/* * MPEG2 transport stream (aka DVB) demux * Copyright (c) 2002-2003 Fabrice Bellard. * * This library 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 of the License, or (at your option) any later version. * * This library 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 this library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include "avformat.h" #include "mpegts.h" //#define DEBUG_SI //#define DEBUG_SEEK /* 1.0 second at 24Mbit/s */ #define MAX_SCAN_PACKETS 32000 /* maximum size in which we look for synchronisation if synchronisation is lost */ #define MAX_RESYNC_SIZE 4096 typedef struct PESContext PESContext; static PESContext* add_pes_stream(MpegTSContext *ts, int pid, int stream_type); static AVStream* new_pes_av_stream(PESContext *pes, uint32_t code); enum MpegTSFilterType { MPEGTS_PES, MPEGTS_SECTION, }; typedef void PESCallback(void *opaque, const uint8_t *buf, int len, int is_start); typedef struct MpegTSPESFilter { PESCallback *pes_cb; void *opaque; } MpegTSPESFilter; typedef void SectionCallback(void *opaque, const uint8_t *buf, int len); typedef void SetServiceCallback(void *opaque, int ret); typedef struct MpegTSSectionFilter { int section_index; int section_h_size; uint8_t *section_buf; int check_crc:1; int end_of_section_reached:1; SectionCallback *section_cb; void *opaque; } MpegTSSectionFilter; typedef struct MpegTSFilter { int pid; int last_cc; /* last cc code (-1 if first packet) */ enum MpegTSFilterType type; union { MpegTSPESFilter pes_filter; MpegTSSectionFilter section_filter; } u; } MpegTSFilter; typedef struct MpegTSService { int running:1; int sid; char *provider_name; char *name; } MpegTSService; 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; int pcr_pid; /* data needed to handle file based ts */ int stop_parse; /* stop parsing loop */ AVPacket *pkt; /* packet containing av data */ /******************************************/ /* private mpegts data */ /* scan context */ MpegTSFilter *sdt_filter; int nb_services; MpegTSService **services; /* set service context (XXX: allocated it ?) */ SetServiceCallback *set_service_cb; void *set_service_opaque; MpegTSFilter *pat_filter; MpegTSFilter *pmt_filter; int req_sid; MpegTSFilter *pids[NB_PID_MAX]; }; static void write_section_data(AVFormatContext *s, MpegTSFilter *tss1, const uint8_t *buf, int buf_size, int is_start) { MpegTSSectionFilter *tss = &tss1->u.section_filter; int len; if (is_start) { memcpy(tss->section_buf, buf, buf_size); tss->section_index = buf_size; tss->section_h_size = -1; tss->end_of_section_reached = 0; } else { if (tss->end_of_section_reached) return; len = 4096 - tss->section_index; if (buf_size < len) len = buf_size; memcpy(tss->section_buf + tss->section_index, buf, len); tss->section_index += len; } /* compute section length if possible */ if (tss->section_h_size == -1 && tss->section_index >= 3) { len = (((tss->section_buf[1] & 0xf) << 8) | tss->section_buf[2]) + 3; if (len > 4096) return; tss->section_h_size = len; } if (tss->section_h_size != -1 && tss->section_index >= tss->section_h_size) { tss->end_of_section_reached = 1; if (!tss->check_crc || mpegts_crc32(tss->section_buf, tss->section_h_size) == 0) tss->section_cb(tss->opaque, tss->section_buf, tss->section_h_size); } } MpegTSFilter *mpegts_open_section_filter(MpegTSContext *ts, unsigned int pid, SectionCallback *section_cb, void *opaque, int check_crc) { 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)); if (!filter) return NULL; ts->pids[pid] = filter; filter->type = MPEGTS_SECTION; filter->pid = pid; filter->last_cc = -1; sec = &filter->u.section_filter; sec->section_cb = section_cb; sec->opaque = opaque; sec->section_buf = av_malloc(MAX_SECTION_SIZE); sec->check_crc = check_crc; if (!sec->section_buf) { av_free(filter); return NULL; } return filter; } MpegTSFilter *mpegts_open_pes_filter(MpegTSContext *ts, unsigned int pid, PESCallback *pes_cb, void *opaque) { MpegTSFilter *filter; MpegTSPESFilter *pes; if (pid >= NB_PID_MAX || ts->pids[pid]) return NULL; filter = av_mallocz(sizeof(MpegTSFilter)); if (!filter) return NULL; ts->pids[pid] = filter; filter->type = MPEGTS_PES; filter->pid = pid; filter->last_cc = -1; pes = &filter->u.pes_filter; pes->pes_cb = pes_cb; pes->opaque = opaque; return filter; } void mpegts_close_filter(MpegTSContext *ts, MpegTSFilter *filter) { int pid; pid = filter->pid; if (filter->type == MPEGTS_SECTION) av_freep(&filter->u.section_filter.section_buf); else if (filter->type == MPEGTS_PES) av_freep(&filter->u.pes_filter.opaque); av_free(filter); ts->pids[pid] = NULL; } static int analyze(const uint8_t *buf, int size, int packet_size, int *index){ int stat[packet_size]; int i; int x=0; int best_score=0; memset(stat, 0, packet_size*sizeof(int)); for(x=i=0; i<size; i++){ if(buf[i] == 0x47){ stat[x]++; if(stat[x] > best_score){ best_score= stat[x]; if(index) *index= x; } } x++; if(x == packet_size) x= 0; } return best_score; } /* autodetect fec presence. Must have at least 1024 bytes */ static int get_packet_size(const uint8_t *buf, int size) { int score, fec_score; if (size < (TS_FEC_PACKET_SIZE * 5 + 1)) return -1; score = analyze(buf, size, TS_PACKET_SIZE, NULL); fec_score= analyze(buf, size, TS_FEC_PACKET_SIZE, NULL); // av_log(NULL, AV_LOG_DEBUG, "score: %d, fec_score: %d \n", score, fec_score); if (score > fec_score) return TS_PACKET_SIZE; else if(score < fec_score) return TS_FEC_PACKET_SIZE; else return -1; } typedef struct SectionHeader { uint8_t tid; uint16_t id; uint8_t version; uint8_t sec_num; uint8_t last_sec_num; } SectionHeader; static inline int get8(const uint8_t **pp, const uint8_t *p_end) { const uint8_t *p; int c; p = *pp; if (p >= p_end) return -1; c = *p++; *pp = p; return c; } static inline int get16(const uint8_t **pp, const uint8_t *p_end) { const uint8_t *p; int c; p = *pp; if ((p + 1) >= p_end) return -1; c = (p[0] << 8) | p[1]; p += 2; *pp = p; return c; } /* read and allocate a DVB string preceeded by its length */ static char *getstr8(const uint8_t **pp, const uint8_t *p_end) { int len; const uint8_t *p; char *str; p = *pp; len = get8(&p, p_end); if (len < 0) return NULL; if ((p + len) > p_end) return NULL; str = av_malloc(len + 1); if (!str) return NULL; memcpy(str, p, len); str[len] = '\0'; p += len; *pp = p; return str; } static int parse_section_header(SectionHeader *h, const uint8_t **pp, const uint8_t *p_end) { int val; val = get8(pp, p_end); if (val < 0) return -1; h->tid = val; *pp += 2; val = get16(pp, p_end); if (val < 0) return -1; h->id = val; val = get8(pp, p_end); if (val < 0) return -1; h->version = (val >> 1) & 0x1f; val = get8(pp, p_end); if (val < 0) return -1; h->sec_num = val; val = get8(pp, p_end); if (val < 0) return -1; h->last_sec_num = val; return 0; } static MpegTSService *new_service(MpegTSContext *ts, int sid, char *provider_name, char *name) { MpegTSService *service; #ifdef DEBUG_SI printf("new_service: sid=0x%04x provider='%s' name='%s'\n", sid, provider_name, name); #endif service = av_mallocz(sizeof(MpegTSService)); if (!service) return NULL; service->sid = sid; service->provider_name = provider_name; service->name = name; dynarray_add(&ts->services, &ts->nb_services, service); return service; } static void pmt_cb(void *opaque, const uint8_t *section, int section_len) { MpegTSContext *ts = opaque; SectionHeader h1, *h = &h1; PESContext *pes; AVStream *st; const uint8_t *p, *p_end, *desc_list_end, *desc_end; int program_info_length, pcr_pid, pid, stream_type; int desc_list_len, desc_len, desc_tag; int comp_page = 0, anc_page = 0; /* initialize to kill warnings */ char language[4]; #ifdef DEBUG_SI printf("PMT:\n"); av_hex_dump(stdout, (uint8_t *)section, section_len); #endif p_end = section + section_len - 4; p = section; if (parse_section_header(h, &p, p_end) < 0) return; #ifdef DEBUG_SI printf("sid=0x%x sec_num=%d/%d\n", h->id, h->sec_num, h->last_sec_num); #endif if (h->tid != PMT_TID || (ts->req_sid >= 0 && h->id != ts->req_sid) ) return; pcr_pid = get16(&p, p_end) & 0x1fff; if (pcr_pid < 0) return; ts->pcr_pid = pcr_pid; #ifdef DEBUG_SI printf("pcr_pid=0x%x\n", pcr_pid); #endif program_info_length = get16(&p, p_end) & 0xfff; if (program_info_length < 0) return; p += program_info_length; if (p >= p_end) return; for(;;) { language[0] = 0; st = 0; stream_type = get8(&p, p_end); if (stream_type < 0) break; pid = get16(&p, p_end) & 0x1fff; if (pid < 0) break; desc_list_len = get16(&p, p_end) & 0xfff; if (desc_list_len < 0) break; desc_list_end = p + desc_list_len; if (desc_list_end > p_end) break; for(;;) { desc_tag = get8(&p, desc_list_end); if (desc_tag < 0) break; desc_len = get8(&p, desc_list_end); desc_end = p + desc_len; if (desc_end > desc_list_end) break; #ifdef DEBUG_SI printf("tag: 0x%02x len=%d\n", desc_tag, desc_len); #endif switch(desc_tag) { case DVB_SUBT_DESCID: if (stream_type == STREAM_TYPE_PRIVATE_DATA) stream_type = STREAM_TYPE_SUBTITLE_DVB; language[0] = get8(&p, desc_end); language[1] = get8(&p, desc_end); language[2] = get8(&p, desc_end); language[3] = 0; get8(&p, desc_end); comp_page = get16(&p, desc_end); anc_page = get16(&p, desc_end); break; case 0x0a: /* ISO 639 language descriptor */ language[0] = get8(&p, desc_end); language[1] = get8(&p, desc_end); language[2] = get8(&p, desc_end); language[3] = 0; break; default: break; } p = desc_end; } p = desc_list_end; #ifdef DEBUG_SI printf("stream_type=%d pid=0x%x\n", stream_type, pid); #endif /* now create ffmpeg stream */ switch(stream_type) { case STREAM_TYPE_AUDIO_MPEG1: case STREAM_TYPE_AUDIO_MPEG2: case STREAM_TYPE_VIDEO_MPEG1: case STREAM_TYPE_VIDEO_MPEG2: case STREAM_TYPE_VIDEO_MPEG4: case STREAM_TYPE_VIDEO_H264: case STREAM_TYPE_AUDIO_AAC: case STREAM_TYPE_AUDIO_AC3: case STREAM_TYPE_AUDIO_DTS: case STREAM_TYPE_SUBTITLE_DVB: pes = add_pes_stream(ts, pid, stream_type); if (pes) st = new_pes_av_stream(pes, 0); break; default: /* we ignore the other streams */ break; } if (st) { if (language[0] != 0) { st->language[0] = language[0]; st->language[1] = language[1]; st->language[2] = language[2]; st->language[3] = language[3]; } if (stream_type == STREAM_TYPE_SUBTITLE_DVB) { st->codec->sub_id = (anc_page << 16) | comp_page; } } } /* all parameters are there */ ts->set_service_cb(ts->set_service_opaque, 0); mpegts_close_filter(ts, ts->pmt_filter); ts->pmt_filter = NULL; } static void pat_cb(void *opaque, const uint8_t *section, int section_len) { MpegTSContext *ts = opaque; SectionHeader h1, *h = &h1; const uint8_t *p, *p_end; int sid, pmt_pid; #ifdef DEBUG_SI printf("PAT:\n"); av_hex_dump(stdout, (uint8_t *)section, section_len); #endif p_end = section + section_len - 4; p = section; if (parse_section_header(h, &p, p_end) < 0) return; if (h->tid != PAT_TID) return; for(;;) { sid = get16(&p, p_end); if (sid < 0) break; pmt_pid = get16(&p, p_end) & 0x1fff; if (pmt_pid < 0) break; #ifdef DEBUG_SI printf("sid=0x%x pid=0x%x\n", sid, pmt_pid); #endif if (sid == 0x0000) { /* NIT info */ } else { if (ts->req_sid == sid) { ts->pmt_filter = mpegts_open_section_filter(ts, pmt_pid, pmt_cb, ts, 1); goto found; } } } /* not found */ ts->set_service_cb(ts->set_service_opaque, -1); found: mpegts_close_filter(ts, ts->pat_filter); ts->pat_filter = NULL; } /* add all services found in the PAT */ static void pat_scan_cb(void *opaque, const uint8_t *section, int section_len) { MpegTSContext *ts = opaque; SectionHeader h1, *h = &h1; const uint8_t *p, *p_end; int sid, pmt_pid; char *provider_name, *name; char buf[256]; #ifdef DEBUG_SI printf("PAT:\n"); av_hex_dump(stdout, (uint8_t *)section, section_len); #endif p_end = section + section_len - 4; p = section; if (parse_section_header(h, &p, p_end) < 0) return; if (h->tid != PAT_TID) return; for(;;) { sid = get16(&p, p_end); if (sid < 0) break; pmt_pid = get16(&p, p_end) & 0x1fff; if (pmt_pid < 0) break; #ifdef DEBUG_SI printf("sid=0x%x pid=0x%x\n", sid, pmt_pid); #endif if (sid == 0x0000) { /* NIT info */ } else { /* add the service with a dummy name */ snprintf(buf, sizeof(buf), "Service %x\n", sid); name = av_strdup(buf); provider_name = av_strdup(""); if (name && provider_name) { new_service(ts, sid, provider_name, name); } else { av_freep(&name); av_freep(&provider_name); } } } ts->stop_parse = 1; /* remove filter */ mpegts_close_filter(ts, ts->pat_filter); ts->pat_filter = NULL; } void mpegts_set_service(MpegTSContext *ts, int sid, SetServiceCallback *set_service_cb, void *opaque) { ts->set_service_cb = set_service_cb; ts->set_service_opaque = opaque; ts->req_sid = sid; ts->pat_filter = mpegts_open_section_filter(ts, PAT_PID, pat_cb, ts, 1); } static void sdt_cb(void *opaque, const uint8_t *section, int section_len) { MpegTSContext *ts = opaque; SectionHeader h1, *h = &h1; const uint8_t *p, *p_end, *desc_list_end, *desc_end; int onid, val, sid, desc_list_len, desc_tag, desc_len, service_type; char *name, *provider_name; #ifdef DEBUG_SI printf("SDT:\n"); av_hex_dump(stdout, (uint8_t *)section, section_len); #endif p_end = section + section_len - 4; p = section; if (parse_section_header(h, &p, p_end) < 0) return; if (h->tid != SDT_TID) return; onid = get16(&p, p_end); if (onid < 0) return; val = get8(&p, p_end); if (val < 0) return; for(;;) { sid = get16(&p, p_end); if (sid < 0) break; val = get8(&p, p_end); if (val < 0) break; desc_list_len = get16(&p, p_end) & 0xfff; if (desc_list_len < 0) break; desc_list_end = p + desc_list_len; if (desc_list_end > p_end) break; for(;;) { desc_tag = get8(&p, desc_list_end); if (desc_tag < 0) break; desc_len = get8(&p, desc_list_end); desc_end = p + desc_len; if (desc_end > desc_list_end) break; #ifdef DEBUG_SI printf("tag: 0x%02x len=%d\n", desc_tag, desc_len); #endif switch(desc_tag) { case 0x48: service_type = get8(&p, p_end); if (service_type < 0) break; provider_name = getstr8(&p, p_end); if (!provider_name) break; name = getstr8(&p, p_end); if (!name) break; new_service(ts, sid, provider_name, name); break; default: break; } p = desc_end; } p = desc_list_end; } ts->stop_parse = 1; /* remove filter */ mpegts_close_filter(ts, ts->sdt_filter); ts->sdt_filter = NULL; } /* scan services in a transport stream by looking at the SDT */ void mpegts_scan_sdt(MpegTSContext *ts) { ts->sdt_filter = mpegts_open_section_filter(ts, SDT_PID, sdt_cb, ts, 1); } /* scan services in a transport stream by looking at the PAT (better than nothing !) */ void mpegts_scan_pat(MpegTSContext *ts) { ts->pat_filter = mpegts_open_section_filter(ts, PAT_PID, pat_scan_cb, ts, 1); } /* TS stream handling */ enum MpegTSState { MPEGTS_HEADER = 0, MPEGTS_PESHEADER_FILL, MPEGTS_PAYLOAD, MPEGTS_SKIP, }; /* enough for PES header + length */ #define PES_START_SIZE 9 #define MAX_PES_HEADER_SIZE (9 + 255) struct PESContext { int pid; int stream_type; MpegTSContext *ts; AVFormatContext *stream; AVStream *st; enum MpegTSState state; /* used to get the format */ int data_index; int total_size; int pes_header_size; int64_t pts, dts; uint8_t header[MAX_PES_HEADER_SIZE]; }; static int64_t get_pts(const uint8_t *p) { int64_t pts; int val; pts = (int64_t)((p[0] >> 1) & 0x07) << 30; val = (p[1] << 8) | p[2]; pts |= (int64_t)(val >> 1) << 15; val = (p[3] << 8) | p[4]; pts |= (int64_t)(val >> 1); return pts; } /* return non zero if a packet could be constructed */ static void mpegts_push_data(void *opaque, const uint8_t *buf, int buf_size, int is_start) { PESContext *pes = opaque; MpegTSContext *ts = pes->ts; const uint8_t *p; int len, code; if (is_start) { pes->state = MPEGTS_HEADER; pes->data_index = 0; } p = buf; while (buf_size > 0) { switch(pes->state) { case MPEGTS_HEADER: len = PES_START_SIZE - pes->data_index; if (len > buf_size) len = buf_size; memcpy(pes->header + pes->data_index, p, len); pes->data_index += len; p += len; buf_size -= len; if (pes->data_index == PES_START_SIZE) { /* we got all the PES or section header. We can now decide */ #if 0 av_hex_dump(pes->header, pes->data_index); #endif if (pes->header[0] == 0x00 && pes->header[1] == 0x00 && pes->header[2] == 0x01) { /* it must be an mpeg2 PES stream */ code = pes->header[3] | 0x100; if (!((code >= 0x1c0 && code <= 0x1df) || (code >= 0x1e0 && code <= 0x1ef) || (code == 0x1bd))) goto skip; if (!pes->st) { /* allocate stream */ new_pes_av_stream(pes, code); } pes->state = MPEGTS_PESHEADER_FILL; pes->total_size = (pes->header[4] << 8) | pes->header[5]; /* NOTE: a zero total size means the PES size is unbounded */ if (pes->total_size) pes->total_size += 6; pes->pes_header_size = pes->header[8] + 9; } else { /* otherwise, it should be a table */ /* skip packet */ skip: pes->state = MPEGTS_SKIP; continue; } } break; /**********************************************/ /* PES packing parsing */ case MPEGTS_PESHEADER_FILL: len = pes->pes_header_size - pes->data_index; if (len > buf_size) len = buf_size; memcpy(pes->header + pes->data_index, p, len); pes->data_index += len; p += len; buf_size -= len; if (pes->data_index == pes->pes_header_size) { const uint8_t *r; unsigned int flags; flags = pes->header[7]; r = pes->header + 9; pes->pts = AV_NOPTS_VALUE; pes->dts = AV_NOPTS_VALUE; if ((flags & 0xc0) == 0x80) { pes->pts = get_pts(r); r += 5; } else if ((flags & 0xc0) == 0xc0) { pes->pts = get_pts(r); r += 5; pes->dts = get_pts(r); r += 5; } /* we got the full header. We parse it and get the payload */ pes->state = MPEGTS_PAYLOAD; } break; case MPEGTS_PAYLOAD: if (pes->total_size) { len = pes->total_size - pes->data_index; if (len > buf_size) len = buf_size; } else { len = buf_size; } if (len > 0) { AVPacket *pkt = ts->pkt; if (pes->st && av_new_packet(pkt, len) == 0) { memcpy(pkt->data, p, len); pkt->stream_index = pes->st->index; pkt->pts = pes->pts; pkt->dts = pes->dts; /* reset pts values */ pes->pts = AV_NOPTS_VALUE; pes->dts = AV_NOPTS_VALUE; ts->stop_parse = 1; return; } } buf_size = 0; break; case MPEGTS_SKIP: buf_size = 0; break; } } } static AVStream* new_pes_av_stream(PESContext *pes, uint32_t code) { AVStream *st; int codec_type, codec_id; switch(pes->stream_type){ case STREAM_TYPE_AUDIO_MPEG1: case STREAM_TYPE_AUDIO_MPEG2: codec_type = CODEC_TYPE_AUDIO; codec_id = CODEC_ID_MP3; break; case STREAM_TYPE_VIDEO_MPEG1: case STREAM_TYPE_VIDEO_MPEG2: codec_type = CODEC_TYPE_VIDEO; codec_id = CODEC_ID_MPEG2VIDEO; break; case STREAM_TYPE_VIDEO_MPEG4: codec_type = CODEC_TYPE_VIDEO; codec_id = CODEC_ID_MPEG4; break; case STREAM_TYPE_VIDEO_H264: codec_type = CODEC_TYPE_VIDEO; codec_id = CODEC_ID_H264; break; case STREAM_TYPE_AUDIO_AAC: codec_type = CODEC_TYPE_AUDIO; codec_id = CODEC_ID_AAC; break; case STREAM_TYPE_AUDIO_AC3: codec_type = CODEC_TYPE_AUDIO; codec_id = CODEC_ID_AC3; break; case STREAM_TYPE_AUDIO_DTS: codec_type = CODEC_TYPE_AUDIO; codec_id = CODEC_ID_DTS; break; case STREAM_TYPE_SUBTITLE_DVB: codec_type = CODEC_TYPE_SUBTITLE; codec_id = CODEC_ID_DVB_SUBTITLE; break; default: if (code >= 0x1c0 && code <= 0x1df) { codec_type = CODEC_TYPE_AUDIO; codec_id = CODEC_ID_MP2; } else if (code == 0x1bd) { codec_type = CODEC_TYPE_AUDIO; codec_id = CODEC_ID_AC3; } else { codec_type = CODEC_TYPE_VIDEO; codec_id = CODEC_ID_MPEG1VIDEO; } break; } st = av_new_stream(pes->stream, pes->pid); if (st) { av_set_pts_info(st, 33, 1, 90000); st->priv_data = pes; st->codec->codec_type = codec_type; st->codec->codec_id = codec_id; st->need_parsing = 1; pes->st = st; } return st; } static PESContext *add_pes_stream(MpegTSContext *ts, int pid, int stream_type) { MpegTSFilter *tss; PESContext *pes; /* if no pid found, then add a pid context */ pes = av_mallocz(sizeof(PESContext)); if (!pes) return 0; pes->ts = ts; pes->stream = ts->stream; pes->pid = pid; pes->stream_type = stream_type; tss = mpegts_open_pes_filter(ts, pid, mpegts_push_data, pes); if (!tss) { av_free(pes); return 0; } return pes; } /* handle one TS packet */ static void handle_packet(MpegTSContext *ts, const uint8_t *packet) { AVFormatContext *s = ts->stream; MpegTSFilter *tss; int len, pid, cc, cc_ok, afc, is_start; const uint8_t *p, *p_end; pid = ((packet[1] & 0x1f) << 8) | packet[2]; is_start = packet[1] & 0x40; tss = ts->pids[pid]; if (ts->auto_guess && tss == NULL && is_start) { add_pes_stream(ts, pid, 0); tss = ts->pids[pid]; } if (!tss) return; /* continuity check (currently not used) */ cc = (packet[3] & 0xf); cc_ok = (tss->last_cc < 0) || ((((tss->last_cc + 1) & 0x0f) == cc)); tss->last_cc = cc; /* skip adaptation field */ afc = (packet[3] >> 4) & 3; p = packet + 4; if (afc == 0) /* reserved value */ return; if (afc == 2) /* adaptation field only */ return; if (afc == 3) { /* skip adapation field */ p += p[0] + 1; } /* if past the end of packet, ignore */ p_end = packet + TS_PACKET_SIZE; if (p >= p_end) return; if (tss->type == MPEGTS_SECTION) { if (is_start) { /* pointer field present */ len = *p++; if (p + len > p_end) return; if (len && cc_ok) { /* write remaining section bytes */ write_section_data(s, tss, p, len, 0); /* check whether filter has been closed */ if (!ts->pids[pid]) return; } p += len; if (p < p_end) { write_section_data(s, tss, p, p_end - p, 1); } } else { if (cc_ok) { write_section_data(s, tss, p, p_end - p, 0); } } } else { tss->u.pes_filter.pes_cb(tss->u.pes_filter.opaque, p, p_end - p, is_start); } } /* XXX: try to find a better synchro over several packets (use get_packet_size() ?) */ static int mpegts_resync(ByteIOContext *pb) { int c, i; for(i = 0;i < MAX_RESYNC_SIZE; i++) { c = url_fgetc(pb); if (c < 0) return -1; if (c == 0x47) { url_fseek(pb, -1, SEEK_CUR); return 0; } } /* no sync found */ return -1; } /* return -1 if error or EOF. Return 0 if OK. */ static int read_packet(ByteIOContext *pb, uint8_t *buf, int raw_packet_size) { 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_PACKET_SIZE]; int packet_num, ret; ts->stop_parse = 0; packet_num = 0; for(;;) { if (ts->stop_parse) break; packet_num++; if (nb_packets != 0 && packet_num >= nb_packets) break; ret = read_packet(pb, packet, ts->raw_packet_size); if (ret != 0) return ret; handle_packet(ts, packet); } return 0; } static int mpegts_probe(AVProbeData *p) { #if 1 const int size= p->buf_size; int score, fec_score; #define CHECK_COUNT 10 if (size < (TS_FEC_PACKET_SIZE * CHECK_COUNT)) return -1; score = analyze(p->buf, TS_PACKET_SIZE *CHECK_COUNT, TS_PACKET_SIZE, NULL); fec_score= analyze(p->buf, TS_FEC_PACKET_SIZE*CHECK_COUNT, TS_FEC_PACKET_SIZE, NULL); // av_log(NULL, AV_LOG_DEBUG, "score: %d, fec_score: %d \n", score, fec_score); // we need a clear definition for the returned score otherwise things will become messy sooner or later if (score > fec_score && score > 6) return AVPROBE_SCORE_MAX + score - CHECK_COUNT; else if( fec_score > 6) return AVPROBE_SCORE_MAX + fec_score - CHECK_COUNT; else return -1; #else /* only use the extension for safer guess */ if (match_ext(p->filename, "ts")) return AVPROBE_SCORE_MAX; else return 0; #endif } void set_service_cb(void *opaque, int ret) { MpegTSContext *ts = opaque; ts->set_service_ret = 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) { MpegTSContext *ts = s->priv_data; ByteIOContext *pb = &s->pb; uint8_t buf[1024]; int len, sid, i; 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)); if (len != sizeof(buf)) goto fail; 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->mpeg2ts_raw) { /* normal demux */ 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); 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) { /* raw transport stream */ ts->auto_guess = 1; s->ctx_flags |= AVFMTCTX_NOHEADER; goto do_pcr; } /* tune to first service found */ for(i=0; i<ts->nb_services && ts->set_service_ret; i++){ service = ts->services[i]; sid = service->sid; #ifdef DEBUG_SI 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 */ do_pcr: st = av_new_stream(s, 0); if (!st) goto fail; av_set_pts_info(st, 60, 1, 27000000); 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++; } ts->pcr_pid = pcr_pid; /* 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; #if 0 printf("start=%0.3f pcr=%0.3f incr=%d\n", st->start_time / 1000000.0, pcrs[0] / 27e6, ts->pcr_incr); #endif } url_fseek(pb, pos, SEEK_SET); return 0; fail: 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; pkt->pos= url_ftell(&s->pb); 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; 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) { MpegTSContext *ts = s->priv_data; int i; for(i=0;i<NB_PID_MAX;i++) if (ts->pids[i]) mpegts_close_filter(ts, ts->pids[i]); return 0; } static int64_t mpegts_get_pcr(AVFormatContext *s, int stream_index, int64_t *ppos, int64_t pos_limit) { MpegTSContext *ts = s->priv_data; int64_t pos, timestamp; uint8_t buf[TS_PACKET_SIZE]; int pcr_l, pid; const int find_next= 1; pos = ((*ppos + ts->raw_packet_size - 1) / ts->raw_packet_size) * ts->raw_packet_size; if (find_next) { for(;;) { url_fseek(&s->pb, pos, SEEK_SET); if (get_buffer(&s->pb, buf, TS_PACKET_SIZE) != TS_PACKET_SIZE) return AV_NOPTS_VALUE; pid = ((buf[1] & 0x1f) << 8) | buf[2]; if (pid == ts->pcr_pid && parse_pcr(×tamp, &pcr_l, buf) == 0) { break; } pos += ts->raw_packet_size; } } else { for(;;) { pos -= ts->raw_packet_size; if (pos < 0) return AV_NOPTS_VALUE; url_fseek(&s->pb, pos, SEEK_SET); if (get_buffer(&s->pb, buf, TS_PACKET_SIZE) != TS_PACKET_SIZE) return AV_NOPTS_VALUE; pid = ((buf[1] & 0x1f) << 8) | buf[2]; if (pid == ts->pcr_pid && parse_pcr(×tamp, &pcr_l, buf) == 0) { break; } } } *ppos = pos; return timestamp; } static int read_seek(AVFormatContext *s, int stream_index, int64_t target_ts, int flags){ MpegTSContext *ts = s->priv_data; uint8_t buf[TS_PACKET_SIZE]; int64_t pos; if(av_seek_frame_binary(s, stream_index, target_ts, flags) < 0) return -1; pos= url_ftell(&s->pb); for(;;) { url_fseek(&s->pb, pos, SEEK_SET); if (get_buffer(&s->pb, buf, TS_PACKET_SIZE) != TS_PACKET_SIZE) return -1; // pid = ((buf[1] & 0x1f) << 8) | buf[2]; if(buf[1] & 0x40) break; pos += ts->raw_packet_size; } url_fseek(&s->pb, pos, SEEK_SET); 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", sizeof(MpegTSContext), mpegts_probe, mpegts_read_header, mpegts_read_packet, mpegts_read_close, read_seek, mpegts_get_pcr, .flags = AVFMT_SHOW_IDS, }; int mpegts_init(void) { av_register_input_format(&mpegts_demux); #ifdef CONFIG_MUXERS av_register_output_format(&mpegts_mux); #endif return 0; }