1 /*
2  * MPEG2 transport stream (aka DVB) demuxer
3  * Copyright (c) 2002-2003 Fabrice Bellard.
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 #include "avformat.h"
22 #include "crc.h"
23 #include "mpegts.h"
24 
25 //#define DEBUG_SI
26 //#define DEBUG_SEEK
27 
28 /* 1.0 second at 24Mbit/s */
29 #define MAX_SCAN_PACKETS 32000
30 
31 /* maximum size in which we look for synchronisation if
32    synchronisation is lost */
33 #define MAX_RESYNC_SIZE 4096
34 #define REGISTRATION_DESCRIPTOR 5
35 
36 typedef struct PESContext PESContext;
37 
38 static PESContext* add_pes_stream(MpegTSContext *ts, int pid, int pcr_pid, int stream_type);
39 static AVStream* new_pes_av_stream(PESContext *pes, uint32_t code);
40 extern void av_set_program_name(AVProgram *program, char *provider_name, char *name);
41 extern void av_program_add_stream_index(AVFormatContext *ac, int progid, unsigned int idx);
42 
43 enum MpegTSFilterType {
44     MPEGTS_PES,
45     MPEGTS_SECTION,
46 };
47 
48 typedef struct MpegTSFilter MpegTSFilter;
49 
50 typedef void PESCallback(MpegTSFilter *f, const uint8_t *buf, int len, int is_start);
51 
52 typedef struct MpegTSPESFilter {
53     PESCallback *pes_cb;
54     void *opaque;
55 } MpegTSPESFilter;
56 
57 typedef void SectionCallback(MpegTSFilter *f, const uint8_t *buf, int len);
58 
59 typedef void SetServiceCallback(void *opaque, int ret);
60 
61 typedef struct MpegTSSectionFilter {
62     int section_index;
63     int section_h_size;
64     uint8_t *section_buf;
65     int check_crc:1;
66     int end_of_section_reached:1;
67     SectionCallback *section_cb;
68     void *opaque;
69 } MpegTSSectionFilter;
70 
71 struct MpegTSFilter {
72     int pid;
73     int last_cc; /* last cc code (-1 if first packet) */
74     enum MpegTSFilterType type;
75     union {
76         MpegTSPESFilter pes_filter;
77         MpegTSSectionFilter section_filter;
78     } u;
79 };
80 
81 #define MAX_PIDS_PER_PROGRAM 64
82 typedef struct {
83     unsigned int id; //program id/service id
84     unsigned int nb_pids;
85     unsigned int pids[MAX_PIDS_PER_PROGRAM];
86 } Program_t;
87 
88 struct MpegTSContext {
89     /* user data */
90     AVFormatContext *stream;
91     /** raw packet size, including FEC if present            */
92     int raw_packet_size;
93 
94     int pos47;
95 
96     /** if true, all pids are analyzed to find streams       */
97     int auto_guess;
98 
99     /** compute exact PCR for each transport stream packet   */
100     int mpeg2ts_compute_pcr;
101 
102     int64_t cur_pcr;    /**< used to estimate the exact PCR  */
103     int pcr_incr;       /**< used to estimate the exact PCR  */
104 
105     /* data needed to handle file based ts */
106     /** stop parsing loop                                    */
107     int stop_parse;
108     /** packet containing Audio/Video data                   */
109     AVPacket *pkt;
110 
111     /******************************************/
112     /* private mpegts data */
113     /* scan context */
114     /** structure to keep track of Program->pids mapping     */
115     unsigned int nb_prg;
116     Program_t *prg;
117 
118 
119     /** filters for various streams specified by PMT + for the PAT and PMT */
120     MpegTSFilter *pids[NB_PID_MAX];
121 };
122 
123 /* TS stream handling */
124 
125 enum MpegTSState {
126     MPEGTS_HEADER = 0,
127     MPEGTS_PESHEADER_FILL,
128     MPEGTS_PAYLOAD,
129     MPEGTS_SKIP,
130 };
131 
132 /* enough for PES header + length */
133 #define PES_START_SIZE 9
134 #define MAX_PES_HEADER_SIZE (9 + 255)
135 
136 struct PESContext {
137     int pid;
138     int pcr_pid; /**< if -1 then all packets containing PCR are considered */
139     int stream_type;
140     MpegTSContext *ts;
141     AVFormatContext *stream;
142     AVStream *st;
143     enum MpegTSState state;
144     /* used to get the format */
145     int data_index;
146     int total_size;
147     int pes_header_size;
148     int64_t pts, dts;
149     uint8_t header[MAX_PES_HEADER_SIZE];
150 };
151 
152 extern AVInputFormat mpegts_demuxer;
153 
clear_program(MpegTSContext * ts,unsigned int programid)154 static void clear_program(MpegTSContext *ts, unsigned int programid)
155 {
156     int i;
157 
158     for(i=0; i<ts->nb_prg; i++)
159         if(ts->prg[i].id == programid)
160             ts->prg[i].nb_pids = 0;
161 }
162 
clear_programs(MpegTSContext * ts)163 static void clear_programs(MpegTSContext *ts)
164 {
165     av_freep(&ts->prg);
166     ts->nb_prg=0;
167 }
168 
add_pat_entry(MpegTSContext * ts,unsigned int programid)169 static void add_pat_entry(MpegTSContext *ts, unsigned int programid)
170 {
171     Program_t *p;
172     void *tmp = av_realloc(ts->prg, (ts->nb_prg+1)*sizeof(Program_t));
173     if(!tmp)
174         return;
175     ts->prg = tmp;
176     p = &ts->prg[ts->nb_prg];
177     p->id = programid;
178     p->nb_pids = 0;
179     ts->nb_prg++;
180 }
181 
add_pid_to_pmt(MpegTSContext * ts,unsigned int programid,unsigned int pid)182 static void add_pid_to_pmt(MpegTSContext *ts, unsigned int programid, unsigned int pid)
183 {
184     int i;
185     Program_t *p = NULL;
186     for(i=0; i<ts->nb_prg; i++) {
187         if(ts->prg[i].id == programid) {
188             p = &ts->prg[i];
189             break;
190         }
191     }
192     if(!p)
193         return;
194 
195     if(p->nb_pids >= MAX_PIDS_PER_PROGRAM)
196         return;
197     p->pids[p->nb_pids++] = pid;
198 }
199 
200 /**
201  * \brief discard_pid() decides if the pid is to be discarded according
202  *                      to caller's programs selection
203  * \param ts    : - TS context
204  * \param pid   : - pid
205  * \return 1 if the pid is only comprised in programs that have .discard=AVDISCARD_ALL
206  *         0 otherwise
207  */
discard_pid(MpegTSContext * ts,unsigned int pid)208 static int discard_pid(MpegTSContext *ts, unsigned int pid)
209 {
210     int i, j, k;
211     int used = 0, discarded = 0;
212     Program_t *p;
213     for(i=0; i<ts->nb_prg; i++) {
214         p = &ts->prg[i];
215         for(j=0; j<p->nb_pids; j++) {
216             if(p->pids[j] != pid)
217                 continue;
218             //is program with id p->id set to be discarded?
219             for(k=0; k<ts->stream->nb_programs; k++) {
220                 if(ts->stream->programs[k]->id == p->id) {
221                     if(ts->stream->programs[k]->discard == AVDISCARD_ALL)
222                         discarded++;
223                     else
224                         used++;
225                 }
226             }
227         }
228     }
229 
230     return (!used && discarded);
231 }
232 
233 /**
234  *  Assembles PES packets out of TS packets, and then calls the "section_cb"
235  *  function when they are complete.
236  */
write_section_data(AVFormatContext * s,MpegTSFilter * tss1,const uint8_t * buf,int buf_size,int is_start)237 static void write_section_data(AVFormatContext *s, MpegTSFilter *tss1,
238                                const uint8_t *buf, int buf_size, int is_start)
239 {
240     MpegTSSectionFilter *tss = &tss1->u.section_filter;
241     int len;
242 
243     if (is_start) {
244         memcpy(tss->section_buf, buf, buf_size);
245         tss->section_index = buf_size;
246         tss->section_h_size = -1;
247         tss->end_of_section_reached = 0;
248     } else {
249         if (tss->end_of_section_reached)
250             return;
251         len = 4096 - tss->section_index;
252         if (buf_size < len)
253             len = buf_size;
254         memcpy(tss->section_buf + tss->section_index, buf, len);
255         tss->section_index += len;
256     }
257 
258     /* compute section length if possible */
259     if (tss->section_h_size == -1 && tss->section_index >= 3) {
260         len = (AV_RB16(tss->section_buf + 1) & 0xfff) + 3;
261         if (len > 4096)
262             return;
263         tss->section_h_size = len;
264     }
265 
266     if (tss->section_h_size != -1 && tss->section_index >= tss->section_h_size) {
267         tss->end_of_section_reached = 1;
268         if (!tss->check_crc ||
269             av_crc(av_crc_get_table(AV_CRC_32_IEEE), -1,
270                    tss->section_buf, tss->section_h_size) == 0)
271             tss->section_cb(tss1, tss->section_buf, tss->section_h_size);
272     }
273 }
274 
mpegts_open_section_filter(MpegTSContext * ts,unsigned int pid,SectionCallback * section_cb,void * opaque,int check_crc)275 static MpegTSFilter *mpegts_open_section_filter(MpegTSContext *ts, unsigned int pid,
276                                          SectionCallback *section_cb, void *opaque,
277                                          int check_crc)
278 
279 {
280     MpegTSFilter *filter;
281     MpegTSSectionFilter *sec;
282 
283 #ifdef DEBUG_SI
284     av_log(ts->stream, AV_LOG_DEBUG, "Filter: pid=0x%x\n", pid);
285 #endif
286     if (pid >= NB_PID_MAX || ts->pids[pid])
287         return NULL;
288     filter = av_mallocz(sizeof(MpegTSFilter));
289     if (!filter)
290         return NULL;
291     ts->pids[pid] = filter;
292     filter->type = MPEGTS_SECTION;
293     filter->pid = pid;
294     filter->last_cc = -1;
295     sec = &filter->u.section_filter;
296     sec->section_cb = section_cb;
297     sec->opaque = opaque;
298     sec->section_buf = av_malloc(MAX_SECTION_SIZE);
299     sec->check_crc = check_crc;
300     if (!sec->section_buf) {
301         av_free(filter);
302         return NULL;
303     }
304     return filter;
305 }
306 
mpegts_open_pes_filter(MpegTSContext * ts,unsigned int pid,PESCallback * pes_cb,void * opaque)307 static MpegTSFilter *mpegts_open_pes_filter(MpegTSContext *ts, unsigned int pid,
308                                      PESCallback *pes_cb,
309                                      void *opaque)
310 {
311     MpegTSFilter *filter;
312     MpegTSPESFilter *pes;
313 
314     if (pid >= NB_PID_MAX || ts->pids[pid])
315         return NULL;
316     filter = av_mallocz(sizeof(MpegTSFilter));
317     if (!filter)
318         return NULL;
319     ts->pids[pid] = filter;
320     filter->type = MPEGTS_PES;
321     filter->pid = pid;
322     filter->last_cc = -1;
323     pes = &filter->u.pes_filter;
324     pes->pes_cb = pes_cb;
325     pes->opaque = opaque;
326     return filter;
327 }
328 
mpegts_close_filter(MpegTSContext * ts,MpegTSFilter * filter)329 static void mpegts_close_filter(MpegTSContext *ts, MpegTSFilter *filter)
330 {
331     int pid;
332 
333     pid = filter->pid;
334     if (filter->type == MPEGTS_SECTION)
335         av_freep(&filter->u.section_filter.section_buf);
336     else if (filter->type == MPEGTS_PES)
337         av_freep(&filter->u.pes_filter.opaque);
338 
339     av_free(filter);
340     ts->pids[pid] = NULL;
341 }
342 
analyze(const uint8_t * buf,int size,int packet_size,int * index)343 static int analyze(const uint8_t *buf, int size, int packet_size, int *index){
344     int stat[packet_size];
345     int i;
346     int x=0;
347     int best_score=0;
348 
349     memset(stat, 0, packet_size*sizeof(int));
350 
351     for(x=i=0; i<size; i++){
352         if(buf[i] == 0x47){
353             stat[x]++;
354             if(stat[x] > best_score){
355                 best_score= stat[x];
356                 if(index) *index= x;
357             }
358         }
359 
360         x++;
361         if(x == packet_size) x= 0;
362     }
363 
364     return best_score;
365 }
366 
367 /* autodetect fec presence. Must have at least 1024 bytes  */
get_packet_size(const uint8_t * buf,int size)368 static int get_packet_size(const uint8_t *buf, int size)
369 {
370     int score, fec_score, dvhs_score;
371 
372     if (size < (TS_FEC_PACKET_SIZE * 5 + 1))
373         return -1;
374 
375     score    = analyze(buf, size, TS_PACKET_SIZE, NULL);
376     dvhs_score    = analyze(buf, size, TS_DVHS_PACKET_SIZE, NULL);
377     fec_score= analyze(buf, size, TS_FEC_PACKET_SIZE, NULL);
378 //    av_log(NULL, AV_LOG_DEBUG, "score: %d, dvhs_score: %d, fec_score: %d \n", score, dvhs_score, fec_score);
379 
380     if     (score > fec_score && score > dvhs_score) return TS_PACKET_SIZE;
381     else if(dvhs_score > score && dvhs_score > fec_score) return TS_DVHS_PACKET_SIZE;
382     else if(score < fec_score && dvhs_score < fec_score) return TS_FEC_PACKET_SIZE;
383     else                       return -1;
384 }
385 
386 typedef struct SectionHeader {
387     uint8_t tid;
388     uint16_t id;
389     uint8_t version;
390     uint8_t sec_num;
391     uint8_t last_sec_num;
392 } SectionHeader;
393 
get8(const uint8_t ** pp,const uint8_t * p_end)394 static inline int get8(const uint8_t **pp, const uint8_t *p_end)
395 {
396     const uint8_t *p;
397     int c;
398 
399     p = *pp;
400     if (p >= p_end)
401         return -1;
402     c = *p++;
403     *pp = p;
404     return c;
405 }
406 
get16(const uint8_t ** pp,const uint8_t * p_end)407 static inline int get16(const uint8_t **pp, const uint8_t *p_end)
408 {
409     const uint8_t *p;
410     int c;
411 
412     p = *pp;
413     if ((p + 1) >= p_end)
414         return -1;
415     c = AV_RB16(p);
416     p += 2;
417     *pp = p;
418     return c;
419 }
420 
421 /* read and allocate a DVB string preceeded by its length */
getstr8(const uint8_t ** pp,const uint8_t * p_end)422 static char *getstr8(const uint8_t **pp, const uint8_t *p_end)
423 {
424     int len;
425     const uint8_t *p;
426     char *str;
427 
428     p = *pp;
429     len = get8(&p, p_end);
430     if (len < 0)
431         return NULL;
432     if ((p + len) > p_end)
433         return NULL;
434     str = av_malloc(len + 1);
435     if (!str)
436         return NULL;
437     memcpy(str, p, len);
438     str[len] = '\0';
439     p += len;
440     *pp = p;
441     return str;
442 }
443 
parse_section_header(SectionHeader * h,const uint8_t ** pp,const uint8_t * p_end)444 static int parse_section_header(SectionHeader *h,
445                                 const uint8_t **pp, const uint8_t *p_end)
446 {
447     int val;
448 
449     val = get8(pp, p_end);
450     if (val < 0)
451         return -1;
452     h->tid = val;
453     *pp += 2;
454     val = get16(pp, p_end);
455     if (val < 0)
456         return -1;
457     h->id = val;
458     val = get8(pp, p_end);
459     if (val < 0)
460         return -1;
461     h->version = (val >> 1) & 0x1f;
462     val = get8(pp, p_end);
463     if (val < 0)
464         return -1;
465     h->sec_num = val;
466     val = get8(pp, p_end);
467     if (val < 0)
468         return -1;
469     h->last_sec_num = val;
470     return 0;
471 }
472 
473 
pmt_cb(MpegTSFilter * filter,const uint8_t * section,int section_len)474 static void pmt_cb(MpegTSFilter *filter, const uint8_t *section, int section_len)
475 {
476     MpegTSContext *ts = filter->u.section_filter.opaque;
477     SectionHeader h1, *h = &h1;
478     PESContext *pes;
479     AVStream *st;
480     const uint8_t *p, *p_end, *desc_list_end, *desc_end;
481     int program_info_length, pcr_pid, pid, stream_type;
482     int desc_list_len, desc_len, desc_tag;
483     int comp_page = 0, anc_page = 0; /* initialize to kill warnings */
484     char language[4] = {0}; /* initialize to kill warnings */
485     int has_hdmv_descr = 0;
486 
487 #ifdef DEBUG_SI
488     av_log(ts->stream, AV_LOG_DEBUG, "PMT: len %i\n", section_len);
489     av_hex_dump_log(ts->stream, AV_LOG_DEBUG, (uint8_t *)section, section_len);
490 #endif
491     p_end = section + section_len - 4;
492     p = section;
493     if (parse_section_header(h, &p, p_end) < 0)
494         return;
495 #ifdef DEBUG_SI
496     av_log(ts->stream, AV_LOG_DEBUG, "sid=0x%x sec_num=%d/%d\n",
497            h->id, h->sec_num, h->last_sec_num);
498 #endif
499     if (h->tid != PMT_TID)
500         return;
501 
502     clear_program(ts, h->id);
503     pcr_pid = get16(&p, p_end) & 0x1fff;
504     if (pcr_pid < 0)
505         return;
506     add_pid_to_pmt(ts, h->id, pcr_pid);
507 #ifdef DEBUG_SI
508     av_log(ts->stream, AV_LOG_DEBUG, "pcr_pid=0x%x\n", pcr_pid);
509 #endif
510     program_info_length = get16(&p, p_end) & 0xfff;
511     if (program_info_length < 0)
512         return;
513     while(program_info_length >= 2) {
514         uint8_t tag, len;
515         tag = get8(&p, p_end);
516         len = get8(&p, p_end);
517         if(len > program_info_length - 2)
518             //something else is broken, exit the program_descriptors_loop
519             break;
520         program_info_length -= len + 2;
521         if(tag == REGISTRATION_DESCRIPTOR && len >= 4) {
522             uint8_t bytes[4];
523             bytes[0] = get8(&p, p_end);
524             bytes[1] = get8(&p, p_end);
525             bytes[2] = get8(&p, p_end);
526             bytes[3] = get8(&p, p_end);
527             len -= 4;
528             if(bytes[0] == 'H' && bytes[1] == 'D' &&
529                bytes[2] == 'M' && bytes[3] == 'V')
530                 has_hdmv_descr = 1;
531         }
532         p += len;
533     }
534     p += program_info_length;
535     if (p >= p_end)
536         return;
537     for(;;) {
538         language[0] = 0;
539         st = 0;
540         stream_type = get8(&p, p_end);
541         if (stream_type < 0)
542             break;
543         pid = get16(&p, p_end) & 0x1fff;
544         if (pid < 0)
545             break;
546         desc_list_len = get16(&p, p_end) & 0xfff;
547         if (desc_list_len < 0)
548             break;
549         desc_list_end = p + desc_list_len;
550         if (desc_list_end > p_end)
551             break;
552         for(;;) {
553             desc_tag = get8(&p, desc_list_end);
554             if (desc_tag < 0)
555                 break;
556             if (stream_type == STREAM_TYPE_PRIVATE_DATA) {
557                 if((desc_tag == 0x6A) || (desc_tag == 0x7A)) {
558                     /*assume DVB AC-3 Audio*/
559                     stream_type = STREAM_TYPE_AUDIO_AC3;
560                 } else if(desc_tag == 0x7B) {
561                     /* DVB DTS audio */
562                     stream_type = STREAM_TYPE_AUDIO_DTS;
563                 }
564             }
565             desc_len = get8(&p, desc_list_end);
566             desc_end = p + desc_len;
567             if (desc_end > desc_list_end)
568                 break;
569 #ifdef DEBUG_SI
570             av_log(ts->stream, AV_LOG_DEBUG, "tag: 0x%02x len=%d\n",
571                    desc_tag, desc_len);
572 #endif
573             switch(desc_tag) {
574             case DVB_SUBT_DESCID:
575                 if (stream_type == STREAM_TYPE_PRIVATE_DATA)
576                     stream_type = STREAM_TYPE_SUBTITLE_DVB;
577 
578                 language[0] = get8(&p, desc_end);
579                 language[1] = get8(&p, desc_end);
580                 language[2] = get8(&p, desc_end);
581                 language[3] = 0;
582                 get8(&p, desc_end);
583                 comp_page = get16(&p, desc_end);
584                 anc_page = get16(&p, desc_end);
585 
586                 break;
587             case 0x0a: /* ISO 639 language descriptor */
588                 language[0] = get8(&p, desc_end);
589                 language[1] = get8(&p, desc_end);
590                 language[2] = get8(&p, desc_end);
591                 language[3] = 0;
592                 break;
593             default:
594                 break;
595             }
596             p = desc_end;
597         }
598         p = desc_list_end;
599 
600 #ifdef DEBUG_SI
601         av_log(ts->stream, AV_LOG_DEBUG, "stream_type=%d pid=0x%x\n",
602                stream_type, pid);
603 #endif
604 
605         /* now create ffmpeg stream */
606         switch(stream_type) {
607         case STREAM_TYPE_AUDIO_MPEG1:
608         case STREAM_TYPE_AUDIO_MPEG2:
609         case STREAM_TYPE_VIDEO_MPEG1:
610         case STREAM_TYPE_VIDEO_MPEG2:
611         case STREAM_TYPE_VIDEO_MPEG4:
612         case STREAM_TYPE_VIDEO_H264:
613         case STREAM_TYPE_VIDEO_VC1:
614         case STREAM_TYPE_AUDIO_AAC:
615         case STREAM_TYPE_AUDIO_AC3:
616         case STREAM_TYPE_AUDIO_DTS:
617         case STREAM_TYPE_AUDIO_HDMV_DTS:
618         case STREAM_TYPE_SUBTITLE_DVB:
619             if(stream_type == STREAM_TYPE_AUDIO_HDMV_DTS && !has_hdmv_descr)
620                 break;
621             if(ts->pids[pid] && ts->pids[pid]->type == MPEGTS_PES){
622                 pes= ts->pids[pid]->u.pes_filter.opaque;
623                 st= pes->st;
624             }else{
625                 if (ts->pids[pid]) mpegts_close_filter(ts, ts->pids[pid]); //wrongly added sdt filter probably
626                 pes = add_pes_stream(ts, pid, pcr_pid, stream_type);
627                 if (pes)
628                     st = new_pes_av_stream(pes, 0);
629             }
630             add_pid_to_pmt(ts, h->id, pid);
631             if(st)
632                 av_program_add_stream_index(ts->stream, h->id, st->index);
633             break;
634         default:
635             /* we ignore the other streams */
636             break;
637         }
638 
639         if (st) {
640             if (language[0] != 0) {
641                 memcpy(st->language, language, 4);
642             }
643 
644             if (stream_type == STREAM_TYPE_SUBTITLE_DVB) {
645                 st->codec->sub_id = (anc_page << 16) | comp_page;
646             }
647         }
648     }
649     /* all parameters are there */
650     ts->stop_parse++;
651     mpegts_close_filter(ts, filter);
652 }
653 
pat_cb(MpegTSFilter * filter,const uint8_t * section,int section_len)654 static void pat_cb(MpegTSFilter *filter, const uint8_t *section, int section_len)
655 {
656     MpegTSContext *ts = filter->u.section_filter.opaque;
657     SectionHeader h1, *h = &h1;
658     const uint8_t *p, *p_end;
659     int sid, pmt_pid;
660 
661 #ifdef DEBUG_SI
662     av_log(ts->stream, AV_LOG_DEBUG, "PAT:\n");
663     av_hex_dump_log(ts->stream, AV_LOG_DEBUG, (uint8_t *)section, section_len);
664 #endif
665     p_end = section + section_len - 4;
666     p = section;
667     if (parse_section_header(h, &p, p_end) < 0)
668         return;
669     if (h->tid != PAT_TID)
670         return;
671 
672     clear_programs(ts);
673     for(;;) {
674         sid = get16(&p, p_end);
675         if (sid < 0)
676             break;
677         pmt_pid = get16(&p, p_end) & 0x1fff;
678         if (pmt_pid < 0)
679             break;
680 #ifdef DEBUG_SI
681         av_log(ts->stream, AV_LOG_DEBUG, "sid=0x%x pid=0x%x\n", sid, pmt_pid);
682 #endif
683         if (sid == 0x0000) {
684             /* NIT info */
685         } else {
686             av_new_program(ts->stream, sid);
687             ts->stop_parse--;
688             mpegts_open_section_filter(ts, pmt_pid, pmt_cb, ts, 1);
689             add_pat_entry(ts, sid);
690             add_pid_to_pmt(ts, sid, 0); //add pat pid to program
691             add_pid_to_pmt(ts, sid, pmt_pid);
692         }
693     }
694     /* not found */
695     ts->stop_parse++;
696 
697     mpegts_close_filter(ts, filter);
698 }
699 
mpegts_set_service(MpegTSContext * ts)700 static void mpegts_set_service(MpegTSContext *ts)
701 {
702     mpegts_open_section_filter(ts, PAT_PID,
703                                                 pat_cb, ts, 1);
704 }
705 
sdt_cb(MpegTSFilter * filter,const uint8_t * section,int section_len)706 static void sdt_cb(MpegTSFilter *filter, const uint8_t *section, int section_len)
707 {
708     MpegTSContext *ts = filter->u.section_filter.opaque;
709     SectionHeader h1, *h = &h1;
710     const uint8_t *p, *p_end, *desc_list_end, *desc_end;
711     int onid, val, sid, desc_list_len, desc_tag, desc_len, service_type;
712     char *name, *provider_name;
713 
714 #ifdef DEBUG_SI
715     av_log(ts->stream, AV_LOG_DEBUG, "SDT:\n");
716     av_hex_dump_log(ts->stream, AV_LOG_DEBUG, (uint8_t *)section, section_len);
717 #endif
718 
719     p_end = section + section_len - 4;
720     p = section;
721     if (parse_section_header(h, &p, p_end) < 0)
722         return;
723     if (h->tid != SDT_TID)
724         return;
725     onid = get16(&p, p_end);
726     if (onid < 0)
727         return;
728     val = get8(&p, p_end);
729     if (val < 0)
730         return;
731     for(;;) {
732         sid = get16(&p, p_end);
733         if (sid < 0)
734             break;
735         val = get8(&p, p_end);
736         if (val < 0)
737             break;
738         desc_list_len = get16(&p, p_end) & 0xfff;
739         if (desc_list_len < 0)
740             break;
741         desc_list_end = p + desc_list_len;
742         if (desc_list_end > p_end)
743             break;
744         for(;;) {
745             desc_tag = get8(&p, desc_list_end);
746             if (desc_tag < 0)
747                 break;
748             desc_len = get8(&p, desc_list_end);
749             desc_end = p + desc_len;
750             if (desc_end > desc_list_end)
751                 break;
752 #ifdef DEBUG_SI
753             av_log(ts->stream, AV_LOG_DEBUG, "tag: 0x%02x len=%d\n",
754                    desc_tag, desc_len);
755 #endif
756             switch(desc_tag) {
757             case 0x48:
758                 service_type = get8(&p, p_end);
759                 if (service_type < 0)
760                     break;
761                 provider_name = getstr8(&p, p_end);
762                 if (!provider_name)
763                     break;
764                 name = getstr8(&p, p_end);
765                 if (name) {
766                     AVProgram *program = av_new_program(ts->stream, sid);
767                     if(program)
768                         av_set_program_name(program, provider_name, name);
769                 }
770                 av_free(name);
771                 av_free(provider_name);
772                 break;
773             default:
774                 break;
775             }
776             p = desc_end;
777         }
778         p = desc_list_end;
779     }
780 }
781 
782 /* scan services in a transport stream by looking at the SDT */
mpegts_scan_sdt(MpegTSContext * ts)783 static void mpegts_scan_sdt(MpegTSContext *ts)
784 {
785     mpegts_open_section_filter(ts, SDT_PID,
786                                                 sdt_cb, ts, 1);
787 }
788 
get_pts(const uint8_t * p)789 static int64_t get_pts(const uint8_t *p)
790 {
791     int64_t pts = (int64_t)((p[0] >> 1) & 0x07) << 30;
792     pts |= (AV_RB16(p + 1) >> 1) << 15;
793     pts |=  AV_RB16(p + 3) >> 1;
794     return pts;
795 }
796 
797 /* return non zero if a packet could be constructed */
mpegts_push_data(MpegTSFilter * filter,const uint8_t * buf,int buf_size,int is_start)798 static void mpegts_push_data(MpegTSFilter *filter,
799                              const uint8_t *buf, int buf_size, int is_start)
800 {
801     PESContext *pes = filter->u.pes_filter.opaque;
802     MpegTSContext *ts = pes->ts;
803     const uint8_t *p;
804     int len, code;
805 
806     if(!ts->pkt)
807         return;
808 
809     if (is_start) {
810         pes->state = MPEGTS_HEADER;
811         pes->data_index = 0;
812     }
813     p = buf;
814     while (buf_size > 0) {
815         switch(pes->state) {
816         case MPEGTS_HEADER:
817             len = PES_START_SIZE - pes->data_index;
818             if (len > buf_size)
819                 len = buf_size;
820             memcpy(pes->header + pes->data_index, p, len);
821             pes->data_index += len;
822             p += len;
823             buf_size -= len;
824             if (pes->data_index == PES_START_SIZE) {
825                 /* we got all the PES or section header. We can now
826                    decide */
827 #if 0
828                 av_hex_dump_log(pes->stream, AV_LOG_DEBUG, pes->header, pes->data_index);
829 #endif
830                 if (pes->header[0] == 0x00 && pes->header[1] == 0x00 &&
831                     pes->header[2] == 0x01) {
832                     /* it must be an mpeg2 PES stream */
833                     code = pes->header[3] | 0x100;
834                     if (!((code >= 0x1c0 && code <= 0x1df) ||
835                           (code >= 0x1e0 && code <= 0x1ef) ||
836                           (code == 0x1bd) || (code == 0x1fd)))
837                         goto skip;
838                     if (!pes->st) {
839                         /* allocate stream */
840                         new_pes_av_stream(pes, code);
841                     }
842                     pes->state = MPEGTS_PESHEADER_FILL;
843                     pes->total_size = AV_RB16(pes->header + 4);
844                     /* NOTE: a zero total size means the PES size is
845                        unbounded */
846                     if (pes->total_size)
847                         pes->total_size += 6;
848                     pes->pes_header_size = pes->header[8] + 9;
849                 } else {
850                     /* otherwise, it should be a table */
851                     /* skip packet */
852                 skip:
853                     pes->state = MPEGTS_SKIP;
854                     continue;
855                 }
856             }
857             break;
858             /**********************************************/
859             /* PES packing parsing */
860         case MPEGTS_PESHEADER_FILL:
861             len = pes->pes_header_size - pes->data_index;
862             if (len > buf_size)
863                 len = buf_size;
864             memcpy(pes->header + pes->data_index, p, len);
865             pes->data_index += len;
866             p += len;
867             buf_size -= len;
868             if (pes->data_index == pes->pes_header_size) {
869                 const uint8_t *r;
870                 unsigned int flags;
871 
872                 flags = pes->header[7];
873                 r = pes->header + 9;
874                 pes->pts = AV_NOPTS_VALUE;
875                 pes->dts = AV_NOPTS_VALUE;
876                 if ((flags & 0xc0) == 0x80) {
877                     pes->pts = get_pts(r);
878                     r += 5;
879                 } else if ((flags & 0xc0) == 0xc0) {
880                     pes->pts = get_pts(r);
881                     r += 5;
882                     pes->dts = get_pts(r);
883                     r += 5;
884                 }
885                 /* we got the full header. We parse it and get the payload */
886                 pes->state = MPEGTS_PAYLOAD;
887             }
888             break;
889         case MPEGTS_PAYLOAD:
890             if (pes->total_size) {
891                 len = pes->total_size - pes->data_index;
892                 if (len > buf_size)
893                     len = buf_size;
894             } else {
895                 len = buf_size;
896             }
897             if (len > 0) {
898                 AVPacket *pkt = ts->pkt;
899                 if (pes->st && av_new_packet(pkt, len) == 0) {
900                     memcpy(pkt->data, p, len);
901                     pkt->stream_index = pes->st->index;
902                     pkt->pts = pes->pts;
903                     pkt->dts = pes->dts;
904                     /* reset pts values */
905                     pes->pts = AV_NOPTS_VALUE;
906                     pes->dts = AV_NOPTS_VALUE;
907                     ts->stop_parse = 1;
908                     return;
909                 }
910             }
911             buf_size = 0;
912             break;
913         case MPEGTS_SKIP:
914             buf_size = 0;
915             break;
916         }
917     }
918 }
919 
new_pes_av_stream(PESContext * pes,uint32_t code)920 static AVStream* new_pes_av_stream(PESContext *pes, uint32_t code)
921 {
922     AVStream *st;
923     int codec_type, codec_id;
924 
925     switch(pes->stream_type){
926     case STREAM_TYPE_AUDIO_MPEG1:
927     case STREAM_TYPE_AUDIO_MPEG2:
928         codec_type = CODEC_TYPE_AUDIO;
929         codec_id = CODEC_ID_MP3;
930         break;
931     case STREAM_TYPE_VIDEO_MPEG1:
932     case STREAM_TYPE_VIDEO_MPEG2:
933         codec_type = CODEC_TYPE_VIDEO;
934         codec_id = CODEC_ID_MPEG2VIDEO;
935         break;
936     case STREAM_TYPE_VIDEO_MPEG4:
937         codec_type = CODEC_TYPE_VIDEO;
938         codec_id = CODEC_ID_MPEG4;
939         break;
940     case STREAM_TYPE_VIDEO_H264:
941         codec_type = CODEC_TYPE_VIDEO;
942         codec_id = CODEC_ID_H264;
943         break;
944     case STREAM_TYPE_VIDEO_VC1:
945         codec_type = CODEC_TYPE_VIDEO;
946         codec_id = CODEC_ID_VC1;
947         break;
948     case STREAM_TYPE_AUDIO_AAC:
949         codec_type = CODEC_TYPE_AUDIO;
950         codec_id = CODEC_ID_AAC;
951         break;
952     case STREAM_TYPE_AUDIO_AC3:
953         codec_type = CODEC_TYPE_AUDIO;
954         codec_id = CODEC_ID_AC3;
955         break;
956     case STREAM_TYPE_AUDIO_DTS:
957     case STREAM_TYPE_AUDIO_HDMV_DTS:
958         codec_type = CODEC_TYPE_AUDIO;
959         codec_id = CODEC_ID_DTS;
960         break;
961     case STREAM_TYPE_SUBTITLE_DVB:
962         codec_type = CODEC_TYPE_SUBTITLE;
963         codec_id = CODEC_ID_DVB_SUBTITLE;
964         break;
965     default:
966         if (code >= 0x1c0 && code <= 0x1df) {
967             codec_type = CODEC_TYPE_AUDIO;
968             codec_id = CODEC_ID_MP2;
969         } else if (code == 0x1bd) {
970             codec_type = CODEC_TYPE_AUDIO;
971             codec_id = CODEC_ID_AC3;
972         } else {
973             codec_type = CODEC_TYPE_VIDEO;
974             codec_id = CODEC_ID_MPEG1VIDEO;
975         }
976         break;
977     }
978     st = av_new_stream(pes->stream, pes->pid);
979     if (st) {
980         av_set_pts_info(st, 33, 1, 90000);
981         st->priv_data = pes;
982         st->codec->codec_type = codec_type;
983         st->codec->codec_id = codec_id;
984         st->need_parsing = AVSTREAM_PARSE_FULL;
985         pes->st = st;
986     }
987     return st;
988 }
989 
990 
add_pes_stream(MpegTSContext * ts,int pid,int pcr_pid,int stream_type)991 static PESContext *add_pes_stream(MpegTSContext *ts, int pid, int pcr_pid, int stream_type)
992 {
993     MpegTSFilter *tss;
994     PESContext *pes;
995 
996     /* if no pid found, then add a pid context */
997     pes = av_mallocz(sizeof(PESContext));
998     if (!pes)
999         return 0;
1000     pes->ts = ts;
1001     pes->stream = ts->stream;
1002     pes->pid = pid;
1003     pes->pcr_pid = pcr_pid;
1004     pes->stream_type = stream_type;
1005     tss = mpegts_open_pes_filter(ts, pid, mpegts_push_data, pes);
1006     if (!tss) {
1007         av_free(pes);
1008         return 0;
1009     }
1010     return pes;
1011 }
1012 
1013 /* handle one TS packet */
handle_packet(MpegTSContext * ts,const uint8_t * packet)1014 static void handle_packet(MpegTSContext *ts, const uint8_t *packet)
1015 {
1016     AVFormatContext *s = ts->stream;
1017     MpegTSFilter *tss;
1018     int len, pid, cc, cc_ok, afc, is_start;
1019     const uint8_t *p, *p_end;
1020 
1021     pid = AV_RB16(packet + 1) & 0x1fff;
1022     if(pid && discard_pid(ts, pid))
1023         return;
1024     is_start = packet[1] & 0x40;
1025     tss = ts->pids[pid];
1026     if (ts->auto_guess && tss == NULL && is_start) {
1027         add_pes_stream(ts, pid, -1, 0);
1028         tss = ts->pids[pid];
1029     }
1030     if (!tss)
1031         return;
1032 
1033     /* continuity check (currently not used) */
1034     cc = (packet[3] & 0xf);
1035     cc_ok = (tss->last_cc < 0) || ((((tss->last_cc + 1) & 0x0f) == cc));
1036     tss->last_cc = cc;
1037 
1038     /* skip adaptation field */
1039     afc = (packet[3] >> 4) & 3;
1040     p = packet + 4;
1041     if (afc == 0) /* reserved value */
1042         return;
1043     if (afc == 2) /* adaptation field only */
1044         return;
1045     if (afc == 3) {
1046         /* skip adapation field */
1047         p += p[0] + 1;
1048     }
1049     /* if past the end of packet, ignore */
1050     p_end = packet + TS_PACKET_SIZE;
1051     if (p >= p_end)
1052         return;
1053 
1054     ts->pos47= url_ftell(ts->stream->pb) % ts->raw_packet_size;
1055 
1056     if (tss->type == MPEGTS_SECTION) {
1057         if (is_start) {
1058             /* pointer field present */
1059             len = *p++;
1060             if (p + len > p_end)
1061                 return;
1062             if (len && cc_ok) {
1063                 /* write remaining section bytes */
1064                 write_section_data(s, tss,
1065                                    p, len, 0);
1066                 /* check whether filter has been closed */
1067                 if (!ts->pids[pid])
1068                     return;
1069             }
1070             p += len;
1071             if (p < p_end) {
1072                 write_section_data(s, tss,
1073                                    p, p_end - p, 1);
1074             }
1075         } else {
1076             if (cc_ok) {
1077                 write_section_data(s, tss,
1078                                    p, p_end - p, 0);
1079             }
1080         }
1081     } else {
1082         tss->u.pes_filter.pes_cb(tss,
1083                                  p, p_end - p, is_start);
1084     }
1085 }
1086 
1087 /* XXX: try to find a better synchro over several packets (use
1088    get_packet_size() ?) */
mpegts_resync(ByteIOContext * pb)1089 static int mpegts_resync(ByteIOContext *pb)
1090 {
1091     int c, i;
1092 
1093     for(i = 0;i < MAX_RESYNC_SIZE; i++) {
1094         c = url_fgetc(pb);
1095         if (c < 0)
1096             return -1;
1097         if (c == 0x47) {
1098             url_fseek(pb, -1, SEEK_CUR);
1099             return 0;
1100         }
1101     }
1102     /* no sync found */
1103     return -1;
1104 }
1105 
1106 /* return -1 if error or EOF. Return 0 if OK. */
read_packet(ByteIOContext * pb,uint8_t * buf,int raw_packet_size)1107 static int read_packet(ByteIOContext *pb, uint8_t *buf, int raw_packet_size)
1108 {
1109     int skip, len;
1110 
1111     for(;;) {
1112         len = get_buffer(pb, buf, TS_PACKET_SIZE);
1113         if (len != TS_PACKET_SIZE)
1114             return AVERROR(EIO);
1115         /* check paquet sync byte */
1116         if (buf[0] != 0x47) {
1117             /* find a new packet start */
1118             url_fseek(pb, -TS_PACKET_SIZE, SEEK_CUR);
1119             if (mpegts_resync(pb) < 0)
1120                 return AVERROR_INVALIDDATA;
1121             else
1122                 continue;
1123         } else {
1124             skip = raw_packet_size - TS_PACKET_SIZE;
1125             if (skip > 0)
1126                 url_fskip(pb, skip);
1127             break;
1128         }
1129     }
1130     return 0;
1131 }
1132 
handle_packets(MpegTSContext * ts,int nb_packets)1133 static int handle_packets(MpegTSContext *ts, int nb_packets)
1134 {
1135     AVFormatContext *s = ts->stream;
1136     ByteIOContext *pb = s->pb;
1137     uint8_t packet[TS_PACKET_SIZE];
1138     int packet_num, ret;
1139 
1140     ts->stop_parse = 0;
1141     packet_num = 0;
1142     for(;;) {
1143         if (ts->stop_parse>0)
1144             break;
1145         packet_num++;
1146         if (nb_packets != 0 && packet_num >= nb_packets)
1147             break;
1148         ret = read_packet(pb, packet, ts->raw_packet_size);
1149         if (ret != 0)
1150             return ret;
1151         handle_packet(ts, packet);
1152     }
1153     return 0;
1154 }
1155 
mpegts_probe(AVProbeData * p)1156 static int mpegts_probe(AVProbeData *p)
1157 {
1158 #if 1
1159     const int size= p->buf_size;
1160     int score, fec_score, dvhs_score;
1161 #define CHECK_COUNT 10
1162 
1163     if (size < (TS_FEC_PACKET_SIZE * CHECK_COUNT))
1164         return -1;
1165 
1166     score    = analyze(p->buf, TS_PACKET_SIZE    *CHECK_COUNT, TS_PACKET_SIZE, NULL);
1167     dvhs_score  = analyze(p->buf, TS_DVHS_PACKET_SIZE    *CHECK_COUNT, TS_DVHS_PACKET_SIZE, NULL);
1168     fec_score= analyze(p->buf, TS_FEC_PACKET_SIZE*CHECK_COUNT, TS_FEC_PACKET_SIZE, NULL);
1169 //    av_log(NULL, AV_LOG_DEBUG, "score: %d, dvhs_score: %d, fec_score: %d \n", score, dvhs_score, fec_score);
1170 
1171 // we need a clear definition for the returned score otherwise things will become messy sooner or later
1172     if     (score > fec_score && score > dvhs_score && score > 6) return AVPROBE_SCORE_MAX + score     - CHECK_COUNT;
1173     else if(dvhs_score > score && dvhs_score > fec_score && dvhs_score > 6) return AVPROBE_SCORE_MAX + dvhs_score  - CHECK_COUNT;
1174     else if(                 fec_score > 6) return AVPROBE_SCORE_MAX + fec_score - CHECK_COUNT;
1175     else                                    return -1;
1176 #else
1177     /* only use the extension for safer guess */
1178     if (match_ext(p->filename, "ts"))
1179         return AVPROBE_SCORE_MAX;
1180     else
1181         return 0;
1182 #endif
1183 }
1184 
1185 /* return the 90 kHz PCR and the extension for the 27 MHz PCR. return
1186    (-1) if not available */
parse_pcr(int64_t * ppcr_high,int * ppcr_low,const uint8_t * packet)1187 static int parse_pcr(int64_t *ppcr_high, int *ppcr_low,
1188                      const uint8_t *packet)
1189 {
1190     int afc, len, flags;
1191     const uint8_t *p;
1192     unsigned int v;
1193 
1194     afc = (packet[3] >> 4) & 3;
1195     if (afc <= 1)
1196         return -1;
1197     p = packet + 4;
1198     len = p[0];
1199     p++;
1200     if (len == 0)
1201         return -1;
1202     flags = *p++;
1203     len--;
1204     if (!(flags & 0x10))
1205         return -1;
1206     if (len < 6)
1207         return -1;
1208     v = AV_RB32(p);
1209     *ppcr_high = ((int64_t)v << 1) | (p[4] >> 7);
1210     *ppcr_low = ((p[4] & 1) << 8) | p[5];
1211     return 0;
1212 }
1213 
mpegts_read_header(AVFormatContext * s,AVFormatParameters * ap)1214 static int mpegts_read_header(AVFormatContext *s,
1215                               AVFormatParameters *ap)
1216 {
1217     MpegTSContext *ts = s->priv_data;
1218     ByteIOContext *pb = s->pb;
1219     uint8_t buf[1024];
1220     int len;
1221     int64_t pos;
1222 
1223     if (ap) {
1224         ts->mpeg2ts_compute_pcr = ap->mpeg2ts_compute_pcr;
1225         if(ap->mpeg2ts_raw){
1226             av_log(s, AV_LOG_ERROR, "use mpegtsraw_demuxer!\n");
1227             return -1;
1228         }
1229     }
1230 
1231     /* read the first 1024 bytes to get packet size */
1232     pos = url_ftell(pb);
1233     len = get_buffer(pb, buf, sizeof(buf));
1234     if (len != sizeof(buf))
1235         goto fail;
1236     ts->raw_packet_size = get_packet_size(buf, sizeof(buf));
1237     if (ts->raw_packet_size <= 0)
1238         goto fail;
1239     ts->stream = s;
1240     ts->auto_guess = 0;
1241 
1242     if (s->iformat == &mpegts_demuxer) {
1243         /* normal demux */
1244 
1245         /* first do a scaning to get all the services */
1246         url_fseek(pb, pos, SEEK_SET);
1247         mpegts_scan_sdt(ts);
1248 
1249         mpegts_set_service(ts);
1250 
1251         handle_packets(ts, s->probesize);
1252         /* if could not find service, enable auto_guess */
1253 
1254         ts->auto_guess = 1;
1255 
1256 #ifdef DEBUG_SI
1257         av_log(ts->stream, AV_LOG_DEBUG, "tuning done\n");
1258 #endif
1259         s->ctx_flags |= AVFMTCTX_NOHEADER;
1260     } else {
1261         AVStream *st;
1262         int pcr_pid, pid, nb_packets, nb_pcrs, ret, pcr_l;
1263         int64_t pcrs[2], pcr_h;
1264         int packet_count[2];
1265         uint8_t packet[TS_PACKET_SIZE];
1266 
1267         /* only read packets */
1268 
1269         st = av_new_stream(s, 0);
1270         if (!st)
1271             goto fail;
1272         av_set_pts_info(st, 60, 1, 27000000);
1273         st->codec->codec_type = CODEC_TYPE_DATA;
1274         st->codec->codec_id = CODEC_ID_MPEG2TS;
1275 
1276         /* we iterate until we find two PCRs to estimate the bitrate */
1277         pcr_pid = -1;
1278         nb_pcrs = 0;
1279         nb_packets = 0;
1280         for(;;) {
1281             ret = read_packet(s->pb, packet, ts->raw_packet_size);
1282             if (ret < 0)
1283                 return -1;
1284             pid = AV_RB16(packet + 1) & 0x1fff;
1285             if ((pcr_pid == -1 || pcr_pid == pid) &&
1286                 parse_pcr(&pcr_h, &pcr_l, packet) == 0) {
1287                 pcr_pid = pid;
1288                 packet_count[nb_pcrs] = nb_packets;
1289                 pcrs[nb_pcrs] = pcr_h * 300 + pcr_l;
1290                 nb_pcrs++;
1291                 if (nb_pcrs >= 2)
1292                     break;
1293             }
1294             nb_packets++;
1295         }
1296 
1297         /* NOTE1: the bitrate is computed without the FEC */
1298         /* NOTE2: it is only the bitrate of the start of the stream */
1299         ts->pcr_incr = (pcrs[1] - pcrs[0]) / (packet_count[1] - packet_count[0]);
1300         ts->cur_pcr = pcrs[0] - ts->pcr_incr * packet_count[0];
1301         s->bit_rate = (TS_PACKET_SIZE * 8) * 27e6 / ts->pcr_incr;
1302         st->codec->bit_rate = s->bit_rate;
1303         st->start_time = ts->cur_pcr;
1304 #if 0
1305         av_log(ts->stream, AV_LOG_DEBUG, "start=%0.3f pcr=%0.3f incr=%d\n",
1306                st->start_time / 1000000.0, pcrs[0] / 27e6, ts->pcr_incr);
1307 #endif
1308     }
1309 
1310     url_fseek(pb, pos, SEEK_SET);
1311     return 0;
1312  fail:
1313     return -1;
1314 }
1315 
1316 #define MAX_PACKET_READAHEAD ((128 * 1024) / 188)
1317 
mpegts_raw_read_packet(AVFormatContext * s,AVPacket * pkt)1318 static int mpegts_raw_read_packet(AVFormatContext *s,
1319                                   AVPacket *pkt)
1320 {
1321     MpegTSContext *ts = s->priv_data;
1322     int ret, i;
1323     int64_t pcr_h, next_pcr_h, pos;
1324     int pcr_l, next_pcr_l;
1325     uint8_t pcr_buf[12];
1326 
1327     if (av_new_packet(pkt, TS_PACKET_SIZE) < 0)
1328         return AVERROR(ENOMEM);
1329     pkt->pos= url_ftell(s->pb);
1330     ret = read_packet(s->pb, pkt->data, ts->raw_packet_size);
1331     if (ret < 0) {
1332         av_free_packet(pkt);
1333         return ret;
1334     }
1335     if (ts->mpeg2ts_compute_pcr) {
1336         /* compute exact PCR for each packet */
1337         if (parse_pcr(&pcr_h, &pcr_l, pkt->data) == 0) {
1338             /* we read the next PCR (XXX: optimize it by using a bigger buffer */
1339             pos = url_ftell(s->pb);
1340             for(i = 0; i < MAX_PACKET_READAHEAD; i++) {
1341                 url_fseek(s->pb, pos + i * ts->raw_packet_size, SEEK_SET);
1342                 get_buffer(s->pb, pcr_buf, 12);
1343                 if (parse_pcr(&next_pcr_h, &next_pcr_l, pcr_buf) == 0) {
1344                     /* XXX: not precise enough */
1345                     ts->pcr_incr = ((next_pcr_h - pcr_h) * 300 + (next_pcr_l - pcr_l)) /
1346                         (i + 1);
1347                     break;
1348                 }
1349             }
1350             url_fseek(s->pb, pos, SEEK_SET);
1351             /* no next PCR found: we use previous increment */
1352             ts->cur_pcr = pcr_h * 300 + pcr_l;
1353         }
1354         pkt->pts = ts->cur_pcr;
1355         pkt->duration = ts->pcr_incr;
1356         ts->cur_pcr += ts->pcr_incr;
1357     }
1358     pkt->stream_index = 0;
1359     return 0;
1360 }
1361 
mpegts_read_packet(AVFormatContext * s,AVPacket * pkt)1362 static int mpegts_read_packet(AVFormatContext *s,
1363                               AVPacket *pkt)
1364 {
1365     MpegTSContext *ts = s->priv_data;
1366 
1367     ts->pkt = pkt;
1368     return handle_packets(ts, 0);
1369 }
1370 
mpegts_read_close(AVFormatContext * s)1371 static int mpegts_read_close(AVFormatContext *s)
1372 {
1373     MpegTSContext *ts = s->priv_data;
1374     int i;
1375 
1376     clear_programs(ts);
1377 
1378     for(i=0;i<NB_PID_MAX;i++)
1379         if (ts->pids[i]) mpegts_close_filter(ts, ts->pids[i]);
1380 
1381     return 0;
1382 }
1383 
mpegts_get_pcr(AVFormatContext * s,int stream_index,int64_t * ppos,int64_t pos_limit)1384 static int64_t mpegts_get_pcr(AVFormatContext *s, int stream_index,
1385                               int64_t *ppos, int64_t pos_limit)
1386 {
1387     MpegTSContext *ts = s->priv_data;
1388     int64_t pos, timestamp;
1389     uint8_t buf[TS_PACKET_SIZE];
1390     int pcr_l, pcr_pid = ((PESContext*)s->streams[stream_index]->priv_data)->pcr_pid;
1391     const int find_next= 1;
1392     pos = ((*ppos  + ts->raw_packet_size - 1 - ts->pos47) / ts->raw_packet_size) * ts->raw_packet_size + ts->pos47;
1393     if (find_next) {
1394         for(;;) {
1395             url_fseek(s->pb, pos, SEEK_SET);
1396             if (get_buffer(s->pb, buf, TS_PACKET_SIZE) != TS_PACKET_SIZE)
1397                 return AV_NOPTS_VALUE;
1398             if ((pcr_pid < 0 || (AV_RB16(buf + 1) & 0x1fff) == pcr_pid) &&
1399                 parse_pcr(&timestamp, &pcr_l, buf) == 0) {
1400                 break;
1401             }
1402             pos += ts->raw_packet_size;
1403         }
1404     } else {
1405         for(;;) {
1406             pos -= ts->raw_packet_size;
1407             if (pos < 0)
1408                 return AV_NOPTS_VALUE;
1409             url_fseek(s->pb, pos, SEEK_SET);
1410             if (get_buffer(s->pb, buf, TS_PACKET_SIZE) != TS_PACKET_SIZE)
1411                 return AV_NOPTS_VALUE;
1412             if ((pcr_pid < 0 || (AV_RB16(buf + 1) & 0x1fff) == pcr_pid) &&
1413                 parse_pcr(&timestamp, &pcr_l, buf) == 0) {
1414                 break;
1415             }
1416         }
1417     }
1418     *ppos = pos;
1419 
1420     return timestamp;
1421 }
1422 
read_seek(AVFormatContext * s,int stream_index,int64_t target_ts,int flags)1423 static int read_seek(AVFormatContext *s, int stream_index, int64_t target_ts, int flags){
1424     MpegTSContext *ts = s->priv_data;
1425     uint8_t buf[TS_PACKET_SIZE];
1426     int64_t pos;
1427 
1428     if(av_seek_frame_binary(s, stream_index, target_ts, flags) < 0)
1429         return -1;
1430 
1431     pos= url_ftell(s->pb);
1432 
1433     for(;;) {
1434         url_fseek(s->pb, pos, SEEK_SET);
1435         if (get_buffer(s->pb, buf, TS_PACKET_SIZE) != TS_PACKET_SIZE)
1436             return -1;
1437 //        pid = AV_RB16(buf + 1) & 0x1fff;
1438         if(buf[1] & 0x40) break;
1439         pos += ts->raw_packet_size;
1440     }
1441     url_fseek(s->pb, pos, SEEK_SET);
1442 
1443     return 0;
1444 }
1445 
1446 /**************************************************************/
1447 /* parsing functions - called from other demuxers such as RTP */
1448 
mpegts_parse_open(AVFormatContext * s)1449 MpegTSContext *mpegts_parse_open(AVFormatContext *s)
1450 {
1451     MpegTSContext *ts;
1452 
1453     ts = av_mallocz(sizeof(MpegTSContext));
1454     if (!ts)
1455         return NULL;
1456     /* no stream case, currently used by RTP */
1457     ts->raw_packet_size = TS_PACKET_SIZE;
1458     ts->stream = s;
1459     ts->auto_guess = 1;
1460     return ts;
1461 }
1462 
1463 /* return the consumed length if a packet was output, or -1 if no
1464    packet is output */
mpegts_parse_packet(MpegTSContext * ts,AVPacket * pkt,const uint8_t * buf,int len)1465 int mpegts_parse_packet(MpegTSContext *ts, AVPacket *pkt,
1466                         const uint8_t *buf, int len)
1467 {
1468     int len1;
1469 
1470     len1 = len;
1471     ts->pkt = pkt;
1472     ts->stop_parse = 0;
1473     for(;;) {
1474         if (ts->stop_parse>0)
1475             break;
1476         if (len < TS_PACKET_SIZE)
1477             return -1;
1478         if (buf[0] != 0x47) {
1479             buf++;
1480             len--;
1481         } else {
1482             handle_packet(ts, buf);
1483             buf += TS_PACKET_SIZE;
1484             len -= TS_PACKET_SIZE;
1485         }
1486     }
1487     return len1 - len;
1488 }
1489 
mpegts_parse_close(MpegTSContext * ts)1490 void mpegts_parse_close(MpegTSContext *ts)
1491 {
1492     int i;
1493 
1494     for(i=0;i<NB_PID_MAX;i++)
1495         av_free(ts->pids[i]);
1496     av_free(ts);
1497 }
1498 
1499 AVInputFormat mpegts_demuxer = {
1500     "mpegts",
1501     "MPEG2 transport stream format",
1502     sizeof(MpegTSContext),
1503     mpegts_probe,
1504     mpegts_read_header,
1505     mpegts_read_packet,
1506     mpegts_read_close,
1507     read_seek,
1508     mpegts_get_pcr,
1509     .flags = AVFMT_SHOW_IDS,
1510 };
1511 
1512 AVInputFormat mpegtsraw_demuxer = {
1513     "mpegtsraw",
1514     "MPEG2 raw transport stream format",
1515     sizeof(MpegTSContext),
1516     NULL,
1517     mpegts_read_header,
1518     mpegts_raw_read_packet,
1519     mpegts_read_close,
1520     read_seek,
1521     mpegts_get_pcr,
1522     .flags = AVFMT_SHOW_IDS,
1523 };
1524