erc_api.c

本源码是H.26L标准的Visual C++源代码

/*
***********************************************************************
* COPYRIGHT AND WARRANTY INFORMATION
*
* Copyright 2001, International Telecommunications Union, Geneva
*
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*
* The ITU does not represent or warrant that the programs furnished
* hereunder are free of infringement of any third-party patents.
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/*!
 *************************************************************************************
 * \file erc_api.c
 *
 * \brief
 *    External (still inside video decoder) interface for error concealment module
 *
 *  \author
 *     - Ari Hourunranta                <[e-mail]>
 *     - Viktor Varsa                     <[e-mail]>
 *     - Ye-Kui Wang                   <[e-mail]>
 *
 *************************************************************************************
 */


#include <stdlib.h>
#include <memory.h>

#include "global.h"
#include "memalloc.h"
#include "erc_api.h"

objectBuffer_t *erc_object_list;
ercVariables_t *erc_errorVar;
frame erc_recfr;
int erc_mvperMB;

/*!
 ************************************************************************
 * \brief
 *    Initinize the error concealment module
 ************************************************************************
 */
void ercInit(int pic_sizex, int pic_sizey, int flag)
{
  erc_object_list = (objectBuffer_t *) calloc((pic_sizex * pic_sizey) >> 6, sizeof(objectBuffer_t));
  if (erc_object_list == NULL) no_mem_exit("ercInit: erc_object_list");
  
  /* the error concelament instance is allocated */
  erc_errorVar = ercOpen();
  
  /* set error concealment ON */
  ercSetErrorConcealment(erc_errorVar, flag);
}

/*!
 ************************************************************************
 * \brief
 *      Allocates data structures used in error concealment.
 *\return
 *      The allocated ercVariables_t is returned.
 ************************************************************************
 */
ercVariables_t *ercOpen( void )
{
  ercVariables_t *errorVar = NULL;
  
  errorVar = (ercVariables_t *)malloc( sizeof(ercVariables_t));
  if ( errorVar == NULL ) no_mem_exit("ercOpen: errorVar");

  errorVar->nOfMBs = 0;
  errorVar->segments = NULL;
  errorVar->currSegment = 0;
  errorVar->yCondition = NULL;
  errorVar->uCondition = NULL;
  errorVar->vCondition = NULL;
  errorVar->prevFrameYCondition = NULL;
  
  errorVar->concealment = 1;
  
  return errorVar;
}

/*!
 ************************************************************************
 * \brief
 *      Resets the variables used in error detection. 
 *      Should be called always when starting to decode a new frame.
 * \param errorVar
 *      Variables for error concealment
 * \param nOfMBs
 *      Number of macroblocks in a frame
 * \param numOfSegments
 *    Estimated number of segments (memory reserved)
 ************************************************************************
 */
void ercReset( ercVariables_t *errorVar, int nOfMBs, int numOfSegments )
{
  int *tmp = NULL;
  
  if ( errorVar && errorVar->concealment ) 
  {
    /* If frame size has been changed */
    if ( nOfMBs != errorVar->nOfMBs && errorVar->yCondition != NULL ) 
    {
      free( errorVar->yCondition );
      errorVar->yCondition = NULL;
      free( errorVar->prevFrameYCondition );
      errorVar->prevFrameYCondition = NULL;
      free( errorVar->uCondition );
      errorVar->uCondition = NULL;
      free( errorVar->vCondition );
      errorVar->vCondition = NULL;
      free( errorVar->segments );
      errorVar->segments = NULL;
    }
    
    /* If the structures are uninitialized (first frame, or frame size is chaned) */
    if ( errorVar->yCondition == NULL ) 
    {
      errorVar->segments = (ercSegment_t *)malloc( numOfSegments*sizeof(ercSegment_t) );
      if ( errorVar->segments == NULL ) no_mem_exit("ercReset: errorVar->segments");
      memset( errorVar->segments, 0, numOfSegments*sizeof(ercSegment_t));
      errorVar->nOfSegments = numOfSegments;
      
      errorVar->yCondition = (int *)malloc( 4*nOfMBs*sizeof(int) );
      if ( errorVar->yCondition == NULL ) no_mem_exit("ercReset: errorVar->yCondition");
      errorVar->prevFrameYCondition = (int *)malloc( 4*nOfMBs*sizeof(int) );
      if ( errorVar->prevFrameYCondition == NULL ) no_mem_exit("ercReset: errorVar->prevFrameYCondition");
      errorVar->uCondition = (int *)malloc( nOfMBs*sizeof(int) );
      if ( errorVar->uCondition == NULL ) no_mem_exit("ercReset: errorVar->uCondition");
      errorVar->vCondition = (int *)malloc( nOfMBs*sizeof(int) );
      if ( errorVar->vCondition == NULL ) no_mem_exit("ercReset: errorVar->vCondition");
      errorVar->nOfMBs = nOfMBs;
    }
    else 
    {
      /* Store the yCondition struct of the previous frame */
      tmp = errorVar->prevFrameYCondition;
      errorVar->prevFrameYCondition = errorVar->yCondition;
      errorVar->yCondition = tmp;
    }
    
    /* Reset tables and parameters */
    memset( errorVar->yCondition, 0, 4*nOfMBs*sizeof(*errorVar->yCondition));
    memset( errorVar->uCondition, 0, nOfMBs*sizeof(*errorVar->uCondition));
    memset( errorVar->vCondition, 0, nOfMBs*sizeof(*errorVar->vCondition));
    
    if (errorVar->nOfSegments != numOfSegments) 
    {
      free( errorVar->segments );
      errorVar->segments = NULL;
      errorVar->segments = (ercSegment_t *)malloc( numOfSegments*sizeof(ercSegment_t) );
      if ( errorVar->segments == NULL ) no_mem_exit("ercReset: errorVar->segments");
      errorVar->nOfSegments = numOfSegments;
    }
    
    memset( errorVar->segments, 0, errorVar->nOfSegments*sizeof(ercSegment_t));
    
    errorVar->currSegment = 0;
    errorVar->currSegmentCorrupted = 0;
    errorVar->nOfCorruptedSegments = 0;
  }
}

/*!
 ************************************************************************
 * \brief
 *      Resets the variables used in error detection. 
 *      Should be called always when starting to decode a new frame.
 * \param errorVar
 *      Variables for error concealment
 ************************************************************************
 */
void ercClose( ercVariables_t *errorVar )
{
  if ( errorVar != NULL ) 
  {
    if (errorVar->yCondition != NULL) 
    {
      free( errorVar->segments );
      free( errorVar->yCondition );
      free( errorVar->uCondition );
      free( errorVar->vCondition );
      free( errorVar->prevFrameYCondition );
    }
    free( errorVar );
  }
  
  free(erc_object_list);
  
}

/*!
 ************************************************************************
 * \brief
 *      Sets error concealment ON/OFF. Can be invoked only between frames, not during a frame
 * \param errorVar