pat.c

libdvbpsi4-0.1.5版本

/*****************************************************************************
 * pat.c: PAT decoder/generator
 *----------------------------------------------------------------------------
 * (c)2001-2002 VideoLAN
 * $Id: pat.c 108 2005-04-19 12:33:21Z gbazin $
 *
 * Authors: Arnaud de Bossoreille de Ribou <[e-mail]>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 *----------------------------------------------------------------------------
 *
 *****************************************************************************/


#include "config.h"

#include <stdio.h>
#include <stdlib.h>

#if defined(HAVE_INTTYPES_H)
#include <inttypes.h>
#elif defined(HAVE_STDINT_H)
#include <stdint.h>
#endif

#include "../dvbpsi.h"
#include "../dvbpsi_private.h"
#include "../psi.h"
#include "pat.h"
#include "pat_private.h"


/*****************************************************************************
 * dvbpsi_AttachPAT
 *****************************************************************************
 * Initialize a PAT decoder and return a handle on it.
 *****************************************************************************/
dvbpsi_handle dvbpsi_AttachPAT(dvbpsi_pat_callback pf_callback,
                               void* p_cb_data)
{
  dvbpsi_handle h_dvbpsi = (dvbpsi_decoder_t*)malloc(sizeof(dvbpsi_decoder_t));
  dvbpsi_pat_decoder_t* p_pat_decoder;
  unsigned int i;

  if(h_dvbpsi == NULL)
    return NULL;

  p_pat_decoder = (dvbpsi_pat_decoder_t*)malloc(sizeof(dvbpsi_pat_decoder_t));

  if(p_pat_decoder == NULL)
  {
    free(h_dvbpsi);
    return NULL;
  }

  /* PSI decoder configuration */
  h_dvbpsi->pf_callback = &dvbpsi_GatherPATSections;
  h_dvbpsi->p_private_decoder = p_pat_decoder;
  h_dvbpsi->i_section_max_size = 1024;
  /* PSI decoder initial state */
  h_dvbpsi->i_continuity_counter = 31;
  h_dvbpsi->b_discontinuity = 1;
  h_dvbpsi->p_current_section = NULL;

  /* PAT decoder information */
  p_pat_decoder->pf_callback = pf_callback;
  p_pat_decoder->p_cb_data = p_cb_data;
  /* PAT decoder initial state */
  p_pat_decoder->b_current_valid = 0;
  p_pat_decoder->p_building_pat = NULL;
  for(i = 0; i <= 255; i++)
    p_pat_decoder->ap_sections[i] = NULL;

  return h_dvbpsi;
}


/*****************************************************************************
 * dvbpsi_DetachPAT
 *****************************************************************************
 * Close a PAT decoder. The handle isn't valid any more.
 *****************************************************************************/
void dvbpsi_DetachPAT(dvbpsi_handle h_dvbpsi)
{
  dvbpsi_pat_decoder_t* p_pat_decoder
                        = (dvbpsi_pat_decoder_t*)h_dvbpsi->p_private_decoder;
  unsigned int i;

  free(p_pat_decoder->p_building_pat);

  for(i = 0; i <= 255; i++)
  {
    if(p_pat_decoder->ap_sections[i])
      free(p_pat_decoder->ap_sections[i]);
  }

  free(h_dvbpsi->p_private_decoder);
  if(h_dvbpsi->p_current_section)
    dvbpsi_DeletePSISections(h_dvbpsi->p_current_section);
  free(h_dvbpsi);
}


/*****************************************************************************
 * dvbpsi_InitPAT
 *****************************************************************************
 * Initialize a pre-allocated dvbpsi_pat_t structure.
 *****************************************************************************/
void dvbpsi_InitPAT(dvbpsi_pat_t* p_pat, uint16_t i_ts_id, uint8_t i_version,
                    int b_current_next)
{
  p_pat->i_ts_id = i_ts_id;
  p_pat->i_version = i_version;
  p_pat->b_current_next = b_current_next;
  p_pat->p_first_program = NULL;
}


/*****************************************************************************
 * dvbpsi_EmptyPAT
 *****************************************************************************
 * Clean a dvbpsi_pat_t structure.
 *****************************************************************************/
void dvbpsi_EmptyPAT(dvbpsi_pat_t* p_pat)
{
  dvbpsi_pat_program_t* p_program = p_pat->p_first_program;

  while(p_program != NULL)
  {
    dvbpsi_pat_program_t* p_tmp = p_program->p_next;
    free(p_program);
    p_program = p_tmp;
  }

  p_pat->p_first_program = NULL;
}


/*****************************************************************************
 * dvbpsi_PATAddProgram
 *****************************************************************************
 * Add a program at the end of the PAT.
 *****************************************************************************/
dvbpsi_pat_program_t* dvbpsi_PATAddProgram(dvbpsi_pat_t* p_pat,
                                           uint16_t i_number, uint16_t i_pid)
{
  dvbpsi_pat_program_t* p_program
                = (dvbpsi_pat_program_t*)malloc(sizeof(dvbpsi_pat_program_t));

  if(p_program)
  {
    p_program->i_number = i_number;
    p_program->i_pid = i_pid;
    p_program->p_next = NULL;

    if(p_pat->p_first_program == NULL)
    {
      p_pat->p_first_program = p_program;
    }
    else
    {
      dvbpsi_pat_program_t* p_last_program = p_pat->p_first_program;
      while(p_last_program->p_next != NULL)
        p_last_program = p_last_program->p_next;
      p_last_program->p_next = p_program;
    }
  }

  return p_program;
}


/*****************************************************************************
 * dvbpsi_GatherPATSections
 *****************************************************************************
 * Callback for the PSI decoder.
 *****************************************************************************/
void dvbpsi_GatherPATSections(dvbpsi_decoder_t* p_decoder,
                              dvbpsi_psi_section_t* p_section)
{
  dvbpsi_pat_decoder_t* p_pat_decoder
                        = (dvbpsi_pat_decoder_t*)p_decoder->p_private_decoder;
  int b_append = 1;
  int b_reinit = 0;
  unsigned int i;

  DVBPSI_DEBUG_ARG("PAT decoder",
                   "Table version %2d, " "i_extension %5d, "
                   "section %3d up to %3d, " "current %1d",
                   p_section->i_version, p_section->i_extension,
                   p_section->i_number, p_section->i_last_number,
                   p_section->b_current_next);

  if(p_section->i_table_id != 0x00)
  {
    /* Invalid table_id value */
    DVBPSI_ERROR_ARG("PAT decoder",
                     "invalid section (table_id == 0x%02x)",
                     p_section->i_table_id);
    b_append = 0;
  }

  if(b_append && !p_section->b_syntax_indicator)
  {
    /* Invalid section_syntax_indicator */
    DVBPSI_ERROR("PAT decoder",
                 "invalid section (section_syntax_indicator == 0)");
    b_append = 0;
  }

  /* Now if b_append is true then we have a valid PAT section */
  if(b_append)
  {
    /* TS discontinuity check */
    if(p_decoder->b_discontinuity)
    {
      b_reinit = 1;
      p_decoder->b_discontinuity = 0;
    }
    else
    {
      /* Perform a few sanity checks */
      if(p_pat_decoder->p_building_pat)
      {
        if(p_pat_decoder->p_building_pat->i_ts_id != p_section->i_extension)
        {
          /* transport_stream_id */
          DVBPSI_ERROR("PAT decoder",
                       "'transport_stream_id' differs"