/*!
 *************************************************************************************
 * \file erc_api.c
 *
 * \brief
 *    External (still inside video decoder) interface for error concealment module
 *
 *  \author
 *     - Ari Hourunranta                <ari.hourunranta@nokia.com>
 *     - Viktor Varsa                     <viktor.varsa@nokia.com>
 *     - Ye-Kui Wang                   <wyk@ieee.org>
 *
 *************************************************************************************
 */


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

/*!
 ************************************************************************
 * \brief
 *    Initinize the error concealment module
 ************************************************************************
 */
void ercInit(VideoParameters *p_Vid, int pic_sizex, int pic_sizey, int flag)
{
	ercClose(p_Vid, p_Vid->erc_errorVar);
	p_Vid->erc_object_list = (objectBuffer_t *) calloc((pic_sizex * pic_sizey) >> 6, sizeof(objectBuffer_t));
	if (p_Vid->erc_object_list == NULL) no_mem_exit("ercInit: erc_object_list");

	// the error concealment instance is allocated
	p_Vid->erc_errorVar = ercOpen();

	// set error concealment ON
	ercSetErrorConcealment(p_Vid->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)
 * \param picSizeX
 *      Width of the frame in pixels.
 ************************************************************************
 */
void ercReset( ercVariables_t *errorVar, int nOfMBs, int numOfSegments, int picSizeX )
{
	if ( errorVar && errorVar->concealment )
	{
		int i = 0;

		// 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 changed)
		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
			int *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));

		for ( ; i < errorVar->nOfSegments; i++ )
		{
			errorVar->segments[i].fCorrupted = 1; //! mark segments as corrupted
			errorVar->segments[i].startMBPos = 0;
			errorVar->segments[i].endMBPos = nOfMBs - 1;
		}

		errorVar->currSegment = 0;
		errorVar->nOfCorruptedSegments = 0;
	}
}

/*!
 ************************************************************************
 * \brief
 *      Resets the variables used in error detection.
 *      Should be called always when starting to decode a new frame.
 * \param p_Vid
 *      VideoParameters variable
 * \param errorVar
 *      Variables for error concealment
 ************************************************************************
 */
void ercClose(VideoParameters *p_Vid,  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 );
		errorVar = NULL;
	}

	if ( p_Vid && p_Vid->erc_object_list)
	{
		free(p_Vid->erc_object_list);
		p_Vid->erc_object_list=NULL;
	}
}

/*!
 ************************************************************************
 * \brief
 *      Sets error concealment ON/OFF. Can be invoked only between frames, not during a frame
 * \param errorVar
 *      Variables for error concealment
 * \param value
 *      New value
 ************************************************************************
 */
void ercSetErrorConcealment( ercVariables_t *errorVar, int value )
{
	if ( errorVar != NULL )
		errorVar->concealment = value;
}

/*!
 ************************************************************************
 * \brief
 *      Creates a new segment in the segment-list, and marks the start MB and bit position.
 *      If the end of the previous segment was not explicitly marked by "ercStopSegment",
 *      also marks the end of the previous segment.
 *      If needed, it reallocates the segment-list for a larger storage place.
 * \param currMBNum
 *      The MB number where the new slice/segment starts
 * \param segment
 *      Segment/Slice No. counted by the caller
 * \param bitPos
 *      Bitstream pointer: number of bits read from the buffer.
 * \param errorVar
 *      Variables for error detector
 ************************************************************************
 */
void ercStartSegment( int currMBNum, int segment, unsigned int bitPos, ercVariables_t *errorVar )
{
	if ( errorVar && errorVar->concealment )
	{
		errorVar->currSegmentCorrupted = 0;

		errorVar->segments[ segment ].fCorrupted = 0;
		errorVar->segments[ segment ].startMBPos = currMBNum;
	}
}

/*!
 ************************************************************************
 * \brief
 *      Marks the end position of a segment.
 * \param currMBNum
 *      The last MB number of the previous segment
 * \param segment
 *      Segment/Slice No. counted by the caller
 *      If (segment<0) the internal segment counter is used.
 * \param bitPos
 *      Bitstream pointer: number of bits read from the buffer.
 * \param errorVar
 *      Variables for error detector
 ************************************************************************
 */
void ercStopSegment( int currMBNum, int segment, unsigned int bitPos, ercVariables_t *errorVar )
{
	if ( errorVar && errorVar->concealment )
	{
		errorVar->segments[ segment ].endMBPos = currMBNum; //! Changed TO 12.11.2001
		errorVar->currSegment++;
	}
}

/*!
 ************************************************************************
 * \brief
 *      Marks the current segment (the one which has the "currMBNum" MB in it)
 *      as lost: all the blocks of the MBs in the segment as corrupted.
 * \param picSizeX
 *      Width of the frame in pixels.
 * \param errorVar
 *      Variables for error detector
 ************************************************************************
 */
void ercMarkCurrSegmentLost(int picSizeX, ercVariables_t *errorVar )
{
	if ( errorVar && errorVar->concealment )
	{
		int current_segment = errorVar->currSegment-1, j;

		if (errorVar->currSegmentCorrupted == 0)
		{
			errorVar->nOfCorruptedSegments++;
			errorVar->currSegmentCorrupted = 1;
		}

		for ( j = errorVar->segments[current_segment].startMBPos; j <= errorVar->segments[current_segment].endMBPos; j++ )
		{
			errorVar->yCondition[MBNum2YBlock (j, 0, picSizeX)] = ERC_BLOCK_CORRUPTED;
			errorVar->yCondition[MBNum2YBlock (j, 1, picSizeX)] = ERC_BLOCK_CORRUPTED;
			errorVar->yCondition[MBNum2YBlock (j, 2, picSizeX)] = ERC_BLOCK_CORRUPTED;
			errorVar->yCondition[MBNum2YBlock (j, 3, picSizeX)] = ERC_BLOCK_CORRUPTED;
			errorVar->uCondition[j] = ERC_BLOCK_CORRUPTED;
			errorVar->vCondition[j] = ERC_BLOCK_CORRUPTED;
		}
		errorVar->segments[current_segment].fCorrupted = 1;
	}
}

/*!
 ************************************************************************
 * \brief
 *      Marks the current segment (the one which has the "currMBNum" MB in it)
 *      as OK: all the blocks of the MBs in the segment as OK.
 * \param picSizeX
 *      Width of the frame in pixels.
 * \param errorVar
 *      Variables for error detector
 ************************************************************************
 */
void ercMarkCurrSegmentOK(int picSizeX, ercVariables_t *errorVar )
{
	if ( errorVar && errorVar->concealment )
	{
		int current_segment = errorVar->currSegment-1, j;

		// mark all the Blocks belonging to the segment as OK */
		for ( j = errorVar->segments[current_segment].startMBPos; j <= errorVar->segments[current_segment].endMBPos; j++ )
		{
			errorVar->yCondition[MBNum2YBlock (j, 0, picSizeX)] = ERC_BLOCK_OK;
			errorVar->yCondition[MBNum2YBlock (j, 1, picSizeX)] = ERC_BLOCK_OK;
			errorVar->yCondition[MBNum2YBlock (j, 2, picSizeX)] = ERC_BLOCK_OK;
			errorVar->yCondition[MBNum2YBlock (j, 3, picSizeX)] = ERC_BLOCK_OK;
			errorVar->uCondition[j] = ERC_BLOCK_OK;
			errorVar->vCondition[j] = ERC_BLOCK_OK;
		}
		errorVar->segments[current_segment].fCorrupted = 0;
	}
}

/*!
 ************************************************************************
 * \brief
 *      Marks the Blocks of the given component (YUV) of the current MB as concealed.
 * \param currMBNum
 *      Selects the segment where this MB number is in.
 * \param comp
 *      Component to mark (0:Y, 1:U, 2:V, <0:All)
 * \param picSizeX
 *      Width of the frame in pixels.
 * \param errorVar
 *      Variables for error detector
 ************************************************************************
 */
void ercMarkCurrMBConcealed( int currMBNum, int comp, int picSizeX, ercVariables_t *errorVar )
{
	int setAll = 0;

	if ( errorVar && errorVar->concealment )
	{
		if (comp < 0)
		{
			setAll = 1;
			comp = 0;
		}

		switch (comp)
		{
			case 0:
				errorVar->yCondition[MBNum2YBlock (currMBNum, 0, picSizeX)] = ERC_BLOCK_CONCEALED;
				errorVar->yCondition[MBNum2YBlock (currMBNum, 1, picSizeX)] = ERC_BLOCK_CONCEALED;
				errorVar->yCondition[MBNum2YBlock (currMBNum, 2, picSizeX)] = ERC_BLOCK_CONCEALED;
				errorVar->yCondition[MBNum2YBlock (currMBNum, 3, picSizeX)] = ERC_BLOCK_CONCEALED;
				if (!setAll)
					break;
			case 1:
				errorVar->uCondition[currMBNum] = ERC_BLOCK_CONCEALED;
				if (!setAll)
					break;
			case 2:
				errorVar->vCondition[currMBNum] = ERC_BLOCK_CONCEALED;
		}
	}
}