dr_08.c

数字电视广播系统mpeg-2的ts流的解复用和分析软件

/*****************************************************************************
 * dr_08.c
 * (c)2001-2002 VideoLAN
 * $Id: dr_08.c,v 1.4 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_08.h"


/*****************************************************************************
 * dvbpsi_DecodeVWindowDr
 *****************************************************************************/
dvbpsi_vwindow_dr_t * dvbpsi_DecodeVWindowDr(dvbpsi_descriptor_t * p_descriptor)
{
  dvbpsi_vwindow_dr_t * p_decoded;

  /* Check the tag */
  if(p_descriptor->i_tag != 0x08)
  {
    DVBPSI_ERROR_ARG("dr_08 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_vwindow_dr_t*)malloc(sizeof(dvbpsi_vwindow_dr_t));
  if(!p_decoded)
  {
    DVBPSI_ERROR("dr_08 decoder", "out of memory");
    return NULL;
  }

  /* Decode data and check the length */
  if(p_descriptor->i_length != 4)
  {
    DVBPSI_ERROR_ARG("dr_08 decoder", "bad length (%d)",
                     p_descriptor->i_length);
    free(p_decoded);
    return NULL;
  }

  p_decoded->i_horizontal_offset =   ((uint16_t)(p_descriptor->p_data[0]) << 6)
                                   | ((p_descriptor->p_data[1] & 0xfc) >> 2);
  p_decoded->i_vertical_offset =
                          ((uint16_t)(p_descriptor->p_data[1] & 0x03) << 12)
                        | ((uint16_t)(p_descriptor->p_data[2]) << 4)
                        | ((p_descriptor->p_data[3] & 0xf0) >> 4);
  p_decoded->i_window_priority = p_descriptor->p_data[3] & 0x0f;

  p_descriptor->p_decoded = (void*)p_decoded;

  return p_decoded;
}


/*****************************************************************************
 * dvbpsi_GenVWindowDr
 *****************************************************************************/
dvbpsi_descriptor_t * dvbpsi_GenVWindowDr(dvbpsi_vwindow_dr_t * p_decoded,
                                          int b_duplicate)
{
  /* Create the descriptor */
  dvbpsi_descriptor_t * p_descriptor = dvbpsi_NewDescriptor(0x08, 4, NULL);

  if(p_descriptor)
  {
    /* Encode data */
    p_descriptor->p_data[0] = p_decoded->i_horizontal_offset >> 6;
    p_descriptor->p_data[1] =   (((uint8_t)p_decoded->i_horizontal_offset) << 2)
                              | (p_decoded->i_vertical_offset >> 12);
    p_descriptor->p_data[2] = p_decoded->i_vertical_offset >> 4;
    p_descriptor->p_data[3] =   (((uint8_t)p_decoded->i_vertical_offset) << 4)
                              | (p_decoded->i_window_priority & 0x0f);

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

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

  return p_descriptor;
}