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

  34. 

  35. enum MpegTSFilterType {

  36.     MPEGTS_PES,

  37.     MPEGTS_SECTION,

  38. };

  39. 

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

  41. 

  42. typedef struct MpegTSPESFilter {

  43.     PESCallback *pes_cb;

  44.     void *opaque;

  45. } MpegTSPESFilter;

  46. 

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

  48. 

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

  50. 

  51. typedef struct MpegTSSectionFilter {

  52.     int section_index;

  53.     int section_h_size;

  54.     uint8_t *section_buf;

  55.     int check_crc:1;

  56.     int end_of_section_reached:1;

  57.     SectionCallback *section_cb;

  58.     void *opaque;

  59. } MpegTSSectionFilter;

  60. 

  61. typedef struct MpegTSFilter {

  62.     int pid;

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

  64.     enum MpegTSFilterType type;

  65.     union {

  66.         MpegTSPESFilter pes_filter;

  67.         MpegTSSectionFilter section_filter;

  68.     } u;

  69. } MpegTSFilter;

  70. 

  71. typedef struct MpegTSService {

  72.     int running:1;

  73.     int sid;

  74.     char *provider_name;

  75.     char *name;

  76. } MpegTSService;

  77. 

  78. struct MpegTSContext {

  79.     /* user data */

  80.     AVFormatContext *stream;

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

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

  83.     int set_service_ret;

  84. 

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

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

  87. 

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

  89.     int64_t cur_pcr;

  90.     int pcr_incr;

  91.     int pcr_pid;

  92.     

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

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

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

  96. 

  97.     /******************************************/

  98.     /* private mpegts data */

  99.     /* scan context */

  100.     MpegTSFilter *sdt_filter;

  101.     int nb_services;

  102.     MpegTSService **services;

  103.     

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

  105.     SetServiceCallback *set_service_cb;

  106.     void *set_service_opaque;

  107.     MpegTSFilter *pat_filter;

  108.     MpegTSFilter *pmt_filter;

  109.     int req_sid;

  110. 

  111.     MpegTSFilter *pids[NB_PID_MAX];

  112. };

  113. 

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

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

  116. {

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

  118.     int len;

  119.     unsigned int crc;

  120.     

  121.     if (is_start) {

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

  123.         tss->section_index = buf_size;

  124.         tss->section_h_size = -1;

  125.         tss->end_of_section_reached = 0;

  126.     } else {

  127.         if (tss->end_of_section_reached)

  128.             return;

  129.         len = 4096 - tss->section_index;

  130.         if (buf_size < len)

  131.             len = buf_size;

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

  133.         tss->section_index += len;

  134.     }

  135. 

  136.     /* compute section length if possible */

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

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

  139.         if (len > 4096)

  140.             return;

  141.         tss->section_h_size = len;

  142.     }

  143. 

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

  145.         if (tss->check_crc) {

  146.             crc = mpegts_crc32(tss->section_buf, tss->section_h_size);

  147.             if (crc != 0)

  148.                 goto invalid_crc;

  149.         }

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

  151.     invalid_crc:

  152.         tss->end_of_section_reached = 1;

  153.     }

  154. }

  155. 

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

  157.                                          SectionCallback *section_cb, void *opaque,

  158.                                          int check_crc)

  159. 

  160. {

  161.     MpegTSFilter *filter;

  162.     MpegTSSectionFilter *sec;

  163.     

  164. #ifdef DEBUG_SI

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

  166. #endif

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

  168.         return NULL;

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

  170.     if (!filter) 

  171.         return NULL;

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

  173.     filter->type = MPEGTS_SECTION;

  174.     filter->pid = pid;

  175.     filter->last_cc = -1;

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

  177.     sec->section_cb = section_cb;

  178.     sec->opaque = opaque;

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

  180.     sec->check_crc = check_crc;

  181.     if (!sec->section_buf) {

  182.         av_free(filter);

  183.         return NULL;

  184.     }

  185.     return filter;

  186. }

  187. 

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

  189.                                      PESCallback *pes_cb,

  190.                                      void *opaque)

  191. {

  192.     MpegTSFilter *filter;

  193.     MpegTSPESFilter *pes;

  194. 

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

  196.         return NULL;

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

  198.     if (!filter) 

  199.         return NULL;

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

  201.     filter->type = MPEGTS_PES;

  202.     filter->pid = pid;

  203.     filter->last_cc = -1;

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

  205.     pes->pes_cb = pes_cb;

  206.     pes->opaque = opaque;

  207.     return filter;

  208. }

  209. 

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

  211. {

  212.     int pid;

  213. 

  214.     pid = filter->pid;

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

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

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

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

  219. 

  220.     av_free(filter);

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

  222. }

  223. 

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

  225.     int stat[packet_size];

  226.     int i;

  227.     int x=0;

  228.     int best_score=0;

  229. 

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

  231. 

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

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

  234.             stat[x]++;

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

  236.                 best_score= stat[x];

  237.                 if(index) *index= x;

  238.             }

  239.         }

  240. 

  241.         x++;

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

  243.     }

  244. 

  245.     return best_score;

  246. }

  247. 

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

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

  250. {

  251.     int score, fec_score;

  252. 

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

  254.         return -1;

  255.         

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

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

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

  259.     

  260.     if     (score > fec_score) return TS_PACKET_SIZE;

  261.     else if(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.     const uint8_t *p, *p_end;

  377.     int program_info_length, pcr_pid, pid, stream_type, desc_length;

  378.     

  379. #ifdef DEBUG_SI

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

  381.     av_hex_dump((uint8_t *)section, section_len);

  382. #endif

  383.     p_end = section + section_len - 4;

  384.     p = section;

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

  386.         return;

  387. #ifdef DEBUG_SI

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

  389. #endif

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

  391.         return;

  392. 

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

  394.     if (pcr_pid < 0)

  395.         return;

  396.     ts->pcr_pid = pcr_pid;

  397. #ifdef DEBUG_SI

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

  399. #endif

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

  401.     if (program_info_length < 0)

  402.         return;

  403.     p += program_info_length;

  404.     if (p >= p_end)

  405.         return;

  406.     for(;;) {

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

  408.         if (stream_type < 0)

  409.             break;

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

  411.         if (pid < 0)

  412.             break;

  413.         desc_length = get16(&p, p_end) & 0xfff;

  414.         if (desc_length < 0)

  415.             break;

  416.         p += desc_length;

  417.         if (p > p_end)

  418.             return;

  419. 

  420. #ifdef DEBUG_SI

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

  422. #endif

  423. 

  424.         /* now create ffmpeg stream */

  425.         switch(stream_type) {

  426.         case STREAM_TYPE_AUDIO_MPEG1:

  427.         case STREAM_TYPE_AUDIO_MPEG2:

  428.         case STREAM_TYPE_VIDEO_MPEG1:

  429.         case STREAM_TYPE_VIDEO_MPEG2:

  430.         case STREAM_TYPE_VIDEO_MPEG4:

  431.         case STREAM_TYPE_VIDEO_H264:

  432.         case STREAM_TYPE_AUDIO_AAC:

  433.         case STREAM_TYPE_AUDIO_AC3:

  434.             add_pes_stream(ts, pid, stream_type);

  435.             break;

  436.         default:

  437.             /* we ignore the other streams */

  438.             break;

  439.         }

  440.     }

  441.     /* all parameters are there */

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

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

  444.     ts->pmt_filter = NULL;

  445. }

  446. 

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

  448. {

  449.     MpegTSContext *ts = opaque;

  450.     SectionHeader h1, *h = &h1;

  451.     const uint8_t *p, *p_end;

  452.     int sid, pmt_pid;

  453. 

  454. #ifdef DEBUG_SI

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

  456.     av_hex_dump((uint8_t *)section, section_len);

  457. #endif

  458.     p_end = section + section_len - 4;

  459.     p = section;

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

  461.         return;

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

  463.         return;

  464. 

  465.     for(;;) {

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

  467.         if (sid < 0)

  468.             break;

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

  470.         if (pmt_pid < 0)

  471.             break;

  472. #ifdef DEBUG_SI

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

  474. #endif

  475.         if (sid == 0x0000) {

  476.             /* NIT info */

  477.         } else {

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

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

  480.                                                             pmt_cb, ts, 1);

  481.                 goto found;

  482.             }

  483.         }

  484.     }

  485.     /* not found */

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

  487. 

  488.  found:

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

  490.     ts->pat_filter = NULL;

  491. }

  492. 

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

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

  495. {

  496.     MpegTSContext *ts = opaque;

  497.     SectionHeader h1, *h = &h1;

  498.     const uint8_t *p, *p_end;

  499.     int sid, pmt_pid;

  500.     char *provider_name, *name;

  501.     char buf[256];

  502. 

  503. #ifdef DEBUG_SI

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

  505.     av_hex_dump((uint8_t *)section, section_len);

  506. #endif

  507.     p_end = section + section_len - 4;

  508.     p = section;

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

  510.         return;

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

  512.         return;

  513. 

  514.     for(;;) {

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

  516.         if (sid < 0)

  517.             break;

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

  519.         if (pmt_pid < 0)

  520.             break;

  521. #ifdef DEBUG_SI

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

  523. #endif

  524.         if (sid == 0x0000) {

  525.             /* NIT info */

  526.         } else {

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

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

  529.             name = av_strdup(buf);

  530.             provider_name = av_strdup("");

  531.             if (name && provider_name) {

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

  533.             } else {

  534.                 av_freep(&name);

  535.                 av_freep(&provider_name);

  536.             }

  537.         }

  538.     }

  539.     ts->stop_parse = 1;

  540. 

  541.     /* remove filter */

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

  543.     ts->pat_filter = NULL;

  544. }

  545. 

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

  547.                         SetServiceCallback *set_service_cb, void *opaque)

  548. {

  549.     ts->set_service_cb = set_service_cb;

  550.     ts->set_service_opaque = opaque;

  551.     ts->req_sid = sid;

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

  553.                                                 pat_cb, ts, 1);

  554. }

  555. 

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

  557. {

  558.     MpegTSContext *ts = opaque;

  559.     SectionHeader h1, *h = &h1;

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

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

  562.     char *name, *provider_name;

  563. 

  564. #ifdef DEBUG_SI

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

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

  567. #endif

  568. 

  569.     p_end = section + section_len - 4;

  570.     p = section;

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

  572.         return;

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

  574.         return;

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

  576.     if (onid < 0)

  577.         return;

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

  579.     if (val < 0)

  580.         return;

  581.     for(;;) {

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

  583.         if (sid < 0)

  584.             break;

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

  586.         if (val < 0)

  587.             break;

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

  589.         if (desc_list_len < 0)

  590.             break;

  591.         desc_list_end = p + desc_list_len;

  592.         if (desc_list_end > p_end)

  593.             break;

  594.         for(;;) {

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

  596.             if (desc_tag < 0)

  597.                 break;

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

  599.             desc_end = p + desc_len;

  600.             if (desc_end > desc_list_end)

  601.                 break;

  602. #ifdef DEBUG_SI

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

  604. #endif

  605.             switch(desc_tag) {

  606.             case 0x48:

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

  608.                 if (service_type < 0)

  609.                     break;

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

  611.                 if (!provider_name)

  612.                     break;

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

  614.                 if (!name)

  615.                     break;

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

  617.                 break;

  618.             default:

  619.                 break;

  620.             }

  621.             p = desc_end;

  622.         }

  623.         p = desc_list_end;

  624.     }

  625.     ts->stop_parse = 1;

  626. 

  627.     /* remove filter */

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

  629.     ts->sdt_filter = NULL;

  630. }

  631. 

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

  633. void mpegts_scan_sdt(MpegTSContext *ts)

  634. {

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

  636.                                                 sdt_cb, ts, 1);

  637. }

  638. 

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

  640.    than nothing !) */

  641. void mpegts_scan_pat(MpegTSContext *ts)

  642. {

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

  644.                                                 pat_scan_cb, ts, 1);

  645. }

  646. 

  647. /* TS stream handling */

  648. 

  649. enum MpegTSState {

  650.     MPEGTS_HEADER = 0,

  651.     MPEGTS_PESHEADER_FILL,

  652.     MPEGTS_PAYLOAD,

  653.     MPEGTS_SKIP,

  654. };

  655. 

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

  657. #define PES_START_SIZE 9

  658. #define MAX_PES_HEADER_SIZE (9 + 255)

  659. 

  660. typedef struct PESContext {

  661.     int pid;

  662.     int stream_type;

  663.     MpegTSContext *ts;

  664.     AVFormatContext *stream;

  665.     AVStream *st;

  666.     enum MpegTSState state;

  667.     /* used to get the format */

  668.     int data_index;

  669.     int total_size;

  670.     int pes_header_size;

  671.     int64_t pts, dts;

  672.     uint8_t header[MAX_PES_HEADER_SIZE];

  673. } PESContext;

  674. 

  675. static int64_t get_pts(const uint8_t *p)

  676. {

  677.     int64_t pts;

  678.     int val;

  679. 

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

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

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

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

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

  685.     return pts;

  686. }

  687. 

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

  689. static void mpegts_push_data(void *opaque,

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

  691. {

  692.     PESContext *pes = opaque;

  693.     MpegTSContext *ts = pes->ts;

  694.     AVStream *st;

  695.     const uint8_t *p;

  696.     int len, code, codec_type, codec_id;

  697.     

  698.     if (is_start) {

  699.         pes->state = MPEGTS_HEADER;

  700.         pes->data_index = 0;

  701.     }

  702.     p = buf;

  703.     while (buf_size > 0) {

  704.         switch(pes->state) {

  705.         case MPEGTS_HEADER:

  706.             len = PES_START_SIZE - pes->data_index;

  707.             if (len > buf_size)

  708.                 len = buf_size;

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

  710.             pes->data_index += len;

  711.             p += len;

  712.             buf_size -= len;

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

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

  715.                    decide */

  716. #if 0

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

  718. #endif

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

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

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

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

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

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

  725.                           (code == 0x1bd)))

  726.                         goto skip;

  727.                     if (!pes->st) {

  728.                         /* allocate stream */

  729.                         switch(pes->stream_type){

  730.                         case STREAM_TYPE_AUDIO_MPEG1:

  731.                         case STREAM_TYPE_AUDIO_MPEG2:

  732.                             codec_type = CODEC_TYPE_AUDIO;

  733.                             codec_id = CODEC_ID_MP3;

  734.                             break;

  735.                         case STREAM_TYPE_VIDEO_MPEG1:

  736.                         case STREAM_TYPE_VIDEO_MPEG2:

  737.                             codec_type = CODEC_TYPE_VIDEO;

  738.                             codec_id = CODEC_ID_MPEG2VIDEO;

  739.                             break;

  740.                         case STREAM_TYPE_VIDEO_MPEG4:

  741.                             codec_type = CODEC_TYPE_VIDEO;

  742.                             codec_id = CODEC_ID_MPEG4;

  743.                             break;

  744.                         case STREAM_TYPE_VIDEO_H264:

  745.                             codec_type = CODEC_TYPE_VIDEO;

  746.                             codec_id = CODEC_ID_H264;

  747.                             break;

  748.                         case STREAM_TYPE_AUDIO_AAC:

  749.                             codec_type = CODEC_TYPE_AUDIO;

  750.                             codec_id = CODEC_ID_AAC;

  751.                             break;

  752.                         case STREAM_TYPE_AUDIO_AC3:

  753.                             codec_type = CODEC_TYPE_AUDIO;

  754.                             codec_id = CODEC_ID_AC3;

  755.                             break;

  756.                         default:

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

  758.                                 codec_type = CODEC_TYPE_AUDIO;

  759.                                 codec_id = CODEC_ID_MP2;

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

  761.                                 codec_type = CODEC_TYPE_AUDIO;

  762.                                 codec_id = CODEC_ID_AC3;

  763.                             } else {

  764.                                 codec_type = CODEC_TYPE_VIDEO;

  765.                                 codec_id = CODEC_ID_MPEG1VIDEO;

  766.                             }

  767.                             break;

  768.                         }

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

  770.                         if (st) {

  771.                             st->priv_data = pes;

  772.                             st->codec.codec_type = codec_type;

  773.                             st->codec.codec_id = codec_id;

  774.                             st->need_parsing = 1;

  775.                             pes->st = st;

  776.                         }

  777.                     }

  778.                     pes->state = MPEGTS_PESHEADER_FILL;

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

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

  781.                        unbounded */

  782.                     if (pes->total_size)

  783.                         pes->total_size += 6;

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

  785.                 } else {

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

  787.                     /* skip packet */

  788.                 skip:

  789.                     pes->state = MPEGTS_SKIP;

  790.                     continue;

  791.                 }

  792.             }

  793.             break;

  794.             /**********************************************/

  795.             /* PES packing parsing */

  796.         case MPEGTS_PESHEADER_FILL:

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

  798.             if (len > buf_size)

  799.                 len = buf_size;

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

  801.             pes->data_index += len;

  802.             p += len;

  803.             buf_size -= len;

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

  805.                 const uint8_t *r;

  806.                 unsigned int flags;

  807. 

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

  809.                 r = pes->header + 9;

  810.                 pes->pts = AV_NOPTS_VALUE;

  811.                 pes->dts = AV_NOPTS_VALUE;

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

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

  814.                     r += 5;

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

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

  817.                     r += 5;

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

  819.                     r += 5;

  820.                 }

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

  822.                 pes->state = MPEGTS_PAYLOAD;

  823.             }

  824.             break;

  825.         case MPEGTS_PAYLOAD:

  826.             if (pes->total_size) {

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

  828.                 if (len > buf_size)

  829.                     len = buf_size;

  830.             } else {

  831.                 len = buf_size;

  832.             }

  833.             if (len > 0) {

  834.                 AVPacket *pkt = ts->pkt;

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

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

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

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

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

  840.                     /* reset pts values */

  841.                     pes->pts = AV_NOPTS_VALUE;

  842.                     pes->dts = AV_NOPTS_VALUE;

  843.                     ts->stop_parse = 1;

  844.                     return;

  845.                 }

  846.             }

  847.             buf_size = 0;

  848.             break;

  849.         case MPEGTS_SKIP:

  850.             buf_size = 0;

  851.             break;

  852.         }

  853.     }

  854. }

  855. 

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

  857. {

  858.     MpegTSFilter *tss;

  859.     PESContext *pes;

  860. 

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

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

  863.     if (!pes)

  864.         return -1;

  865.     pes->ts = ts;

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

  867.     pes->pid = pid;

  868.     pes->stream_type = stream_type;

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

  870.     if (!tss) {

  871.         av_free(pes);

  872.         return -1;

  873.     }

  874.     return 0;

  875. }

  876. 

  877. /* handle one TS packet */

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

  879. {

  880.     AVFormatContext *s = ts->stream;

  881.     MpegTSFilter *tss;

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

  883.     const uint8_t *p, *p_end;

  884. 

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

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

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

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

  889.         add_pes_stream(ts, pid, 0);

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

  891.     }

  892.     if (!tss)

  893.         return;

  894. 

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

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

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

  898.     tss->last_cc = cc;

  899.     

  900.     /* skip adaptation field */

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

  902.     p = packet + 4;

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

  904.         return;

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

  906.         return;

  907.     if (afc == 3) {

  908.         /* skip adapation field */

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

  910.     }

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

  912.     p_end = packet + TS_PACKET_SIZE;

  913.     if (p >= p_end)

  914.         return;

  915.     

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

  917.         if (is_start) {

  918.             /* pointer field present */

  919.             len = *p++;

  920.             if (p + len > p_end)

  921.                 return;

  922.             if (len && cc_ok) {

  923.                 /* write remaning section bytes */

  924.                 write_section_data(s, tss, 

  925.                                    p, len, 0);

  926.             }

  927.             p += len;

  928.             if (p < p_end) {

  929.                 write_section_data(s, tss, 

  930.                                    p, p_end - p, 1);

  931.             }

  932.         } else {

  933.             if (cc_ok) {

  934.                 write_section_data(s, tss, 

  935.                                    p, p_end - p, 0);

  936.             }

  937.         }

  938.     } else {

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

  940.                                  p, p_end - p, is_start);

  941.     }

  942. }

  943. 

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

  945.    get_packet_size() ?) */

  946. static int mpegts_resync(ByteIOContext *pb)

  947. {

  948.     int c, i;

  949. 

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

  951.         c = url_fgetc(pb);

  952.         if (c < 0)

  953.             return -1;

  954.         if (c == 0x47) {

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

  956.             return 0;

  957.         }

  958.     }

  959.     /* no sync found */

  960.     return -1;

  961. }

  962. 

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

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

  965. {

  966.     int skip, len;

  967. 

  968.     for(;;) {

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

  970.         if (len != TS_PACKET_SIZE)

  971.             return AVERROR_IO;

  972.         /* check paquet sync byte */

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

  974.             /* find a new packet start */

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

  976.             if (mpegts_resync(pb) < 0)

  977.                 return AVERROR_INVALIDDATA;

  978.             else

  979.                 continue;

  980.         } else {

  981.             skip = raw_packet_size - TS_PACKET_SIZE;

  982.             if (skip > 0)

  983.                 url_fskip(pb, skip);

  984.             break;

  985.         }

  986.     }

  987.     return 0;

  988. }

  989. 

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

  991. {

  992.     AVFormatContext *s = ts->stream;

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

  994.     uint8_t packet[TS_PACKET_SIZE];

  995.     int packet_num, ret;

  996. 

  997.     ts->stop_parse = 0;

  998.     packet_num = 0;

  999.     for(;;) {

  1000.         if (ts->stop_parse)

  1001.             break;

  1002.         packet_num++;

  1003.         if (nb_packets != 0 && packet_num >= nb_packets)

  1004.             break;

  1005.         ret = read_packet(pb, packet, ts->raw_packet_size);

  1006.         if (ret != 0)

  1007.             return ret;

  1008.         handle_packet(ts, packet);

  1009.     }

  1010.     return 0;

  1011. }

  1012. 

  1013. static int mpegts_probe(AVProbeData *p)

  1014. {

  1015. #if 1

  1016.     const int size= p->buf_size;

  1017.     int score, fec_score;

  1018. #define CHECK_COUNT 10

  1019.     

  1020.     if (size < (TS_FEC_PACKET_SIZE * CHECK_COUNT))

  1021.         return -1;

  1022.     

  1023.     score    = analyze(p->buf, TS_PACKET_SIZE    *CHECK_COUNT, TS_PACKET_SIZE, NULL);

  1024.     fec_score= analyze(p->buf, TS_FEC_PACKET_SIZE*CHECK_COUNT, TS_FEC_PACKET_SIZE, NULL);

  1025. //    av_log(NULL, AV_LOG_DEBUG, "score: %d, fec_score: %d \n", score, fec_score);

  1026.   

  1027. // we need a clear definition for the returned score otherwise things will become messy sooner or later

  1028.     if     (score > fec_score && score > 6) return AVPROBE_SCORE_MAX + score     - CHECK_COUNT;

  1029.     else if(                 fec_score > 6) return AVPROBE_SCORE_MAX + fec_score - CHECK_COUNT;

  1030.     else                                    return -1;

  1031. #else

  1032.     /* only use the extension for safer guess */

  1033.     if (match_ext(p->filename, "ts"))

  1034.         return AVPROBE_SCORE_MAX;

  1035.     else

  1036.         return 0;

  1037. #endif

  1038. }

  1039. 

  1040. void set_service_cb(void *opaque, int ret)

  1041. {

  1042.     MpegTSContext *ts = opaque;

  1043.     ts->set_service_ret = ret;

  1044.     ts->stop_parse = 1;

  1045. }

  1046. 

  1047. /* return the 90 kHz PCR and the extension for the 27 MHz PCR. return

  1048.    (-1) if not available */

  1049. static int parse_pcr(int64_t *ppcr_high, int *ppcr_low, 

  1050.                      const uint8_t *packet)

  1051. {

  1052.     int afc, len, flags;

  1053.     const uint8_t *p;

  1054.     unsigned int v;

  1055. 

  1056.     afc = (packet[3] >> 4) & 3;

  1057.     if (afc <= 1)

  1058.         return -1;

  1059.     p = packet + 4;

  1060.     len = p[0];

  1061.     p++;

  1062.     if (len == 0)

  1063.         return -1;

  1064.     flags = *p++;

  1065.     len--;

  1066.     if (!(flags & 0x10))

  1067.         return -1;

  1068.     if (len < 6)

  1069.         return -1;

  1070.     v = (p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3];

  1071.     *ppcr_high = ((int64_t)v << 1) | (p[4] >> 7);

  1072.     *ppcr_low = ((p[4] & 1) << 8) | p[5];

  1073.     return 0;

  1074. }

  1075. 

  1076. static int mpegts_read_header(AVFormatContext *s,

  1077.                               AVFormatParameters *ap)

  1078. {

  1079.     MpegTSContext *ts = s->priv_data;

  1080.     ByteIOContext *pb = &s->pb;

  1081.     uint8_t buf[1024];

  1082.     int len, sid;

  1083.     int64_t pos;

  1084.     MpegTSService *service;

  1085.     

  1086.     if (ap) {

  1087.         ts->mpeg2ts_raw = ap->mpeg2ts_raw;

  1088.         ts->mpeg2ts_compute_pcr = ap->mpeg2ts_compute_pcr;

  1089.     }

  1090. 

  1091.     /* read the first 1024 bytes to get packet size */

  1092.     pos = url_ftell(pb);

  1093.     len = get_buffer(pb, buf, sizeof(buf));

  1094.     if (len != sizeof(buf))

  1095.         goto fail;

  1096.     ts->raw_packet_size = get_packet_size(buf, sizeof(buf));

  1097.     if (ts->raw_packet_size <= 0)

  1098.         goto fail;

  1099.     ts->stream = s;

  1100.     ts->auto_guess = 0;

  1101. 

  1102.     if (!ts->mpeg2ts_raw) {

  1103.         /* normal demux */

  1104. 

  1105.         if (!ts->auto_guess) {

  1106.             ts->set_service_ret = -1;

  1107. 

  1108.             /* first do a scaning to get all the services */

  1109.             url_fseek(pb, pos, SEEK_SET);

  1110.             mpegts_scan_sdt(ts);

  1111.             

  1112.             handle_packets(ts, MAX_SCAN_PACKETS);

  1113.             

  1114.             if (ts->nb_services <= 0) {

  1115.                 /* no SDT found, we try to look at the PAT */

  1116.                 

  1117.                 /* First remove the SDT filters from each PID */

  1118.                 int i;

  1119.                 for (i=0; i < NB_PID_MAX; i++) {

  1120.                     if (ts->pids[i])

  1121.                         mpegts_close_filter(ts, ts->pids[i]);

  1122.                 }

  1123.                 url_fseek(pb, pos, SEEK_SET);

  1124.                 mpegts_scan_pat(ts);

  1125.                 

  1126.                 handle_packets(ts, MAX_SCAN_PACKETS);

  1127.             }

  1128.             

  1129.             if (ts->nb_services <= 0)

  1130.                 return -1;

  1131.             

  1132.             /* tune to first service found */

  1133.             service = ts->services[0];

  1134.             sid = service->sid;

  1135. #ifdef DEBUG_SI

  1136.             printf("tuning to '%s'\n", service->name);

  1137. #endif

  1138.             

  1139.             /* now find the info for the first service if we found any,

  1140.                otherwise try to filter all PATs */

  1141.             

  1142.             url_fseek(pb, pos, SEEK_SET);

  1143.             mpegts_set_service(ts, sid, set_service_cb, ts);

  1144.             

  1145.             handle_packets(ts, MAX_SCAN_PACKETS);

  1146.             

  1147.             /* if could not find service, exit */

  1148.             if (ts->set_service_ret != 0)

  1149.                 return -1;

  1150.             

  1151. #ifdef DEBUG_SI

  1152.             printf("tuning done\n");

  1153. #endif

  1154.         }

  1155.         s->ctx_flags |= AVFMTCTX_NOHEADER;

  1156.     } else {

  1157.         AVStream *st;

  1158.         int pcr_pid, pid, nb_packets, nb_pcrs, ret, pcr_l;

  1159.         int64_t pcrs[2], pcr_h;

  1160.         int packet_count[2];

  1161.         uint8_t packet[TS_PACKET_SIZE];

  1162.         

  1163.         /* only read packets */

  1164. 

  1165.         s->pts_num = 1;

  1166.         s->pts_den = 27000000;

  1167.         

  1168.         st = av_new_stream(s, 0);

  1169.         if (!st)

  1170.             goto fail;

  1171.         st->codec.codec_type = CODEC_TYPE_DATA;

  1172.         st->codec.codec_id = CODEC_ID_MPEG2TS;

  1173.         

  1174.         /* we iterate until we find two PCRs to estimate the bitrate */

  1175.         pcr_pid = -1;

  1176.         nb_pcrs = 0;

  1177.         nb_packets = 0;

  1178.         for(;;) {

  1179.             ret = read_packet(&s->pb, packet, ts->raw_packet_size);

  1180.             if (ret < 0)

  1181.                 return -1;

  1182.             pid = ((packet[1] & 0x1f) << 8) | packet[2];

  1183.             if ((pcr_pid == -1 || pcr_pid == pid) &&

  1184.                 parse_pcr(&pcr_h, &pcr_l, packet) == 0) {

  1185.                 pcr_pid = pid;

  1186.                 packet_count[nb_pcrs] = nb_packets;

  1187.                 pcrs[nb_pcrs] = pcr_h * 300 + pcr_l;

  1188.                 nb_pcrs++;

  1189.                 if (nb_pcrs >= 2)

  1190.                     break;

  1191.             }

  1192.             nb_packets++;

  1193.         }

  1194.         ts->pcr_pid = pcr_pid;

  1195. 

  1196.         /* NOTE1: the bitrate is computed without the FEC */

  1197.         /* NOTE2: it is only the bitrate of the start of the stream */

  1198.         ts->pcr_incr = (pcrs[1] - pcrs[0]) / (packet_count[1] - packet_count[0]);

  1199.         ts->cur_pcr = pcrs[0] - ts->pcr_incr * packet_count[0];

  1200.         s->bit_rate = (TS_PACKET_SIZE * 8) * 27e6 / ts->pcr_incr;

  1201.         st->codec.bit_rate = s->bit_rate;

  1202.         st->start_time = ts->cur_pcr * 1000000.0 / 27.0e6;

  1203. #if 0

  1204.         printf("start=%0.3f pcr=%0.3f incr=%d\n",

  1205.                st->start_time / 1000000.0, pcrs[0] / 27e6, ts->pcr_incr);

  1206. #endif

  1207.     }

  1208. 

  1209.     url_fseek(pb, pos, SEEK_SET);

  1210.     return 0;

  1211.  fail:

  1212.     return -1;

  1213. }

  1214. 

  1215. #define MAX_PACKET_READAHEAD ((128 * 1024) / 188)

  1216. 

  1217. static int mpegts_raw_read_packet(AVFormatContext *s,

  1218.                                   AVPacket *pkt)

  1219. {

  1220.     MpegTSContext *ts = s->priv_data;

  1221.     int ret, i;

  1222.     int64_t pcr_h, next_pcr_h, pos;

  1223.     int pcr_l, next_pcr_l;

  1224.     uint8_t pcr_buf[12];

  1225. 

  1226.     if (av_new_packet(pkt, TS_PACKET_SIZE) < 0)

  1227.         return -ENOMEM;

  1228.     ret = read_packet(&s->pb, pkt->data, ts->raw_packet_size);

  1229.     if (ret < 0) {

  1230.         av_free_packet(pkt);

  1231.         return ret;

  1232.     }

  1233.     if (ts->mpeg2ts_compute_pcr) {

  1234.         /* compute exact PCR for each packet */

  1235.         if (parse_pcr(&pcr_h, &pcr_l, pkt->data) == 0) {

  1236.             /* we read the next PCR (XXX: optimize it by using a bigger buffer */

  1237.             pos = url_ftell(&s->pb);

  1238.             for(i = 0; i < MAX_PACKET_READAHEAD; i++) {

  1239.                 url_fseek(&s->pb, pos + i * ts->raw_packet_size, SEEK_SET);

  1240.                 get_buffer(&s->pb, pcr_buf, 12);

  1241.                 if (parse_pcr(&next_pcr_h, &next_pcr_l, pcr_buf) == 0) {

  1242.                     /* XXX: not precise enough */

  1243.                     ts->pcr_incr = ((next_pcr_h - pcr_h) * 300 + (next_pcr_l - pcr_l)) / 

  1244.                         (i + 1);

  1245.                     break;

  1246.                 }

  1247.             }

  1248.             url_fseek(&s->pb, pos, SEEK_SET);

  1249.             /* no next PCR found: we use previous increment */

  1250.             ts->cur_pcr = pcr_h * 300 + pcr_l;

  1251.         }

  1252.         pkt->pts = ts->cur_pcr;

  1253.         pkt->duration = ts->pcr_incr;

  1254.         ts->cur_pcr += ts->pcr_incr;

  1255.     }

  1256.     pkt->stream_index = 0;

  1257.     return 0;

  1258. }

  1259. 

  1260. static int mpegts_read_packet(AVFormatContext *s,

  1261.                               AVPacket *pkt)

  1262. {

  1263.     MpegTSContext *ts = s->priv_data;

  1264. 

  1265.     if (!ts->mpeg2ts_raw) {

  1266.         ts->pkt = pkt;

  1267.         return handle_packets(ts, 0);

  1268.     } else {

  1269.         return mpegts_raw_read_packet(s, pkt);

  1270.     }

  1271. }

  1272. 

  1273. static int mpegts_read_close(AVFormatContext *s)

  1274. {

  1275.     MpegTSContext *ts = s->priv_data;

  1276.     int i;

  1277.     for(i=0;i<NB_PID_MAX;i++)

  1278.         if (ts->pids[i]) mpegts_close_filter(ts, ts->pids[i]);

  1279.     return 0;

  1280. }

  1281. 

  1282. static int64_t mpegts_get_pcr(AVFormatContext *s, int stream_index, 

  1283.                               int64_t *ppos, int find_next)

  1284. {

  1285.     MpegTSContext *ts = s->priv_data;

  1286.     int64_t pos, timestamp;

  1287.     uint8_t buf[TS_PACKET_SIZE];

  1288.     int pcr_l, pid;

  1289. 

  1290.     pos = *ppos;

  1291.     if (find_next) {

  1292.         for(;;) {

  1293.             url_fseek(&s->pb, pos, SEEK_SET);

  1294.             if (get_buffer(&s->pb, buf, TS_PACKET_SIZE) != TS_PACKET_SIZE)

  1295.                 return AV_NOPTS_VALUE;

  1296.             pid = ((buf[1] & 0x1f) << 8) | buf[2];

  1297.             if (pid == ts->pcr_pid &&

  1298.                 parse_pcr(&timestamp, &pcr_l, buf) == 0) {

  1299.                 break;

  1300.             }

  1301.             pos += ts->raw_packet_size;

  1302.         }

  1303.     } else {

  1304.         for(;;) {

  1305.             pos -= ts->raw_packet_size;

  1306.             if (pos < 0)

  1307.                 return AV_NOPTS_VALUE;

  1308.             url_fseek(&s->pb, pos, SEEK_SET);

  1309.             if (get_buffer(&s->pb, buf, TS_PACKET_SIZE) != TS_PACKET_SIZE)

  1310.                 return AV_NOPTS_VALUE;

  1311.             pid = ((buf[1] & 0x1f) << 8) | buf[2];

  1312.             if (pid == ts->pcr_pid &&

  1313.                 parse_pcr(&timestamp, &pcr_l, buf) == 0) {

  1314.                 break;

  1315.             }

  1316.         }

  1317.     }

  1318.     *ppos = pos;

  1319.     return timestamp;

  1320. }

  1321. 

  1322. typedef int64_t ReadTimestampFunc(AVFormatContext *s, int stream_index, 

  1323.                                   int64_t *ppos, int find_next);

  1324. 

  1325. static int64_t do_block_align(int64_t val, int block_align)

  1326. {

  1327.     return (val / block_align) * block_align;

  1328. }

  1329. 

  1330. /* XXX: use it in other formats */

  1331. static int timestamp_read_seek(AVFormatContext *s, 

  1332.                                int stream_index, int64_t timestamp,

  1333.                                ReadTimestampFunc *read_timestamp,

  1334.                                int block_align)

  1335. {

  1336.     int64_t pos_min, pos_max, pos;

  1337.     int64_t dts_min, dts_max, dts;

  1338. 

  1339. #ifdef DEBUG_SEEK

  1340.     printf("read_seek: %d %0.3f\n", stream_index, timestamp / 90000.0);

  1341. #endif

  1342. 

  1343.     pos_min = 0;

  1344.     dts_min = read_timestamp(s, stream_index, &pos_min, 1);

  1345.     if (dts_min == AV_NOPTS_VALUE) {

  1346.         /* we can reach this case only if no PTS are present in

  1347.            the whole stream */

  1348.         return -1;

  1349.     }

  1350.     pos_max = do_block_align(url_filesize(url_fileno(&s->pb)), block_align) - 

  1351.         block_align;

  1352.     dts_max = read_timestamp(s, stream_index, &pos_max, 0);

  1353.     

  1354.     while (pos_min <= pos_max) {

  1355. #ifdef DEBUG_SEEK

  1356.         printf("pos_min=0x%llx pos_max=0x%llx dts_min=%0.3f dts_max=%0.3f\n", 

  1357.                pos_min, pos_max,

  1358.                dts_min / 90000.0, dts_max / 90000.0);

  1359. #endif

  1360.         if (timestamp <= dts_min) {

  1361.             pos = pos_min;

  1362.             goto found;

  1363.         } else if (timestamp >= dts_max) {

  1364.             pos = pos_max;

  1365.             goto found;

  1366.         } else {

  1367.             /* interpolate position (better than dichotomy) */

  1368.             pos = (int64_t)((double)(pos_max - pos_min) * 

  1369.                             (double)(timestamp - dts_min) /

  1370.                             (double)(dts_max - dts_min)) + pos_min;

  1371.             pos = do_block_align(pos, block_align);

  1372.         }

  1373. #ifdef DEBUG_SEEK

  1374.         printf("pos=0x%llx\n", pos);

  1375. #endif

  1376.         /* read the next timestamp */

  1377.         dts = read_timestamp(s, stream_index, &pos, 1);

  1378.         /* check if we are lucky */

  1379.         if (dts == AV_NOPTS_VALUE) {

  1380.             /* should never happen */

  1381.             pos = pos_min;

  1382.             goto found;

  1383.         } else if (timestamp == dts) {

  1384.             goto found;

  1385.         } else if (timestamp < dts) {

  1386.             pos_max = pos;

  1387.             dts_max = read_timestamp(s, stream_index, &pos_max, 0);

  1388.             if (dts_max == AV_NOPTS_VALUE) {

  1389.                 /* should never happen */

  1390.                 break;

  1391.             } else if (timestamp >= dts_max) {

  1392.                 pos = pos_max;

  1393.                 goto found;

  1394.             }

  1395.         } else {

  1396.             pos_min = pos + block_align;

  1397.             dts_min = read_timestamp(s, stream_index, &pos_min, 1);

  1398.             if (dts_min == AV_NOPTS_VALUE) {

  1399.                 /* should never happen */

  1400.                 goto found;

  1401.             } else if (timestamp <= dts_min) {

  1402.                 goto found;

  1403.             }

  1404.         }

  1405.     }

  1406.     pos = pos_min;

  1407.  found:

  1408. #ifdef DEBUG_SEEK

  1409.     pos_min = pos;

  1410.     dts_min = read_timestamp(s, stream_index, &pos_min, 1);

  1411.     pos_min += block_align;

  1412.     dts_max = read_timestamp(s, stream_index, &pos_min, 1);

  1413.     printf("pos=0x%llx %0.3f<=%0.3f<=%0.3f\n", 

  1414.            pos, dts_min / 90000.0, timestamp / 90000.0, dts_max / 90000.0);

  1415. #endif

  1416.     /* do the seek */

  1417.     url_fseek(&s->pb, pos, SEEK_SET);

  1418.     return 0;

  1419. }

  1420. 

  1421. static int mpegts_read_seek(AVFormatContext *s, 

  1422.                             int stream_index, int64_t timestamp)

  1423. {

  1424.     MpegTSContext *ts = s->priv_data;

  1425. 

  1426.     timestamp = (timestamp * 90000) / AV_TIME_BASE;

  1427. 

  1428.     return timestamp_read_seek(s, stream_index, timestamp, 

  1429.                                mpegts_get_pcr, ts->raw_packet_size);

  1430. }

  1431. 

  1432. /**************************************************************/

  1433. /* parsing functions - called from other demuxers such as RTP */

  1434. 

  1435. MpegTSContext *mpegts_parse_open(AVFormatContext *s)

  1436. {

  1437.     MpegTSContext *ts;

  1438.     

  1439.     ts = av_mallocz(sizeof(MpegTSContext));

  1440.     if (!ts)

  1441.         return NULL;

  1442.     /* no stream case, currently used by RTP */

  1443.     ts->raw_packet_size = TS_PACKET_SIZE;

  1444.     ts->stream = s;

  1445.     ts->auto_guess = 1;

  1446.     return ts;

  1447. }

  1448. 

  1449. /* return the consumed length if a packet was output, or -1 if no

  1450.    packet is output */

  1451. int mpegts_parse_packet(MpegTSContext *ts, AVPacket *pkt,

  1452.                         const uint8_t *buf, int len)

  1453. {

  1454.     int len1;

  1455. 

  1456.     len1 = len;

  1457.     ts->pkt = pkt;

  1458.     ts->stop_parse = 0;

  1459.     for(;;) {

  1460.         if (ts->stop_parse)

  1461.             break;

  1462.         if (len < TS_PACKET_SIZE)

  1463.             return -1;

  1464.         if (buf[0] != 0x47) {

  1465.             buf--;

  1466.             len--;

  1467.         } else {

  1468.             handle_packet(ts, buf);

  1469.             buf += TS_PACKET_SIZE;

  1470.             len -= TS_PACKET_SIZE;

  1471.         }

  1472.     }

  1473.     return len1 - len;

  1474. }

  1475. 

  1476. void mpegts_parse_close(MpegTSContext *ts)

  1477. {

  1478.     int i;

  1479. 

  1480.     for(i=0;i<NB_PID_MAX;i++)

  1481.         av_free(ts->pids[i]);

  1482.     av_free(ts);

  1483. }

  1484. 

  1485. AVInputFormat mpegts_demux = {

  1486.     "mpegts",

  1487.     "MPEG2 transport stream format",

  1488.     sizeof(MpegTSContext),

  1489.     mpegts_probe,

  1490.     mpegts_read_header,

  1491.     mpegts_read_packet,

  1492.     mpegts_read_close,

  1493.     mpegts_read_seek,

  1494.     .flags = AVFMT_SHOW_IDS,

  1495. };

  1496. 

  1497. int mpegts_init(void)

  1498. {

  1499.     av_register_input_format(&mpegts_demux);

  1500. #ifdef CONFIG_ENCODERS

  1501.     av_register_output_format(&mpegts_mux);

  1502. #endif

  1503.     return 0;

  1504. }