text: /*
   * MPEG2 transport stream (aka DVB) demuxer
   * Copyright (c) 2002-2003 Fabrice Bellard
   *
   * This file is part of FFmpeg.
   *
   * FFmpeg is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * FFmpeg is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with FFmpeg; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
   */
  
  #include "libavutil/buffer.h"
  #include "libavutil/crc.h"
  #include "libavutil/intreadwrite.h"
  #include "libavutil/log.h"
  #include "libavutil/dict.h"
  #include "libavutil/mathematics.h"
  #include "libavutil/opt.h"
  #include "libavutil/avassert.h"
  #include "libavcodec/bytestream.h"
  #include "libavcodec/get_bits.h"
  #include "avformat.h"
  #include "mpegts.h"
  #include "internal.h"
  #include "avio_internal.h"
  #include "seek.h"
  #include "mpeg.h"
  #include "isom.h"
  
  /* maximum size in which we look for synchronisation if
   * synchronisation is lost */
  #define MAX_RESYNC_SIZE 65536
  
  #define MAX_PES_PAYLOAD 200 * 1024
  
  #define MAX_MP4_DESCR_COUNT 16
  
  #define MOD_UNLIKELY(modulus, dividend, divisor, prev_dividend)                \
      do {                                                                       \
          if ((prev_dividend) == 0 || (dividend) - (prev_dividend) != (divisor)) \
              (modulus) = (dividend) % (divisor);                                \
          (prev_dividend) = (dividend);                                          \
      } while (0)
  
  enum MpegTSFilterType {
      MPEGTS_PES,
      MPEGTS_SECTION,
      MPEGTS_PCR,
  };
  
  typedef struct MpegTSFilter MpegTSFilter;
  
  typedef int PESCallback (MpegTSFilter *f, const uint8_t *buf, int len,
                           int is_start, int64_t pos);
  
  typedef struct MpegTSPESFilter {
      PESCallback *pes_cb;
      void *opaque;
  } MpegTSPESFilter;
  
  typedef void SectionCallback (MpegTSFilter *f, const uint8_t *buf, int len);
  
  typedef void SetServiceCallback (void *opaque, int ret);
  
  typedef struct MpegTSSectionFilter {
      int section_index;
      int section_h_size;
      uint8_t *section_buf;
      unsigned int check_crc : 1;
      unsigned int end_of_section_reached : 1;
      SectionCallback *section_cb;
      void *opaque;
  } MpegTSSectionFilter;
  
  struct MpegTSFilter {
      int pid;
      int es_id;
      int last_cc; /* last cc code (-1 if first packet) */
      int64_t last_pcr;
      enum MpegTSFilterType type;
      union {
          MpegTSPESFilter pes_filter;
          MpegTSSectionFilter section_filter;
      } u;
  };
  
  #define MAX_PIDS_PER_PROGRAM 64
  struct Program {
      unsigned int id; // program id/service id
      unsigned int nb_pids;
      unsigned int pids[MAX_PIDS_PER_PROGRAM];
  
      /** have we found pmt for this program */
      int pmt_found;
  };
  
  struct MpegTSContext {
      const AVClass *class;
      /* user data */
      AVFormatContext *stream;
      /** raw packet size, including FEC if present */
      int raw_packet_size;
  
      int size_stat[3];
      int size_stat_count;
  #define SIZE_STAT_THRESHOLD 10
  
      int64_t pos47_full;
  
      /** if true, all pids are analyzed to find streams */
      int auto_guess;
  
      /** compute exact PCR for each transport stream packet */
      int mpeg2ts_compute_pcr;
  
      /** fix dvb teletext pts                                 */
      int fix_teletext_pts;
  
      int64_t cur_pcr;    /**< used to estimate the exact PCR */
      int pcr_incr;       /**< used to estimate the exact PCR */
  
      /* data needed to handle file based ts */
      /** stop parsing loop */
      int stop_parse;
      /** packet containing Audio/Video data */
      AVPacket *pkt;
      /** to detect seek */
      int64_t last_pos;
  
      int skip_changes;
      int skip_clear;
  
      int resync_size;
  
      /******************************************/
      /* private mpegts data */
      /* scan context */
      /** structure to keep track of Program->pids mapping */
      unsigned int nb_prg;
      struct Program *prg;
  
      int8_t crc_validity[NB_PID_MAX];
      /** filters for various streams specified by PMT + for the PAT and PMT */
      MpegTSFilter *pids[NB_PID_MAX];
      int current_pid;
  };
  
  #define MPEGTS_OPTIONS \
      { "resync_size",   "Size limit for looking up a new synchronization.", offsetof(MpegTSContext, resync_size), AV_OPT_TYPE_INT,  { .i64 =  MAX_RESYNC_SIZE}, 0, INT_MAX,  AV_OPT_FLAG_DECODING_PARAM }
  
  static const AVOption options[] = {
      MPEGTS_OPTIONS,
  	{"fix_teletext_pts", "Try to fix pts values of dvb teletext streams.", offsetof(MpegTSContext, fix_teletext_pts), AV_OPT_TYPE_INT,
       {.i64 = 1}, 0, 1, AV_OPT_FLAG_DECODING_PARAM },
      {"ts_packetsize", "Output option carrying the raw packet size.", offsetof(MpegTSContext, raw_packet_size), AV_OPT_TYPE_INT,
       {.i64 = 0}, 0, 0, AV_OPT_FLAG_DECODING_PARAM | AV_OPT_FLAG_EXPORT | AV_OPT_FLAG_READONLY },
      {"skip_changes", "Skip changing / adding streams / programs.", offsetof(MpegTSContext, skip_changes), AV_OPT_TYPE_INT,
       {.i64 = 0}, 0, 1, 0 },
      {"skip_clear", "Skip clearing programs.", offsetof(MpegTSContext, skip_clear), AV_OPT_TYPE_INT,
       {.i64 = 0}, 0, 1, 0 },
  	{ NULL },
  };
  
  static const AVClass mpegts_class = {
  	.class_name = "mpegts demuxer",
      .item_name  = av_default_item_name,
      .option     = options,
      .version    = LIBAVUTIL_VERSION_INT,
  };
  
  static const AVOption raw_options[] = {
      MPEGTS_OPTIONS,
  	{ "compute_pcr",   "Compute exact PCR for each transport stream packet.",
            offsetof(MpegTSContext, mpeg2ts_compute_pcr), AV_OPT_TYPE_INT,
            { .i64 = 0 }, 0, 1,  AV_OPT_FLAG_DECODING_PARAM },
      { "ts_packetsize", "Output option carrying the raw packet size.",
        offsetof(MpegTSContext, raw_packet_size), AV_OPT_TYPE_INT,
        { .i64 = 0 }, 0, 0,
        AV_OPT_FLAG_DECODING_PARAM | AV_OPT_FLAG_EXPORT | AV_OPT_FLAG_READONLY },
  	{ NULL },
  };
  
  static const AVClass mpegtsraw_class = {
  	.class_name = "mpegtsraw demuxer",
      .item_name  = av_default_item_name,
      .option     = raw_options,
      .version    = LIBAVUTIL_VERSION_INT,
  };
  
  /* TS stream handling */
  
  enum MpegTSState {
      MPEGTS_HEADER = 0,
      MPEGTS_PESHEADER,
      MPEGTS_PESHEADER_FILL,
      MPEGTS_PAYLOAD,
      MPEGTS_SKIP,
  };
  
  /* enough for PES header + length */
  #define PES_START_SIZE  6
  #define PES_HEADER_SIZE 9
  #define MAX_PES_HEADER_SIZE (9 + 255)
  
  typedef struct PESContext {
      int pid;
      int pcr_pid; /**< if -1 then all packets containing PCR are considered */
      int stream_type;
      MpegTSContext *ts;
      AVFormatContext *stream;
      AVStream *st;
      AVStream *sub_st; /**< stream for the embedded AC3 stream in HDMV TrueHD */
      enum MpegTSState state;
      /* used to get the format */
      int data_index;
      int flags; /**< copied to the AVPacket flags */
      int total_size;
      int pes_header_size;
      int extended_stream_id;
      int64_t pts, dts;
      int64_t ts_packet_pos; /**< position of first TS packet of this PES packet */
      uint8_t header[MAX_PES_HEADER_SIZE];
      AVBufferRef *buffer;
      SLConfigDescr sl;
  } PESContext;
  
  extern AVInputFormat ff_mpegts_demuxer;
  
  static struct Program * get_program(MpegTSContext *ts, unsigned int programid)
  {
      int i;
      for (i = 0; i < ts->nb_prg; i++) {
          if (ts->prg[i].id == programid) {
              return &ts->prg[i];
          }
      }
      return NULL;
  }
  
  static void clear_avprogram(MpegTSContext *ts, unsigned int programid)
  {
      AVProgram *prg = NULL;
      int i;
  
      for (i = 0; i < ts->stream->nb_programs; i++)
          if (ts->stream->programs[i]->id == programid) {
              prg = ts->stream->programs[i];
              break;
          }
      if (!prg)
          return;
      prg->nb_stream_indexes = 0;
  }
  
  static void clear_program(MpegTSContext *ts, unsigned int programid)
  {
      int i;
  
      clear_avprogram(ts, programid);
      for (i = 0; i < ts->nb_prg; i++)
          if (ts->prg[i].id == programid) {
              ts->prg[i].nb_pids = 0;
              ts->prg[i].pmt_found = 0;
          }
  }
  
  static void clear_programs(MpegTSContext *ts)
  {
      av_freep(&ts->prg);
      ts->nb_prg = 0;
  }
  
  static void add_pat_entry(MpegTSContext *ts, unsigned int programid)
  {
      struct Program *p;
      if (av_reallocp_array(&ts->prg, ts->nb_prg + 1, sizeof(*ts->prg)) < 0) {
          ts->nb_prg = 0;
          return;
      }
      p = &ts->prg[ts->nb_prg];
      p->id = programid;
      p->nb_pids = 0;
      p->pmt_found = 0;
      ts->nb_prg++;
  }
  
  static void add_pid_to_pmt(MpegTSContext *ts, unsigned int programid,
                             unsigned int pid)
  {
      struct Program *p = get_program(ts, programid);
      if (!p)
          return;
  
      if (p->nb_pids >= MAX_PIDS_PER_PROGRAM)
          return;
      p->pids[p->nb_pids++] = pid;
  }
  
  static void set_pmt_found(MpegTSContext *ts, unsigned int programid)
  {
      struct Program *p = get_program(ts, programid);
      if (!p)
          return;
  
      p->pmt_found = 1;
  }
  
  static void set_pcr_pid(AVFormatContext *s, unsigned int programid, unsigned int pid)
  {
      int i;
      for (i = 0; i < s->nb_programs; i++) {
          if (s->programs[i]->id == programid) {
              s->programs[i]->pcr_pid = pid;
              break;
          }
      }
  }
  
  /**
   * @brief discard_pid() decides if the pid is to be discarded according
   *                      to caller's programs selection
   * @param ts    : - TS context
   * @param pid   : - pid
   * @return 1 if the pid is only comprised in programs that have .discard=AVDISCARD_ALL
   *         0 otherwise
   */
  static int discard_pid(MpegTSContext *ts, unsigned int pid)
  {
      int i, j, k;
      int used = 0, discarded = 0;
      struct Program *p;
  
      /* If none of the programs have .discard=AVDISCARD_ALL then there's
       * no way we have to discard this packet */
      for (k = 0; k < ts->stream->nb_programs; k++)
          if (ts->stream->programs[k]->discard == AVDISCARD_ALL)
              break;
      if (k == ts->stream->nb_programs)
          return 0;
  
      for (i = 0; i < ts->nb_prg; i++) {
          p = &ts->prg[i];
          for (j = 0; j < p->nb_pids; j++) {
              if (p->pids[j] != pid)
                  continue;
              // is program with id p->id set to be discarded?
              for (k = 0; k < ts->stream->nb_programs; k++) {
                  if (ts->stream->programs[k]->id == p->id) {
                      if (ts->stream->programs[k]->discard == AVDISCARD_ALL)
                          discarded++;
                      else
                          used++;
                  }
              }
          }
      }
  
      return !used && discarded;
  }
  
  /**
   *  Assemble PES packets out of TS packets, and then call the "section_cb"
   *  function when they are complete.
   */
  static void write_section_data(MpegTSContext *ts, MpegTSFilter *tss1,
                                 const uint8_t *buf, int buf_size, int is_start)
  {
      MpegTSSectionFilter *tss = &tss1->u.section_filter;
      int len;
  
      if (is_start) {
          memcpy(tss->section_buf, buf, buf_size);
          tss->section_index = buf_size;
          tss->section_h_size = -1;
          tss->end_of_section_reached = 0;
      } else {
          if (tss->end_of_section_reached)
              return;
          len = 4096 - tss->section_index;
          if (buf_size < len)
              len = buf_size;
          memcpy(tss->section_buf + tss->section_index, buf, len);
          tss->section_index += len;
      }
  
      /* compute section length if possible */
      if (tss->section_h_size == -1 && tss->section_index >= 3) {
          len = (AV_RB16(tss->section_buf + 1) & 0xfff) + 3;
          if (len > 4096)
              return;
          tss->section_h_size = len;
      }
  
      if (tss->section_h_size != -1 &&
          tss->section_index >= tss->section_h_size) {
          int crc_valid = 1;
          tss->end_of_section_reached = 1;
  
          if (tss->check_crc) {
              crc_valid = !av_crc(av_crc_get_table(AV_CRC_32_IEEE), -1, tss->section_buf, tss->section_h_size);
              if (crc_valid) {
                  ts->crc_validity[ tss1->pid ] = 100;
              }else if (ts->crc_validity[ tss1->pid ] > -10) {
                  ts->crc_validity[ tss1->pid ]--;
              }else
                  crc_valid = 2;
          }
          if (crc_valid)
              tss->section_cb(tss1, tss->section_buf, tss->section_h_size);
      }
  }
  
  static MpegTSFilter *mpegts_open_filter(MpegTSContext *ts, unsigned int pid,
                                          enum MpegTSFilterType type)
  {
      MpegTSFilter *filter;
  
      av_dlog(ts->stream, "Filter: pid=0x%x\n", pid);
  
      if (pid >= NB_PID_MAX || ts->pids[pid])
          return NULL;
      filter = av_mallocz(sizeof(MpegTSFilter));
      if (!filter)
          return NULL;
      ts->pids[pid] = filter;
  
      filter->type    = type;
      filter->pid     = pid;
      filter->es_id   = -1;
      filter->last_cc = -1;
      filter->last_pcr= -1;
  
      return filter;
  }
  
  static MpegTSFilter *mpegts_open_section_filter(MpegTSContext *ts,
                                                  unsigned int pid,
                                                  SectionCallback *section_cb,
                                                  void *opaque,
                                                  int check_crc)
  {
      MpegTSFilter *filter;
      MpegTSSectionFilter *sec;
  
      if (!(filter = mpegts_open_filter(ts, pid, MPEGTS_SECTION)))
          return NULL;
      sec = &filter->u.section_filter;
      sec->section_cb  = section_cb;
      sec->opaque      = opaque;
      sec->section_buf = av_malloc(MAX_SECTION_SIZE);
      sec->check_crc   = check_crc;
      if (!sec->section_buf) {
          av_free(filter);
          return NULL;
      }
      return filter;
  }
  
  static MpegTSFilter *mpegts_open_pes_filter(MpegTSContext *ts, unsigned int pid,
                                              PESCallback *pes_cb,
                                              void *opaque)
  {
      MpegTSFilter *filter;
      MpegTSPESFilter *pes;
  
      if (!(filter = mpegts_open_filter(ts, pid, MPEGTS_PES)))
          return NULL;
  
      pes = &filter->u.pes_filter;
      pes->pes_cb = pes_cb;
      pes->opaque = opaque;
      return filter;
  }
  
  static MpegTSFilter *mpegts_open_pcr_filter(MpegTSContext *ts, unsigned int pid)
  {
      return mpegts_open_filter(ts, pid, MPEGTS_PCR);
  }
  
  static void mpegts_close_filter(MpegTSContext *ts, MpegTSFilter *filter)
  {
      int pid;
  
      pid = filter->pid;
      if (filter->type == MPEGTS_SECTION)
          av_freep(&filter->u.section_filter.section_buf);
      else if (filter->type == MPEGTS_PES) {
          PESContext *pes = filter->u.pes_filter.opaque;
          av_buffer_unref(&pes->buffer);
          /* referenced private data will be freed later in
           * avformat_close_input */
          if (!((PESContext *)filter->u.pes_filter.opaque)->st) {
              av_freep(&filter->u.pes_filter.opaque);
          }
      }
  
      av_free(filter);
      ts->pids[pid] = NULL;
  }
  
  static int analyze(const uint8_t *buf, int size, int packet_size, int *index)
  {
      int stat[TS_MAX_PACKET_SIZE];
      int stat_all = 0;
      int i;
      int best_score = 0;
  
      memset(stat, 0, packet_size * sizeof(*stat));
  
      for (i = 0; i < size - 3; i++) {
          if (buf[i] == 0x47 && !(buf[i + 1] & 0x80) && buf[i + 3] != 0x47) {
              int x = i % packet_size;
              stat[x]++;
              stat_all++;
              if (stat[x] > best_score) {
                  best_score = stat[x];
                  if (index)
                      *index = x;
              }
          }
      }
  
      return best_score - FFMAX(stat_all - 10*best_score, 0)/10;
  }
  
  /* autodetect fec presence. Must have at least 1024 bytes  */
  static int get_packet_size(const uint8_t *buf, int size)
  {
      int score, fec_score, dvhs_score;
  
      if (size < (TS_FEC_PACKET_SIZE * 5 + 1))
          return AVERROR_INVALIDDATA;
  
      score      = analyze(buf, size, TS_PACKET_SIZE, NULL);
      dvhs_score = analyze(buf, size, TS_DVHS_PACKET_SIZE, NULL);
      fec_score  = analyze(buf, size, TS_FEC_PACKET_SIZE, NULL);
      av_dlog(NULL, "score: %d, dvhs_score: %d, fec_score: %d \n",
              score, dvhs_score, fec_score);
  
      if (score > fec_score && score > dvhs_score)
          return TS_PACKET_SIZE;
      else if (dvhs_score > score && dvhs_score > fec_score)
          return TS_DVHS_PACKET_SIZE;
      else if (score < fec_score && dvhs_score < fec_score)
          return TS_FEC_PACKET_SIZE;
      else
          return AVERROR_INVALIDDATA;
  }
  
  typedef struct SectionHeader {
      uint8_t tid;
      uint16_t id;
      uint8_t version;
      uint8_t sec_num;
      uint8_t last_sec_num;
  } SectionHeader;
  
  static inline int get8(const uint8_t **pp, const uint8_t *p_end)
  {
      const uint8_t *p;
      int c;
  
      p = *pp;
      if (p >= p_end)
          return AVERROR_INVALIDDATA;
      c   = *p++;
      *pp = p;
      return c;
  }
  
  static inline int get16(const uint8_t **pp, const uint8_t *p_end)
  {
      const uint8_t *p;
      int c;
  
      p = *pp;
      if ((p + 1) >= p_end)
          return AVERROR_INVALIDDATA;
      c   = AV_RB16(p);
      p  += 2;
      *pp = p;
      return c;
  }
  
  /* read and allocate a DVB string preceded by its length */
  static char *getstr8(const uint8_t **pp, const uint8_t *p_end)
  {
      int len;
      const uint8_t *p;
      char *str;
  
      p   = *pp;
      len = get8(&p, p_end);
      if (len < 0)
          return NULL;
      if ((p + len) > p_end)
          return NULL;
      str = av_malloc(len + 1);
      if (!str)
          return NULL;
      memcpy(str, p, len);
      str[len] = '\0';
      p  += len;
      *pp = p;
      return str;
  }
  
  static int parse_section_header(SectionHeader *h,
                                  const uint8_t **pp, const uint8_t *p_end)
  {
      int val;
  
      val = get8(pp, p_end);
      if (val < 0)
          return val;
      h->tid = val;
      *pp += 2;
      val  = get16(pp, p_end);
      if (val < 0)
          return val;
      h->id = val;
      val = get8(pp, p_end);
      if (val < 0)
          return val;
      h->version = (val >> 1) & 0x1f;
      val = get8(pp, p_end);
      if (val < 0)
          return val;
      h->sec_num = val;
      val = get8(pp, p_end);
      if (val < 0)
          return val;
      h->last_sec_num = val;
      return 0;
  }
  
  typedef struct {
      uint32_t stream_type;
      enum AVMediaType codec_type;
      enum AVCodecID codec_id;
  } StreamType;
  
  static const StreamType ISO_types[] = {
      { 0x01, AVMEDIA_TYPE_VIDEO, AV_CODEC_ID_MPEG2VIDEO },
      { 0x02, AVMEDIA_TYPE_VIDEO, AV_CODEC_ID_MPEG2VIDEO },
      { 0x03, AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_MP3        },
      { 0x04, AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_MP3        },
      { 0x0f, AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_AAC        },
      { 0x10, AVMEDIA_TYPE_VIDEO, AV_CODEC_ID_MPEG4      },
      /* Makito encoder sets stream type 0x11 for AAC,
       * so auto-detect LOAS/LATM instead of hardcoding it. */
  #if !CONFIG_LOAS_DEMUXER
      { 0x11, AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_AAC_LATM   }, /* LATM syntax */
  #endif
      { 0x1b, AVMEDIA_TYPE_VIDEO, AV_CODEC_ID_H264       },
      { 0x24, AVMEDIA_TYPE_VIDEO, AV_CODEC_ID_HEVC       },
      { 0x42, AVMEDIA_TYPE_VIDEO, AV_CODEC_ID_CAVS       },
      { 0xd1, AVMEDIA_TYPE_VIDEO, AV_CODEC_ID_DIRAC      },
      { 0xea, AVMEDIA_TYPE_VIDEO, AV_CODEC_ID_VC1        },
      { 0 },
  };
  
  static const StreamType HDMV_types[] = {
      { 0x80, AVMEDIA_TYPE_AUDIO,    AV_CODEC_ID_PCM_BLURAY        },
      { 0x81, AVMEDIA_TYPE_AUDIO,    AV_CODEC_ID_AC3               },
      { 0x82, AVMEDIA_TYPE_AUDIO,    AV_CODEC_ID_DTS               },
      { 0x83, AVMEDIA_TYPE_AUDIO,    AV_CODEC_ID_TRUEHD            },
      { 0x84, AVMEDIA_TYPE_AUDIO,    AV_CODEC_ID_EAC3              },
      { 0x85, AVMEDIA_TYPE_AUDIO,    AV_CODEC_ID_DTS               }, /* DTS HD */
      { 0x86, AVMEDIA_TYPE_AUDIO,    AV_CODEC_ID_DTS               }, /* DTS HD MASTER*/
      { 0xa1, AVMEDIA_TYPE_AUDIO,    AV_CODEC_ID_EAC3              }, /* E-AC3 Secondary Audio */
      { 0xa2, AVMEDIA_TYPE_AUDIO,    AV_CODEC_ID_DTS               }, /* DTS Express Secondary Audio */
      { 0x90, AVMEDIA_TYPE_SUBTITLE, AV_CODEC_ID_HDMV_PGS_SUBTITLE },
      { 0 },
  };
  
  /* ATSC ? */
  static const StreamType MISC_types[] = {
      { 0x81, AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_AC3 },
      { 0x8a, AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_DTS },
      { 0 },
  };
  
  static const StreamType REGD_types[] = {
      { MKTAG('d', 'r', 'a', 'c'), AVMEDIA_TYPE_VIDEO, AV_CODEC_ID_DIRAC },
      { MKTAG('A', 'C', '-', '3'), AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_AC3   },
      { MKTAG('B', 'S', 'S', 'D'), AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_S302M },
      { MKTAG('D', 'T', 'S', '1'), AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_DTS   },
      { MKTAG('D', 'T', 'S', '2'), AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_DTS   },
      { MKTAG('D', 'T', 'S', '3'), AVMEDIA_TYPE_AUDIO, AV_CODEC_ID_DTS   },
      { MKTAG('H', 'E', 'V', 'C'), AVMEDIA_TYPE_VIDEO, AV_CODEC_ID_HEVC  },
      { MKTAG('K', 'L', 'V', 'A'), AVMEDIA_TYPE_DATA,  AV_CODEC_ID_SMPTE_KLV },
      { MKTAG('V', 'C', '-', '1'), AVMEDIA_TYPE_VIDEO, AV_CODEC_ID_VC1   },
      { 0 },
  };
  
  static const StreamType METADATA_types[] = {
      { MKTAG('K','L','V','A'), AVMEDIA_TYPE_DATA, AV_CODEC_ID_SMPTE_KLV },
      { MKTAG('I','D','3',' '), AVMEDIA_TYPE_DATA, AV_CODEC_ID_TIMED_ID3 },
      { 0 },
  };
  
  /* descriptor present */
  static const StreamType DESC_types[] = {
      { 0x6a, AVMEDIA_TYPE_AUDIO,    AV_CODEC_ID_AC3          }, /* AC-3 descriptor */
      { 0x7a, AVMEDIA_TYPE_AUDIO,    AV_CODEC_ID_EAC3         }, /* E-AC-3 descriptor */
      { 0x7b, AVMEDIA_TYPE_AUDIO,    AV_CODEC_ID_DTS          },
      { 0x56, AVMEDIA_TYPE_SUBTITLE, AV_CODEC_ID_DVB_TELETEXT },
      { 0x59, AVMEDIA_TYPE_SUBTITLE, AV_CODEC_ID_DVB_SUBTITLE }, /* subtitling descriptor */
      { 0 },
  };
  
  static void mpegts_find_stream_type(AVStream *st,
                                      uint32_t stream_type,
                                      const StreamType *types)
  {
      if (avcodec_is_open(st->codec)) {
          av_log(NULL, AV_LOG_DEBUG, "cannot set stream info, codec is open\n");
          return;
      }
  
      for (; types->stream_type; types++)
          if (stream_type == types->stream_type) {
              st->codec->codec_type = types->codec_type;
              st->codec->codec_id   = types->codec_id;
              st->request_probe     = 0;
              return;
          }
  }
  
  static int mpegts_set_stream_info(AVStream *st, PESContext *pes,
                                    uint32_t stream_type, uint32_t prog_reg_desc)
  {
      int old_codec_type = st->codec->codec_type;
      int old_codec_id  = st->codec->codec_id;
  
      if (avcodec_is_open(st->codec)) {
          av_log(pes->stream, AV_LOG_DEBUG, "cannot set stream info, codec is open\n");
          return 0;
      }
  
      avpriv_set_pts_info(st, 33, 1, 90000);
      st->priv_data         = pes;
      st->codec->codec_type = AVMEDIA_TYPE_DATA;
      st->codec->codec_id   = AV_CODEC_ID_NONE;
      st->need_parsing      = AVSTREAM_PARSE_FULL;
      pes->st          = st;
      pes->stream_type = stream_type;
  
      av_log(pes->stream, AV_LOG_DEBUG,
             "stream=%d stream_type=%x pid=%x prog_reg_desc=%.4s\n",
             st->index, pes->stream_type, pes->pid, (char *)&prog_reg_desc);
  
      st->codec->codec_tag = pes->stream_type;
  
      mpegts_find_stream_type(st, pes->stream_type, ISO_types);
      if ((prog_reg_desc == AV_RL32("HDMV") ||
           prog_reg_desc == AV_RL32("HDPR")) &&
          st->codec->codec_id == AV_CODEC_ID_NONE) {
          mpegts_find_stream_type(st, pes->stream_type, HDMV_types);
          if (pes->stream_type == 0x83) {
              // HDMV TrueHD streams also contain an AC3 coded version of the
              // audio track - add a second stream for this
              AVStream *sub_st;
              // priv_data cannot be shared between streams
              PESContext *sub_pes = av_malloc(sizeof(*sub_pes));
              if (!sub_pes)
                  return AVERROR(ENOMEM);
              memcpy(sub_pes, pes, sizeof(*sub_pes));
  
              sub_st = avformat_new_stream(pes->stream, NULL);
              if (!sub_st) {
                  av_free(sub_pes);
                  return AVERROR(ENOMEM);
              }
  
              sub_st->id = pes->pid;
              avpriv_set_pts_info(sub_st, 33, 1, 90000);
              sub_st->priv_data         = sub_pes;
              sub_st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
              sub_st->codec->codec_id   = AV_CODEC_ID_AC3;
              sub_st->need_parsing      = AVSTREAM_PARSE_FULL;
              sub_pes->sub_st           = pes->sub_st = sub_st;
          }
      }
      if (st->codec->codec_id == AV_CODEC_ID_NONE)
          mpegts_find_stream_type(st, pes->stream_type, MISC_types);
      if (st->codec->codec_id == AV_CODEC_ID_NONE) {
          st->codec->codec_id  = old_codec_id;
          st->codec->codec_type = old_codec_type;
      }
  
      return 0;
  }
  
  static void reset_pes_packet_state(PESContext *pes)
  {
      pes->pts        = AV_NOPTS_VALUE;
      pes->dts        = AV_NOPTS_VALUE;
      pes->data_index = 0;
      pes->flags      = 0;
      av_buffer_unref(&pes->buffer);
  }
  
  static void new_pes_packet(PESContext *pes, AVPacket *pkt)
  {
      av_init_packet(pkt);
  
      pkt->buf  = pes->buffer;
      pkt->data = pes->buffer->data;
      pkt->size = pes->data_index;
  
      if (pes->total_size != MAX_PES_PAYLOAD &&
          pes->pes_header_size + pes->data_index != pes->total_size +
          PES_START_SIZE) {
          av_log(pes->stream, AV_LOG_WARNING, "PES packet size mismatch\n");
          pes->flags |= AV_PKT_FLAG_CORRUPT;
      }
      memset(pkt->data + pkt->size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
  
      // Separate out the AC3 substream from an HDMV combined TrueHD/AC3 PID
      if (pes->sub_st && pes->stream_type == 0x83 && pes->extended_stream_id == 0x76)
          pkt->stream_index = pes->sub_st->index;
      else
          pkt->stream_index = pes->st->index;
      pkt->pts = pes->pts;
      pkt->dts = pes->dts;
      /* store position of first TS packet of this PES packet */
      pkt->pos   = pes->ts_packet_pos;
      pkt->flags = pes->flags;
  
      pes->buffer = NULL;
      reset_pes_packet_state(pes);
  }
  
  static uint64_t get_ts64(GetBitContext *gb, int bits)
  {
      if (get_bits_left(gb) < bits)
          return AV_NOPTS_VALUE;
      return get_bits64(gb, bits);
  }
  
  static int read_sl_header(PESContext *pes, SLConfigDescr *sl,
                            const uint8_t *buf, int buf_size)
  {
      GetBitContext gb;
      int au_start_flag = 0, au_end_flag = 0, ocr_flag = 0, idle_flag = 0;
      int padding_flag = 0, padding_bits = 0, inst_bitrate_flag = 0;
      int dts_flag = -1, cts_flag = -1;
      int64_t dts = AV_NOPTS_VALUE, cts = AV_NOPTS_VALUE;
      uint8_t buf_padded[128 + FF_INPUT_BUFFER_PADDING_SIZE];
      int buf_padded_size = FFMIN(buf_size, sizeof(buf_padded) - FF_INPUT_BUFFER_PADDING_SIZE);
  
      memcpy(buf_padded, buf, buf_padded_size);
  
      init_get_bits(&gb, buf_padded, buf_padded_size * 8);
  
      if (sl->use_au_start)
          au_start_flag = get_bits1(&gb);
      if (sl->use_au_end)
          au_end_flag = get_bits1(&gb);
      if (!sl->use_au_start && !sl->use_au_end)
          au_start_flag = au_end_flag = 1;
      if (sl->ocr_len > 0)
          ocr_flag = get_bits1(&gb);
      if (sl->use_idle)
          idle_flag = get_bits1(&gb);
      if (sl->use_padding)
          padding_flag = get_bits1(&gb);
      if (padding_flag)
          padding_bits = get_bits(&gb, 3);
  
      if (!idle_flag && (!padding_flag || padding_bits != 0)) {
          if (sl->packet_seq_num_len)
              skip_bits_long(&gb, sl->packet_seq_num_len);
          if (sl->degr_prior_len)
              if (get_bits1(&gb))
                  skip_bits(&gb, sl->degr_prior_len);
          if (ocr_flag)
              skip_bits_long(&gb, sl->ocr_len);
          if (au_start_flag) {
              if (sl->use_rand_acc_pt)
                  get_bits1(&gb);
              if (sl->au_seq_num_len > 0)
                  skip_bits_long(&gb, sl->au_seq_num_len);
              if (sl->use_timestamps) {
                  dts_flag = get_bits1(&gb);
                  cts_flag = get_bits1(&gb);
              }
          }
          if (sl->inst_bitrate_len)
              inst_bitrate_flag = get_bits1(&gb);
          if (dts_flag == 1)
              dts = get_ts64(&gb, sl->timestamp_len);
          if (cts_flag == 1)
              cts = get_ts64(&gb, sl->timestamp_len);
          if (sl->au_len > 0)
              skip_bits_long(&gb, sl->au_len);
          if (inst_bitrate_flag)
              skip_bits_long(&gb, sl->inst_bitrate_len);
      }
  
      if (dts != AV_NOPTS_VALUE)
          pes->dts = dts;
      if (cts != AV_NOPTS_VALUE)
          pes->pts = cts;
  
      if (sl->timestamp_len && sl->timestamp_res)
          avpriv_set_pts_info(pes->st, sl->timestamp_len, 1, sl->timestamp_res);
  
      return (get_bits_count(&gb) + 7) >> 3;
  }
  
  /* return non zero if a packet could be constructed */
  static int mpegts_push_data(MpegTSFilter *filter,
                              const uint8_t *buf, int buf_size, int is_start,
                              int64_t pos)
  {
      PESContext *pes   = filter->u.pes_filter.opaque;
      MpegTSContext *ts = pes->ts;
      const uint8_t *p;
      int len, code;
  
      if (!ts->pkt)
          return 0;
  
      if (is_start) {
          if (pes->state == MPEGTS_PAYLOAD && pes->data_index > 0) {
              new_pes_packet(pes, ts->pkt);
              ts->stop_parse = 1;
          } else {
              reset_pes_packet_state(pes);
          }
          pes->state         = MPEGTS_HEADER;
          pes->ts_packet_pos = pos;
      }
      p = buf;
      while (buf_size > 0) {
          switch (pes->state) {
          case MPEGTS_HEADER:
              len = PES_START_SIZE - pes->data_index;
              if (len > buf_size)
                  len = buf_size;
              memcpy(pes->header + pes->data_index, p, len);
              pes->data_index += len;
              p += len;
              buf_size -= len;
              if (pes->data_index == PES_START_SIZE) {
                  /* we got all the PES or section header. We can now
                   * decide */
                  if (pes->header[0] == 0x00 && pes->header[1] == 0x00 &&
                      pes->header[2] == 0x01) {
                      /* it must be an mpeg2 PES stream */
                      code = pes->header[3] | 0x100;
                      av_dlog(pes->stream, "pid=%x pes_code=%#x\n", pes->pid,
                              code);
  
                      if ((pes->st && pes->st->discard == AVDISCARD_ALL &&
                           (!pes->sub_st ||
                            pes->sub_st->discard == AVDISCARD_ALL)) ||
                          code == 0x1be) /* padding_stream */
                          goto skip;
  
                      /* stream not present in PMT */
                      if (!pes->st) {
                          if (ts->skip_changes)
                              goto skip;
  
                          pes->st = avformat_new_stream(ts->stream, NULL);
                          if (!pes->st)
                              return AVERROR(ENOMEM);
                          pes->st->id = pes->pid;
                          mpegts_set_stream_info(pes->st, pes, 0, 0);
                      }
  
                      pes->total_size = AV_RB16(pes->header + 4);
                      /* NOTE: a zero total size means the PES size is
                       * unbounded */
                      if (!pes->total_size)
                          pes->total_size = MAX_PES_PAYLOAD;
  
                      /* allocate pes buffer */
                      pes->buffer = av_buffer_alloc(pes->total_size +
                                                    FF_INPUT_BUFFER_PADDING_SIZE);
                      if (!pes->buffer)
                          return AVERROR(ENOMEM);
  
                      if (code != 0x1bc && code != 0x1bf && /* program_stream_map, private_stream_2 */
                          code != 0x1f0 && code != 0x1f1 && /* ECM, EMM */
                          code != 0x1ff && code != 0x1f2 && /* program_stream_directory, DSMCC_stream */
                          code != 0x1f8) {                  /* ITU-T Rec. H.222.1 type E stream */
                          pes->state = MPEGTS_PESHEADER;
                          if (pes->st->codec->codec_id == AV_CODEC_ID_NONE && !pes->st->request_probe) {
                              av_dlog(pes->stream,
                                      "pid=%x stream_type=%x probing\n",
                                      pes->pid,
                                      pes->stream_type);
                              pes->st->request_probe = 1;
                          }
                      } else {
                          pes->state      = MPEGTS_PAYLOAD;
                          pes->data_index = 0;
                      }
                  } else {
                      /* otherwise, it should be a table */
                      /* skip packet */
  skip:
                      pes->state = MPEGTS_SKIP;
                      continue;
                  }
              }
              break;
          /**********************************************/
          /* PES packing parsing */
          case MPEGTS_PESHEADER:
              len = PES_HEADER_SIZE - pes->data_index;
              if (len < 0)
                  return AVERROR_INVALIDDATA;
              if (len > buf_size)
                  len = buf_size;
              memcpy(pes->header + pes->data_index, p, len);
              pes->data_index += len;
              p += len;
              buf_size -= len;
              if (pes->data_index == PES_HEADER_SIZE) {
                  pes->pes_header_size = pes->header[8] + 9;
                  pes->state           = MPEGTS_PESHEADER_FILL;
              }
              break;
          case MPEGTS_PESHEADER_FILL:
              len = pes->pes_header_size - pes->data_index;
              if (len < 0)
                  return AVERROR_INVALIDDATA;
              if (len > buf_size)
                  len = buf_size;
              memcpy(pes->header + pes->data_index, p, len);
              pes->data_index += len;
              p += len;
              buf_size -= len;
              if (pes->data_index == pes->pes_header_size) {
                  const uint8_t *r;
                  unsigned int flags, pes_ext, skip;
  
                  flags = pes->header[7];
                  r = pes->header + 9;
                  pes->pts = AV_NOPTS_VALUE;
                  pes->dts = AV_NOPTS_VALUE;
                  if ((flags & 0xc0) == 0x80) {
                      pes->dts = pes->pts = ff_parse_pes_pts(r);
                      r += 5;
                  } else if ((flags & 0xc0) == 0xc0) {
                      pes->pts = ff_parse_pes_pts(r);
                      r += 5;
                      pes->dts = ff_parse_pes_pts(r);
                      r += 5;
                  }
                  pes->extended_stream_id = -1;
                  if (flags & 0x01) { /* PES extension */
                      pes_ext = *r++;
                      /* Skip PES private data, program packet sequence counter and P-STD buffer */
                      skip  = (pes_ext >> 4) & 0xb;
                      skip += skip & 0x9;
                      r    += skip;
                      if ((pes_ext & 0x41) == 0x01 &&
                          (r + 2) <= (pes->header + pes->pes_header_size)) {
                          /* PES extension 2 */
                          if ((r[0] & 0x7f) > 0 && (r[1] & 0x80) == 0)
                              pes->extended_stream_id = r[1];
                      }
                  }
  
                  /* we got the full header. We parse it and get the payload */
                  pes->state = MPEGTS_PAYLOAD;
                  pes->data_index = 0;
                  if (pes->stream_type == 0x12 && buf_size > 0) {
                      int sl_header_bytes = read_sl_header(pes, &pes->sl, p,
                                                           buf_size);
                      pes->pes_header_size += sl_header_bytes;
                      p += sl_header_bytes;
                      buf_size -= sl_header_bytes;
                  }
                  if (pes->stream_type == 0x15 && buf_size >= 5) {
                      /* skip metadata access unit header */
                      pes->pes_header_size += 5;
                      p += 5;
                      buf_size -= 5;
                  }
                  if (pes->ts->fix_teletext_pts && pes->st->codec->codec_id == AV_CODEC_ID_DVB_TELETEXT) {
                      AVProgram *p = NULL;
                      while ((p = av_find_program_from_stream(pes->stream, p, pes->st->index))) {
                          if (p->pcr_pid != -1 && p->discard != AVDISCARD_ALL) {
                              MpegTSFilter *f = pes->ts->pids[p->pcr_pid];
                              if (f) {
                                  AVStream *st = NULL;
                                  if (f->type == MPEGTS_PES) {
                                      PESContext *pcrpes = f->u.pes_filter.opaque;
                                      if (pcrpes)
                                          st = pcrpes->st;
                                  } else if (f->type == MPEGTS_PCR) {
                                      int i;
                                      for (i = 0; i < p->nb_stream_indexes; i++) {
                                          AVStream *pst = pes->stream->streams[p->stream_index[i]];
                                          if (pst->codec->codec_type == AVMEDIA_TYPE_VIDEO)
                                              st = pst;
                                      }
                                  }
                                  if (f->last_pcr != -1 && st && st->discard != AVDISCARD_ALL) {
                                      // teletext packets do not always have correct timestamps,
                                      // the standard says they should be handled after 40.6 ms at most,
                                      // and the pcr error to this packet should be no more than 100 ms.
                                      // TODO: we should interpolate the PCR, not just use the last one
                                      int64_t pcr = f->last_pcr / 300;
                                      pes->st->pts_wrap_reference = st->pts_wrap_reference;
                                      pes->st->pts_wrap_behavior = st->pts_wrap_behavior;
                                      if (pes->dts == AV_NOPTS_VALUE || pes->dts < pcr) {
                                          pes->pts = pes->dts = pcr;
                                      } else if (pes->dts > pcr + 3654 + 9000) {
                                          pes->pts = pes->dts = pcr + 3654 + 9000;
                                      }
                                      break;
                                  }
                              }
                          }
                      }
                  }
              }
              break;
          case MPEGTS_PAYLOAD:
              if (pes->buffer) {
                  if (pes->data_index > 0 &&
                      pes->data_index + buf_size > pes->total_size) {
                      new_pes_packet(pes, ts->pkt);
                      pes->total_size = MAX_PES_PAYLOAD;
                      pes->buffer = av_buffer_alloc(pes->total_size +
                                                    FF_INPUT_BUFFER_PADDING_SIZE);
                      if (!pes->buffer)
                          return AVERROR(ENOMEM);
                      ts->stop_parse = 1;
                  } else if (pes->data_index == 0 &&
                             buf_size > pes->total_size) {
                      // pes packet size is < ts size packet and pes data is padded with 0xff
                      // not sure if this is legal in ts but see issue #2392
                      buf_size = pes->total_size;
                  }
                  memcpy(pes->buffer->data + pes->data_index, p, buf_size);
                  pes->data_index += buf_size;
                  /* emit complete packets with known packet size
                   * decreases demuxer delay for infrequent packets like subtitles from
                   * a couple of seconds to milliseconds for properly muxed files.
                   * total_size is the number of bytes following pes_packet_length
                   * in the pes header, i.e. not counting the first PES_START_SIZE bytes */
                  if (!ts->stop_parse && pes->total_size < MAX_PES_PAYLOAD &&
                      pes->pes_header_size + pes->data_index == pes->total_size + PES_START_SIZE) {
                      ts->stop_parse = 1;
                      new_pes_packet(pes, ts->pkt);
                  }
              }
              buf_size = 0;
              break;
          case MPEGTS_SKIP:
              buf_size = 0;
              break;
          }
      }
  
      return 0;
  }
  
  static PESContext *add_pes_stream(MpegTSContext *ts, int pid, int pcr_pid)
  {
      MpegTSFilter *tss;
      PESContext *pes;
  
      /* if no pid found, then add a pid context */
      pes = av_mallocz(sizeof(PESContext));
      if (!pes)
          return 0;
      pes->ts      = ts;
      pes->stream  = ts->stream;
      pes->pid     = pid;
      pes->pcr_pid = pcr_pid;
      pes->state   = MPEGTS_SKIP;
      pes->pts     = AV_NOPTS_VALUE;
      pes->dts     = AV_NOPTS_VALUE;
      tss          = mpegts_open_pes_filter(ts, pid, mpegts_push_data, pes);
      if (!tss) {
          av_free(pes);
          return 0;
      }
      return pes;
  }
  
  #define MAX_LEVEL 4
  typedef struct {
      AVFormatContext *s;
      AVIOContext pb;
      Mp4Descr *descr;
      Mp4Descr *active_descr;
      int descr_count;
      int max_descr_count;
      int level;
      int predefined_SLConfigDescriptor_seen;
  } MP4DescrParseContext;
  
  static int init_MP4DescrParseContext(MP4DescrParseContext *d, AVFormatContext *s,
                                       const uint8_t *buf, unsigned size,
                                       Mp4Descr *descr, int max_descr_count)
  {
      int ret;
      if (size > (1 << 30))
          return AVERROR_INVALIDDATA;
  
      if ((ret = ffio_init_context(&d->pb, (unsigned char *)buf, size, 0,
                                   NULL, NULL, NULL, NULL)) < 0)
          return ret;
  
      d->s               = s;
      d->level           = 0;
      d->descr_count     = 0;
      d->descr           = descr;
      d->active_descr    = NULL;
      d->max_descr_count = max_descr_count;
  
      return 0;
  }
  
  static void update_offsets(AVIOContext *pb, int64_t *off, int *len)
  {
      int64_t new_off = avio_tell(pb);
      (*len) -= new_off - *off;
      *off    = new_off;
  }
  
  static int parse_mp4_descr(MP4DescrParseContext *d, int64_t off, int len,
                             int target_tag);
  
  static int parse_mp4_descr_arr(MP4DescrParseContext *d, int64_t off, int len)
  {
      while (len > 0) {
          int ret = parse_mp4_descr(d, off, len, 0);
          if (ret < 0)
              return ret;
          update_offsets(&d->pb, &off, &len);
      }
      return 0;
  }
  
  static int parse_MP4IODescrTag(MP4DescrParseContext *d, int64_t off, int len)
  {
      avio_rb16(&d->pb); // ID
      avio_r8(&d->pb);
      avio_r8(&d->pb);
      avio_r8(&d->pb);
      avio_r8(&d->pb);
      avio_r8(&d->pb);
      update_offsets(&d->pb, &off, &len);
      return parse_mp4_descr_arr(d, off, len);
  }
  
  static int parse_MP4ODescrTag(MP4DescrParseContext *d, int64_t off, int len)
  {
      int id_flags;
      if (len < 2)
          return 0;
      id_flags = avio_rb16(&d->pb);
      if (!(id_flags & 0x0020)) { // URL_Flag
          update_offsets(&d->pb, &off, &len);
          return parse_mp4_descr_arr(d, off, len); // ES_Descriptor[]
      } else {
          return 0;
      }
  }
  
  static int parse_MP4ESDescrTag(MP4DescrParseContext *d, int64_t off, int len)
  {
      int es_id = 0;
      if (d->descr_count >= d->max_descr_count)
          return AVERROR_INVALIDDATA;
      ff_mp4_parse_es_descr(&d->pb, &es_id);
      d->active_descr = d->descr + (d->descr_count++);
  
      d->active_descr->es_id = es_id;
      update_offsets(&d->pb, &off, &len);
      parse_mp4_descr(d, off, len, MP4DecConfigDescrTag);
      update_offsets(&d->pb, &off, &len);
      if (len > 0)
          parse_mp4_descr(d, off, len, MP4SLDescrTag);
      d->active_descr = NULL;
      return 0;
  }
  
  static int parse_MP4DecConfigDescrTag(MP4DescrParseContext *d, int64_t off,
                                        int len)
  {
      Mp4Descr *descr = d->active_descr;
      if (!descr)
          return AVERROR_INVALIDDATA;
      d->active_descr->dec_config_descr = av_malloc(len);
      if (!descr->dec_config_descr)
          return AVERROR(ENOMEM);
      descr->dec_config_descr_len = len;
      avio_read(&d->pb, descr->dec_config_descr, len);
      return 0;
  }
  
  static int parse_MP4SLDescrTag(MP4DescrParseContext *d, int64_t off, int len)
  {
      Mp4Descr *descr = d->active_descr;
      int predefined;
      if (!descr)
          return AVERROR_INVALIDDATA;
  
      predefined = avio_r8(&d->pb);
      if (!predefined) {
          int lengths;
          int flags = avio_r8(&d->pb);
          descr->sl.use_au_start    = !!(flags & 0x80);
          descr->sl.use_au_end      = !!(flags & 0x40);
          descr->sl.use_rand_acc_pt = !!(flags & 0x20);
          descr->sl.use_padding     = !!(flags & 0x08);
          descr->sl.use_timestamps  = !!(flags & 0x04);
          descr->sl.use_idle        = !!(flags & 0x02);
          descr->sl.timestamp_res   = avio_rb32(&d->pb);
          avio_rb32(&d->pb);
          descr->sl.timestamp_len      = avio_r8(&d->pb);
          if (descr->sl.timestamp_len > 64) {
              avpriv_request_sample(NULL, "timestamp_len > 64");
              descr->sl.timestamp_len = 64;
              return AVERROR_PATCHWELCOME;
          }
          descr->sl.ocr_len            = avio_r8(&d->pb);
          descr->sl.au_len             = avio_r8(&d->pb);
          descr->sl.inst_bitrate_len   = avio_r8(&d->pb);
          lengths                      = avio_rb16(&d->pb);
          descr->sl.degr_prior_len     = lengths >> 12;
          descr->sl.au_seq_num_len     = (lengths >> 7) & 0x1f;
          descr->sl.packet_seq_num_len = (lengths >> 2) & 0x1f;
      } else if (!d->predefined_SLConfigDescriptor_seen){
          avpriv_report_missing_feature(d->s, "Predefined SLConfigDescriptor");
          d->predefined_SLConfigDescriptor_seen = 1;
      }
      return 0;
  }
  
  static int parse_mp4_descr(MP4DescrParseContext *d, int64_t off, int len,
                             int target_tag)
  {
      int tag;
      int len1 = ff_mp4_read_descr(d->s, &d->pb, &tag);
      update_offsets(&d->pb, &off, &len);
      if (len < 0 || len1 > len || len1 <= 0) {
          av_log(d->s, AV_LOG_ERROR,
                 "Tag %x length violation new length %d bytes remaining %d\n",
                 tag, len1, len);
          return AVERROR_INVALIDDATA;
      }
  
      if (d->level++ >= MAX_LEVEL) {
          av_log(d->s, AV_LOG_ERROR, "Maximum MP4 descriptor level exceeded\n");
          goto done;
      }
  
      if (target_tag && tag != target_tag) {
          av_log(d->s, AV_LOG_ERROR, "Found tag %x expected %x\n", tag,
                 target_tag);
          goto done;
      }
  
      switch (tag) {
      case MP4IODescrTag:
          parse_MP4IODescrTag(d, off, len1);
          break;
      case MP4ODescrTag:
          parse_MP4ODescrTag(d, off, len1);
          break;
      case MP4ESDescrTag:
          parse_MP4ESDescrTag(d, off, len1);
          break;
      case MP4DecConfigDescrTag:
          parse_MP4DecConfigDescrTag(d, off, len1);
          break;
      case MP4SLDescrTag:
          parse_MP4SLDescrTag(d, off, len1);
          break;
      }
  
  
  done:
      d->level--;
      avio_seek(&d->pb, off + len1, SEEK_SET);
      return 0;
  }
  
  static int mp4_read_iods(AVFormatContext *s, const uint8_t *buf, unsigned size,
                           Mp4Descr *descr, int *descr_count, int max_descr_count)
  {
      MP4DescrParseContext d;
      int ret;
  
      ret = init_MP4DescrParseContext(&d, s, buf, size, descr, max_descr_count);
      if (ret < 0)
          return ret;
  
      ret = parse_mp4_descr(&d, avio_tell(&d.pb), size, MP4IODescrTag);
  
      *descr_count = d.descr_count;
      return ret;
  }
  
  static int mp4_read_od(AVFormatContext *s, const uint8_t *buf, unsigned size,
                         Mp4Descr *descr, int *descr_count, int max_descr_count)
  {
      MP4DescrParseContext d;
      int ret;
  
      ret = init_MP4DescrParseContext(&d, s, buf, size, descr, max_descr_count);
      if (ret < 0)
          return ret;
  
      ret = parse_mp4_descr_arr(&d, avio_tell(&d.pb), size);
  
      *descr_count = d.descr_count;
      return ret;
  }
  
  static void m4sl_cb(MpegTSFilter *filter, const uint8_t *section,
                      int section_len)
  {
      MpegTSContext *ts = filter->u.section_filter.opaque;
      SectionHeader h;
      const uint8_t *p, *p_end;
      AVIOContext pb;
      int mp4_descr_count = 0;
      Mp4Descr mp4_descr[MAX_MP4_DESCR_COUNT] = { { 0 } };
      int i, pid;
      AVFormatContext *s = ts->stream;
  
      p_end = section + section_len - 4;
      p = section;
      if (parse_section_header(&h, &p, p_end) < 0)
          return;
      if (h.tid != M4OD_TID)
          return;
  
      mp4_read_od(s, p, (unsigned) (p_end - p), mp4_descr, &mp4_descr_count,
                  MAX_MP4_DESCR_COUNT);
  
      for (pid = 0; pid < NB_PID_MAX; pid++) {
          if (!ts->pids[pid])
              continue;
          for (i = 0; i < mp4_descr_count; i++) {
              PESContext *pes;
              AVStream *st;
              if (ts->pids[pid]->es_id != mp4_descr[i].es_id)
                  continue;
              if (ts->pids[pid]->type != MPEGTS_PES) {
                  av_log(s, AV_LOG_ERROR, "pid %x is not PES\n", pid);
                  continue;
              }
              pes = ts->pids[pid]->u.pes_filter.opaque;
              st  = pes->st;
              if (!st)
                  continue;
  
              pes->sl = mp4_descr[i].sl;
  
              ffio_init_context(&pb, mp4_descr[i].dec_config_descr,
                                mp4_descr[i].dec_config_descr_len, 0,
                                NULL, NULL, NULL, NULL);
              ff_mp4_read_dec_config_descr(s, st, &pb);
              if (st->codec->codec_id == AV_CODEC_ID_AAC &&
                  st->codec->extradata_size > 0)
                  st->need_parsing = 0;
              if (st->codec->codec_id == AV_CODEC_ID_H264 &&
                  st->codec->extradata_size > 0)
                  st->need_parsing = 0;
  
              if (st->codec->codec_id <= AV_CODEC_ID_NONE) {
                  // do nothing
              } else if (st->codec->codec_id < AV_CODEC_ID_FIRST_AUDIO)
                  st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
              else if (st->codec->codec_id < AV_CODEC_ID_FIRST_SUBTITLE)
                  st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
              else if (st->codec->codec_id < AV_CODEC_ID_FIRST_UNKNOWN)
                  st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
          }
      }
      for (i = 0; i < mp4_descr_count; i++)
          av_free(mp4_descr[i].dec_config_descr);
  }
  
  int ff_parse_mpeg2_descriptor(AVFormatContext *fc, AVStream *st, int stream_type,
                                const uint8_t **pp, const uint8_t *desc_list_end,
                                Mp4Descr *mp4_descr, int mp4_descr_count, int pid,
                                MpegTSContext *ts)
  {
      const uint8_t *desc_end;
      int desc_len, desc_tag, desc_es_id;
      char language[252];
      int i;
  
      desc_tag = get8(pp, desc_list_end);
      if (desc_tag < 0)
          return AVERROR_INVALIDDATA;
      desc_len = get8(pp, desc_list_end);
      if (desc_len < 0)
          return AVERROR_INVALIDDATA;
      desc_end = *pp + desc_len;
      if (desc_end > desc_list_end)
          return AVERROR_INVALIDDATA;
  
      av_dlog(fc, "tag: 0x%02x len=%d\n", desc_tag, desc_len);
  
      if ((st->codec->codec_id == AV_CODEC_ID_NONE || st->request_probe > 0) &&
          stream_type == STREAM_TYPE_PRIVATE_DATA)
          mpegts_find_stream_type(st, desc_tag, DESC_types);
  
      switch (desc_tag) {
      case 0x1E: /* SL descriptor */
          desc_es_id = get16(pp, desc_end);
          if (ts && ts->pids[pid])
              ts->pids[pid]->es_id = desc_es_id;
          for (i = 0; i < mp4_descr_count; i++)
              if (mp4_descr[i].dec_config_descr_len &&
                  mp4_descr[i].es_id == desc_es_id) {
                  AVIOContext pb;
                  ffio_init_context(&pb, mp4_descr[i].dec_config_descr,
                                    mp4_descr[i].dec_config_descr_len, 0,
                                    NULL, NULL, NULL, NULL);
                  ff_mp4_read_dec_config_descr(fc, st, &pb);
                  if (st->codec->codec_id == AV_CODEC_ID_AAC &&
                      st->codec->extradata_size > 0)
                      st->need_parsing = 0;
                  if (st->codec->codec_id == AV_CODEC_ID_MPEG4SYSTEMS)
                      mpegts_open_section_filter(ts, pid, m4sl_cb, ts, 1);
              }
          break;
      case 0x1F: /* FMC descriptor */
          get16(pp, desc_end);
          if (mp4_descr_count > 0 &&
              (st->codec->codec_id == AV_CODEC_ID_AAC_LATM || st->request_probe > 0) &&
              mp4_descr->dec_config_descr_len && mp4_descr->es_id == pid) {
              AVIOContext pb;
              ffio_init_context(&pb, mp4_descr->dec_config_descr,
                                mp4_descr->dec_config_descr_len, 0,
                                NULL, NULL, NULL, NULL);
              ff_mp4_read_dec_config_descr(fc, st, &pb);
              if (st->codec->codec_id == AV_CODEC_ID_AAC &&
                  st->codec->extradata_size > 0) {
                  st->request_probe = st->need_parsing = 0;
                  st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
              }
          }
          break;
      case 0x56: /* DVB teletext descriptor */
          {
              uint8_t *extradata = NULL;
              int language_count = desc_len / 5;
  
              if (desc_len > 0 && desc_len % 5 != 0)
                  return AVERROR_INVALIDDATA;
  
              if (language_count > 0) {
                  /* 4 bytes per language code (3 bytes) with comma or NUL byte should fit language buffer */
                  if (language_count > sizeof(language) / 4) {
                      language_count = sizeof(language) / 4;
                  }
  
                  if (st->codec->extradata == NULL) {
                      if (ff_alloc_extradata(st->codec, language_count * 2)) {
                          return AVERROR(ENOMEM);
                      }
                  }
  
                 if (st->codec->extradata_size < language_count * 2)
                     return AVERROR_INVALIDDATA;
  
                 extradata = st->codec->extradata;
  
                  for (i = 0; i < language_count; i++) {
                      language[i * 4 + 0] = get8(pp, desc_end);
                      language[i * 4 + 1] = get8(pp, desc_end);
                      language[i * 4 + 2] = get8(pp, desc_end);
                      language[i * 4 + 3] = ',';
  
                      memcpy(extradata, *pp, 2);
                      extradata += 2;
  
                      *pp += 2;
                  }
  
                  language[i * 4 - 1] = 0;
                  av_dict_set(&st->metadata, "language", language, 0);
              }
          }
          break;
      case 0x59: /* subtitling descriptor */
          {
              /* 8 bytes per DVB subtitle substream data:
               * ISO_639_language_code (3 bytes),
               * subtitling_type (1 byte),
               * composition_page_id (2 bytes),
               * ancillary_page_id (2 bytes) */
              int language_count = desc_len / 8;
  
              if (desc_len > 0 && desc_len % 8 != 0)
                  return AVERROR_INVALIDDATA;
  
              if (language_count > 1) {
                  avpriv_request_sample(fc, "DVB subtitles with multiple languages");
              }
  
              if (language_count > 0) {
                  uint8_t *extradata;
  
                  /* 4 bytes per language code (3 bytes) with comma or NUL byte should fit language buffer */
                  if (language_count > sizeof(language) / 4) {
                      language_count = sizeof(language) / 4;
                  }
  
                  if (st->codec->extradata == NULL) {
                      if (ff_alloc_extradata(st->codec, language_count * 5)) {
                          return AVERROR(ENOMEM);
                      }
                  }
  
                  if (st->codec->extradata_size < language_count * 5)
                      return AVERROR_INVALIDDATA;
  
                  extradata = st->codec->extradata;
  
                  for (i = 0; i < language_count; i++) {
                      language[i * 4 + 0] = get8(pp, desc_end);
                      language[i * 4 + 1] = get8(pp, desc_end);
                      language[i * 4 + 2] = get8(pp, desc_end);
                      language[i * 4 + 3] = ',';
  
                      /* hearing impaired subtitles detection using subtitling_type */
                      switch (*pp[0]) {
                      case 0x20: /* DVB subtitles (for the hard of hearing) with no monitor aspect ratio criticality */
                      case 0x21: /* DVB subtitles (for the hard of hearing) for display on 4:3 aspect ratio monitor */
                      case 0x22: /* DVB subtitles (for the hard of hearing) for display on 16:9 aspect ratio monitor */
                      case 0x23: /* DVB subtitles (for the hard of hearing) for display on 2.21:1 aspect ratio monitor */
                      case 0x24: /* DVB subtitles (for the hard of hearing) for display on a high definition monitor */
                      case 0x25: /* DVB subtitles (for the hard of hearing) with plano-stereoscopic disparity for display on a high definition monitor */
                          st->disposition |= AV_DISPOSITION_HEARING_IMPAIRED;
                          break;
                      }
  
                      extradata[4] = get8(pp, desc_end); /* subtitling_type */
                      memcpy(extradata, *pp, 4); /* composition_page_id and ancillary_page_id */
                      extradata += 5;
  
                      *pp += 4;
                  }
  
                  language[i * 4 - 1] = 0;
                  av_dict_set(&st->metadata, "language", language, 0);
              }
          }
          break;
      case 0x0a: /* ISO 639 language descriptor */
          for (i = 0; i + 4 <= desc_len; i += 4) {
              language[i + 0] = get8(pp, desc_end);
              language[i + 1] = get8(pp, desc_end);
              language[i + 2] = get8(pp, desc_end);
              language[i + 3] = ',';
              switch (get8(pp, desc_end)) {
              case 0x01:
                  st->disposition |= AV_DISPOSITION_CLEAN_EFFECTS;
                  break;
              case 0x02:
                  st->disposition |= AV_DISPOSITION_HEARING_IMPAIRED;
                  break;
              case 0x03:
                  st->disposition |= AV_DISPOSITION_VISUAL_IMPAIRED;
                  break;
              }
          }
          if (i && language[0]) {
              language[i - 1] = 0;
              av_dict_set(&st->metadata, "language", language, 0);
          }
          break;
      case 0x05: /* registration descriptor */
          st->codec->codec_tag = bytestream_get_le32(pp);
          av_dlog(fc, "reg_desc=%.4s\n", (char *)&st->codec->codec_tag);
          if (st->codec->codec_id == AV_CODEC_ID_NONE)
              mpegts_find_stream_type(st, st->codec->codec_tag, REGD_types);
          break;
      case 0x52: /* stream identifier descriptor */
          st->stream_identifier = 1 + get8(pp, desc_end);
          break;
      case 0x26: /* metadata descriptor */
          if (get16(pp, desc_end) == 0xFFFF)
              *pp += 4;
          if (get8(pp, desc_end) == 0xFF) {
              st->codec->codec_tag = bytestream_get_le32(pp);
              if (st->codec->codec_id == AV_CODEC_ID_NONE)
                  mpegts_find_stream_type(st, st->codec->codec_tag, METADATA_types);
          }
          break;
      default:
          break;
      }
      *pp = desc_end;
      return 0;
  }
  
  static void pmt_cb(MpegTSFilter *filter, const uint8_t *section, int section_len)
  {
      MpegTSContext *ts = filter->u.section_filter.opaque;
      SectionHeader h1, *h = &h1;
      PESContext *pes;
      AVStream *st;
      const uint8_t *p, *p_end, *desc_list_end;
      int program_info_length, pcr_pid, pid, stream_type;
      int desc_list_len;
      uint32_t prog_reg_desc = 0; /* registration descriptor */
  
      int mp4_descr_count = 0;
      Mp4Descr mp4_descr[MAX_MP4_DESCR_COUNT] = { { 0 } };
      int i;
  
      av_dlog(ts->stream, "PMT: len %i\n", section_len);
      hex_dump_debug(ts->stream, section, section_len);
  
      p_end = section + section_len - 4;
      p = section;
      if (parse_section_header(h, &p, p_end) < 0)
          return;
  
      av_dlog(ts->stream, "sid=0x%x sec_num=%d/%d\n",
              h->id, h->sec_num, h->last_sec_num);
  
      if (h->tid != PMT_TID)
          return;
      if (ts->skip_changes)
          return;
  
      clear_program(ts, h->id);
      pcr_pid = get16(&p, p_end);
      if (pcr_pid < 0)
          return;
      pcr_pid &= 0x1fff;
      add_pid_to_pmt(ts, h->id, pcr_pid);
      set_pcr_pid(ts->stream, h->id, pcr_pid);
  
      av_dlog(ts->stream, "pcr_pid=0x%x\n", pcr_pid);
  
      program_info_length = get16(&p, p_end);
      if (program_info_length < 0)
          return;
      program_info_length &= 0xfff;
      while (program_info_length >= 2) {
          uint8_t tag, len;
          tag = get8(&p, p_end);
          len = get8(&p, p_end);
  
          av_dlog(ts->stream, "program tag: 0x%02x len=%d\n", tag, len);
  
          if (len > program_info_length - 2)
              // something else is broken, exit the program_descriptors_loop
              break;
          program_info_length -= len + 2;
          if (tag == 0x1d) { // IOD descriptor
              get8(&p, p_end); // scope
              get8(&p, p_end); // label
              len -= 2;
              mp4_read_iods(ts->stream, p, len, mp4_descr + mp4_descr_count,
                            &mp4_descr_count, MAX_MP4_DESCR_COUNT);
          } else if (tag == 0x05 && len >= 4) { // registration descriptor
              prog_reg_desc = bytestream_get_le32(&p);
              len -= 4;
          }
          p += len;
      }
      p += program_info_length;
      if (p >= p_end)
          goto out;
  
      // stop parsing after pmt, we found header
      if (!ts->stream->nb_streams)
          ts->stop_parse = 2;
  
      set_pmt_found(ts, h->id);
  
  
      for (;;) {
          st = 0;
          pes = NULL;
          stream_type = get8(&p, p_end);
          if (stream_type < 0)
              break;
          pid = get16(&p, p_end);
          if (pid < 0)
              goto out;
          pid &= 0x1fff;
          if (pid == ts->current_pid)
              goto out;
  
          /* now create stream */
          if (ts->pids[pid] && ts->pids[pid]->type == MPEGTS_PES) {
              pes = ts->pids[pid]->u.pes_filter.opaque;
              if (!pes->st) {
                  pes->st     = avformat_new_stream(pes->stream, NULL);
                  if (!pes->st)
                      goto out;
                  pes->st->id = pes->pid;
              }
              st = pes->st;
          } else if (stream_type != 0x13) {
              if (ts->pids[pid])
                  mpegts_close_filter(ts, ts->pids[pid]); // wrongly added sdt filter probably
              pes = add_pes_stream(ts, pid, pcr_pid);
              if (pes) {
                  st = avformat_new_stream(pes->stream, NULL);
                  if (!st)
                      goto out;
                  st->id = pes->pid;
              }
          } else {
              int idx = ff_find_stream_index(ts->stream, pid);
              if (idx >= 0) {
                  st = ts->stream->streams[idx];
              } else {
                  st = avformat_new_stream(ts->stream, NULL);
                  if (!st)
                      goto out;
                  st->id = pid;
                  st->codec->codec_type = AVMEDIA_TYPE_DATA;
              }
          }
  
          if (!st)
              goto out;
  
          if (pes && !pes->stream_type)
              mpegts_set_stream_info(st, pes, stream_type, prog_reg_desc);
  
          add_pid_to_pmt(ts, h->id, pid);
  
          ff_program_add_stream_index(ts->stream, h->id, st->index);
  
          desc_list_len = get16(&p, p_end);
          if (desc_list_len < 0)
              goto out;
          desc_list_len &= 0xfff;
          desc_list_end  = p + desc_list_len;
          if (desc_list_end > p_end)
              goto out;
          for (;;) {
              if (ff_parse_mpeg2_descriptor(ts->stream, st, stream_type, &p,
                                            desc_list_end, mp4_descr,
                                            mp4_descr_count, pid, ts) < 0)
                  break;
  
              if (pes && prog_reg_desc == AV_RL32("HDMV") &&
                  stream_type == 0x83 && pes->sub_st) {
                  ff_program_add_stream_index(ts->stream, h->id,
                                              pes->sub_st->index);
                  pes->sub_st->codec->codec_tag = st->codec->codec_tag;
              }
          }
          p = desc_list_end;
      }
  
      if (!ts->pids[pcr_pid])
          mpegts_open_pcr_filter(ts, pcr_pid);
  
  out:
      for (i = 0; i < mp4_descr_count; i++)
          av_free(mp4_descr[i].dec_config_descr);
  }
  
  static void pat_cb(MpegTSFilter *filter, const uint8_t *section, int section_len)
  {
      MpegTSContext *ts = filter->u.section_filter.opaque;
      SectionHeader h1, *h = &h1;
      const uint8_t *p, *p_end;
      int sid, pmt_pid;
      AVProgram *program;
  
      av_dlog(ts->stream, "PAT:\n");
      hex_dump_debug(ts->stream, section, section_len);
  
      p_end = section + section_len - 4;
      p     = section;
      if (parse_section_header(h, &p, p_end) < 0)
          return;
      if (h->tid != PAT_TID)
          return;
      if (ts->skip_changes)
          return;
  
      ts->stream->ts_id = h->id;
  
      clear_programs(ts);
      for (;;) {
          sid = get16(&p, p_end);
          if (sid < 0)
              break;
          pmt_pid = get16(&p, p_end);
          if (pmt_pid < 0)
              break;
          pmt_pid &= 0x1fff;
  
          if (pmt_pid == ts->current_pid)
              break;
  
          av_dlog(ts->stream, "sid=0x%x pid=0x%x\n", sid, pmt_pid);
  
          if (sid == 0x0000) {
              /* NIT info */
          } else {
              MpegTSFilter *fil = ts->pids[pmt_pid];
              program = av_new_program(ts->stream, sid);
              program->program_num = sid;
              program->pmt_pid = pmt_pid;
              if (fil)
                  if (   fil->type != MPEGTS_SECTION
                      || fil->pid != pmt_pid
                      || fil->u.section_filter.section_cb != pmt_cb)
                      mpegts_close_filter(ts, ts->pids[pmt_pid]);
  
              if (!ts->pids[pmt_pid])
                  mpegts_open_section_filter(ts, pmt_pid, pmt_cb, ts, 1);
              add_pat_entry(ts, sid);
              add_pid_to_pmt(ts, sid, 0); // add pat pid to program
              add_pid_to_pmt(ts, sid, pmt_pid);
          }
      }
  
      if (sid < 0) {
          int i,j;
          for (j=0; j<ts->stream->nb_programs; j++) {
              for (i = 0; i < ts->nb_prg; i++)
                  if (ts->prg[i].id == ts->stream->programs[j]->id)
                      break;
              if (i==ts->nb_prg && !ts->skip_clear)
                  clear_avprogram(ts, ts->stream->programs[j]->id);
          }
      }
  }
  
  static void sdt_cb(MpegTSFilter *filter, const uint8_t *section, int section_len)
  {
      MpegTSContext *ts = filter->u.section_filter.opaque;
      SectionHeader h1, *h = &h1;
      const uint8_t *p, *p_end, *desc_list_end, *desc_end;
      int onid, val, sid, desc_list_len, desc_tag, desc_len, service_type;
      char *name, *provider_name;
  
      av_dlog(ts->stream, "SDT:\n");
      hex_dump_debug(ts->stream, section, section_len);
  
      p_end = section + section_len - 4;
      p     = section;
      if (parse_section_header(h, &p, p_end) < 0)
          return;
      if (h->tid != SDT_TID)
          return;
      if (ts->skip_changes)
          return;
      onid = get16(&p, p_end);
      if (onid < 0)
          return;
      val = get8(&p, p_end);
      if (val < 0)
          return;
      for (;;) {
          sid = get16(&p, p_end);
          if (sid < 0)
              break;
          val = get8(&p, p_end);
          if (val < 0)
              break;
          desc_list_len = get16(&p, p_end);
          if (desc_list_len < 0)
              break;
          desc_list_len &= 0xfff;
          desc_list_end  = p + desc_list_len;
          if (desc_list_end > p_end)
              break;
          for (;;) {
              desc_tag = get8(&p, desc_list_end);
              if (desc_tag < 0)
                  break;
              desc_len = get8(&p, desc_list_end);
              desc_end = p + desc_len;
              if (desc_len < 0 || desc_end > desc_list_end)
                  break;
  
              av_dlog(ts->stream, "tag: 0x%02x len=%d\n",
                      desc_tag, desc_len);
  
              switch (desc_tag) {
              case 0x48:
                  service_type = get8(&p, p_end);
                  if (service_type < 0)
                      break;
                  provider_name = getstr8(&p, p_end);
                  if (!provider_name)
                      break;
                  name = getstr8(&p, p_end);
                  if (name) {
                      AVProgram *program = av_new_program(ts->stream, sid);
                      if (program) {
                          av_dict_set(&program->metadata, "service_name", name, 0);
                          av_dict_set(&program->metadata, "service_provider",
                                      provider_name, 0);
                      }
                  }
                  av_free(name);
                  av_free(provider_name);
                  break;
              default:
                  break;
              }
              p = desc_end;
          }
          p = desc_list_end;
      }
  }
  
  static int parse_pcr(int64_t *ppcr_high, int *ppcr_low,
                       const uint8_t *packet);
  
  /* handle one TS packet */
  static int handle_packet(MpegTSContext *ts, const uint8_t *packet)
  {
      MpegTSFilter *tss;
      int len, pid, cc, expected_cc, cc_ok, afc, is_start, is_discontinuity,
          has_adaptation, has_payload;
      const uint8_t *p, *p_end;
      int64_t pos;
  
      pid = AV_RB16(packet + 1) & 0x1fff;
      if (pid && discard_pid(ts, pid))
          return 0;
      is_start = packet[1] & 0x40;
      tss = ts->pids[pid];
      if (ts->auto_guess && !tss && is_start) {
          add_pes_stream(ts, pid, -1);
          tss = ts->pids[pid];
      }
      if (!tss)
          return 0;
      ts->current_pid = pid;
  
      afc = (packet[3] >> 4) & 3;
      if (afc == 0) /* reserved value */
          return 0;
      has_adaptation   = afc & 2;
      has_payload      = afc & 1;
      is_discontinuity = has_adaptation &&
                         packet[4] != 0 && /* with length > 0 */
                         (packet[5] & 0x80); /* and discontinuity indicated */
  
      /* continuity check (currently not used) */
      cc = (packet[3] & 0xf);
      expected_cc = has_payload ? (tss->last_cc + 1) & 0x0f : tss->last_cc;
      cc_ok = pid == 0x1FFF || // null packet PID
              is_discontinuity ||
              tss->last_cc < 0 ||
              expected_cc == cc;
  
      tss->last_cc = cc;
      if (!cc_ok) {
          av_log(ts->stream, AV_LOG_DEBUG,
                 "Continuity check failed for pid %d expected %d got %d\n",
                 pid, expected_cc, cc);
          if (tss->type == MPEGTS_PES) {
              PESContext *pc = tss->u.pes_filter.opaque;
              pc->flags |= AV_PKT_FLAG_CORRUPT;
          }
      }
  
      p = packet + 4;
      if (has_adaptation) {
          int64_t pcr_h;
          int pcr_l;
          if (parse_pcr(&pcr_h, &pcr_l, packet) == 0)
              tss->last_pcr = pcr_h * 300 + pcr_l;
          /* skip adaptation field */
          p += p[0] + 1;
      }
      /* if past the end of packet, ignore */
      p_end = packet + TS_PACKET_SIZE;
      if (p >= p_end || !has_payload)
          return 0;
  
      pos = avio_tell(ts->stream->pb);
      if (pos >= 0) {
          av_assert0(pos >= TS_PACKET_SIZE);
          ts->pos47_full = pos - TS_PACKET_SIZE;
      }
  
      if (tss->type == MPEGTS_SECTION) {
          if (is_start) {
              /* pointer field present */
              len = *p++;
              if (p + len > p_end)
                  return 0;
              if (len && cc_ok) {
                  /* write remaining section bytes */
                  write_section_data(ts, tss,
                                     p, len, 0);
                  /* check whether filter has been closed */
                  if (!ts->pids[pid])
                      return 0;
              }
              p += len;
              if (p < p_end) {
                  write_section_data(ts, tss,
                                     p, p_end - p, 1);
              }
          } else {
              if (cc_ok) {
                  write_section_data(ts, tss,
                                     p, p_end - p, 0);
              }
          }
  
          // stop find_stream_info from waiting for more streams
          // when all programs have received a PMT
          if (ts->stream->ctx_flags & AVFMTCTX_NOHEADER) {
              int i;
              for (i = 0; i < ts->nb_prg; i++) {
                  if (!ts->prg[i].pmt_found)
                      break;
              }
              if (i == ts->nb_prg && ts->nb_prg > 0) {
                  if (ts->stream->nb_streams > 1 || pos > 100000) {
                      av_log(ts->stream, AV_LOG_DEBUG, "All programs have pmt, headers found\n");
                      ts->stream->ctx_flags &= ~AVFMTCTX_NOHEADER;
                  }
              }
          }
  
      } else {
          int ret;
          // Note: The position here points actually behind the current packet.
          if (tss->type == MPEGTS_PES) {
              if ((ret = tss->u.pes_filter.pes_cb(tss, p, p_end - p, is_start,
                                                  pos - ts->raw_packet_size)) < 0)
                  return ret;
          }
      }
  
      return 0;
  }
  
  static void reanalyze(MpegTSContext *ts) {
      AVIOContext *pb = ts->stream->pb;
      int64_t pos = avio_tell(pb);
      if (pos < 0)
          return;
      pos -= ts->pos47_full;
      if (pos == TS_PACKET_SIZE) {
          ts->size_stat[0] ++;
      } else if (pos == TS_DVHS_PACKET_SIZE) {
          ts->size_stat[1] ++;
      } else if (pos == TS_FEC_PACKET_SIZE) {
          ts->size_stat[2] ++;
      }
  
      ts->size_stat_count ++;
      if (ts->size_stat_count > SIZE_STAT_THRESHOLD) {
          int newsize = 0;
          if (ts->size_stat[0] > SIZE_STAT_THRESHOLD) {
              newsize = TS_PACKET_SIZE;
          } else if (ts->size_stat[1] > SIZE_STAT_THRESHOLD) {
              newsize = TS_DVHS_PACKET_SIZE;
          } else if (ts->size_stat[2] > SIZE_STAT_THRESHOLD) {
              newsize = TS_FEC_PACKET_SIZE;
          }
          if (newsize && newsize != ts->raw_packet_size) {
              av_log(ts->stream, AV_LOG_WARNING, "changing packet size to %d\n", newsize);
              ts->raw_packet_size = newsize;
          }
          ts->size_stat_count = 0;
          memset(ts->size_stat, 0, sizeof(ts->size_stat));
      }
  }
  
  /* XXX: try to find a better synchro over several packets (use
   * get_packet_size() ?) */
  static int mpegts_resync(AVFormatContext *s)
  {
      MpegTSContext *ts = s->priv_data;
      AVIOContext *pb = s->pb;
      int c, i;
  
      for (i = 0; i < ts->resync_size; i++) {
          c = avio_r8(pb);
          if (avio_feof(pb))
              return AVERROR_EOF;
          if (c == 0x47) {
              avio_seek(pb, -1, SEEK_CUR);
              reanalyze(s->priv_data);
              return 0;
          }
      }
      av_log(s, AV_LOG_ERROR,
             "max resync size reached, could not find sync byte\n");
      /* no sync found */
      return AVERROR_INVALIDDATA;
  }
  
  /* return AVERROR_something if error or EOF. Return 0 if OK. */
  static int read_packet(AVFormatContext *s, uint8_t *buf, int raw_packet_size,
                         const uint8_t **data)
  {
      AVIOContext *pb = s->pb;
      int len;
  
      for (;;) {
          len = ffio_read_indirect(pb, buf, TS_PACKET_SIZE, data);
          if (len != TS_PACKET_SIZE)
              return len < 0 ? len : AVERROR_EOF;
          /* check packet sync byte */
          if ((*data)[0] != 0x47) {
              /* find a new packet start */
              uint64_t pos = avio_tell(pb);
              avio_seek(pb, -FFMIN(raw_packet_size, pos), SEEK_CUR);
  
              if (mpegts_resync(s) < 0)
                  return AVERROR(EAGAIN);
              else
                  continue;
          } else {
              break;
          }
      }
      return 0;
  }
  
  static void finished_reading_packet(AVFormatContext *s, int raw_packet_size)
  {
      AVIOContext *pb = s->pb;
      int skip = raw_packet_size - TS_PACKET_SIZE;
      if (skip > 0)
          avio_skip(pb, skip);
  }
  
  static int handle_packets(MpegTSContext *ts, int64_t nb_packets)
  {
      AVFormatContext *s = ts->stream;
      uint8_t packet[TS_PACKET_SIZE + FF_INPUT_BUFFER_PADDING_SIZE];
      const uint8_t *data;
      int64_t packet_num;
      int ret = 0;
  
      if (avio_tell(s->pb) != ts->last_pos) {
          int i;
          av_dlog(ts->stream, "Skipping after seek\n");
          /* seek detected, flush pes buffer */
          for (i = 0; i < NB_PID_MAX; i++) {
              if (ts->pids[i]) {
                  if (ts->pids[i]->type == MPEGTS_PES) {
                      PESContext *pes = ts->pids[i]->u.pes_filter.opaque;
                      av_buffer_unref(&pes->buffer);
                      pes->data_index = 0;
                      pes->state = MPEGTS_SKIP; /* skip until pes header */
                  }
                  ts->pids[i]->last_cc = -1;
                  ts->pids[i]->last_pcr = -1;
              }
          }
      }
  
      ts->stop_parse = 0;
      packet_num = 0;
      memset(packet + TS_PACKET_SIZE, 0, FF_INPUT_BUFFER_PADDING_SIZE);
      for (;;) {
          packet_num++;
          if (nb_packets != 0 && packet_num >= nb_packets ||
              ts->stop_parse > 1) {
              ret = AVERROR(EAGAIN);
              break;
          }
          if (ts->stop_parse > 0)
              break;
  
          ret = read_packet(s, packet, ts->raw_packet_size, &data);
          if (ret != 0)
              break;
          ret = handle_packet(ts, data);
          finished_reading_packet(s, ts->raw_packet_size);
          if (ret != 0)
              break;
      }
      ts->last_pos = avio_tell(s->pb);
      return ret;
  }
  
  static int mpegts_probe(AVProbeData *p)
  {
      const int size = p->buf_size;
      int maxscore = 0;
      int sumscore = 0;
      int i;
      int check_count = size / TS_FEC_PACKET_SIZE;
  #define CHECK_COUNT 10
  #define CHECK_BLOCK 100
  
      if (check_count < CHECK_COUNT)
          return AVERROR_INVALIDDATA;
  
      for (i = 0; i<check_count; i+=CHECK_BLOCK) {
          int left = FFMIN(check_count - i, CHECK_BLOCK);
          int score      = analyze(p->buf + TS_PACKET_SIZE     *i, TS_PACKET_SIZE     *left, TS_PACKET_SIZE     , NULL);
          int dvhs_score = analyze(p->buf + TS_DVHS_PACKET_SIZE*i, TS_DVHS_PACKET_SIZE*left, TS_DVHS_PACKET_SIZE, NULL);
          int fec_score  = analyze(p->buf + TS_FEC_PACKET_SIZE *i, TS_FEC_PACKET_SIZE *left, TS_FEC_PACKET_SIZE , NULL);
          score = FFMAX3(score, dvhs_score, fec_score);
          sumscore += score;
          maxscore = FFMAX(maxscore, score);
      }
  
      sumscore = sumscore * CHECK_COUNT / check_count;
      maxscore = maxscore * CHECK_COUNT / CHECK_BLOCK;
  
      av_dlog(0, "TS score: %d %d\n", sumscore, maxscore);
  
      if      (sumscore > 6) return AVPROBE_SCORE_MAX   + sumscore - CHECK_COUNT;
      else if (maxscore > 6) return AVPROBE_SCORE_MAX/2 + sumscore - CHECK_COUNT;
      else
          return AVERROR_INVALIDDATA;
  }
  
  /* return the 90kHz PCR and the extension for the 27MHz PCR. return
   * (-1) if not available */
  static int parse_pcr(int64_t *ppcr_high, int *ppcr_low, const uint8_t *packet)
  {
      int afc, len, flags;
      const uint8_t *p;
      unsigned int v;
  
      afc = (packet[3] >> 4) & 3;
      if (afc <= 1)
          return AVERROR_INVALIDDATA;
      p   = packet + 4;
      len = p[0];
      p++;
      if (len == 0)
          return AVERROR_INVALIDDATA;
      flags = *p++;
      len--;
      if (!(flags & 0x10))
          return AVERROR_INVALIDDATA;
      if (len < 6)
          return AVERROR_INVALIDDATA;
      v          = AV_RB32(p);
      *ppcr_high = ((int64_t) v << 1) | (p[4] >> 7);
      *ppcr_low  = ((p[4] & 1) << 8) | p[5];
      return 0;
  }
  
  static void seek_back(AVFormatContext *s, AVIOContext *pb, int64_t pos) {
  
      /* NOTE: We attempt to seek on non-seekable files as well, as the
       * probe buffer usually is big enough. Only warn if the seek failed
       * on files where the seek should work. */
      if (avio_seek(pb, pos, SEEK_SET) < 0)
          av_log(s, pb->seekable ? AV_LOG_ERROR : AV_LOG_INFO, "Unable to seek back to the start\n");
  }
  
  static int mpegts_read_header(AVFormatContext *s)
  {
      MpegTSContext *ts = s->priv_data;
      AVIOContext *pb   = s->pb;
      uint8_t buf[8 * 1024] = {0};
      int len;
      int64_t pos, probesize = s->probesize ? s->probesize : s->probesize2;
  
      ffio_ensure_seekback(pb, probesize);
  
      /* read the first 8192 bytes to get packet size */
      pos = avio_tell(pb);
      len = avio_read(pb, buf, sizeof(buf));
      ts->raw_packet_size = get_packet_size(buf, len);
      if (ts->raw_packet_size <= 0) {
          av_log(s, AV_LOG_WARNING, "Could not detect TS packet size, defaulting to non-FEC/DVHS\n");
          ts->raw_packet_size = TS_PACKET_SIZE;
      }
      ts->stream     = s;
      ts->auto_guess = 0;
  
      if (s->iformat == &ff_mpegts_demuxer) {
          /* normal demux */
  
          /* first do a scan to get all the services */
          seek_back(s, pb, pos);
  
          mpegts_open_section_filter(ts, SDT_PID, sdt_cb, ts, 1);
  
          mpegts_open_section_filter(ts, PAT_PID, pat_cb, ts, 1);
  
          handle_packets(ts, probesize / ts->raw_packet_size);
          /* if could not find service, enable auto_guess */
  
          ts->auto_guess = 1;
  
          av_dlog(ts->stream, "tuning done\n");
  
          s->ctx_flags |= AVFMTCTX_NOHEADER;
      } else {
          AVStream *st;
          int pcr_pid, pid, nb_packets, nb_pcrs, ret, pcr_l;
          int64_t pcrs[2], pcr_h;
          int packet_count[2];
          uint8_t packet[TS_PACKET_SIZE];
          const uint8_t *data;
  
          /* only read packets */
  
          st = avformat_new_stream(s, NULL);
          if (!st)
              return AVERROR(ENOMEM);
          avpriv_set_pts_info(st, 60, 1, 27000000);
          st->codec->codec_type = AVMEDIA_TYPE_DATA;
          st->codec->codec_id   = AV_CODEC_ID_MPEG2TS;
  
          /* we iterate until we find two PCRs to estimate the bitrate */
          pcr_pid    = -1;
          nb_pcrs    = 0;
          nb_packets = 0;
          for (;;) {
              ret = read_packet(s, packet, ts->raw_packet_size, &data);
              if (ret < 0)
                  return ret;
              pid = AV_RB16(data + 1) & 0x1fff;
              if ((pcr_pid == -1 || pcr_pid == pid) &&
                  parse_pcr(&pcr_h, &pcr_l, data) == 0) {
                  finished_reading_packet(s, ts->raw_packet_size);
                  pcr_pid = pid;
                  packet_count[nb_pcrs] = nb_packets;
                  pcrs[nb_pcrs] = pcr_h * 300 + pcr_l;
                  nb_pcrs++;
                  if (nb_pcrs >= 2)
                      break;
              } else {
                  finished_reading_packet(s, ts->raw_packet_size);
              }
              nb_packets++;
          }
  
          /* NOTE1: the bitrate is computed without the FEC */
          /* NOTE2: it is only the bitrate of the start of the stream */
          ts->pcr_incr = (pcrs[1] - pcrs[0]) / (packet_count[1] - packet_count[0]);
          ts->cur_pcr  = pcrs[0] - ts->pcr_incr * packet_count[0];
          s->bit_rate  = TS_PACKET_SIZE * 8 * 27e6 / ts->pcr_incr;
          st->codec->bit_rate = s->bit_rate;
          st->start_time      = ts->cur_pcr;
          av_dlog(ts->stream, "start=%0.3f pcr=%0.3f incr=%d\n",
                  st->start_time / 1000000.0, pcrs[0] / 27e6, ts->pcr_incr);
      }
  
      seek_back(s, pb, pos);
      return 0;
  }
  
  #define MAX_PACKET_READAHEAD ((128 * 1024) / 188)
  
  static int mpegts_raw_read_packet(AVFormatContext *s, AVPacket *pkt)
  {
      MpegTSContext *ts = s->priv_data;
      int ret, i;
      int64_t pcr_h, next_pcr_h, pos;
      int pcr_l, next_pcr_l;
      uint8_t pcr_buf[12];
      const uint8_t *data;
  
      if (av_new_packet(pkt, TS_PACKET_SIZE) < 0)
          return AVERROR(ENOMEM);
      ret = read_packet(s, pkt->data, ts->raw_packet_size, &data);
      pkt->pos = avio_tell(s->pb);
      if (ret < 0) {
          av_free_packet(pkt);
          return ret;
      }
      if (data != pkt->data)
          memcpy(pkt->data, data, ts->raw_packet_size);
      finished_reading_packet(s, ts->raw_packet_size);
      if (ts->mpeg2ts_compute_pcr) {
          /* compute exact PCR for each packet */
          if (parse_pcr(&pcr_h, &pcr_l, pkt->data) == 0) {
              /* we read the next PCR (XXX: optimize it by using a bigger buffer */
              pos = avio_tell(s->pb);
              for (i = 0; i < MAX_PACKET_READAHEAD; i++) {
                  avio_seek(s->pb, pos + i * ts->raw_packet_size, SEEK_SET);
                  avio_read(s->pb, pcr_buf, 12);
                  if (parse_pcr(&next_pcr_h, &next_pcr_l, pcr_buf) == 0) {
                      /* XXX: not precise enough */
                      ts->pcr_incr =
                          ((next_pcr_h - pcr_h) * 300 + (next_pcr_l - pcr_l)) /
                          (i + 1);
                      break;
                  }
              }
              avio_seek(s->pb, pos, SEEK_SET);
              /* no next PCR found: we use previous increment */
              ts->cur_pcr = pcr_h * 300 + pcr_l;
          }
          pkt->pts      = ts->cur_pcr;
          pkt->duration = ts->pcr_incr;
          ts->cur_pcr  += ts->pcr_incr;
      }
      pkt->stream_index = 0;
      return 0;
  }
  
  static int mpegts_read_packet(AVFormatContext *s, AVPacket *pkt)
  {
      MpegTSContext *ts = s->priv_data;
      int ret, i;
  
      pkt->size = -1;
      ts->pkt = pkt;
      ret = handle_packets(ts, 0);
      if (ret < 0) {
          av_free_packet(ts->pkt);
          /* flush pes data left */
          for (i = 0; i < NB_PID_MAX; i++)
              if (ts->pids[i] && ts->pids[i]->type == MPEGTS_PES) {
                  PESContext *pes = ts->pids[i]->u.pes_filter.opaque;
                  if (pes->state == MPEGTS_PAYLOAD && pes->data_index > 0) {
                      new_pes_packet(pes, pkt);
                      pes->state = MPEGTS_SKIP;
                      ret = 0;
                      break;
                  }
              }
      }
  
      if (!ret && pkt->size < 0)
          ret = AVERROR(EINTR);
      return ret;
  }
  
  static void mpegts_free(MpegTSContext *ts)
  {
      int i;
  
      clear_programs(ts);
  
      for (i = 0; i < NB_PID_MAX; i++)
          if (ts->pids[i])
              mpegts_close_filter(ts, ts->pids[i]);
  }
  
  static int mpegts_read_close(AVFormatContext *s)
  {
      MpegTSContext *ts = s->priv_data;
      mpegts_free(ts);
      return 0;
  }
  
  static av_unused int64_t mpegts_get_pcr(AVFormatContext *s, int stream_index,
                                int64_t *ppos, int64_t pos_limit)
  {
      MpegTSContext *ts = s->priv_data;
      int64_t pos, timestamp;
      uint8_t buf[TS_PACKET_SIZE];
      int pcr_l, pcr_pid =
          ((PESContext *)s->streams[stream_index]->priv_data)->pcr_pid;
      int pos47 = ts->pos47_full % ts->raw_packet_size;
      pos =
          ((*ppos + ts->raw_packet_size - 1 - pos47) / ts->raw_packet_size) *
          ts->raw_packet_size + pos47;
      while(pos < pos_limit) {
          if (avio_seek(s->pb, pos, SEEK_SET) < 0)
              return AV_NOPTS_VALUE;
          if (avio_read(s->pb, buf, TS_PACKET_SIZE) != TS_PACKET_SIZE)
              return AV_NOPTS_VALUE;
          if (buf[0] != 0x47) {
              avio_seek(s->pb, -TS_PACKET_SIZE, SEEK_CUR);
              if (mpegts_resync(s) < 0)
                  return AV_NOPTS_VALUE;
              pos = avio_tell(s->pb);
              continue;
          }
          if ((pcr_pid < 0 || (AV_RB16(buf + 1) & 0x1fff) == pcr_pid) &&
              parse_pcr(&timestamp, &pcr_l, buf) == 0) {
              *ppos = pos;
              return timestamp;
          }
          pos += ts->raw_packet_size;
      }
  
      return AV_NOPTS_VALUE;
  }
  
  static int64_t mpegts_get_dts(AVFormatContext *s, int stream_index,
                                int64_t *ppos, int64_t pos_limit)
  {
      MpegTSContext *ts = s->priv_data;
      int64_t pos;
      int pos47 = ts->pos47_full % ts->raw_packet_size;
      pos = ((*ppos  + ts->raw_packet_size - 1 - pos47) / ts->raw_packet_size) * ts->raw_packet_size + pos47;
      ff_read_frame_flush(s);
      if (avio_seek(s->pb, pos, SEEK_SET) < 0)
          return AV_NOPTS_VALUE;
      while(pos < pos_limit) {
          int ret;
          AVPacket pkt;
          av_init_packet(&pkt);
          ret = av_read_frame(s, &pkt);
          if (ret < 0)
              return AV_NOPTS_VALUE;
          av_free_packet(&pkt);
          if (pkt.dts != AV_NOPTS_VALUE && pkt.pos >= 0) {
              ff_reduce_index(s, pkt.stream_index);
              av_add_index_entry(s->streams[pkt.stream_index], pkt.pos, pkt.dts, 0, 0, AVINDEX_KEYFRAME /* FIXME keyframe? */);
              if (pkt.stream_index == stream_index && pkt.pos >= *ppos) {
                  *ppos = pkt.pos;
                  return pkt.dts;
              }
          }
          pos = pkt.pos;
      }
  
      return AV_NOPTS_VALUE;
  }
  
  /**************************************************************/
  /* parsing functions - called from other demuxers such as RTP */
  
  MpegTSContext *avpriv_mpegts_parse_open(AVFormatContext *s)
  {
      MpegTSContext *ts;
  
      ts = av_mallocz(sizeof(MpegTSContext));
      if (!ts)
          return NULL;
      /* no stream case, currently used by RTP */
      ts->raw_packet_size = TS_PACKET_SIZE;
      ts->stream = s;
      ts->auto_guess = 1;
      mpegts_open_section_filter(ts, SDT_PID, sdt_cb, ts, 1);
      mpegts_open_section_filter(ts, PAT_PID, pat_cb, ts, 1);
  
      return ts;
  }
  
  /* return the consumed length if a packet was output, or -1 if no
   * packet is output */
  int avpriv_mpegts_parse_packet(MpegTSContext *ts, AVPacket *pkt,
                                 const uint8_t *buf, int len)
  {
      int len1;
  
      len1 = len;
      ts->pkt = pkt;
      for (;;) {
          ts->stop_parse = 0;
          if (len < TS_PACKET_SIZE)
              return AVERROR_INVALIDDATA;
          if (buf[0] != 0x47) {
              buf++;
              len--;
          } else {
              handle_packet(ts, buf);
              buf += TS_PACKET_SIZE;
              len -= TS_PACKET_SIZE;
              if (ts->stop_parse == 1)
                  break;
          }
      }
      return len1 - len;
  }
  
  void avpriv_mpegts_parse_close(MpegTSContext *ts)
  {
      mpegts_free(ts);
      av_free(ts);
  }
  
  AVInputFormat ff_mpegts_demuxer = {
  	.name           = "mpegts",
      .long_name      = NULL_IF_CONFIG_SMALL("MPEG-TS (MPEG-2 Transport Stream)"),
      .priv_data_size = sizeof(MpegTSContext),
      .read_probe     = mpegts_probe,
      .read_header    = mpegts_read_header,
      .read_packet    = mpegts_read_packet,
      .read_close     = mpegts_read_close,
      .read_timestamp = mpegts_get_dts,
      .flags          = AVFMT_SHOW_IDS | AVFMT_TS_DISCONT,
      .priv_class     = &mpegts_class,
  };
  
  AVInputFormat ff_mpegtsraw_demuxer = {
  	.name           = "mpegtsraw",
      .long_name      = NULL_IF_CONFIG_SMALL("raw MPEG-TS (MPEG-2 Transport Stream)"),
      .priv_data_size = sizeof(MpegTSContext),
      .read_header    = mpegts_read_header,
      .read_packet    = mpegts_raw_read_packet,
      .read_close     = mpegts_read_close,
      .read_timestamp = mpegts_get_dts,
      .flags          = AVFMT_SHOW_IDS | AVFMT_TS_DISCONT,
      .priv_class     = &mpegtsraw_class,
  };
  