dr_09.c

ARM单单片机应用程序,将TS流转换为PSI的源程序,了解TS流的结构

/*****************************************************************************
 * dr_09.c
 * (c)2001-2002 VideoLAN
 * $Id: dr_09.c,v 1.5 2003/07/25 20:20:40 fenrir Exp $
 *
 * 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>
#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_09.h"


/*****************************************************************************
 * dvbpsi_DecodeCADr
 *****************************************************************************/
dvbpsi_ca_dr_t * dvbpsi_DecodeCADr(dvbpsi_descriptor_t * p_descriptor)
{
  dvbpsi_ca_dr_t * p_decoded;

  /* Check the tag */
  if(p_descriptor->i_tag != 0x09)
  {
    DVBPSI_ERROR_ARG("dr_09 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;

  /* Allocate memory */
  p_decoded = (dvbpsi_ca_dr_t*)malloc(sizeof(dvbpsi_ca_dr_t));
  if(!p_decoded)
  {
    DVBPSI_ERROR("dr_09 decoder", "out of memory");
    return NULL;
  }

  /* Decode data and check the length */
  if(p_descriptor->i_length < 4)
  {
    DVBPSI_ERROR_ARG("dr_09 decoder", "bad length (%d)",
                     p_descriptor->i_length);
    free(p_decoded);
    return NULL;
  }

  p_decoded->i_ca_system_id =   ((uint16_t)(p_descriptor->p_data[0]) << 8)
                              | p_descriptor->p_data[1];
  p_decoded->i_ca_pid =   ((uint16_t)(p_descriptor->p_data[2] & 0x1f) << 8)
                        | p_descriptor->p_data[3];
  p_decoded->i_private_length = p_descriptor->i_length - 4;
  if(p_decoded->i_private_length)
    memcpy(p_decoded->i_private_data,
           p_descriptor->p_data + 4,
           p_decoded->i_private_length);

  p_descriptor->p_decoded = (void*)p_decoded;

  return p_decoded;
}


/*****************************************************************************
 * dvbpsi_GenCADr
 *****************************************************************************/
dvbpsi_descriptor_t * dvbpsi_GenCADr(dvbpsi_ca_dr_t * p_decoded,
                                     int b_duplicate)
{
  /* Create the descriptor */
  dvbpsi_descriptor_t * p_descriptor =
        dvbpsi_NewDescriptor(0x09, p_decoded->i_private_length + 4, NULL);

  if(p_descriptor)
  {
    /* Encode data */
    p_descriptor->p_data[0] = p_decoded->i_ca_system_id >> 8;
    p_descriptor->p_data[1] = p_decoded->i_ca_system_id;
    p_descriptor->p_data[2] = 0xe0 | ((p_decoded->i_ca_pid >> 8) & 0x1f);
    p_descriptor->p_data[3] = p_decoded->i_ca_pid;
    if(p_decoded->i_private_length)
      memcpy(p_descriptor->p_data + 4,
             p_decoded->i_private_data,
             p_decoded->i_private_length);

    if(b_duplicate)
    {
      /* Duplicate decoded data */
      dvbpsi_ca_dr_t * p_dup_decoded =
                        (dvbpsi_ca_dr_t*)malloc(sizeof(dvbpsi_ca_dr_t));
      if(p_dup_decoded)
        memcpy(p_dup_decoded, p_decoded, sizeof(dvbpsi_ca_dr_t));

      p_descriptor->p_decoded = (void*)p_dup_decoded;
    }
  }

  return p_descriptor;
}