dr_02.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_02.c
 * (c)2001-2002 VideoLAN
 * $Id: dr_02.c,v 1.7 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_02.h"


/*****************************************************************************
 * dvbpsi_DecodeVStreamDr
 *****************************************************************************/
dvbpsi_vstream_dr_t * dvbpsi_DecodeVStreamDr(dvbpsi_descriptor_t * p_descriptor)
{
  dvbpsi_vstream_dr_t * p_decoded;

  /* Check the tag */
  if(p_descriptor->i_tag != 0x02)
  {
    DVBPSI_ERROR_ARG("dr_02 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_vstream_dr_t*)malloc(sizeof(dvbpsi_vstream_dr_t));
  if(!p_decoded)
  {
    DVBPSI_ERROR("dr_02 decoder", "out of memory");
    return NULL;
  }

  /* Decode data and check the length */
  p_decoded->b_mpeg2 = (p_descriptor->p_data[0] & 0x04) ? 1 : 0;

  if(    (!p_decoded->b_mpeg2 && (p_descriptor->i_length != 1))
      || (p_decoded->b_mpeg2 && (p_descriptor->i_length != 3)))
  {
    DVBPSI_ERROR_ARG("dr_02 decoder", "bad length (%d)",
                     p_descriptor->i_length);
    free(p_decoded);

    return NULL;
  }

  p_decoded->b_multiple_frame_rate = (p_descriptor->p_data[0] & 0x80) ? 1 : 0;
  p_decoded->i_frame_rate_code = (p_descriptor->p_data[0] & 0x78) >> 3;
  p_decoded->b_constrained_parameter = (p_descriptor->p_data[0] & 0x02) ? 1 : 0;
  p_decoded->b_still_picture = (p_descriptor->p_data[0] & 0x01) ? 1 : 0;

  if(p_decoded->b_mpeg2)
  {
    p_decoded->i_profile_level_indication = p_descriptor->p_data[1];
    p_decoded->i_chroma_format = (p_descriptor->p_data[2] & 0xc0) >> 6;
    p_decoded->b_frame_rate_extension =
                                (p_descriptor->p_data[2] & 0x20) ? 1 : 0;
  }

  p_descriptor->p_decoded = (void*)p_decoded;

  return p_decoded;
}


/*****************************************************************************
 * dvbpsi_GenVStreamDr
 *****************************************************************************/
dvbpsi_descriptor_t * dvbpsi_GenVStreamDr(dvbpsi_vstream_dr_t * p_decoded,
                                          int b_duplicate)
{
  /* Create the descriptor */
  dvbpsi_descriptor_t * p_descriptor =
                dvbpsi_NewDescriptor(0x02, p_decoded->b_mpeg2 ? 3 : 1, NULL);

  if(p_descriptor)
  {
    /* Encode data */
    p_descriptor->p_data[0] = 0;
    if(p_decoded->b_multiple_frame_rate)
      p_descriptor->p_data[0] |= 0x80;
    p_descriptor->p_data[0] |= (p_decoded->i_frame_rate_code & 0x0f) << 3;
    if(p_decoded->b_constrained_parameter)
      p_descriptor->p_data[0] |= 0x02;
    if(p_decoded->b_still_picture)
      p_descriptor->p_data[0] |= 0x01;

    if(p_decoded->b_mpeg2)
    {
      p_descriptor->p_data[0] |= 0x04;
      p_descriptor->p_data[1] = p_decoded->i_profile_level_indication;
      p_descriptor->p_data[2] = 0x1f;
      p_descriptor->p_data[2] |= (p_decoded->i_chroma_format & 0x03) << 6;
      if(p_decoded->b_frame_rate_extension)
        p_descriptor->p_data[2] |= 0x20;
    }

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

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

  return p_descriptor;
}