atsc_eit.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

eit.c

Decode PSIP Virtual Channel 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/eit.h"

#include "objects.h"

typedef struct dvbpsi_atsc_eit_decoder_s
{
  dvbpsi_atsc_eit_callback      pf_callback;
  void *                        p_cb_data;

  dvbpsi_atsc_eit_t             current_eit;
  dvbpsi_atsc_eit_t *           p_building_eit;

  int                           b_current_valid;

  uint8_t                       i_last_section_number;
  dvbpsi_psi_section_t *        ap_sections [256];

} dvbpsi_atsc_eit_decoder_t;


dvbpsi_atsc_eit_event_t *dvbpsi_atsc_EITAddEvent(dvbpsi_atsc_eit_t* p_eit,
                                            uint16_t i_event_id,
                                            uint32_t i_start_time,
                                            uint8_t  i_etm_location,
                                            uint32_t i_length_seconds,
                                            uint8_t i_title_length,
                                            uint8_t *p_title);

dvbpsi_descriptor_t *dvbpsi_atsc_EITEventAddDescriptor(
                                               dvbpsi_atsc_eit_event_t *p_table,
                                               uint8_t i_tag, uint8_t i_length,
                                               uint8_t *p_data);

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

void dvbpsi_atsc_DecodeEITSections(dvbpsi_atsc_eit_t* p_eit,
                              dvbpsi_psi_section_t* p_section);

/*****************************************************************************
 * dvbpsi_atsc_AttachEIT
 *****************************************************************************
 * Initialize a EIT subtable decoder.
 *****************************************************************************/
int dvbpsi_atsc_AttachEIT(dvbpsi_decoder_t * p_psi_decoder, uint8_t i_table_id, uint16_t i_extension,
                          dvbpsi_atsc_eit_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_eit_decoder_t*  p_eit_decoder;
  unsigned int i;

  if(dvbpsi_demuxGetSubDec(p_demux, i_table_id, i_extension))
  {
    DVBPSI_ERROR_ARG("EIT decoder",
                     "Already a decoder for (table_id == 0x%02x extension == 0x%04x)",
                     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_eit_decoder = (dvbpsi_atsc_eit_decoder_t*)malloc(sizeof(dvbpsi_atsc_eit_decoder_t));

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

  /* subtable decoder configuration */
  p_subdec->pf_callback = &dvbpsi_atsc_GatherEITSections;
  p_subdec->p_cb_data = p_eit_decoder;
  p_subdec->i_id = ((uint32_t)i_table_id << 16) | i_extension;
  p_subdec->pf_detach = dvbpsi_atsc_DetachEIT;

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

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

  return 0;
}


/*****************************************************************************
 * dvbpsi_atsc_DetachEIT
 *****************************************************************************
 * Close a EIT decoder.
 *****************************************************************************/
void dvbpsi_atsc_DetachEIT(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_eit_decoder_t* p_eit_decoder;

  unsigned int i;

  p_subdec = dvbpsi_demuxGetSubDec(p_demux, i_table_id, i_extension);

  if(p_demux == NULL)
  {
    DVBPSI_ERROR_ARG("EIT Decoder",
                     "No such EIT decoder (table_id == 0x%02x,"
                     "extension == 0x%04x)",
                     i_table_id, i_extension);
    return;
  }

  p_eit_decoder = (dvbpsi_atsc_eit_decoder_t*)p_subdec->p_cb_data;
  if (p_eit_decoder->p_building_eit)
  {
    ObjectRefDec(p_eit_decoder->p_building_eit);
  }

  for(i = 0; i <= 255; i++)
  {
    if(p_eit_decoder->ap_sections[i])
      dvbpsi_DeletePSISections(p_eit_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_atsc_InitEIT
 *****************************************************************************
 * Initialize a pre-allocated dvbpsi_atsc_eit_t structure.
 *****************************************************************************/
void dvbpsi_atsc_InitEIT(dvbpsi_atsc_eit_t* p_eit,uint8_t i_version, int b_current_next,
                       uint8_t i_protocol, uint16_t i_source_id)
{
  p_eit->i_version = i_version;
  p_eit->b_current_next = b_current_next;
  p_eit->i_protocol = i_protocol;
  p_eit->i_source_id = i_source_id;
  p_eit->p_first_event = NULL;
}


/*****************************************************************************
 * dvbpsi_atsc_EmptyEIT
 *****************************************************************************
 * Clean a dvbpsi_atsc_eit_t structure.
 *****************************************************************************/
void dvbpsi_atsc_EmptyEIT(dvbpsi_atsc_eit_t* p_eit)
{
  dvbpsi_atsc_eit_event_t* p_event = p_eit->p_first_event;

  while(p_event != NULL)
  {
    dvbpsi_atsc_eit_event_t* p_tmp = p_event->p_next;
    dvbpsi_DeleteDescriptors(p_event->p_first_descriptor);
    free(p_event);
    p_event = p_tmp;
  }
  p_eit->p_first_event = NULL;
}

/*****************************************************************************
 * dvbpsi_atsc_EITAddChannel
 *****************************************************************************
 * Add a Channel description at the end of the EIT.
 *****************************************************************************/
dvbpsi_atsc_eit_event_t *dvbpsi_atsc_EITAddEvent(dvbpsi_atsc_eit_t* p_eit,
                                            uint16_t i_event_id,
                                            uint32_t i_start_time,
                                            uint8_t  i_etm_location,
                                            uint32_t i_length_seconds,
                                            uint8_t i_title_length,
                                            uint8_t *p_title)
{
  dvbpsi_atsc_eit_event_t * p_event
                = (dvbpsi_atsc_eit_event_t*)malloc(sizeof(dvbpsi_atsc_eit_event_t));

  if(p_event)
  {
    p_event->i_event_id = i_event_id;
    p_event->i_start_time = i_start_time;
    p_event->i_etm_location = i_etm_location;
    p_event->i_length_seconds = i_length_seconds;
    p_event->i_title_length = i_title_length;
    
    memcpy(p_event->i_title, p_title, i_title_length);
    
    p_event->p_first_descriptor = NULL;
    p_event->p_next = NULL;

    if(p_eit->p_first_event== NULL)
    {
      p_eit->p_first_event = p_event;
    }
    else
    {
      dvbpsi_atsc_eit_event_t * p_last_event = p_eit->p_first_event;
      while(p_last_event->p_next != NULL)
        p_last_event = p_last_event->p_next;
      p_last_event->p_next = p_event;
    }
  }

  return p_event;
}


/*****************************************************************************
 * dvbpsi_EITTableAddDescriptor
 *****************************************************************************
 * Add a descriptor in the EIT table description.
 *****************************************************************************/
dvbpsi_descriptor_t *dvbpsi_atsc_EITChannelAddDescriptor(
                                               dvbpsi_atsc_eit_event_t *p_event,
                                               uint8_t i_tag, uint8_t i_length,