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FFmpeg/libavformat/mpegts.c

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  1. /*

  2.  * MPEG2 transport stream (aka DVB) demuxer

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

  4.  *

  5.  * This file is part of FFmpeg.

  6.  *

  7.  * FFmpeg is free software; you can redistribute it and/or

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

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

  10.  * version 2.1 of the License, or (at your option) any later version.

  11.  *

  12.  * FFmpeg is distributed in the hope that it will be useful,

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

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

  15.  * Lesser General Public License for more details.

  16.  *

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

  18.  * License along with FFmpeg; if not, write to the Free Software

  19.  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

  20.  */

  21. #include "avformat.h"

  22. #include "crc.h"

  23. #include "mpegts.h"

  24. #include "allformats.h"

  25. 

  26. //#define DEBUG_SI

  27. //#define DEBUG_SEEK

  28. 

  29. /* 1.0 second at 24Mbit/s */

  30. #define MAX_SCAN_PACKETS 32000

  31. 

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

  33.    synchronisation is lost */

  34. #define MAX_RESYNC_SIZE 4096

  35. 

  36. typedef struct PESContext PESContext;

  37. 

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

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

  40. 

  41. enum MpegTSFilterType {

  42.     MPEGTS_PES,

  43.     MPEGTS_SECTION,

  44. };

  45. 

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

  47. 

  48. typedef struct MpegTSPESFilter {

  49.     PESCallback *pes_cb;

  50.     void *opaque;

  51. } MpegTSPESFilter;

  52. 

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

  54. 

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

  56. 

  57. typedef struct MpegTSSectionFilter {

  58.     int section_index;

  59.     int section_h_size;

  60.     uint8_t *section_buf;

  61.     int check_crc:1;

  62.     int end_of_section_reached:1;

  63.     SectionCallback *section_cb;

  64.     void *opaque;

  65. } MpegTSSectionFilter;

  66. 

  67. typedef struct MpegTSFilter {

  68.     int pid;

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

  70.     enum MpegTSFilterType type;

  71.     union {

  72.         MpegTSPESFilter pes_filter;

  73.         MpegTSSectionFilter section_filter;

  74.     } u;

  75. } MpegTSFilter;

  76. 

  77. typedef struct MpegTSService {

  78.     int running:1;

  79.     int sid;    /**< MPEG Program Number of stream */

  80.     char *provider_name; /**< DVB Network name, "" if not DVB stream */

  81.     char *name; /**< DVB Service name, "MPEG Program [sid]" if not DVB stream*/

  82. } MpegTSService;

  83. 

  84. struct MpegTSContext {

  85.     /* user data */

  86.     AVFormatContext *stream;

  87.     /** raw packet size, including FEC if present            */

  88.     int raw_packet_size;

  89.     /** if true, all pids are analyzed to find streams       */

  90.     int auto_guess;

  91. 

  92.     /** compute exact PCR for each transport stream packet   */

  93.     int mpeg2ts_compute_pcr;

  94. 

  95.     int64_t cur_pcr;    /**< used to estimate the exact PCR  */

  96.     int pcr_incr;       /**< used to estimate the exact PCR  */

  97.     int pcr_pid;        /**< used to estimate the exact PCR  */

  98. 

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

  100.     /** stop parsing loop                                    */

  101.     int stop_parse;

  102.     /** packet containing Audio/Video data                   */

  103.     AVPacket *pkt;

  104. 

  105.     /******************************************/

  106.     /* private mpegts data */

  107.     /* scan context */

  108.     /** number of PMTs in the last PAT seen                  */

  109.     int nb_services;

  110.     /** list of PMTs in the last PAT seen                    */

  111.     MpegTSService **services;

  112. 

  113. 

  114.     /** filters for various streams specified by PMT + for the PAT and PMT */

  115.     MpegTSFilter *pids[NB_PID_MAX];

  116. };

  117. 

  118. /* TS stream handling */

  119. 

  120. enum MpegTSState {

  121.     MPEGTS_HEADER = 0,

  122.     MPEGTS_PESHEADER_FILL,

  123.     MPEGTS_PAYLOAD,

  124.     MPEGTS_SKIP,

  125. };

  126. 

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

  128. #define PES_START_SIZE 9

  129. #define MAX_PES_HEADER_SIZE (9 + 255)

  130. 

  131. struct PESContext {

  132.     int pid;

  133.     int stream_type;

  134.     MpegTSContext *ts;

  135.     AVFormatContext *stream;

  136.     AVStream *st;

  137.     enum MpegTSState state;

  138.     /* used to get the format */

  139.     int data_index;

  140.     int total_size;

  141.     int pes_header_size;

  142.     int64_t pts, dts;

  143.     uint8_t header[MAX_PES_HEADER_SIZE];

  144. };

  145. 

  146. /**

  147.  *  Assembles PES packets out of TS packets, and then calls the "section_cb"

  148.  *  function when they are complete.

  149.  */

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

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

  152. {

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

  154.     int len;

  155. 

  156.     if (is_start) {

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

  158.         tss->section_index = buf_size;

  159.         tss->section_h_size = -1;

  160.         tss->end_of_section_reached = 0;

  161.     } else {

  162.         if (tss->end_of_section_reached)

  163.             return;

  164.         len = 4096 - tss->section_index;

  165.         if (buf_size < len)

  166.             len = buf_size;

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

  168.         tss->section_index += len;

  169.     }

  170. 

  171.     /* compute section length if possible */

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

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

  174.         if (len > 4096)

  175.             return;

  176.         tss->section_h_size = len;

  177.     }

  178. 

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

  180.         tss->end_of_section_reached = 1;

  181.         if (!tss->check_crc ||

  182.             av_crc(av_crc04C11DB7, -1, tss->section_buf, tss->section_h_size) == 0)

  183.             tss->section_cb(tss1, tss->section_buf, tss->section_h_size);

  184.     }

  185. }

  186. 

  187. static MpegTSFilter *mpegts_open_section_filter(MpegTSContext *ts, unsigned int pid,

  188.                                          SectionCallback *section_cb, void *opaque,

  189.                                          int check_crc)

  190. 

  191. {

  192.     MpegTSFilter *filter;

  193.     MpegTSSectionFilter *sec;

  194. 

  195. #ifdef DEBUG_SI

  196.     av_log(ts->stream, AV_LOG_DEBUG, "Filter: pid=0x%x\n", pid);

  197. #endif

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

  199.         return NULL;

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

  201.     if (!filter)

  202.         return NULL;

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

  204.     filter->type = MPEGTS_SECTION;

  205.     filter->pid = pid;

  206.     filter->last_cc = -1;

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

  208.     sec->section_cb = section_cb;

  209.     sec->opaque = opaque;

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

  211.     sec->check_crc = check_crc;

  212.     if (!sec->section_buf) {

  213.         av_free(filter);

  214.         return NULL;

  215.     }

  216.     return filter;

  217. }

  218. 

  219. static MpegTSFilter *mpegts_open_pes_filter(MpegTSContext *ts, unsigned int pid,

  220.                                      PESCallback *pes_cb,

  221.                                      void *opaque)

  222. {

  223.     MpegTSFilter *filter;

  224.     MpegTSPESFilter *pes;

  225. 

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

  227.         return NULL;

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

  229.     if (!filter)

  230.         return NULL;

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

  232.     filter->type = MPEGTS_PES;

  233.     filter->pid = pid;

  234.     filter->last_cc = -1;

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

  236.     pes->pes_cb = pes_cb;

  237.     pes->opaque = opaque;

  238.     return filter;

  239. }

  240. 

  241. static void mpegts_close_filter(MpegTSContext *ts, MpegTSFilter *filter)

  242. {

  243.     int pid;

  244. 

  245.     pid = filter->pid;

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

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

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

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

  250. 

  251.     av_free(filter);

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

  253. }

  254. 

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

  256.     int stat[packet_size];

  257.     int i;

  258.     int x=0;

  259.     int best_score=0;

  260. 

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

  262. 

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

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

  265.             stat[x]++;

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

  267.                 best_score= stat[x];

  268.                 if(index) *index= x;

  269.             }

  270.         }

  271. 

  272.         x++;

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

  274.     }

  275. 

  276.     return best_score;

  277. }

  278. 

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

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

  281. {

  282.     int score, fec_score, dvhs_score;

  283. 

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

  285.         return -1;

  286. 

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

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

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

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

  291. 

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

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

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

  295.     else                       return -1;

  296. }

  297. 

  298. typedef struct SectionHeader {

  299.     uint8_t tid;

  300.     uint16_t id;

  301.     uint8_t version;

  302.     uint8_t sec_num;

  303.     uint8_t last_sec_num;

  304. } SectionHeader;

  305. 

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

  307. {

  308.     const uint8_t *p;

  309.     int c;

  310. 

  311.     p = *pp;

  312.     if (p >= p_end)

  313.         return -1;

  314.     c = *p++;

  315.     *pp = p;

  316.     return c;

  317. }

  318. 

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

  320. {

  321.     const uint8_t *p;

  322.     int c;

  323. 

  324.     p = *pp;

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

  326.         return -1;

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

  328.     p += 2;

  329.     *pp = p;

  330.     return c;

  331. }

  332. 

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

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

  335. {

  336.     int len;

  337.     const uint8_t *p;

  338.     char *str;

  339. 

  340.     p = *pp;

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

  342.     if (len < 0)

  343.         return NULL;

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

  345.         return NULL;

  346.     str = av_malloc(len + 1);

  347.     if (!str)

  348.         return NULL;

  349.     memcpy(str, p, len);

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

  351.     p += len;

  352.     *pp = p;

  353.     return str;

  354. }

  355. 

  356. static int parse_section_header(SectionHeader *h,

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

  358. {

  359.     int val;

  360. 

  361.     val = get8(pp, p_end);

  362.     if (val < 0)

  363.         return -1;

  364.     h->tid = val;

  365.     *pp += 2;

  366.     val = get16(pp, p_end);

  367.     if (val < 0)

  368.         return -1;

  369.     h->id = val;

  370.     val = get8(pp, p_end);

  371.     if (val < 0)

  372.         return -1;

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

  374.     val = get8(pp, p_end);

  375.     if (val < 0)

  376.         return -1;

  377.     h->sec_num = val;

  378.     val = get8(pp, p_end);

  379.     if (val < 0)

  380.         return -1;

  381.     h->last_sec_num = val;

  382.     return 0;

  383. }

  384. 

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

  386.                                   char *provider_name, char *name)

  387. {

  388.     MpegTSService *service=NULL;

  389.     int i;

  390. 

  391. #ifdef DEBUG_SI

  392.     av_log(ts->stream, AV_LOG_DEBUG, "new_service: "

  393.            "sid=0x%04x provider='%s' name='%s'\n",

  394.            sid, provider_name, name);

  395. #endif

  396. 

  397.     for(i=0; i<ts->nb_services; i++)

  398.         if(ts->services[i]->sid == sid)

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

  400. 

  401.     if(!service){

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

  403.         if (!service)

  404.             return NULL;

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

  406.     }

  407.     service->sid = sid;

  408.     assert((!provider_name) == (!name));

  409.     if(name){

  410.         av_free(service->provider_name);

  411.         av_free(service->         name);

  412.         service->provider_name = provider_name;

  413.         service->         name =          name;

  414.     }

  415.     return service;

  416. }

  417. 

  418. static void pmt_cb(MpegTSFilter *filter, const uint8_t *section, int section_len)

  419. {

  420.     MpegTSContext *ts = filter->u.section_filter.opaque;

  421.     SectionHeader h1, *h = &h1;

  422.     PESContext *pes;

  423.     AVStream *st;

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

  425.     int program_info_length, pcr_pid, pid, stream_type;

  426.     int desc_list_len, desc_len, desc_tag;

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

  428.     char language[4] = {0}; /* initialize to kill warnings */

  429. 

  430. #ifdef DEBUG_SI

  431.     av_log(ts->stream, AV_LOG_DEBUG, "PMT: len %i\n", section_len);

  432.     av_hex_dump_log(ts->stream, AV_LOG_DEBUG, (uint8_t *)section, section_len);

  433. #endif

  434.     p_end = section + section_len - 4;

  435.     p = section;

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

  437.         return;

  438. #ifdef DEBUG_SI

  439.     av_log(ts->stream, AV_LOG_DEBUG, "sid=0x%x sec_num=%d/%d\n",

  440.            h->id, h->sec_num, h->last_sec_num);

  441. #endif

  442.     if (h->tid != PMT_TID)

  443.         return;

  444. 

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

  446.     if (pcr_pid < 0)

  447.         return;

  448.     ts->pcr_pid = pcr_pid;

  449. #ifdef DEBUG_SI

  450.     av_log(ts->stream, AV_LOG_DEBUG, "pcr_pid=0x%x\n", pcr_pid);

  451. #endif

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

  453.     if (program_info_length < 0)

  454.         return;

  455.     p += program_info_length;

  456.     if (p >= p_end)

  457.         return;

  458.     for(;;) {

  459.         language[0] = 0;

  460.         st = 0;

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

  462.         if (stream_type < 0)

  463.             break;

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

  465.         if (pid < 0)

  466.             break;

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

  468.         if (desc_list_len < 0)

  469.             break;

  470.         desc_list_end = p + desc_list_len;

  471.         if (desc_list_end > p_end)

  472.             break;

  473.         for(;;) {

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

  475.             if (desc_tag < 0)

  476.                 break;

  477.             if (stream_type == STREAM_TYPE_PRIVATE_DATA) {

  478.                 if((desc_tag == 0x6A) || (desc_tag == 0x7A)) {

  479.                     /*assume DVB AC-3 Audio*/

  480.                     stream_type = STREAM_TYPE_AUDIO_AC3;

  481.                 } else if(desc_tag == 0x7B) {

  482.                     /* DVB DTS audio */

  483.                     stream_type = STREAM_TYPE_AUDIO_DTS;

  484.                 }

  485.             }

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

  487.             desc_end = p + desc_len;

  488.             if (desc_end > desc_list_end)

  489.                 break;

  490. #ifdef DEBUG_SI

  491.             av_log(ts->stream, AV_LOG_DEBUG, "tag: 0x%02x len=%d\n",

  492.                    desc_tag, desc_len);

  493. #endif

  494.             switch(desc_tag) {

  495.             case DVB_SUBT_DESCID:

  496.                 if (stream_type == STREAM_TYPE_PRIVATE_DATA)

  497.                     stream_type = STREAM_TYPE_SUBTITLE_DVB;

  498. 

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

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

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

  502.                 language[3] = 0;

  503.                 get8(&p, desc_end);

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

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

  506. 

  507.                 break;

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

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

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

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

  512.                 language[3] = 0;

  513.                 break;

  514.             default:

  515.                 break;

  516.             }

  517.             p = desc_end;

  518.         }

  519.         p = desc_list_end;

  520. 

  521. #ifdef DEBUG_SI

  522.         av_log(ts->stream, AV_LOG_DEBUG, "stream_type=%d pid=0x%x\n",

  523.                stream_type, pid);

  524. #endif

  525. 

  526.         /* now create ffmpeg stream */

  527.         switch(stream_type) {

  528.         case STREAM_TYPE_AUDIO_MPEG1:

  529.         case STREAM_TYPE_AUDIO_MPEG2:

  530.         case STREAM_TYPE_VIDEO_MPEG1:

  531.         case STREAM_TYPE_VIDEO_MPEG2:

  532.         case STREAM_TYPE_VIDEO_MPEG4:

  533.         case STREAM_TYPE_VIDEO_H264:

  534.         case STREAM_TYPE_VIDEO_VC1:

  535.         case STREAM_TYPE_AUDIO_AAC:

  536.         case STREAM_TYPE_AUDIO_AC3:

  537.         case STREAM_TYPE_AUDIO_DTS:

  538.         case STREAM_TYPE_SUBTITLE_DVB:

  539.             if(ts->pids[pid]){

  540.                 assert(ts->pids[pid].type == MPEGTS_PES);

  541.                 pes= ts->pids[pid]->u.pes_filter.opaque;

  542.                 st= pes->st;

  543.             }else{

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

  545.                 if (pes)

  546.                     st = new_pes_av_stream(pes, 0);

  547.             }

  548.             break;

  549.         default:

  550.             /* we ignore the other streams */

  551.             break;

  552.         }

  553. 

  554.         if (st) {

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

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

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

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

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

  560.             }

  561. 

  562.             if (stream_type == STREAM_TYPE_SUBTITLE_DVB) {

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

  564.             }

  565.         }

  566.     }

  567.     /* all parameters are there */

  568.     ts->stop_parse++;

  569.     mpegts_close_filter(ts, filter);

  570. }

  571. 

  572. static void pat_cb(MpegTSFilter *filter, const uint8_t *section, int section_len)

  573. {

  574.     MpegTSContext *ts = filter->u.section_filter.opaque;

  575.     SectionHeader h1, *h = &h1;

  576.     const uint8_t *p, *p_end;

  577.     int sid, pmt_pid;

  578. 

  579. #ifdef DEBUG_SI

  580.     av_log(ts->stream, AV_LOG_DEBUG, "PAT:\n");

  581.     av_hex_dump_log(ts->stream, AV_LOG_DEBUG, (uint8_t *)section, section_len);

  582. #endif

  583.     p_end = section + section_len - 4;

  584.     p = section;

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

  586.         return;

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

  588.         return;

  589. 

  590.     for(;;) {

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

  592.         if (sid < 0)

  593.             break;

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

  595.         if (pmt_pid < 0)

  596.             break;

  597. #ifdef DEBUG_SI

  598.         av_log(ts->stream, AV_LOG_DEBUG, "sid=0x%x pid=0x%x\n", sid, pmt_pid);

  599. #endif

  600.         if (sid == 0x0000) {

  601.             /* NIT info */

  602.         } else {

  603.             new_service(ts, sid, NULL, NULL);

  604.             ts->stop_parse--;

  605.             mpegts_open_section_filter(ts, pmt_pid, pmt_cb, ts, 1);

  606.         }

  607.     }

  608.     /* not found */

  609.     ts->stop_parse++;

  610. 

  611.     mpegts_close_filter(ts, filter);

  612. }

  613. 

  614. static void mpegts_set_service(MpegTSContext *ts)

  615. {

  616.     mpegts_open_section_filter(ts, PAT_PID,

  617.                                                 pat_cb, ts, 1);

  618. }

  619. 

  620. static void sdt_cb(MpegTSFilter *filter, const uint8_t *section, int section_len)

  621. {

  622.     MpegTSContext *ts = filter->u.section_filter.opaque;

  623.     SectionHeader h1, *h = &h1;

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

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

  626.     char *name, *provider_name;

  627. 

  628. #ifdef DEBUG_SI

  629.     av_log(ts->stream, AV_LOG_DEBUG, "SDT:\n");

  630.     av_hex_dump_log(ts->stream, AV_LOG_DEBUG, (uint8_t *)section, section_len);

  631. #endif

  632. 

  633.     p_end = section + section_len - 4;

  634.     p = section;

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

  636.         return;

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

  638.         return;

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

  640.     if (onid < 0)

  641.         return;

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

  643.     if (val < 0)

  644.         return;

  645.     for(;;) {

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

  647.         if (sid < 0)

  648.             break;

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

  650.         if (val < 0)

  651.             break;

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

  653.         if (desc_list_len < 0)

  654.             break;

  655.         desc_list_end = p + desc_list_len;

  656.         if (desc_list_end > p_end)

  657.             break;

  658.         for(;;) {

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

  660.             if (desc_tag < 0)

  661.                 break;

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

  663.             desc_end = p + desc_len;

  664.             if (desc_end > desc_list_end)

  665.                 break;

  666. #ifdef DEBUG_SI

  667.             av_log(ts->stream, AV_LOG_DEBUG, "tag: 0x%02x len=%d\n",

  668.                    desc_tag, desc_len);

  669. #endif

  670.             switch(desc_tag) {

  671.             case 0x48:

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

  673.                 if (service_type < 0)

  674.                     break;

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

  676.                 if (!provider_name)

  677.                     break;

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

  679.                 if (!name)

  680.                     break;

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

  682.                 break;

  683.             default:

  684.                 break;

  685.             }

  686.             p = desc_end;

  687.         }

  688.         p = desc_list_end;

  689.     }

  690. }

  691. 

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

  693. static void mpegts_scan_sdt(MpegTSContext *ts)

  694. {

  695.     mpegts_open_section_filter(ts, SDT_PID,

  696.                                                 sdt_cb, ts, 1);

  697. }

  698. 

  699. static int64_t get_pts(const uint8_t *p)

  700. {

  701.     int64_t pts;

  702.     int val;

  703. 

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

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

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

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

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

  709.     return pts;

  710. }

  711. 

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

  713. static void mpegts_push_data(MpegTSFilter *filter,

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

  715. {

  716.     PESContext *pes = filter->u.pes_filter.opaque;

  717.     MpegTSContext *ts = pes->ts;

  718.     const uint8_t *p;

  719.     int len, code;

  720. 

  721.     if(!ts->pkt)

  722.         return;

  723. 

  724.     if (is_start) {

  725.         pes->state = MPEGTS_HEADER;

  726.         pes->data_index = 0;

  727.     }

  728.     p = buf;

  729.     while (buf_size > 0) {

  730.         switch(pes->state) {

  731.         case MPEGTS_HEADER:

  732.             len = PES_START_SIZE - pes->data_index;

  733.             if (len > buf_size)

  734.                 len = buf_size;

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

  736.             pes->data_index += len;

  737.             p += len;

  738.             buf_size -= len;

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

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

  741.                    decide */

  742. #if 0

  743.                 av_hex_dump_log(pes->stream, AV_LOG_DEBUG, pes->header, pes->data_index);

  744. #endif

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

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

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

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

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

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

  751.                           (code == 0x1bd) || (code == 0x1fd)))

  752.                         goto skip;

  753.                     if (!pes->st) {

  754.                         /* allocate stream */

  755.                         new_pes_av_stream(pes, code);

  756.                     }

  757.                     pes->state = MPEGTS_PESHEADER_FILL;

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

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

  760.                        unbounded */

  761.                     if (pes->total_size)

  762.                         pes->total_size += 6;

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

  764.                 } else {

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

  766.                     /* skip packet */

  767.                 skip:

  768.                     pes->state = MPEGTS_SKIP;

  769.                     continue;

  770.                 }

  771.             }

  772.             break;

  773.             /**********************************************/

  774.             /* PES packing parsing */

  775.         case MPEGTS_PESHEADER_FILL:

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

  777.             if (len > buf_size)

  778.                 len = buf_size;

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

  780.             pes->data_index += len;

  781.             p += len;

  782.             buf_size -= len;

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

  784.                 const uint8_t *r;

  785.                 unsigned int flags;

  786. 

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

  788.                 r = pes->header + 9;

  789.                 pes->pts = AV_NOPTS_VALUE;

  790.                 pes->dts = AV_NOPTS_VALUE;

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

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

  793.                     r += 5;

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

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

  796.                     r += 5;

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

  798.                     r += 5;

  799.                 }

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

  801.                 pes->state = MPEGTS_PAYLOAD;

  802.             }

  803.             break;

  804.         case MPEGTS_PAYLOAD:

  805.             if (pes->total_size) {

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

  807.                 if (len > buf_size)

  808.                     len = buf_size;

  809.             } else {

  810.                 len = buf_size;

  811.             }

  812.             if (len > 0) {

  813.                 AVPacket *pkt = ts->pkt;

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

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

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

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

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

  819.                     /* reset pts values */

  820.                     pes->pts = AV_NOPTS_VALUE;

  821.                     pes->dts = AV_NOPTS_VALUE;

  822.                     ts->stop_parse = 1;

  823.                     return;

  824.                 }

  825.             }

  826.             buf_size = 0;

  827.             break;

  828.         case MPEGTS_SKIP:

  829.             buf_size = 0;

  830.             break;

  831.         }

  832.     }

  833. }

  834. 

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

  836. {

  837.     AVStream *st;

  838.     int codec_type, codec_id;

  839. 

  840.     switch(pes->stream_type){

  841.     case STREAM_TYPE_AUDIO_MPEG1:

  842.     case STREAM_TYPE_AUDIO_MPEG2:

  843.         codec_type = CODEC_TYPE_AUDIO;

  844.         codec_id = CODEC_ID_MP3;

  845.         break;

  846.     case STREAM_TYPE_VIDEO_MPEG1:

  847.     case STREAM_TYPE_VIDEO_MPEG2:

  848.         codec_type = CODEC_TYPE_VIDEO;

  849.         codec_id = CODEC_ID_MPEG2VIDEO;

  850.         break;

  851.     case STREAM_TYPE_VIDEO_MPEG4:

  852.         codec_type = CODEC_TYPE_VIDEO;

  853.         codec_id = CODEC_ID_MPEG4;

  854.         break;

  855.     case STREAM_TYPE_VIDEO_H264:

  856.         codec_type = CODEC_TYPE_VIDEO;

  857.         codec_id = CODEC_ID_H264;

  858.         break;

  859.     case STREAM_TYPE_VIDEO_VC1:

  860.         codec_type = CODEC_TYPE_VIDEO;

  861.         codec_id = CODEC_ID_VC1;

  862.         break;

  863.     case STREAM_TYPE_AUDIO_AAC:

  864.         codec_type = CODEC_TYPE_AUDIO;

  865.         codec_id = CODEC_ID_AAC;

  866.         break;

  867.     case STREAM_TYPE_AUDIO_AC3:

  868.         codec_type = CODEC_TYPE_AUDIO;

  869.         codec_id = CODEC_ID_AC3;

  870.         break;

  871.     case STREAM_TYPE_AUDIO_DTS:

  872.         codec_type = CODEC_TYPE_AUDIO;

  873.         codec_id = CODEC_ID_DTS;

  874.         break;

  875.     case STREAM_TYPE_SUBTITLE_DVB:

  876.         codec_type = CODEC_TYPE_SUBTITLE;

  877.         codec_id = CODEC_ID_DVB_SUBTITLE;

  878.         break;

  879.     default:

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

  881.             codec_type = CODEC_TYPE_AUDIO;

  882.             codec_id = CODEC_ID_MP2;

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

  884.             codec_type = CODEC_TYPE_AUDIO;

  885.             codec_id = CODEC_ID_AC3;

  886.         } else {

  887.             codec_type = CODEC_TYPE_VIDEO;

  888.             codec_id = CODEC_ID_MPEG1VIDEO;

  889.         }

  890.         break;

  891.     }

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

  893.     if (st) {

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

  895.         st->priv_data = pes;

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

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

  898.         st->need_parsing = AVSTREAM_PARSE_FULL;

  899.         pes->st = st;

  900.     }

  901.     return st;

  902. }

  903. 

  904. 

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

  906. {

  907.     MpegTSFilter *tss;

  908.     PESContext *pes;

  909. 

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

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

  912.     if (!pes)

  913.         return 0;

  914.     pes->ts = ts;

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

  916.     pes->pid = pid;

  917.     pes->stream_type = stream_type;

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

  919.     if (!tss) {

  920.         av_free(pes);

  921.         return 0;

  922.     }

  923.     return pes;

  924. }

  925. 

  926. /* handle one TS packet */

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

  928. {

  929.     AVFormatContext *s = ts->stream;

  930.     MpegTSFilter *tss;

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

  932.     const uint8_t *p, *p_end;

  933. 

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

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

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

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

  938.         add_pes_stream(ts, pid, 0);

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

  940.     }

  941.     if (!tss)

  942.         return;

  943. 

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

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

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

  947.     tss->last_cc = cc;

  948. 

  949.     /* skip adaptation field */

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

  951.     p = packet + 4;

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

  953.         return;

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

  955.         return;

  956.     if (afc == 3) {

  957.         /* skip adapation field */

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

  959.     }

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

  961.     p_end = packet + TS_PACKET_SIZE;

  962.     if (p >= p_end)

  963.         return;

  964. 

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

  966.         if (is_start) {

  967.             /* pointer field present */

  968.             len = *p++;

  969.             if (p + len > p_end)

  970.                 return;

  971.             if (len && cc_ok) {

  972.                 /* write remaining section bytes */

  973.                 write_section_data(s, tss,

  974.                                    p, len, 0);

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

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

  977.                     return;

  978.             }

  979.             p += len;

  980.             if (p < p_end) {

  981.                 write_section_data(s, tss,

  982.                                    p, p_end - p, 1);

  983.             }

  984.         } else {

  985.             if (cc_ok) {

  986.                 write_section_data(s, tss,

  987.                                    p, p_end - p, 0);

  988.             }

  989.         }

  990.     } else {

  991.         tss->u.pes_filter.pes_cb(tss,

  992.                                  p, p_end - p, is_start);

  993.     }

  994. }

  995. 

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

  997.    get_packet_size() ?) */

  998. static int mpegts_resync(ByteIOContext *pb)

  999. {

  1000.     int c, i;

  1001. 

  1002.     for(i = 0;i < MAX_RESYNC_SIZE; i++) {

  1003.         c = url_fgetc(pb);

  1004.         if (c < 0)

  1005.             return -1;

  1006.         if (c == 0x47) {

  1007.             url_fseek(pb, -1, SEEK_CUR);

  1008.             return 0;

  1009.         }

  1010.     }

  1011.     /* no sync found */

  1012.     return -1;

  1013. }

  1014. 

  1015. /* return -1 if error or EOF. Return 0 if OK. */

  1016. static int read_packet(ByteIOContext *pb, uint8_t *buf, int raw_packet_size)

  1017. {

  1018.     int skip, len;

  1019. 

  1020.     for(;;) {

  1021.         len = get_buffer(pb, buf, TS_PACKET_SIZE);

  1022.         if (len != TS_PACKET_SIZE)

  1023.             return AVERROR_IO;

  1024.         /* check paquet sync byte */

  1025.         if (buf[0] != 0x47) {

  1026.             /* find a new packet start */

  1027.             url_fseek(pb, -TS_PACKET_SIZE, SEEK_CUR);

  1028.             if (mpegts_resync(pb) < 0)

  1029.                 return AVERROR_INVALIDDATA;

  1030.             else

  1031.                 continue;

  1032.         } else {

  1033.             skip = raw_packet_size - TS_PACKET_SIZE;

  1034.             if (skip > 0)

  1035.                 url_fskip(pb, skip);

  1036.             break;

  1037.         }

  1038.     }

  1039.     return 0;

  1040. }

  1041. 

  1042. static int handle_packets(MpegTSContext *ts, int nb_packets)

  1043. {

  1044.     AVFormatContext *s = ts->stream;

  1045.     ByteIOContext *pb = &s->pb;

  1046.     uint8_t packet[TS_PACKET_SIZE];

  1047.     int packet_num, ret;

  1048. 

  1049.     ts->stop_parse = 0;

  1050.     packet_num = 0;

  1051.     for(;;) {

  1052.         if (ts->stop_parse>0)

  1053.             break;

  1054.         packet_num++;

  1055.         if (nb_packets != 0 && packet_num >= nb_packets)

  1056.             break;

  1057.         ret = read_packet(pb, packet, ts->raw_packet_size);

  1058.         if (ret != 0)

  1059.             return ret;

  1060.         handle_packet(ts, packet);

  1061.     }

  1062.     return 0;

  1063. }

  1064. 

  1065. static int mpegts_probe(AVProbeData *p)

  1066. {

  1067. #if 1

  1068.     const int size= p->buf_size;

  1069.     int score, fec_score, dvhs_score;

  1070. #define CHECK_COUNT 10

  1071. 

  1072.     if (size < (TS_FEC_PACKET_SIZE * CHECK_COUNT))

  1073.         return -1;

  1074. 

  1075.     score    = analyze(p->buf, TS_PACKET_SIZE    *CHECK_COUNT, TS_PACKET_SIZE, NULL);

  1076.     dvhs_score  = analyze(p->buf, TS_DVHS_PACKET_SIZE    *CHECK_COUNT, TS_DVHS_PACKET_SIZE, NULL);

  1077.     fec_score= analyze(p->buf, TS_FEC_PACKET_SIZE*CHECK_COUNT, TS_FEC_PACKET_SIZE, NULL);

  1078. //    av_log(NULL, AV_LOG_DEBUG, "score: %d, dvhs_score: %d, fec_score: %d \n", score, dvhs_score, fec_score);

  1079. 

  1080. // we need a clear definition for the returned score otherwise things will become messy sooner or later

  1081.     if     (score > fec_score && score > dvhs_score && score > 6) return AVPROBE_SCORE_MAX + score     - CHECK_COUNT;

  1082.     else if(dvhs_score > score && dvhs_score > fec_score && dvhs_score > 6) return AVPROBE_SCORE_MAX + dvhs_score  - CHECK_COUNT;

  1083.     else if(                 fec_score > 6) return AVPROBE_SCORE_MAX + fec_score - CHECK_COUNT;

  1084.     else                                    return -1;

  1085. #else

  1086.     /* only use the extension for safer guess */

  1087.     if (match_ext(p->filename, "ts"))

  1088.         return AVPROBE_SCORE_MAX;

  1089.     else

  1090.         return 0;

  1091. #endif

  1092. }

  1093. 

  1094. /* return the 90 kHz PCR and the extension for the 27 MHz PCR. return

  1095.    (-1) if not available */

  1096. static int parse_pcr(int64_t *ppcr_high, int *ppcr_low,

  1097.                      const uint8_t *packet)

  1098. {

  1099.     int afc, len, flags;

  1100.     const uint8_t *p;

  1101.     unsigned int v;

  1102. 

  1103.     afc = (packet[3] >> 4) & 3;

  1104.     if (afc <= 1)

  1105.         return -1;

  1106.     p = packet + 4;

  1107.     len = p[0];

  1108.     p++;

  1109.     if (len == 0)

  1110.         return -1;

  1111.     flags = *p++;

  1112.     len--;

  1113.     if (!(flags & 0x10))

  1114.         return -1;

  1115.     if (len < 6)

  1116.         return -1;

  1117.     v = (p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3];

  1118.     *ppcr_high = ((int64_t)v << 1) | (p[4] >> 7);

  1119.     *ppcr_low = ((p[4] & 1) << 8) | p[5];

  1120.     return 0;

  1121. }

  1122. 

  1123. static int mpegts_read_header(AVFormatContext *s,

  1124.                               AVFormatParameters *ap)

  1125. {

  1126.     MpegTSContext *ts = s->priv_data;

  1127.     ByteIOContext *pb = &s->pb;

  1128.     uint8_t buf[1024];

  1129.     int len;

  1130.     int64_t pos;

  1131. 

  1132.     if (ap) {

  1133.         ts->mpeg2ts_compute_pcr = ap->mpeg2ts_compute_pcr;

  1134.         if(ap->mpeg2ts_raw){

  1135.             av_log(s, AV_LOG_ERROR, "use mpegtsraw_demuxer!\n");

  1136.             return -1;

  1137.         }

  1138.     }

  1139. 

  1140.     /* read the first 1024 bytes to get packet size */

  1141.     pos = url_ftell(pb);

  1142.     len = get_buffer(pb, buf, sizeof(buf));

  1143.     if (len != sizeof(buf))

  1144.         goto fail;

  1145.     ts->raw_packet_size = get_packet_size(buf, sizeof(buf));

  1146.     if (ts->raw_packet_size <= 0)

  1147.         goto fail;

  1148.     ts->stream = s;

  1149.     ts->auto_guess = 0;

  1150. 

  1151.     if (s->iformat == &mpegts_demuxer) {

  1152.         /* normal demux */

  1153. 

  1154.         /* first do a scaning to get all the services */

  1155.         url_fseek(pb, pos, SEEK_SET);

  1156.         mpegts_scan_sdt(ts);

  1157. 

  1158.         if (ts->nb_services <= 0 && 0) {

  1159.             /* raw transport stream */

  1160.             ts->auto_guess = 1;

  1161.             s->ctx_flags |= AVFMTCTX_NOHEADER;

  1162.             goto do_pcr;

  1163.         }

  1164. 

  1165.         mpegts_set_service(ts);

  1166. 

  1167.         handle_packets(ts, s->probesize);

  1168.         /* if could not find service, enable auto_guess */

  1169. 

  1170.         ts->auto_guess = 1;

  1171. 

  1172. #ifdef DEBUG_SI

  1173.         av_log(ts->stream, AV_LOG_DEBUG, "tuning done\n");

  1174. #endif

  1175.         s->ctx_flags |= AVFMTCTX_NOHEADER;

  1176.     } else {

  1177.         AVStream *st;

  1178.         int pcr_pid, pid, nb_packets, nb_pcrs, ret, pcr_l;

  1179.         int64_t pcrs[2], pcr_h;

  1180.         int packet_count[2];

  1181.         uint8_t packet[TS_PACKET_SIZE];

  1182. 

  1183.         /* only read packets */

  1184. 

  1185.     do_pcr:

  1186.         st = av_new_stream(s, 0);

  1187.         if (!st)

  1188.             goto fail;

  1189.         av_set_pts_info(st, 60, 1, 27000000);

  1190.         st->codec->codec_type = CODEC_TYPE_DATA;

  1191.         st->codec->codec_id = CODEC_ID_MPEG2TS;

  1192. 

  1193.         /* we iterate until we find two PCRs to estimate the bitrate */

  1194.         pcr_pid = -1;

  1195.         nb_pcrs = 0;

  1196.         nb_packets = 0;

  1197.         for(;;) {

  1198.             ret = read_packet(&s->pb, packet, ts->raw_packet_size);

  1199.             if (ret < 0)

  1200.                 return -1;

  1201.             pid = ((packet[1] & 0x1f) << 8) | packet[2];

  1202.             if ((pcr_pid == -1 || pcr_pid == pid) &&

  1203.                 parse_pcr(&pcr_h, &pcr_l, packet) == 0) {

  1204.                 pcr_pid = pid;

  1205.                 packet_count[nb_pcrs] = nb_packets;

  1206.                 pcrs[nb_pcrs] = pcr_h * 300 + pcr_l;

  1207.                 nb_pcrs++;

  1208.                 if (nb_pcrs >= 2)

  1209.                     break;

  1210.             }

  1211.             nb_packets++;

  1212.         }

  1213.         ts->pcr_pid = pcr_pid;

  1214. 

  1215.         /* NOTE1: the bitrate is computed without the FEC */

  1216.         /* NOTE2: it is only the bitrate of the start of the stream */

  1217.         ts->pcr_incr = (pcrs[1] - pcrs[0]) / (packet_count[1] - packet_count[0]);

  1218.         ts->cur_pcr = pcrs[0] - ts->pcr_incr * packet_count[0];

  1219.         s->bit_rate = (TS_PACKET_SIZE * 8) * 27e6 / ts->pcr_incr;

  1220.         st->codec->bit_rate = s->bit_rate;

  1221.         st->start_time = ts->cur_pcr;

  1222. #if 0

  1223.         av_log(ts->stream, AV_LOG_DEBUG, "start=%0.3f pcr=%0.3f incr=%d\n",

  1224.                st->start_time / 1000000.0, pcrs[0] / 27e6, ts->pcr_incr);

  1225. #endif

  1226.     }

  1227. 

  1228.     url_fseek(pb, pos, SEEK_SET);

  1229.     return 0;

  1230.  fail:

  1231.     return -1;

  1232. }

  1233. 

  1234. #define MAX_PACKET_READAHEAD ((128 * 1024) / 188)

  1235. 

  1236. static int mpegts_raw_read_packet(AVFormatContext *s,

  1237.                                   AVPacket *pkt)

  1238. {

  1239.     MpegTSContext *ts = s->priv_data;

  1240.     int ret, i;

  1241.     int64_t pcr_h, next_pcr_h, pos;

  1242.     int pcr_l, next_pcr_l;

  1243.     uint8_t pcr_buf[12];

  1244. 

  1245.     if (av_new_packet(pkt, TS_PACKET_SIZE) < 0)

  1246.         return AVERROR(ENOMEM);

  1247.     pkt->pos= url_ftell(&s->pb);

  1248.     ret = read_packet(&s->pb, pkt->data, ts->raw_packet_size);

  1249.     if (ret < 0) {

  1250.         av_free_packet(pkt);

  1251.         return ret;

  1252.     }

  1253.     if (ts->mpeg2ts_compute_pcr) {

  1254.         /* compute exact PCR for each packet */

  1255.         if (parse_pcr(&pcr_h, &pcr_l, pkt->data) == 0) {

  1256.             /* we read the next PCR (XXX: optimize it by using a bigger buffer */

  1257.             pos = url_ftell(&s->pb);

  1258.             for(i = 0; i < MAX_PACKET_READAHEAD; i++) {

  1259.                 url_fseek(&s->pb, pos + i * ts->raw_packet_size, SEEK_SET);

  1260.                 get_buffer(&s->pb, pcr_buf, 12);

  1261.                 if (parse_pcr(&next_pcr_h, &next_pcr_l, pcr_buf) == 0) {

  1262.                     /* XXX: not precise enough */

  1263.                     ts->pcr_incr = ((next_pcr_h - pcr_h) * 300 + (next_pcr_l - pcr_l)) /

  1264.                         (i + 1);

  1265.                     break;

  1266.                 }

  1267.             }

  1268.             url_fseek(&s->pb, pos, SEEK_SET);

  1269.             /* no next PCR found: we use previous increment */

  1270.             ts->cur_pcr = pcr_h * 300 + pcr_l;

  1271.         }

  1272.         pkt->pts = ts->cur_pcr;

  1273.         pkt->duration = ts->pcr_incr;

  1274.         ts->cur_pcr += ts->pcr_incr;

  1275.     }

  1276.     pkt->stream_index = 0;

  1277.     return 0;

  1278. }

  1279. 

  1280. static int mpegts_read_packet(AVFormatContext *s,

  1281.                               AVPacket *pkt)

  1282. {

  1283.     MpegTSContext *ts = s->priv_data;

  1284. 

  1285.     ts->pkt = pkt;

  1286.     return handle_packets(ts, 0);

  1287. }

  1288. 

  1289. static int mpegts_read_close(AVFormatContext *s)

  1290. {

  1291.     MpegTSContext *ts = s->priv_data;

  1292.     int i;

  1293.     for(i=0;i<NB_PID_MAX;i++)

  1294.         if (ts->pids[i]) mpegts_close_filter(ts, ts->pids[i]);

  1295. 

  1296.     for(i = 0; i < ts->nb_services; i++){

  1297.         av_free(ts->services[i]->provider_name);

  1298.         av_free(ts->services[i]->name);

  1299.         av_free(ts->services[i]);

  1300.     }

  1301.     av_freep(&ts->services);

  1302. 

  1303.     return 0;

  1304. }

  1305. 

  1306. static int64_t mpegts_get_pcr(AVFormatContext *s, int stream_index,

  1307.                               int64_t *ppos, int64_t pos_limit)

  1308. {

  1309.     MpegTSContext *ts = s->priv_data;

  1310.     int64_t pos, timestamp;

  1311.     uint8_t buf[TS_PACKET_SIZE];

  1312.     int pcr_l, pid;

  1313.     const int find_next= 1;

  1314.     pos = ((*ppos  + ts->raw_packet_size - 1) / ts->raw_packet_size) * ts->raw_packet_size;

  1315.     if (find_next) {

  1316.         for(;;) {

  1317.             url_fseek(&s->pb, pos, SEEK_SET);

  1318.             if (get_buffer(&s->pb, buf, TS_PACKET_SIZE) != TS_PACKET_SIZE)

  1319.                 return AV_NOPTS_VALUE;

  1320.             pid = ((buf[1] & 0x1f) << 8) | buf[2];

  1321.             if (pid == ts->pcr_pid &&

  1322.                 parse_pcr(&timestamp, &pcr_l, buf) == 0) {

  1323.                 break;

  1324.             }

  1325.             pos += ts->raw_packet_size;

  1326.         }

  1327.     } else {

  1328.         for(;;) {

  1329.             pos -= ts->raw_packet_size;

  1330.             if (pos < 0)

  1331.                 return AV_NOPTS_VALUE;

  1332.             url_fseek(&s->pb, pos, SEEK_SET);

  1333.             if (get_buffer(&s->pb, buf, TS_PACKET_SIZE) != TS_PACKET_SIZE)

  1334.                 return AV_NOPTS_VALUE;

  1335.             pid = ((buf[1] & 0x1f) << 8) | buf[2];

  1336.             if (pid == ts->pcr_pid &&

  1337.                 parse_pcr(&timestamp, &pcr_l, buf) == 0) {

  1338.                 break;

  1339.             }

  1340.         }

  1341.     }

  1342.     *ppos = pos;

  1343. 

  1344.     return timestamp;

  1345. }

  1346. 

  1347. static int read_seek(AVFormatContext *s, int stream_index, int64_t target_ts, int flags){

  1348.     MpegTSContext *ts = s->priv_data;

  1349.     uint8_t buf[TS_PACKET_SIZE];

  1350.     int64_t pos;

  1351. 

  1352.     if(av_seek_frame_binary(s, stream_index, target_ts, flags) < 0)

  1353.         return -1;

  1354. 

  1355.     pos= url_ftell(&s->pb);

  1356. 

  1357.     for(;;) {

  1358.         url_fseek(&s->pb, pos, SEEK_SET);

  1359.         if (get_buffer(&s->pb, buf, TS_PACKET_SIZE) != TS_PACKET_SIZE)

  1360.             return -1;

  1361. //        pid = ((buf[1] & 0x1f) << 8) | buf[2];

  1362.         if(buf[1] & 0x40) break;

  1363.         pos += ts->raw_packet_size;

  1364.     }

  1365.     url_fseek(&s->pb, pos, SEEK_SET);

  1366. 

  1367.     return 0;

  1368. }

  1369. 

  1370. /**************************************************************/

  1371. /* parsing functions - called from other demuxers such as RTP */

  1372. 

  1373. MpegTSContext *mpegts_parse_open(AVFormatContext *s)

  1374. {

  1375.     MpegTSContext *ts;

  1376. 

  1377.     ts = av_mallocz(sizeof(MpegTSContext));

  1378.     if (!ts)

  1379.         return NULL;

  1380.     /* no stream case, currently used by RTP */

  1381.     ts->raw_packet_size = TS_PACKET_SIZE;

  1382.     ts->stream = s;

  1383.     ts->auto_guess = 1;

  1384.     return ts;

  1385. }

  1386. 

  1387. /* return the consumed length if a packet was output, or -1 if no

  1388.    packet is output */

  1389. int mpegts_parse_packet(MpegTSContext *ts, AVPacket *pkt,

  1390.                         const uint8_t *buf, int len)

  1391. {

  1392.     int len1;

  1393. 

  1394.     len1 = len;

  1395.     ts->pkt = pkt;

  1396.     ts->stop_parse = 0;

  1397.     for(;;) {

  1398.         if (ts->stop_parse>0)

  1399.             break;

  1400.         if (len < TS_PACKET_SIZE)

  1401.             return -1;

  1402.         if (buf[0] != 0x47) {

  1403.             buf++;

  1404.             len--;

  1405.         } else {

  1406.             handle_packet(ts, buf);

  1407.             buf += TS_PACKET_SIZE;

  1408.             len -= TS_PACKET_SIZE;

  1409.         }

  1410.     }

  1411.     return len1 - len;

  1412. }

  1413. 

  1414. void mpegts_parse_close(MpegTSContext *ts)

  1415. {

  1416.     int i;

  1417. 

  1418.     for(i=0;i<NB_PID_MAX;i++)

  1419.         av_free(ts->pids[i]);

  1420.     av_free(ts);

  1421. }

  1422. 

  1423. AVInputFormat mpegts_demuxer = {

  1424.     "mpegts",

  1425.     "MPEG2 transport stream format",

  1426.     sizeof(MpegTSContext),

  1427.     mpegts_probe,

  1428.     mpegts_read_header,

  1429.     mpegts_read_packet,

  1430.     mpegts_read_close,

  1431.     read_seek,

  1432.     mpegts_get_pcr,

  1433.     .flags = AVFMT_SHOW_IDS,

  1434. };

  1435. 

  1436. AVInputFormat mpegtsraw_demuxer = {

  1437.     "mpegtsraw",

  1438.     "MPEG2 raw transport stream format",

  1439.     sizeof(MpegTSContext),

  1440.     mpegts_probe,

  1441.     mpegts_read_header,

  1442.     mpegts_raw_read_packet,

  1443.     mpegts_read_close,

  1444.     read_seek,

  1445.     mpegts_get_pcr,

  1446.     .flags = AVFMT_SHOW_IDS,

  1447. };