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FFmpeg/libavformat/mpegts.c

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  1. /*

  2.  * MPEG2 transport stream (aka DVB) demux

  3.  * Copyright (c) 2002-2003 Fabrice Bellard.

  4.  *

  5.  * This library is free software; you can redistribute it and/or

  6.  * modify it under the terms of the GNU Lesser General Public

  7.  * License as published by the Free Software Foundation; either

  8.  * version 2 of the License, or (at your option) any later version.

  9.  *

  10.  * This library is distributed in the hope that it will be useful,

  11.  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  12.  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

  13.  * Lesser General Public License for more details.

  14.  *

  15.  * You should have received a copy of the GNU Lesser General Public

  16.  * License along with this library; if not, write to the Free Software

  17.  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

  18.  */

  19. #include "avformat.h"

  20. 

  21. #include "mpegts.h"

  22. 

  23. //#define DEBUG_SI

  24. //#define DEBUG_SEEK

  25. 

  26. /* 1.0 second at 24Mbit/s */

  27. #define MAX_SCAN_PACKETS 32000

  28. 

  29. /* maximum size in which we look for synchronisation if

  30.    synchronisation is lost */

  31. #define MAX_RESYNC_SIZE 4096

  32. 

  33. typedef struct PESContext PESContext;

  34. 

  35. static PESContext* add_pes_stream(MpegTSContext *ts, int pid, int stream_type);

  36. static AVStream* new_pes_av_stream(PESContext *pes, uint32_t code);

  37. 

  38. enum MpegTSFilterType {

  39.     MPEGTS_PES,

  40.     MPEGTS_SECTION,

  41. };

  42. 

  43. typedef void PESCallback(void *opaque, const uint8_t *buf, int len, int is_start);

  44. 

  45. typedef struct MpegTSPESFilter {

  46.     PESCallback *pes_cb;

  47.     void *opaque;

  48. } MpegTSPESFilter;

  49. 

  50. typedef void SectionCallback(void *opaque, const uint8_t *buf, int len);

  51. 

  52. typedef void SetServiceCallback(void *opaque, int ret);

  53. 

  54. typedef struct MpegTSSectionFilter {

  55.     int section_index;

  56.     int section_h_size;

  57.     uint8_t *section_buf;

  58.     int check_crc:1;

  59.     int end_of_section_reached:1;

  60.     SectionCallback *section_cb;

  61.     void *opaque;

  62. } MpegTSSectionFilter;

  63. 

  64. typedef struct MpegTSFilter {

  65.     int pid;

  66.     int last_cc; /* last cc code (-1 if first packet) */

  67.     enum MpegTSFilterType type;

  68.     union {

  69.         MpegTSPESFilter pes_filter;

  70.         MpegTSSectionFilter section_filter;

  71.     } u;

  72. } MpegTSFilter;

  73. 

  74. typedef struct MpegTSService {

  75.     int running:1;

  76.     int sid;

  77.     char *provider_name;

  78.     char *name;

  79. } MpegTSService;

  80. 

  81. struct MpegTSContext {

  82.     /* user data */

  83.     AVFormatContext *stream;

  84.     int raw_packet_size; /* raw packet size, including FEC if present */

  85.     int auto_guess; /* if true, all pids are analized to find streams */

  86.     int set_service_ret;

  87. 

  88.     int mpeg2ts_raw;  /* force raw MPEG2 transport stream output, if possible */

  89.     int mpeg2ts_compute_pcr; /* compute exact PCR for each transport stream packet */

  90. 

  91.     /* used to estimate the exact PCR */

  92.     int64_t cur_pcr;

  93.     int pcr_incr;

  94.     int pcr_pid;

  95. 

  96.     /* data needed to handle file based ts */

  97.     int stop_parse; /* stop parsing loop */

  98.     AVPacket *pkt; /* packet containing av data */

  99. 

  100.     /******************************************/

  101.     /* private mpegts data */

  102.     /* scan context */

  103.     MpegTSFilter *sdt_filter;

  104.     int nb_services;

  105.     MpegTSService **services;

  106. 

  107.     /* set service context (XXX: allocated it ?) */

  108.     SetServiceCallback *set_service_cb;

  109.     void *set_service_opaque;

  110.     MpegTSFilter *pat_filter;

  111.     MpegTSFilter *pmt_filter;

  112.     int req_sid;

  113. 

  114.     MpegTSFilter *pids[NB_PID_MAX];

  115. };

  116. 

  117. static void write_section_data(AVFormatContext *s, MpegTSFilter *tss1,

  118.                                const uint8_t *buf, int buf_size, int is_start)

  119. {

  120.     MpegTSSectionFilter *tss = &tss1->u.section_filter;

  121.     int len;

  122. 

  123.     if (is_start) {

  124.         memcpy(tss->section_buf, buf, buf_size);

  125.         tss->section_index = buf_size;

  126.         tss->section_h_size = -1;

  127.         tss->end_of_section_reached = 0;

  128.     } else {

  129.         if (tss->end_of_section_reached)

  130.             return;

  131.         len = 4096 - tss->section_index;

  132.         if (buf_size < len)

  133.             len = buf_size;

  134.         memcpy(tss->section_buf + tss->section_index, buf, len);

  135.         tss->section_index += len;

  136.     }

  137. 

  138.     /* compute section length if possible */

  139.     if (tss->section_h_size == -1 && tss->section_index >= 3) {

  140.         len = (((tss->section_buf[1] & 0xf) << 8) | tss->section_buf[2]) + 3;

  141.         if (len > 4096)

  142.             return;

  143.         tss->section_h_size = len;

  144.     }

  145. 

  146.     if (tss->section_h_size != -1 && tss->section_index >= tss->section_h_size) {

  147.         tss->end_of_section_reached = 1;

  148.         if (!tss->check_crc ||

  149.             mpegts_crc32(tss->section_buf, tss->section_h_size) == 0)

  150.             tss->section_cb(tss->opaque, tss->section_buf, tss->section_h_size);

  151.     }

  152. }

  153. 

  154. MpegTSFilter *mpegts_open_section_filter(MpegTSContext *ts, unsigned int pid,

  155.                                          SectionCallback *section_cb, void *opaque,

  156.                                          int check_crc)

  157. 

  158. {

  159.     MpegTSFilter *filter;

  160.     MpegTSSectionFilter *sec;

  161. 

  162. #ifdef DEBUG_SI

  163.     printf("Filter: pid=0x%x\n", pid);

  164. #endif

  165.     if (pid >= NB_PID_MAX || ts->pids[pid])

  166.         return NULL;

  167.     filter = av_mallocz(sizeof(MpegTSFilter));

  168.     if (!filter)

  169.         return NULL;

  170.     ts->pids[pid] = filter;

  171.     filter->type = MPEGTS_SECTION;

  172.     filter->pid = pid;

  173.     filter->last_cc = -1;

  174.     sec = &filter->u.section_filter;

  175.     sec->section_cb = section_cb;

  176.     sec->opaque = opaque;

  177.     sec->section_buf = av_malloc(MAX_SECTION_SIZE);

  178.     sec->check_crc = check_crc;

  179.     if (!sec->section_buf) {

  180.         av_free(filter);

  181.         return NULL;

  182.     }

  183.     return filter;

  184. }

  185. 

  186. MpegTSFilter *mpegts_open_pes_filter(MpegTSContext *ts, unsigned int pid,

  187.                                      PESCallback *pes_cb,

  188.                                      void *opaque)

  189. {

  190.     MpegTSFilter *filter;

  191.     MpegTSPESFilter *pes;

  192. 

  193.     if (pid >= NB_PID_MAX || ts->pids[pid])

  194.         return NULL;

  195.     filter = av_mallocz(sizeof(MpegTSFilter));

  196.     if (!filter)

  197.         return NULL;

  198.     ts->pids[pid] = filter;

  199.     filter->type = MPEGTS_PES;

  200.     filter->pid = pid;

  201.     filter->last_cc = -1;

  202.     pes = &filter->u.pes_filter;

  203.     pes->pes_cb = pes_cb;

  204.     pes->opaque = opaque;

  205.     return filter;

  206. }

  207. 

  208. void mpegts_close_filter(MpegTSContext *ts, MpegTSFilter *filter)

  209. {

  210.     int pid;

  211. 

  212.     pid = filter->pid;

  213.     if (filter->type == MPEGTS_SECTION)

  214.         av_freep(&filter->u.section_filter.section_buf);

  215.     else if (filter->type == MPEGTS_PES)

  216.         av_freep(&filter->u.pes_filter.opaque);

  217. 

  218.     av_free(filter);

  219.     ts->pids[pid] = NULL;

  220. }

  221. 

  222. static int analyze(const uint8_t *buf, int size, int packet_size, int *index){

  223.     int stat[packet_size];

  224.     int i;

  225.     int x=0;

  226.     int best_score=0;

  227. 

  228.     memset(stat, 0, packet_size*sizeof(int));

  229. 

  230.     for(x=i=0; i<size; i++){

  231.         if(buf[i] == 0x47){

  232.             stat[x]++;

  233.             if(stat[x] > best_score){

  234.                 best_score= stat[x];

  235.                 if(index) *index= x;

  236.             }

  237.         }

  238. 

  239.         x++;

  240.         if(x == packet_size) x= 0;

  241.     }

  242. 

  243.     return best_score;

  244. }

  245. 

  246. /* autodetect fec presence. Must have at least 1024 bytes  */

  247. static int get_packet_size(const uint8_t *buf, int size)

  248. {

  249.     int score, fec_score, dvhs_score;

  250. 

  251.     if (size < (TS_FEC_PACKET_SIZE * 5 + 1))

  252.         return -1;

  253. 

  254.     score    = analyze(buf, size, TS_PACKET_SIZE, NULL);

  255.     dvhs_score    = analyze(buf, size, TS_DVHS_PACKET_SIZE, NULL);

  256.     fec_score= analyze(buf, size, TS_FEC_PACKET_SIZE, NULL);

  257. //    av_log(NULL, AV_LOG_DEBUG, "score: %d, dvhs_score: %d, fec_score: %d \n", score, dvhs_score, fec_score);

  258. 

  259.     if     (score > fec_score && score > dvhs_score) return TS_PACKET_SIZE;

  260.     else if(dvhs_score > score && dvhs_score > fec_score) return TS_DVHS_PACKET_SIZE;

  261.     else if(score < fec_score && dvhs_score < fec_score) return TS_FEC_PACKET_SIZE;

  262.     else                       return -1;

  263. }

  264. 

  265. typedef struct SectionHeader {

  266.     uint8_t tid;

  267.     uint16_t id;

  268.     uint8_t version;

  269.     uint8_t sec_num;

  270.     uint8_t last_sec_num;

  271. } SectionHeader;

  272. 

  273. static inline int get8(const uint8_t **pp, const uint8_t *p_end)

  274. {

  275.     const uint8_t *p;

  276.     int c;

  277. 

  278.     p = *pp;

  279.     if (p >= p_end)

  280.         return -1;

  281.     c = *p++;

  282.     *pp = p;

  283.     return c;

  284. }

  285. 

  286. static inline int get16(const uint8_t **pp, const uint8_t *p_end)

  287. {

  288.     const uint8_t *p;

  289.     int c;

  290. 

  291.     p = *pp;

  292.     if ((p + 1) >= p_end)

  293.         return -1;

  294.     c = (p[0] << 8) | p[1];

  295.     p += 2;

  296.     *pp = p;

  297.     return c;

  298. }

  299. 

  300. /* read and allocate a DVB string preceeded by its length */

  301. static char *getstr8(const uint8_t **pp, const uint8_t *p_end)

  302. {

  303.     int len;

  304.     const uint8_t *p;

  305.     char *str;

  306. 

  307.     p = *pp;

  308.     len = get8(&p, p_end);

  309.     if (len < 0)

  310.         return NULL;

  311.     if ((p + len) > p_end)

  312.         return NULL;

  313.     str = av_malloc(len + 1);

  314.     if (!str)

  315.         return NULL;

  316.     memcpy(str, p, len);

  317.     str[len] = '\0';

  318.     p += len;

  319.     *pp = p;

  320.     return str;

  321. }

  322. 

  323. static int parse_section_header(SectionHeader *h,

  324.                                 const uint8_t **pp, const uint8_t *p_end)

  325. {

  326.     int val;

  327. 

  328.     val = get8(pp, p_end);

  329.     if (val < 0)

  330.         return -1;

  331.     h->tid = val;

  332.     *pp += 2;

  333.     val = get16(pp, p_end);

  334.     if (val < 0)

  335.         return -1;

  336.     h->id = val;

  337.     val = get8(pp, p_end);

  338.     if (val < 0)

  339.         return -1;

  340.     h->version = (val >> 1) & 0x1f;

  341.     val = get8(pp, p_end);

  342.     if (val < 0)

  343.         return -1;

  344.     h->sec_num = val;

  345.     val = get8(pp, p_end);

  346.     if (val < 0)

  347.         return -1;

  348.     h->last_sec_num = val;

  349.     return 0;

  350. }

  351. 

  352. static MpegTSService *new_service(MpegTSContext *ts, int sid,

  353.                                   char *provider_name, char *name)

  354. {

  355.     MpegTSService *service;

  356. 

  357. #ifdef DEBUG_SI

  358.     printf("new_service: sid=0x%04x provider='%s' name='%s'\n",

  359.            sid, provider_name, name);

  360. #endif

  361. 

  362.     service = av_mallocz(sizeof(MpegTSService));

  363.     if (!service)

  364.         return NULL;

  365.     service->sid = sid;

  366.     service->provider_name = provider_name;

  367.     service->name = name;

  368.     dynarray_add(&ts->services, &ts->nb_services, service);

  369.     return service;

  370. }

  371. 

  372. static void pmt_cb(void *opaque, const uint8_t *section, int section_len)

  373. {

  374.     MpegTSContext *ts = opaque;

  375.     SectionHeader h1, *h = &h1;

  376.     PESContext *pes;

  377.     AVStream *st;

  378.     const uint8_t *p, *p_end, *desc_list_end, *desc_end;

  379.     int program_info_length, pcr_pid, pid, stream_type;

  380.     int desc_list_len, desc_len, desc_tag;

  381.     int comp_page = 0, anc_page = 0; /* initialize to kill warnings */

  382.     char language[4];

  383. 

  384. #ifdef DEBUG_SI

  385.     printf("PMT:\n");

  386.     av_hex_dump(stdout, (uint8_t *)section, section_len);

  387. #endif

  388.     p_end = section + section_len - 4;

  389.     p = section;

  390.     if (parse_section_header(h, &p, p_end) < 0)

  391.         return;

  392. #ifdef DEBUG_SI

  393.     printf("sid=0x%x sec_num=%d/%d\n", h->id, h->sec_num, h->last_sec_num);

  394. #endif

  395.     if (h->tid != PMT_TID || (ts->req_sid >= 0 && h->id != ts->req_sid) )

  396.         return;

  397. 

  398.     pcr_pid = get16(&p, p_end) & 0x1fff;

  399.     if (pcr_pid < 0)

  400.         return;

  401.     ts->pcr_pid = pcr_pid;

  402. #ifdef DEBUG_SI

  403.     printf("pcr_pid=0x%x\n", pcr_pid);

  404. #endif

  405.     program_info_length = get16(&p, p_end) & 0xfff;

  406.     if (program_info_length < 0)

  407.         return;

  408.     p += program_info_length;

  409.     if (p >= p_end)

  410.         return;

  411.     for(;;) {

  412.         language[0] = 0;

  413.         st = 0;

  414.         stream_type = get8(&p, p_end);

  415.         if (stream_type < 0)

  416.             break;

  417.         pid = get16(&p, p_end) & 0x1fff;

  418.         if (pid < 0)

  419.             break;

  420.         desc_list_len = get16(&p, p_end) & 0xfff;

  421.         if (desc_list_len < 0)

  422.             break;

  423.         desc_list_end = p + desc_list_len;

  424.         if (desc_list_end > p_end)

  425.             break;

  426.         for(;;) {

  427.             desc_tag = get8(&p, desc_list_end);

  428.             if (desc_tag < 0)

  429.                 break;

  430.             desc_len = get8(&p, desc_list_end);

  431.             desc_end = p + desc_len;

  432.             if (desc_end > desc_list_end)

  433.                 break;

  434. #ifdef DEBUG_SI

  435.             printf("tag: 0x%02x len=%d\n", desc_tag, desc_len);

  436. #endif

  437.             switch(desc_tag) {

  438.             case DVB_SUBT_DESCID:

  439.                 if (stream_type == STREAM_TYPE_PRIVATE_DATA)

  440.                     stream_type = STREAM_TYPE_SUBTITLE_DVB;

  441. 

  442.                 language[0] = get8(&p, desc_end);

  443.                 language[1] = get8(&p, desc_end);

  444.                 language[2] = get8(&p, desc_end);

  445.                 language[3] = 0;

  446.                 get8(&p, desc_end);

  447.                 comp_page = get16(&p, desc_end);

  448.                 anc_page = get16(&p, desc_end);

  449. 

  450.                 break;

  451.             case 0x0a: /* ISO 639 language descriptor */

  452.                 language[0] = get8(&p, desc_end);

  453.                 language[1] = get8(&p, desc_end);

  454.                 language[2] = get8(&p, desc_end);

  455.                 language[3] = 0;

  456.                 break;

  457.             default:

  458.                 break;

  459.             }

  460.             p = desc_end;

  461.         }

  462.         p = desc_list_end;

  463. 

  464. #ifdef DEBUG_SI

  465.         printf("stream_type=%d pid=0x%x\n", stream_type, pid);

  466. #endif

  467. 

  468.         /* now create ffmpeg stream */

  469.         switch(stream_type) {

  470.         case STREAM_TYPE_AUDIO_MPEG1:

  471.         case STREAM_TYPE_AUDIO_MPEG2:

  472.         case STREAM_TYPE_VIDEO_MPEG1:

  473.         case STREAM_TYPE_VIDEO_MPEG2:

  474.         case STREAM_TYPE_VIDEO_MPEG4:

  475.         case STREAM_TYPE_VIDEO_H264:

  476.         case STREAM_TYPE_AUDIO_AAC:

  477.         case STREAM_TYPE_AUDIO_AC3:

  478.         case STREAM_TYPE_AUDIO_DTS:

  479.         case STREAM_TYPE_SUBTITLE_DVB:

  480.             pes = add_pes_stream(ts, pid, stream_type);

  481.             if (pes)

  482.                 st = new_pes_av_stream(pes, 0);

  483.             break;

  484.         default:

  485.             /* we ignore the other streams */

  486.             break;

  487.         }

  488. 

  489.         if (st) {

  490.             if (language[0] != 0) {

  491.                 st->language[0] = language[0];

  492.                 st->language[1] = language[1];

  493.                 st->language[2] = language[2];

  494.                 st->language[3] = language[3];

  495.             }

  496. 

  497.             if (stream_type == STREAM_TYPE_SUBTITLE_DVB) {

  498.                 st->codec->sub_id = (anc_page << 16) | comp_page;

  499.             }

  500.         }

  501.     }

  502.     /* all parameters are there */

  503.     ts->set_service_cb(ts->set_service_opaque, 0);

  504.     mpegts_close_filter(ts, ts->pmt_filter);

  505.     ts->pmt_filter = NULL;

  506. }

  507. 

  508. static void pat_cb(void *opaque, const uint8_t *section, int section_len)

  509. {

  510.     MpegTSContext *ts = opaque;

  511.     SectionHeader h1, *h = &h1;

  512.     const uint8_t *p, *p_end;

  513.     int sid, pmt_pid;

  514. 

  515. #ifdef DEBUG_SI

  516.     printf("PAT:\n");

  517.     av_hex_dump(stdout, (uint8_t *)section, section_len);

  518. #endif

  519.     p_end = section + section_len - 4;

  520.     p = section;

  521.     if (parse_section_header(h, &p, p_end) < 0)

  522.         return;

  523.     if (h->tid != PAT_TID)

  524.         return;

  525. 

  526.     for(;;) {

  527.         sid = get16(&p, p_end);

  528.         if (sid < 0)

  529.             break;

  530.         pmt_pid = get16(&p, p_end) & 0x1fff;

  531.         if (pmt_pid < 0)

  532.             break;

  533. #ifdef DEBUG_SI

  534.         printf("sid=0x%x pid=0x%x\n", sid, pmt_pid);

  535. #endif

  536.         if (sid == 0x0000) {

  537.             /* NIT info */

  538.         } else {

  539.             if (ts->req_sid == sid) {

  540.                 ts->pmt_filter = mpegts_open_section_filter(ts, pmt_pid,

  541.                                                             pmt_cb, ts, 1);

  542.                 goto found;

  543.             }

  544.         }

  545.     }

  546.     /* not found */

  547.     ts->set_service_cb(ts->set_service_opaque, -1);

  548. 

  549.  found:

  550.     mpegts_close_filter(ts, ts->pat_filter);

  551.     ts->pat_filter = NULL;

  552. }

  553. 

  554. /* add all services found in the PAT */

  555. static void pat_scan_cb(void *opaque, const uint8_t *section, int section_len)

  556. {

  557.     MpegTSContext *ts = opaque;

  558.     SectionHeader h1, *h = &h1;

  559.     const uint8_t *p, *p_end;

  560.     int sid, pmt_pid;

  561.     char *provider_name, *name;

  562.     char buf[256];

  563. 

  564. #ifdef DEBUG_SI

  565.     printf("PAT:\n");

  566.     av_hex_dump(stdout, (uint8_t *)section, section_len);

  567. #endif

  568.     p_end = section + section_len - 4;

  569.     p = section;

  570.     if (parse_section_header(h, &p, p_end) < 0)

  571.         return;

  572.     if (h->tid != PAT_TID)

  573.         return;

  574. 

  575.     for(;;) {

  576.         sid = get16(&p, p_end);

  577.         if (sid < 0)

  578.             break;

  579.         pmt_pid = get16(&p, p_end) & 0x1fff;

  580.         if (pmt_pid < 0)

  581.             break;

  582. #ifdef DEBUG_SI

  583.         printf("sid=0x%x pid=0x%x\n", sid, pmt_pid);

  584. #endif

  585.         if (sid == 0x0000) {

  586.             /* NIT info */

  587.         } else {

  588.             /* add the service with a dummy name */

  589.             snprintf(buf, sizeof(buf), "Service %x\n", sid);

  590.             name = av_strdup(buf);

  591.             provider_name = av_strdup("");

  592.             if (name && provider_name) {

  593.                 new_service(ts, sid, provider_name, name);

  594.             } else {

  595.                 av_freep(&name);

  596.                 av_freep(&provider_name);

  597.             }

  598.         }

  599.     }

  600.     ts->stop_parse = 1;

  601. 

  602.     /* remove filter */

  603.     mpegts_close_filter(ts, ts->pat_filter);

  604.     ts->pat_filter = NULL;

  605. }

  606. 

  607. void mpegts_set_service(MpegTSContext *ts, int sid,

  608.                         SetServiceCallback *set_service_cb, void *opaque)

  609. {

  610.     ts->set_service_cb = set_service_cb;

  611.     ts->set_service_opaque = opaque;

  612.     ts->req_sid = sid;

  613.     ts->pat_filter = mpegts_open_section_filter(ts, PAT_PID,

  614.                                                 pat_cb, ts, 1);

  615. }

  616. 

  617. static void sdt_cb(void *opaque, const uint8_t *section, int section_len)

  618. {

  619.     MpegTSContext *ts = opaque;

  620.     SectionHeader h1, *h = &h1;

  621.     const uint8_t *p, *p_end, *desc_list_end, *desc_end;

  622.     int onid, val, sid, desc_list_len, desc_tag, desc_len, service_type;

  623.     char *name, *provider_name;

  624. 

  625. #ifdef DEBUG_SI

  626.     printf("SDT:\n");

  627.     av_hex_dump(stdout, (uint8_t *)section, section_len);

  628. #endif

  629. 

  630.     p_end = section + section_len - 4;

  631.     p = section;

  632.     if (parse_section_header(h, &p, p_end) < 0)

  633.         return;

  634.     if (h->tid != SDT_TID)

  635.         return;

  636.     onid = get16(&p, p_end);

  637.     if (onid < 0)

  638.         return;

  639.     val = get8(&p, p_end);

  640.     if (val < 0)

  641.         return;

  642.     for(;;) {

  643.         sid = get16(&p, p_end);

  644.         if (sid < 0)

  645.             break;

  646.         val = get8(&p, p_end);

  647.         if (val < 0)

  648.             break;

  649.         desc_list_len = get16(&p, p_end) & 0xfff;

  650.         if (desc_list_len < 0)

  651.             break;

  652.         desc_list_end = p + desc_list_len;

  653.         if (desc_list_end > p_end)

  654.             break;

  655.         for(;;) {

  656.             desc_tag = get8(&p, desc_list_end);

  657.             if (desc_tag < 0)

  658.                 break;

  659.             desc_len = get8(&p, desc_list_end);

  660.             desc_end = p + desc_len;

  661.             if (desc_end > desc_list_end)

  662.                 break;

  663. #ifdef DEBUG_SI

  664.             printf("tag: 0x%02x len=%d\n", desc_tag, desc_len);

  665. #endif

  666.             switch(desc_tag) {

  667.             case 0x48:

  668.                 service_type = get8(&p, p_end);

  669.                 if (service_type < 0)

  670.                     break;

  671.                 provider_name = getstr8(&p, p_end);

  672.                 if (!provider_name)

  673.                     break;

  674.                 name = getstr8(&p, p_end);

  675.                 if (!name)

  676.                     break;

  677.                 new_service(ts, sid, provider_name, name);

  678.                 break;

  679.             default:

  680.                 break;

  681.             }

  682.             p = desc_end;

  683.         }

  684.         p = desc_list_end;

  685.     }

  686.     ts->stop_parse = 1;

  687. 

  688.     /* remove filter */

  689.     mpegts_close_filter(ts, ts->sdt_filter);

  690.     ts->sdt_filter = NULL;

  691. }

  692. 

  693. /* scan services in a transport stream by looking at the SDT */

  694. void mpegts_scan_sdt(MpegTSContext *ts)

  695. {

  696.     ts->sdt_filter = mpegts_open_section_filter(ts, SDT_PID,

  697.                                                 sdt_cb, ts, 1);

  698. }

  699. 

  700. /* scan services in a transport stream by looking at the PAT (better

  701.    than nothing !) */

  702. void mpegts_scan_pat(MpegTSContext *ts)

  703. {

  704.     ts->pat_filter = mpegts_open_section_filter(ts, PAT_PID,

  705.                                                 pat_scan_cb, ts, 1);

  706. }

  707. 

  708. /* TS stream handling */

  709. 

  710. enum MpegTSState {

  711.     MPEGTS_HEADER = 0,

  712.     MPEGTS_PESHEADER_FILL,

  713.     MPEGTS_PAYLOAD,

  714.     MPEGTS_SKIP,

  715. };

  716. 

  717. /* enough for PES header + length */

  718. #define PES_START_SIZE 9

  719. #define MAX_PES_HEADER_SIZE (9 + 255)

  720. 

  721. struct PESContext {

  722.     int pid;

  723.     int stream_type;

  724.     MpegTSContext *ts;

  725.     AVFormatContext *stream;

  726.     AVStream *st;

  727.     enum MpegTSState state;

  728.     /* used to get the format */

  729.     int data_index;

  730.     int total_size;

  731.     int pes_header_size;

  732.     int64_t pts, dts;

  733.     uint8_t header[MAX_PES_HEADER_SIZE];

  734. };

  735. 

  736. static int64_t get_pts(const uint8_t *p)

  737. {

  738.     int64_t pts;

  739.     int val;

  740. 

  741.     pts = (int64_t)((p[0] >> 1) & 0x07) << 30;

  742.     val = (p[1] << 8) | p[2];

  743.     pts |= (int64_t)(val >> 1) << 15;

  744.     val = (p[3] << 8) | p[4];

  745.     pts |= (int64_t)(val >> 1);

  746.     return pts;

  747. }

  748. 

  749. /* return non zero if a packet could be constructed */

  750. static void mpegts_push_data(void *opaque,

  751.                              const uint8_t *buf, int buf_size, int is_start)

  752. {

  753.     PESContext *pes = opaque;

  754.     MpegTSContext *ts = pes->ts;

  755.     const uint8_t *p;

  756.     int len, code;

  757. 

  758.     if (is_start) {

  759.         pes->state = MPEGTS_HEADER;

  760.         pes->data_index = 0;

  761.     }

  762.     p = buf;

  763.     while (buf_size > 0) {

  764.         switch(pes->state) {

  765.         case MPEGTS_HEADER:

  766.             len = PES_START_SIZE - pes->data_index;

  767.             if (len > buf_size)

  768.                 len = buf_size;

  769.             memcpy(pes->header + pes->data_index, p, len);

  770.             pes->data_index += len;

  771.             p += len;

  772.             buf_size -= len;

  773.             if (pes->data_index == PES_START_SIZE) {

  774.                 /* we got all the PES or section header. We can now

  775.                    decide */

  776. #if 0

  777.                 av_hex_dump(pes->header, pes->data_index);

  778. #endif

  779.                 if (pes->header[0] == 0x00 && pes->header[1] == 0x00 &&

  780.                     pes->header[2] == 0x01) {

  781.                     /* it must be an mpeg2 PES stream */

  782.                     code = pes->header[3] | 0x100;

  783.                     if (!((code >= 0x1c0 && code <= 0x1df) ||

  784.                           (code >= 0x1e0 && code <= 0x1ef) ||

  785.                           (code == 0x1bd)))

  786.                         goto skip;

  787.                     if (!pes->st) {

  788.                         /* allocate stream */

  789.                         new_pes_av_stream(pes, code);

  790.                     }

  791.                     pes->state = MPEGTS_PESHEADER_FILL;

  792.                     pes->total_size = (pes->header[4] << 8) | pes->header[5];

  793.                     /* NOTE: a zero total size means the PES size is

  794.                        unbounded */

  795.                     if (pes->total_size)

  796.                         pes->total_size += 6;

  797.                     pes->pes_header_size = pes->header[8] + 9;

  798.                 } else {

  799.                     /* otherwise, it should be a table */

  800.                     /* skip packet */

  801.                 skip:

  802.                     pes->state = MPEGTS_SKIP;

  803.                     continue;

  804.                 }

  805.             }

  806.             break;

  807.             /**********************************************/

  808.             /* PES packing parsing */

  809.         case MPEGTS_PESHEADER_FILL:

  810.             len = pes->pes_header_size - pes->data_index;

  811.             if (len > buf_size)

  812.                 len = buf_size;

  813.             memcpy(pes->header + pes->data_index, p, len);

  814.             pes->data_index += len;

  815.             p += len;

  816.             buf_size -= len;

  817.             if (pes->data_index == pes->pes_header_size) {

  818.                 const uint8_t *r;

  819.                 unsigned int flags;

  820. 

  821.                 flags = pes->header[7];

  822.                 r = pes->header + 9;

  823.                 pes->pts = AV_NOPTS_VALUE;

  824.                 pes->dts = AV_NOPTS_VALUE;

  825.                 if ((flags & 0xc0) == 0x80) {

  826.                     pes->pts = get_pts(r);

  827.                     r += 5;

  828.                 } else if ((flags & 0xc0) == 0xc0) {

  829.                     pes->pts = get_pts(r);

  830.                     r += 5;

  831.                     pes->dts = get_pts(r);

  832.                     r += 5;

  833.                 }

  834.                 /* we got the full header. We parse it and get the payload */

  835.                 pes->state = MPEGTS_PAYLOAD;

  836.             }

  837.             break;

  838.         case MPEGTS_PAYLOAD:

  839.             if (pes->total_size) {

  840.                 len = pes->total_size - pes->data_index;

  841.                 if (len > buf_size)

  842.                     len = buf_size;

  843.             } else {

  844.                 len = buf_size;

  845.             }

  846.             if (len > 0) {

  847.                 AVPacket *pkt = ts->pkt;

  848.                 if (pes->st && av_new_packet(pkt, len) == 0) {

  849.                     memcpy(pkt->data, p, len);

  850.                     pkt->stream_index = pes->st->index;

  851.                     pkt->pts = pes->pts;

  852.                     pkt->dts = pes->dts;

  853.                     /* reset pts values */

  854.                     pes->pts = AV_NOPTS_VALUE;

  855.                     pes->dts = AV_NOPTS_VALUE;

  856.                     ts->stop_parse = 1;

  857.                     return;

  858.                 }

  859.             }

  860.             buf_size = 0;

  861.             break;

  862.         case MPEGTS_SKIP:

  863.             buf_size = 0;

  864.             break;

  865.         }

  866.     }

  867. }

  868. 

  869. static AVStream* new_pes_av_stream(PESContext *pes, uint32_t code)

  870. {

  871.     AVStream *st;

  872.     int codec_type, codec_id;

  873. 

  874.     switch(pes->stream_type){

  875.     case STREAM_TYPE_AUDIO_MPEG1:

  876.     case STREAM_TYPE_AUDIO_MPEG2:

  877.         codec_type = CODEC_TYPE_AUDIO;

  878.         codec_id = CODEC_ID_MP3;

  879.         break;

  880.     case STREAM_TYPE_VIDEO_MPEG1:

  881.     case STREAM_TYPE_VIDEO_MPEG2:

  882.         codec_type = CODEC_TYPE_VIDEO;

  883.         codec_id = CODEC_ID_MPEG2VIDEO;

  884.         break;

  885.     case STREAM_TYPE_VIDEO_MPEG4:

  886.         codec_type = CODEC_TYPE_VIDEO;

  887.         codec_id = CODEC_ID_MPEG4;

  888.         break;

  889.     case STREAM_TYPE_VIDEO_H264:

  890.         codec_type = CODEC_TYPE_VIDEO;

  891.         codec_id = CODEC_ID_H264;

  892.         break;

  893.     case STREAM_TYPE_AUDIO_AAC:

  894.         codec_type = CODEC_TYPE_AUDIO;

  895.         codec_id = CODEC_ID_AAC;

  896.         break;

  897.     case STREAM_TYPE_AUDIO_AC3:

  898.         codec_type = CODEC_TYPE_AUDIO;

  899.         codec_id = CODEC_ID_AC3;

  900.         break;

  901.     case STREAM_TYPE_AUDIO_DTS:

  902.         codec_type = CODEC_TYPE_AUDIO;

  903.         codec_id = CODEC_ID_DTS;

  904.         break;

  905.     case STREAM_TYPE_SUBTITLE_DVB:

  906.         codec_type = CODEC_TYPE_SUBTITLE;

  907.         codec_id = CODEC_ID_DVB_SUBTITLE;

  908.         break;

  909.     default:

  910.         if (code >= 0x1c0 && code <= 0x1df) {

  911.             codec_type = CODEC_TYPE_AUDIO;

  912.             codec_id = CODEC_ID_MP2;

  913.         } else if (code == 0x1bd) {

  914.             codec_type = CODEC_TYPE_AUDIO;

  915.             codec_id = CODEC_ID_AC3;

  916.         } else {

  917.             codec_type = CODEC_TYPE_VIDEO;

  918.             codec_id = CODEC_ID_MPEG1VIDEO;

  919.         }

  920.         break;

  921.     }

  922.     st = av_new_stream(pes->stream, pes->pid);

  923.     if (st) {

  924.         av_set_pts_info(st, 33, 1, 90000);

  925.         st->priv_data = pes;

  926.         st->codec->codec_type = codec_type;

  927.         st->codec->codec_id = codec_id;

  928.         st->need_parsing = 1;

  929.         pes->st = st;

  930.     }

  931.     return st;

  932. }

  933. 

  934. 

  935. static PESContext *add_pes_stream(MpegTSContext *ts, int pid, int stream_type)

  936. {

  937.     MpegTSFilter *tss;

  938.     PESContext *pes;

  939. 

  940.     /* if no pid found, then add a pid context */

  941.     pes = av_mallocz(sizeof(PESContext));

  942.     if (!pes)

  943.         return 0;

  944.     pes->ts = ts;

  945.     pes->stream = ts->stream;

  946.     pes->pid = pid;

  947.     pes->stream_type = stream_type;

  948.     tss = mpegts_open_pes_filter(ts, pid, mpegts_push_data, pes);

  949.     if (!tss) {

  950.         av_free(pes);

  951.         return 0;

  952.     }

  953.     return pes;

  954. }

  955. 

  956. /* handle one TS packet */

  957. static void handle_packet(MpegTSContext *ts, const uint8_t *packet)

  958. {

  959.     AVFormatContext *s = ts->stream;

  960.     MpegTSFilter *tss;

  961.     int len, pid, cc, cc_ok, afc, is_start;

  962.     const uint8_t *p, *p_end;

  963. 

  964.     pid = ((packet[1] & 0x1f) << 8) | packet[2];

  965.     is_start = packet[1] & 0x40;

  966.     tss = ts->pids[pid];

  967.     if (ts->auto_guess && tss == NULL && is_start) {

  968.         add_pes_stream(ts, pid, 0);

  969.         tss = ts->pids[pid];

  970.     }

  971.     if (!tss)

  972.         return;

  973. 

  974.     /* continuity check (currently not used) */

  975.     cc = (packet[3] & 0xf);

  976.     cc_ok = (tss->last_cc < 0) || ((((tss->last_cc + 1) & 0x0f) == cc));

  977.     tss->last_cc = cc;

  978. 

  979.     /* skip adaptation field */

  980.     afc = (packet[3] >> 4) & 3;

  981.     p = packet + 4;

  982.     if (afc == 0) /* reserved value */

  983.         return;

  984.     if (afc == 2) /* adaptation field only */

  985.         return;

  986.     if (afc == 3) {

  987.         /* skip adapation field */

  988.         p += p[0] + 1;

  989.     }

  990.     /* if past the end of packet, ignore */

  991.     p_end = packet + TS_PACKET_SIZE;

  992.     if (p >= p_end)

  993.         return;

  994. 

  995.     if (tss->type == MPEGTS_SECTION) {

  996.         if (is_start) {

  997.             /* pointer field present */

  998.             len = *p++;

  999.             if (p + len > p_end)

  1000.                 return;

  1001.             if (len && cc_ok) {

  1002.                 /* write remaining section bytes */

  1003.                 write_section_data(s, tss,

  1004.                                    p, len, 0);

  1005.                 /* check whether filter has been closed */

  1006.                 if (!ts->pids[pid])

  1007.                     return;

  1008.             }

  1009.             p += len;

  1010.             if (p < p_end) {

  1011.                 write_section_data(s, tss,

  1012.                                    p, p_end - p, 1);

  1013.             }

  1014.         } else {

  1015.             if (cc_ok) {

  1016.                 write_section_data(s, tss,

  1017.                                    p, p_end - p, 0);

  1018.             }

  1019.         }

  1020.     } else {

  1021.         tss->u.pes_filter.pes_cb(tss->u.pes_filter.opaque,

  1022.                                  p, p_end - p, is_start);

  1023.     }

  1024. }

  1025. 

  1026. /* XXX: try to find a better synchro over several packets (use

  1027.    get_packet_size() ?) */

  1028. static int mpegts_resync(ByteIOContext *pb)

  1029. {

  1030.     int c, i;

  1031. 

  1032.     for(i = 0;i < MAX_RESYNC_SIZE; i++) {

  1033.         c = url_fgetc(pb);

  1034.         if (c < 0)

  1035.             return -1;

  1036.         if (c == 0x47) {

  1037.             url_fseek(pb, -1, SEEK_CUR);

  1038.             return 0;

  1039.         }

  1040.     }

  1041.     /* no sync found */

  1042.     return -1;

  1043. }

  1044. 

  1045. /* return -1 if error or EOF. Return 0 if OK. */

  1046. static int read_packet(ByteIOContext *pb, uint8_t *buf, int raw_packet_size)

  1047. {

  1048.     int skip, len;

  1049. 

  1050.     for(;;) {

  1051.         len = get_buffer(pb, buf, TS_PACKET_SIZE);

  1052.         if (len != TS_PACKET_SIZE)

  1053.             return AVERROR_IO;

  1054.         /* check paquet sync byte */

  1055.         if (buf[0] != 0x47) {

  1056.             /* find a new packet start */

  1057.             url_fseek(pb, -TS_PACKET_SIZE, SEEK_CUR);

  1058.             if (mpegts_resync(pb) < 0)

  1059.                 return AVERROR_INVALIDDATA;

  1060.             else

  1061.                 continue;

  1062.         } else {

  1063.             skip = raw_packet_size - TS_PACKET_SIZE;

  1064.             if (skip > 0)

  1065.                 url_fskip(pb, skip);

  1066.             break;

  1067.         }

  1068.     }

  1069.     return 0;

  1070. }

  1071. 

  1072. static int handle_packets(MpegTSContext *ts, int nb_packets)

  1073. {

  1074.     AVFormatContext *s = ts->stream;

  1075.     ByteIOContext *pb = &s->pb;

  1076.     uint8_t packet[TS_PACKET_SIZE];

  1077.     int packet_num, ret;

  1078. 

  1079.     ts->stop_parse = 0;

  1080.     packet_num = 0;

  1081.     for(;;) {

  1082.         if (ts->stop_parse)

  1083.             break;

  1084.         packet_num++;

  1085.         if (nb_packets != 0 && packet_num >= nb_packets)

  1086.             break;

  1087.         ret = read_packet(pb, packet, ts->raw_packet_size);

  1088.         if (ret != 0)

  1089.             return ret;

  1090.         handle_packet(ts, packet);

  1091.     }

  1092.     return 0;

  1093. }

  1094. 

  1095. static int mpegts_probe(AVProbeData *p)

  1096. {

  1097. #if 1

  1098.     const int size= p->buf_size;

  1099.     int score, fec_score, dvhs_score;

  1100. #define CHECK_COUNT 10

  1101. 

  1102.     if (size < (TS_FEC_PACKET_SIZE * CHECK_COUNT))

  1103.         return -1;

  1104. 

  1105.     score    = analyze(p->buf, TS_PACKET_SIZE    *CHECK_COUNT, TS_PACKET_SIZE, NULL);

  1106.     dvhs_score  = analyze(p->buf, TS_DVHS_PACKET_SIZE    *CHECK_COUNT, TS_DVHS_PACKET_SIZE, NULL);

  1107.     fec_score= analyze(p->buf, TS_FEC_PACKET_SIZE*CHECK_COUNT, TS_FEC_PACKET_SIZE, NULL);

  1108. //    av_log(NULL, AV_LOG_DEBUG, "score: %d, dvhs_score: %d, fec_score: %d \n", score, dvhs_score, fec_score);

  1109. 

  1110. // we need a clear definition for the returned score otherwise things will become messy sooner or later

  1111.     if     (score > fec_score && score > dvhs_score && score > 6) return AVPROBE_SCORE_MAX + score     - CHECK_COUNT;

  1112.     else if(dvhs_score > score && dvhs_score > fec_score && dvhs_score > 6) return AVPROBE_SCORE_MAX + dvhs_score  - CHECK_COUNT;

  1113.     else if(                 fec_score > 6) return AVPROBE_SCORE_MAX + fec_score - CHECK_COUNT;

  1114.     else                                    return -1;

  1115. #else

  1116.     /* only use the extension for safer guess */

  1117.     if (match_ext(p->filename, "ts"))

  1118.         return AVPROBE_SCORE_MAX;

  1119.     else

  1120.         return 0;

  1121. #endif

  1122. }

  1123. 

  1124. void set_service_cb(void *opaque, int ret)

  1125. {

  1126.     MpegTSContext *ts = opaque;

  1127.     ts->set_service_ret = ret;

  1128.     ts->stop_parse = 1;

  1129. }

  1130. 

  1131. /* return the 90 kHz PCR and the extension for the 27 MHz PCR. return

  1132.    (-1) if not available */

  1133. static int parse_pcr(int64_t *ppcr_high, int *ppcr_low,

  1134.                      const uint8_t *packet)

  1135. {

  1136.     int afc, len, flags;

  1137.     const uint8_t *p;

  1138.     unsigned int v;

  1139. 

  1140.     afc = (packet[3] >> 4) & 3;

  1141.     if (afc <= 1)

  1142.         return -1;

  1143.     p = packet + 4;

  1144.     len = p[0];

  1145.     p++;

  1146.     if (len == 0)

  1147.         return -1;

  1148.     flags = *p++;

  1149.     len--;

  1150.     if (!(flags & 0x10))

  1151.         return -1;

  1152.     if (len < 6)

  1153.         return -1;

  1154.     v = (p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3];

  1155.     *ppcr_high = ((int64_t)v << 1) | (p[4] >> 7);

  1156.     *ppcr_low = ((p[4] & 1) << 8) | p[5];

  1157.     return 0;

  1158. }

  1159. 

  1160. static int mpegts_read_header(AVFormatContext *s,

  1161.                               AVFormatParameters *ap)

  1162. {

  1163.     MpegTSContext *ts = s->priv_data;

  1164.     ByteIOContext *pb = &s->pb;

  1165.     uint8_t buf[1024];

  1166.     int len, sid, i;

  1167.     int64_t pos;

  1168.     MpegTSService *service;

  1169. 

  1170.     if (ap) {

  1171.         ts->mpeg2ts_raw = ap->mpeg2ts_raw;

  1172.         ts->mpeg2ts_compute_pcr = ap->mpeg2ts_compute_pcr;

  1173.     }

  1174. 

  1175.     /* read the first 1024 bytes to get packet size */

  1176.     pos = url_ftell(pb);

  1177.     len = get_buffer(pb, buf, sizeof(buf));

  1178.     if (len != sizeof(buf))

  1179.         goto fail;

  1180.     ts->raw_packet_size = get_packet_size(buf, sizeof(buf));

  1181.     if (ts->raw_packet_size <= 0)

  1182.         goto fail;

  1183.     ts->stream = s;

  1184.     ts->auto_guess = 0;

  1185. 

  1186. goto_auto_guess:

  1187.     if (!ts->mpeg2ts_raw) {

  1188.         /* normal demux */

  1189. 

  1190.         if (!ts->auto_guess) {

  1191.             ts->set_service_ret = -1;

  1192. 

  1193.             /* first do a scaning to get all the services */

  1194.             url_fseek(pb, pos, SEEK_SET);

  1195.             mpegts_scan_sdt(ts);

  1196. 

  1197.             handle_packets(ts, MAX_SCAN_PACKETS);

  1198. 

  1199.             if (ts->nb_services <= 0) {

  1200.                 /* no SDT found, we try to look at the PAT */

  1201. 

  1202.                 /* First remove the SDT filters from each PID */

  1203.                 int i;

  1204.                 for (i=0; i < NB_PID_MAX; i++) {

  1205.                     if (ts->pids[i])

  1206.                         mpegts_close_filter(ts, ts->pids[i]);

  1207.                 }

  1208.                 url_fseek(pb, pos, SEEK_SET);

  1209.                 mpegts_scan_pat(ts);

  1210. 

  1211.                 handle_packets(ts, MAX_SCAN_PACKETS);

  1212.             }

  1213. 

  1214.             if (ts->nb_services <= 0) {

  1215.                 /* raw transport stream */

  1216.                 ts->auto_guess = 1;

  1217.                 s->ctx_flags |= AVFMTCTX_NOHEADER;

  1218.                 goto do_pcr;

  1219.             }

  1220. 

  1221.             /* tune to first service found */

  1222.             for(i=0; i<ts->nb_services && ts->set_service_ret; i++){

  1223.                 service = ts->services[i];

  1224.                 sid = service->sid;

  1225. #ifdef DEBUG_SI

  1226.                 printf("tuning to '%s'\n", service->name);

  1227. #endif

  1228. 

  1229.                 /* now find the info for the first service if we found any,

  1230.                 otherwise try to filter all PATs */

  1231. 

  1232.                 url_fseek(pb, pos, SEEK_SET);

  1233.                 mpegts_set_service(ts, sid, set_service_cb, ts);

  1234. 

  1235.                 handle_packets(ts, MAX_SCAN_PACKETS);

  1236.             }

  1237.             /* if could not find service, exit */

  1238. 

  1239.             if (ts->set_service_ret != 0) {

  1240.                 if(ts->auto_guess)

  1241.                   return -1;

  1242.                 else {

  1243.                   //let's retry with auto_guess set

  1244.                  ts->auto_guess = 1;

  1245.                  goto goto_auto_guess;

  1246.                 }

  1247.             }

  1248. 

  1249. #ifdef DEBUG_SI

  1250.             printf("tuning done\n");

  1251. #endif

  1252.         }

  1253.         s->ctx_flags |= AVFMTCTX_NOHEADER;

  1254.     } else {

  1255.         AVStream *st;

  1256.         int pcr_pid, pid, nb_packets, nb_pcrs, ret, pcr_l;

  1257.         int64_t pcrs[2], pcr_h;

  1258.         int packet_count[2];

  1259.         uint8_t packet[TS_PACKET_SIZE];

  1260. 

  1261.         /* only read packets */

  1262. 

  1263.     do_pcr:

  1264.         st = av_new_stream(s, 0);

  1265.         if (!st)

  1266.             goto fail;

  1267.         av_set_pts_info(st, 60, 1, 27000000);

  1268.         st->codec->codec_type = CODEC_TYPE_DATA;

  1269.         st->codec->codec_id = CODEC_ID_MPEG2TS;

  1270. 

  1271.         /* we iterate until we find two PCRs to estimate the bitrate */

  1272.         pcr_pid = -1;

  1273.         nb_pcrs = 0;

  1274.         nb_packets = 0;

  1275.         for(;;) {

  1276.             ret = read_packet(&s->pb, packet, ts->raw_packet_size);

  1277.             if (ret < 0)

  1278.                 return -1;

  1279.             pid = ((packet[1] & 0x1f) << 8) | packet[2];

  1280.             if ((pcr_pid == -1 || pcr_pid == pid) &&

  1281.                 parse_pcr(&pcr_h, &pcr_l, packet) == 0) {

  1282.                 pcr_pid = pid;

  1283.                 packet_count[nb_pcrs] = nb_packets;

  1284.                 pcrs[nb_pcrs] = pcr_h * 300 + pcr_l;

  1285.                 nb_pcrs++;

  1286.                 if (nb_pcrs >= 2)

  1287.                     break;

  1288.             }

  1289.             nb_packets++;

  1290.         }

  1291.         ts->pcr_pid = pcr_pid;

  1292. 

  1293.         /* NOTE1: the bitrate is computed without the FEC */

  1294.         /* NOTE2: it is only the bitrate of the start of the stream */

  1295.         ts->pcr_incr = (pcrs[1] - pcrs[0]) / (packet_count[1] - packet_count[0]);

  1296.         ts->cur_pcr = pcrs[0] - ts->pcr_incr * packet_count[0];

  1297.         s->bit_rate = (TS_PACKET_SIZE * 8) * 27e6 / ts->pcr_incr;

  1298.         st->codec->bit_rate = s->bit_rate;

  1299.         st->start_time = ts->cur_pcr;

  1300. #if 0

  1301.         printf("start=%0.3f pcr=%0.3f incr=%d\n",

  1302.                st->start_time / 1000000.0, pcrs[0] / 27e6, ts->pcr_incr);

  1303. #endif

  1304.     }

  1305. 

  1306.     url_fseek(pb, pos, SEEK_SET);

  1307.     return 0;

  1308.  fail:

  1309.     return -1;

  1310. }

  1311. 

  1312. #define MAX_PACKET_READAHEAD ((128 * 1024) / 188)

  1313. 

  1314. static int mpegts_raw_read_packet(AVFormatContext *s,

  1315.                                   AVPacket *pkt)

  1316. {

  1317.     MpegTSContext *ts = s->priv_data;

  1318.     int ret, i;

  1319.     int64_t pcr_h, next_pcr_h, pos;

  1320.     int pcr_l, next_pcr_l;

  1321.     uint8_t pcr_buf[12];

  1322. 

  1323.     if (av_new_packet(pkt, TS_PACKET_SIZE) < 0)

  1324.         return -ENOMEM;

  1325.     pkt->pos= url_ftell(&s->pb);

  1326.     ret = read_packet(&s->pb, pkt->data, ts->raw_packet_size);

  1327.     if (ret < 0) {

  1328.         av_free_packet(pkt);

  1329.         return ret;

  1330.     }

  1331.     if (ts->mpeg2ts_compute_pcr) {

  1332.         /* compute exact PCR for each packet */

  1333.         if (parse_pcr(&pcr_h, &pcr_l, pkt->data) == 0) {

  1334.             /* we read the next PCR (XXX: optimize it by using a bigger buffer */

  1335.             pos = url_ftell(&s->pb);

  1336.             for(i = 0; i < MAX_PACKET_READAHEAD; i++) {

  1337.                 url_fseek(&s->pb, pos + i * ts->raw_packet_size, SEEK_SET);

  1338.                 get_buffer(&s->pb, pcr_buf, 12);

  1339.                 if (parse_pcr(&next_pcr_h, &next_pcr_l, pcr_buf) == 0) {

  1340.                     /* XXX: not precise enough */

  1341.                     ts->pcr_incr = ((next_pcr_h - pcr_h) * 300 + (next_pcr_l - pcr_l)) /

  1342.                         (i + 1);

  1343.                     break;

  1344.                 }

  1345.             }

  1346.             url_fseek(&s->pb, pos, SEEK_SET);

  1347.             /* no next PCR found: we use previous increment */

  1348.             ts->cur_pcr = pcr_h * 300 + pcr_l;

  1349.         }

  1350.         pkt->pts = ts->cur_pcr;

  1351.         pkt->duration = ts->pcr_incr;

  1352.         ts->cur_pcr += ts->pcr_incr;

  1353.     }

  1354.     pkt->stream_index = 0;

  1355.     return 0;

  1356. }

  1357. 

  1358. static int mpegts_read_packet(AVFormatContext *s,

  1359.                               AVPacket *pkt)

  1360. {

  1361.     MpegTSContext *ts = s->priv_data;

  1362. 

  1363.     if (!ts->mpeg2ts_raw) {

  1364.         ts->pkt = pkt;

  1365.         return handle_packets(ts, 0);

  1366.     } else {

  1367.         return mpegts_raw_read_packet(s, pkt);

  1368.     }

  1369. }

  1370. 

  1371. static int mpegts_read_close(AVFormatContext *s)

  1372. {

  1373.     MpegTSContext *ts = s->priv_data;

  1374.     int i;

  1375.     for(i=0;i<NB_PID_MAX;i++)

  1376.         if (ts->pids[i]) mpegts_close_filter(ts, ts->pids[i]);

  1377.     return 0;

  1378. }

  1379. 

  1380. static int64_t mpegts_get_pcr(AVFormatContext *s, int stream_index,

  1381.                               int64_t *ppos, int64_t pos_limit)

  1382. {

  1383.     MpegTSContext *ts = s->priv_data;

  1384.     int64_t pos, timestamp;

  1385.     uint8_t buf[TS_PACKET_SIZE];

  1386.     int pcr_l, pid;

  1387.     const int find_next= 1;

  1388.     pos = ((*ppos  + ts->raw_packet_size - 1) / ts->raw_packet_size) * ts->raw_packet_size;

  1389.     if (find_next) {

  1390.         for(;;) {

  1391.             url_fseek(&s->pb, pos, SEEK_SET);

  1392.             if (get_buffer(&s->pb, buf, TS_PACKET_SIZE) != TS_PACKET_SIZE)

  1393.                 return AV_NOPTS_VALUE;

  1394.             pid = ((buf[1] & 0x1f) << 8) | buf[2];

  1395.             if (pid == ts->pcr_pid &&

  1396.                 parse_pcr(&timestamp, &pcr_l, buf) == 0) {

  1397.                 break;

  1398.             }

  1399.             pos += ts->raw_packet_size;

  1400.         }

  1401.     } else {

  1402.         for(;;) {

  1403.             pos -= ts->raw_packet_size;

  1404.             if (pos < 0)

  1405.                 return AV_NOPTS_VALUE;

  1406.             url_fseek(&s->pb, pos, SEEK_SET);

  1407.             if (get_buffer(&s->pb, buf, TS_PACKET_SIZE) != TS_PACKET_SIZE)

  1408.                 return AV_NOPTS_VALUE;

  1409.             pid = ((buf[1] & 0x1f) << 8) | buf[2];

  1410.             if (pid == ts->pcr_pid &&

  1411.                 parse_pcr(&timestamp, &pcr_l, buf) == 0) {

  1412.                 break;

  1413.             }

  1414.         }

  1415.     }

  1416.     *ppos = pos;

  1417. 

  1418.     return timestamp;

  1419. }

  1420. 

  1421. static int read_seek(AVFormatContext *s, int stream_index, int64_t target_ts, int flags){

  1422.     MpegTSContext *ts = s->priv_data;

  1423.     uint8_t buf[TS_PACKET_SIZE];

  1424.     int64_t pos;

  1425. 

  1426.     if(av_seek_frame_binary(s, stream_index, target_ts, flags) < 0)

  1427.         return -1;

  1428. 

  1429.     pos= url_ftell(&s->pb);

  1430. 

  1431.     for(;;) {

  1432.         url_fseek(&s->pb, pos, SEEK_SET);

  1433.         if (get_buffer(&s->pb, buf, TS_PACKET_SIZE) != TS_PACKET_SIZE)

  1434.             return -1;

  1435. //        pid = ((buf[1] & 0x1f) << 8) | buf[2];

  1436.         if(buf[1] & 0x40) break;

  1437.         pos += ts->raw_packet_size;

  1438.     }

  1439.     url_fseek(&s->pb, pos, SEEK_SET);

  1440. 

  1441.     return 0;

  1442. }

  1443. 

  1444. /**************************************************************/

  1445. /* parsing functions - called from other demuxers such as RTP */

  1446. 

  1447. MpegTSContext *mpegts_parse_open(AVFormatContext *s)

  1448. {

  1449.     MpegTSContext *ts;

  1450. 

  1451.     ts = av_mallocz(sizeof(MpegTSContext));

  1452.     if (!ts)

  1453.         return NULL;

  1454.     /* no stream case, currently used by RTP */

  1455.     ts->raw_packet_size = TS_PACKET_SIZE;

  1456.     ts->stream = s;

  1457.     ts->auto_guess = 1;

  1458.     return ts;

  1459. }

  1460. 

  1461. /* return the consumed length if a packet was output, or -1 if no

  1462.    packet is output */

  1463. int mpegts_parse_packet(MpegTSContext *ts, AVPacket *pkt,

  1464.                         const uint8_t *buf, int len)

  1465. {

  1466.     int len1;

  1467. 

  1468.     len1 = len;

  1469.     ts->pkt = pkt;

  1470.     ts->stop_parse = 0;

  1471.     for(;;) {

  1472.         if (ts->stop_parse)

  1473.             break;

  1474.         if (len < TS_PACKET_SIZE)

  1475.             return -1;

  1476.         if (buf[0] != 0x47) {

  1477.             buf++;

  1478.             len--;

  1479.         } else {

  1480.             handle_packet(ts, buf);

  1481.             buf += TS_PACKET_SIZE;

  1482.             len -= TS_PACKET_SIZE;

  1483.         }

  1484.     }

  1485.     return len1 - len;

  1486. }

  1487. 

  1488. void mpegts_parse_close(MpegTSContext *ts)

  1489. {

  1490.     int i;

  1491. 

  1492.     for(i=0;i<NB_PID_MAX;i++)

  1493.         av_free(ts->pids[i]);

  1494.     av_free(ts);

  1495. }

  1496. 

  1497. AVInputFormat mpegts_demux = {

  1498.     "mpegts",

  1499.     "MPEG2 transport stream format",

  1500.     sizeof(MpegTSContext),

  1501.     mpegts_probe,

  1502.     mpegts_read_header,

  1503.     mpegts_read_packet,

  1504.     mpegts_read_close,

  1505.     read_seek,

  1506.     mpegts_get_pcr,

  1507.     .flags = AVFMT_SHOW_IDS,

  1508. };

  1509. 

  1510. int mpegts_init(void)

  1511. {

  1512.     av_register_input_format(&mpegts_demux);

  1513. #ifdef CONFIG_MUXERS

  1514.     av_register_output_format(&mpegts_mux);

  1515. #endif

  1516.     return 0;

  1517. }