dr_0c.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_0c.c
 * (c)2001-2002 VideoLAN
 * $Id: dr_0c.c,v 1.3 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_0c.h"


/*****************************************************************************
 * dvbpsi_DecodeMxBuffUtilizationDr
 *****************************************************************************/
dvbpsi_mx_buff_utilization_dr_t * dvbpsi_DecodeMxBuffUtilizationDr(
                                        dvbpsi_descriptor_t * p_descriptor)
{
  dvbpsi_mx_buff_utilization_dr_t * p_decoded;

  /* Check the tag */
  if(p_descriptor->i_tag != 0x0c)
  {
    DVBPSI_ERROR_ARG("dr_0c 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_mx_buff_utilization_dr_t*)
                        malloc(sizeof(dvbpsi_mx_buff_utilization_dr_t));
  if(!p_decoded)
  {
    DVBPSI_ERROR("dr_0c decoder", "out of memory");
    return NULL;
  }

  /* Decode data and check the length */
  if(p_descriptor->i_length != 3)
  {
    DVBPSI_ERROR_ARG("dr_0c decoder", "bad length (%d)",
                     p_descriptor->i_length);
    free(p_decoded);
    return NULL;
  }

  p_decoded->b_mdv_valid = (p_descriptor->p_data[0] & 0x80) ? 1 : 0;
  p_decoded->i_mx_delay_variation =
                          ((uint16_t)(p_descriptor->p_data[0] & 0x7f) << 8)
                        | p_descriptor->p_data[1];
  p_decoded->i_mx_strategy = (p_descriptor->p_data[2] & 0xe0) >> 5;

  p_descriptor->p_decoded = (void*)p_decoded;

  return p_decoded;
}


/*****************************************************************************
 * dvbpsi_GenMxBuffUtilizationDr
 *****************************************************************************/
dvbpsi_descriptor_t * dvbpsi_GenMxBuffUtilizationDr(
                                dvbpsi_mx_buff_utilization_dr_t * p_decoded,
                                int b_duplicate)
{
  /* Create the descriptor */
  dvbpsi_descriptor_t * p_descriptor =
        dvbpsi_NewDescriptor(0x0c, 3, NULL);

  if(p_descriptor)
  {
    /* Encode data */
    p_descriptor->p_data[0] = (p_decoded->i_mx_delay_variation >> 8) & 0x7f;
    if(p_decoded->b_mdv_valid)
      p_descriptor->p_data[0] |= 0x80;
    p_descriptor->p_data[1] = p_decoded->i_mx_delay_variation;
    p_descriptor->p_data[2] = 0x1f | p_decoded->i_mx_strategy << 5;

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

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

  return p_descriptor;
}