dr_56.c

libdvbpsi4-0.1.5版本

/*****************************************************************************
 * dr_56.c
 * (c)2004 VideoLAN
 * $Id: dr_56.c 93 2004-10-19 19:17:49Z massiot $
 *
 * Authors: Derk-Jan Hartman <hartman at videolan dot org>
 *
 * 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 "../descriptor.h"

#include "dr_56.h"


/*****************************************************************************
 * dvbpsi_DecodeTeletextDr
 *****************************************************************************/
dvbpsi_teletext_dr_t * dvbpsi_DecodeTeletextDr(
                                        dvbpsi_descriptor_t * p_descriptor)
{
  int i_pages_number, i;      
  dvbpsi_teletext_dr_t * p_decoded;

  /* Check the tag */
  if(p_descriptor->i_tag != 0x56)
  {
    DVBPSI_ERROR_ARG("dr_56 decoder", "bad tag (0x%x)", p_descriptor->i_tag);
    return NULL;
  }

  /* Don't decode twice */
  if(p_descriptor->p_decoded)
    return p_descriptor->p_decoded;

  /* Decode data and check the length */
  if(p_descriptor->i_length < 3)
  {
    DVBPSI_ERROR_ARG("dr_56 decoder", "bad length (%d)",
                     p_descriptor->i_length);
    return NULL;
  }

  if(p_descriptor->i_length % 5)
  {
    DVBPSI_ERROR_ARG("dr_56 decoder", "length not multiple of 5(%d)",
                     p_descriptor->i_length);
    return NULL;
  }
  
  i_pages_number = p_descriptor->i_length / 5;
  
  /* Allocate memory */
  p_decoded =
        (dvbpsi_teletext_dr_t*)malloc(sizeof(dvbpsi_teletext_dr_t));
  if(!p_decoded)
  {
    DVBPSI_ERROR("dr_56 decoder", "out of memory");
    return NULL;
  }
  
  p_decoded->i_pages_number = i_pages_number;
  
  for(i=0; i < i_pages_number; i++)
  {
    memcpy(p_decoded->p_pages[i].i_iso6392_language_code,
                     p_descriptor->p_data + 5 * i, 3);

    p_decoded->p_pages[i].i_teletext_type = 
                ((uint8_t)(p_descriptor->p_data[5 * i + 3]) >> 3);
    
    p_decoded->p_pages[i].i_teletext_magazine_number = 
              ((uint16_t)(p_descriptor->p_data[5 * i + 3]) & 0x07)
            | p_descriptor->p_data[5 * i + 5];
    
    p_decoded->p_pages[i].i_teletext_page_number = p_descriptor->p_data[4 * i + 4]; 
  }
  
  p_descriptor->p_decoded = (void*)p_decoded;

  return p_decoded;
}


/*****************************************************************************
 * dvbpsi_GenTeletextDr
 *****************************************************************************/
dvbpsi_descriptor_t * dvbpsi_GenTeletextDr(
                                        dvbpsi_teletext_dr_t * p_decoded,
                                        int b_duplicate)
{
  int i;
  
  /* Create the descriptor */
  dvbpsi_descriptor_t * p_descriptor =
      dvbpsi_NewDescriptor(0x56, p_decoded->i_pages_number * 8 , NULL);
  
  if(p_descriptor)
  {
    /* Encode data */
    for (i=0; i < p_decoded->i_pages_number; i++ )
    {     
      memcpy( p_descriptor->p_data + 8 * i,
              p_decoded->p_pages[i].i_iso6392_language_code,
              3);
         
      p_descriptor->p_data[8 * i + 3] =
                            (uint8_t) ( ( (uint8_t) p_decoded->p_pages[i].i_teletext_type << 3 ) | 
                            ( (uint8_t) p_decoded->p_pages[i].i_teletext_magazine_number & 0x07 ) );

      p_descriptor->p_data[8 * i + 4] = 
                            p_decoded->p_pages[i].i_teletext_page_number;
    }
    
    if(b_duplicate)
    {
      /* Duplicate decoded data */
      dvbpsi_teletext_dr_t * p_dup_decoded =
        (dvbpsi_teletext_dr_t*)malloc(sizeof(dvbpsi_teletext_dr_t));
      if(p_dup_decoded)
        memcpy(p_dup_decoded, p_decoded, sizeof(dvbpsi_teletext_dr_t));
  
      p_descriptor->p_decoded = (void*)p_dup_decoded;
    }
  }

  return p_descriptor;
}