atsc_mgt.c

Dvbstreamer 用在解析MPTS的部分内容

/*
Copyright (C) 2006  Adam Charrett

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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA

mgt.c

Decode PSIP Master Guide Table.

*/
#include "config.h"

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

#include "dvbpsi.h"
#include "dvbpsi_private.h"
#include "psi.h"
#include "descriptor.h"
#include "demux.h"
#include "atsc/mgt.h"

#include "objects.h"

typedef struct dvbpsi_atsc_mgt_decoder_s
{
  dvbpsi_atsc_mgt_callback      pf_callback;
  void *                        p_cb_data;

  dvbpsi_atsc_mgt_t            current_mgt;
  dvbpsi_atsc_mgt_t *          p_building_mgt;

  int                           b_current_valid;

  uint8_t                       i_last_section_number;
  dvbpsi_psi_section_t *        ap_sections [256];

} dvbpsi_atsc_mgt_decoder_t;

dvbpsi_descriptor_t *dvbpsi_atsc_MGTAddDescriptor(
                                               dvbpsi_atsc_mgt_t *p_mgt,
                                               uint8_t i_tag, uint8_t i_length,
                                               uint8_t *p_data);

dvbpsi_atsc_mgt_table_t *dvbpsi_atsc_MGTAddTable(dvbpsi_atsc_mgt_t* p_mgt,
                                           uint16_t i_type,
                                           uint16_t i_pid,
                                           uint8_t i_version,
                                           uint32_t i_number_bytes);

dvbpsi_descriptor_t *dvbpsi_atsc_MGTTableAddDescriptor(
                                               dvbpsi_atsc_mgt_table_t *p_table,
                                               uint8_t i_tag, uint8_t i_length,
                                               uint8_t *p_data);

void dvbpsi_atsc_GatherMGTSections(dvbpsi_decoder_t * p_psi_decoder,
                              void * p_private_decoder,
                              dvbpsi_psi_section_t * p_section);

void dvbpsi_atsc_DecodeMGTSections(dvbpsi_atsc_mgt_t* p_mgt,
                              dvbpsi_psi_section_t* p_section);

/*****************************************************************************
 * dvbpsi_atsc_AttachMGT
 *****************************************************************************
 * Initialize a MGT subtable decoder.
 *****************************************************************************/
int dvbpsi_atsc_AttachMGT(dvbpsi_decoder_t * p_psi_decoder, uint8_t i_table_id, 
                          dvbpsi_atsc_mgt_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_atsc_mgt_decoder_t*  p_mgt_decoder;
  unsigned int i;

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

    return 1;
  }

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

  p_mgt_decoder = (dvbpsi_atsc_mgt_decoder_t*)malloc(sizeof(dvbpsi_atsc_mgt_decoder_t));

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

  /* subtable decoder configuration */
  p_subdec->pf_callback = &dvbpsi_atsc_GatherMGTSections;
  p_subdec->p_cb_data = p_mgt_decoder;
  p_subdec->i_id = (uint32_t)i_table_id << 16;
  p_subdec->pf_detach = dvbpsi_atsc_DetachMGT;

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

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

  return 0;
}


/*****************************************************************************
 * dvbpsi_atsc_DetachMGT
 *****************************************************************************
 * Close a MGT decoder.
 *****************************************************************************/
void dvbpsi_atsc_DetachMGT(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_atsc_mgt_decoder_t* p_mgt_decoder;

  unsigned int i;

  p_subdec = dvbpsi_demuxGetSubDec(p_demux, i_table_id, 0);

  if(p_demux == NULL)
  {
    DVBPSI_ERROR_ARG("MGT Decoder",
                     "No such MGT decoder (table_id == 0x%02x,"
                     "extension == 0x00)",
                     i_table_id);
    return;
  }

  p_mgt_decoder = (dvbpsi_atsc_mgt_decoder_t*)p_subdec->p_cb_data;

  if (p_mgt_decoder->p_building_mgt)
  {
    ObjectRefDec(p_mgt_decoder->p_building_mgt);
  }

  for(i = 0; i <= 255; i++)
  {
    if(p_mgt_decoder->ap_sections[i])
      dvbpsi_DeletePSISections(p_mgt_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_InitMGT
 *****************************************************************************
 * Initialize a pre-allocated dvbpsi_atsc_mgt_t structure.
 *****************************************************************************/
void dvbpsi_atsc_InitMGT(dvbpsi_atsc_mgt_t* p_mgt,uint8_t i_version, int b_current_next,
                       uint8_t i_protocol)
{
  p_mgt->i_version = i_version;
  p_mgt->b_current_next = b_current_next;
  p_mgt->i_protocol = i_protocol;
  p_mgt->p_first_table = NULL;  
  p_mgt->p_first_descriptor = NULL;
}


/*****************************************************************************
 * dvbpsi_EmptyMGT
 *****************************************************************************
 * Clean a dvbpsi_atsc_mgt_t structure.
 *****************************************************************************/
void dvbpsi_atsc_EmptyMGT(dvbpsi_atsc_mgt_t* p_mgt)
{
  dvbpsi_atsc_mgt_table_t* p_table = p_mgt->p_first_table;

  while(p_table != NULL)
  {
    dvbpsi_atsc_mgt_table_t* p_tmp = p_table->p_next;
    dvbpsi_DeleteDescriptors(p_table->p_first_descriptor);
    free(p_table);
    p_table = p_tmp;
  }
  dvbpsi_DeleteDescriptors(p_mgt->p_first_descriptor);    
  p_mgt->p_first_table = NULL;
  p_mgt->p_first_descriptor = NULL;
}

/*****************************************************************************
 * dvbpsi_atsc_MGTAddDescriptor
 *****************************************************************************
 * Add a descriptor to the MGT table.
 *****************************************************************************/
dvbpsi_descriptor_t *dvbpsi_atsc_MGTAddDescriptor(
                                               dvbpsi_atsc_mgt_t *p_mgt,
                                               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_mgt->p_first_descriptor == NULL)
    {
      p_mgt->p_first_descriptor = p_descriptor;
    }
    else
    {
      dvbpsi_descriptor_t * p_last_descriptor = p_mgt->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_atsc_MGTAddTable
 *****************************************************************************
 * Add a table description at the end of the MGT.
 *****************************************************************************/
dvbpsi_atsc_mgt_table_t *dvbpsi_atsc_MGTAddTable(dvbpsi_atsc_mgt_t* p_mgt,
                                           uint16_t i_type,
                                           uint16_t i_pid,
                                           uint8_t i_version,
                                           uint32_t i_number_bytes)
{
  dvbpsi_atsc_mgt_table_t * p_table
                = (dvbpsi_atsc_mgt_table_t*)malloc(sizeof(dvbpsi_atsc_mgt_table_t));

  if(p_table)
  {
    p_table->i_type = i_type;
    p_table->i_pid = i_pid;
    p_table->i_version = i_version;
    p_table->i_number_bytes = i_number_bytes;
    p_table->p_first_descriptor = NULL;
    p_table->p_next = NULL;

    if(p_mgt->p_first_table == NULL)
    {
      p_mgt->p_first_table = p_table;
    }
    else
    {
      dvbpsi_atsc_mgt_table_t * p_last_table = p_mgt->p_first_table;
      while(p_last_table->p_next != NULL)
        p_last_table = p_last_table->p_next;
      p_last_table->p_next = p_table;