sdt.c

Dvbstreamer 用在解析MPTS的部分内容

/*****************************************************************************
 * sdt.c: SDT decoder/generator
 *----------------------------------------------------------------------------
 * (c)2001-2002 VideoLAN
 * $Id: sdt.c 110 2005-06-04 12:52:02Z gbazin $
 *
 * Authors: Johan Bilien <[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>
#include <string.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 "descriptor.h"
#include "demux.h"
#include "sdt.h"
#include "sdt_private.h"

#include "objects.h"


/*****************************************************************************
 * dvbpsi_AttachSDT
 *****************************************************************************
 * Initialize a SDT subtable decoder.
 *****************************************************************************/
int dvbpsi_AttachSDT(dvbpsi_decoder_t * p_psi_decoder, uint8_t i_table_id,
          uint16_t i_extension, dvbpsi_sdt_callback pf_callback,
                               void* p_cb_data)
{
  dvbpsi_demux_t* p_demux = (dvbpsi_demux_t*)p_psi_decoder->p_private_decoder;
  dvbpsi_demux_subdec_t* p_subdec;
  dvbpsi_sdt_decoder_t*  p_sdt_decoder;
  unsigned int i;

  if(dvbpsi_demuxGetSubDec(p_demux, i_table_id, i_extension))
  {
    DVBPSI_ERROR_ARG("SDT decoder",
                     "Already a decoder for (table_id == 0x%02x,"
                     "extension == 0x%02x)",
                     i_table_id, i_extension);

    return 1;
  }

  p_subdec = (dvbpsi_demux_subdec_t*)malloc(sizeof(dvbpsi_demux_subdec_t));
  if(p_subdec == NULL)
  {
    return 1;
  }

  p_sdt_decoder = (dvbpsi_sdt_decoder_t*)malloc(sizeof(dvbpsi_sdt_decoder_t));

  if(p_sdt_decoder == NULL)
  {
    free(p_subdec);
    return 1;
  }

  /* subtable decoder configuration */
  p_subdec->pf_callback = &dvbpsi_GatherSDTSections;
  p_subdec->p_cb_data = p_sdt_decoder;
  p_subdec->i_id = (uint32_t)i_table_id << 16 | (uint32_t)i_extension;
  p_subdec->pf_detach = dvbpsi_DetachSDT;

  /* Attach the subtable decoder to the demux */
  p_subdec->p_next = p_demux->p_first_subdec;
  p_demux->p_first_subdec = p_subdec;

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

  return 0;
}


/*****************************************************************************
 * dvbpsi_DetachSDT
 *****************************************************************************
 * Close a SDT decoder.
 *****************************************************************************/
void dvbpsi_DetachSDT(dvbpsi_demux_t * p_demux, uint8_t i_table_id,
          uint16_t i_extension)
{
  dvbpsi_demux_subdec_t* p_subdec;
  dvbpsi_demux_subdec_t** pp_prev_subdec;
  dvbpsi_sdt_decoder_t* p_sdt_decoder;

  unsigned int i;

  p_subdec = dvbpsi_demuxGetSubDec(p_demux, i_table_id, i_extension);

  if(p_demux == NULL)
  {
    DVBPSI_ERROR_ARG("SDT Decoder",
                     "No such SDT decoder (table_id == 0x%02x,"
                     "extension == 0x%02x)",
                     i_table_id, i_extension);
    return;
  }

  p_sdt_decoder = (dvbpsi_sdt_decoder_t*)p_subdec->p_cb_data;
  if (p_sdt_decoder->p_building_sdt)
  {
    ObjectRefDec(p_sdt_decoder->p_building_sdt);
  }

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

  free(p_subdec->p_cb_data);

  pp_prev_subdec = &p_demux->p_first_subdec;
  while(*pp_prev_subdec != p_subdec)
    pp_prev_subdec = &(*pp_prev_subdec)->p_next;

  *pp_prev_subdec = p_subdec->p_next;
  free(p_subdec);
}


/*****************************************************************************
 * dvbpsi_InitSDT
 *****************************************************************************
 * Initialize a pre-allocated dvbpsi_sdt_t structure.
 *****************************************************************************/
void dvbpsi_InitSDT(dvbpsi_sdt_t* p_sdt, uint16_t i_ts_id, uint8_t i_version,
                    int b_current_next, uint16_t i_network_id)
{
  p_sdt->i_ts_id = i_ts_id;
  p_sdt->i_version = i_version;
  p_sdt->b_current_next = b_current_next;
  p_sdt->i_network_id = i_network_id;
  p_sdt->p_first_service = NULL;
}


/*****************************************************************************
 * dvbpsi_EmptySDT
 *****************************************************************************
 * Clean a dvbpsi_sdt_t structure.
 *****************************************************************************/
void dvbpsi_EmptySDT(dvbpsi_sdt_t* p_sdt)
{
  dvbpsi_sdt_service_t* p_service = p_sdt->p_first_service;

  while(p_service != NULL)
  {
    dvbpsi_sdt_service_t* p_tmp = p_service->p_next;
    dvbpsi_DeleteDescriptors(p_service->p_first_descriptor);
    free(p_service);
    p_service = p_tmp;
  }

  p_sdt->p_first_service = NULL;
}


/*****************************************************************************
 * dvbpsi_SDTAddService
 *****************************************************************************
 * Add a service description at the end of the SDT.
 *****************************************************************************/
dvbpsi_sdt_service_t *dvbpsi_SDTAddService(dvbpsi_sdt_t* p_sdt,
                                           uint16_t i_service_id,
                                           int b_eit_schedule,
                                           int b_eit_present,
                                           uint8_t i_running_status,
                                           int b_free_ca)
{
  dvbpsi_sdt_service_t * p_service
                = (dvbpsi_sdt_service_t*)malloc(sizeof(dvbpsi_sdt_service_t));

  if(p_service)
  {
    p_service->i_service_id = i_service_id;
    p_service->b_eit_schedule = b_eit_schedule;
    p_service->b_eit_present = b_eit_present;
    p_service->i_running_status = i_running_status;
    p_service->b_free_ca = b_free_ca;
    p_service->p_next = NULL;
    p_service->p_first_descriptor = NULL;

    if(p_sdt->p_first_service == NULL)
    {
      p_sdt->p_first_service = p_service;
    }
    else
    {
      dvbpsi_sdt_service_t * p_last_service = p_sdt->p_first_service;
      while(p_last_service->p_next != NULL)
        p_last_service = p_last_service->p_next;
      p_last_service->p_next = p_service;
    }
  }

  return p_service;
}


/*****************************************************************************
 * dvbpsi_SDTServiceAddDescriptor
 *****************************************************************************
 * Add a descriptor in the SDT service description.
 *****************************************************************************/
dvbpsi_descriptor_t *dvbpsi_SDTServiceAddDescriptor(
                                               dvbpsi_sdt_service_t *p_service,
                                               uint8_t i_tag, uint8_t i_length,
                                               uint8_t *p_data)
{
  dvbpsi_descriptor_t * p_descriptor
                        = dvbpsi_NewDescriptor(i_tag, i_length, p_data);

  if(p_descriptor)
  {
    if(p_service->p_first_descriptor == NULL)
    {
      p_service->p_first_descriptor = p_descriptor;
    }
    else
    {
      dvbpsi_descriptor_t * p_last_descriptor = p_service->p_first_descriptor;
      while(p_last_descriptor->p_next != NULL)
        p_last_descriptor = p_last_descriptor->p_next;
      p_last_descriptor->p_next = p_descriptor;
    }
  }

  return p_descriptor;
}


/*****************************************************************************
 * dvbpsi_GatherSDTSections
 *****************************************************************************
 * Callback for the subtable demultiplexor.
 *****************************************************************************/
void dvbpsi_GatherSDTSections(dvbpsi_decoder_t * p_psi_decoder,
                              void * p_private_decoder,
                              dvbpsi_psi_section_t * p_section)
{
  dvbpsi_sdt_decoder_t * p_sdt_decoder
                        = (dvbpsi_sdt_decoder_t*)p_private_decoder;
  int b_append = 1;
  int b_reinit = 0;
  unsigned int i;

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

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

  /* Now if b_append is true then we have a valid SDT section */
  if(b_append)
  {
    /* TS discontinuity check */
    if(p_psi_decoder->b_discontinuity)
    {
      b_reinit = 1;
      p_psi_decoder->b_discontinuity = 0;
    }