigger buffer */ + pos = url_ftell(&s->pb); + for(i = 0; i < MAX_PACKET_READAHEAD; i++) { + url_fseek(&s->pb, pos + i * ts->raw_packet_size, SEEK_SET); + get_buffer(&s->pb, pcr_buf, 12); + if (parse_pcr(&next_pcr_h, &next_pcr_l, pcr_buf) == 0) { + /* XXX: not precise enough */ + ts->pcr_incr = ((next_pcr_h - pcr_h) * 300 + (next_pcr_l - pcr_l)) / + (i + 1); + break; + } + } + url_fseek(&s->pb, pos, SEEK_SET); + /* no next PCR found: we use previous increment */ + ts->cur_pcr = pcr_h * 300 + pcr_l; + } + pkt->pts = ts->cur_pcr; + pkt->duration = ts->pcr_incr; + ts->cur_pcr += ts->pcr_incr; + } + pkt->stream_index = 0; + return 0; +} + static int mpegts_read_packet(AVFormatContext *s, AVPacket *pkt) { MpegTSContext *ts = s->priv_data; - ts->pkt = pkt; - return handle_packets(s, 0); + + if (!ts->mpeg2ts_raw) { + ts->pkt = pkt; + return handle_packets(ts, 0); + } else { + return mpegts_raw_read_packet(s, pkt); + } } static int mpegts_read_close(AVFormatContext *s) @@ -1039,6 +1204,59 @@ static int mpegts_read_close(AVFormatContext *s) return 0; } +/**************************************************************/ +/* parsing functions - called from other demuxers such as RTP */ + +MpegTSContext *mpegts_parse_open(AVFormatContext *s) +{ + MpegTSContext *ts; + + ts = av_mallocz(sizeof(MpegTSContext)); + if (!ts) + return NULL; + /* no stream case, currently used by RTP */ + ts->raw_packet_size = TS_PACKET_SIZE; + ts->stream = s; + ts->auto_guess = 1; + return ts; +} + +/* return the consumed length if a packet was output, or -1 if no + packet is output */ +int mpegts_parse_packet(MpegTSContext *ts, AVPacket *pkt, + const uint8_t *buf, int len) +{ + int len1; + + len1 = len; + ts->pkt = pkt; + ts->stop_parse = 0; + for(;;) { + if (ts->stop_parse) + break; + if (len < TS_PACKET_SIZE) + return -1; + if (buf[0] != 0x47) { + buf--; + len--; + } else { + handle_packet(ts, buf); + buf += TS_PACKET_SIZE; + len -= TS_PACKET_SIZE; + } + } + return len1 - len; +} + +void mpegts_parse_close(MpegTSContext *ts) +{ + int i; + + for(i=0;i<NB_PID_MAX;i++) + av_free(ts->pids[i]); + av_free(ts); +} + AVInputFormat mpegts_demux = { "mpegts", "MPEG2 transport stream format", @@ -1047,7 +1265,7 @@ AVInputFormat mpegts_demux = { mpegts_read_header, mpegts_read_packet, mpegts_read_close, - .flags = AVFMT_NOHEADER | AVFMT_SHOW_IDS, + .flags = AVFMT_SHOW_IDS, }; int mpegts_init(void) diff --git a/libavformat/mpegts.h b/libavformat/mpegts.h index 6e56a8e44c..6ffb7562e2 100644 --- a/libavformat/mpegts.h +++ b/libavformat/mpegts.h @@ -42,3 +42,10 @@ unsigned int mpegts_crc32(const uint8_t *data, int len); extern AVOutputFormat mpegts_mux; + +typedef struct MpegTSContext MpegTSContext; + +MpegTSContext *mpegts_parse_open(AVFormatContext *s); +int mpegts_parse_packet(MpegTSContext *ts, AVPacket *pkt, + const uint8_t *buf, int len); +void mpegts_parse_close(MpegTSContext *ts); |