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/* ------------------------------------------------------------------
* Copyright (C) 1998-2009 PacketVideo
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
* express or implied.
* See the License for the specific language governing permissions
* and limitations under the License.
* -------------------------------------------------------------------
*/
/*
------------------------------------------------------------------------------
INPUT AND OUTPUT DEFINITIONS
Inputs:
input_ptr = pointer to the buffer containing values of type UChar
in a 2D block of data.
min_ptr = pointer to the minimum value of type Int to be found in a
square block of size BLKSIZE contained in 2D block of data.
max_ptr = pointer to the maximum value of type Int to be found in a
square block of size BLKSIZE contained in 2D block of data.
incr = value of type Int representing the width of 2D block of data.
Local Stores/Buffers/Pointers Needed:
None
Global Stores/Buffers/Pointers Needed:
None
Outputs:
None
Pointers and Buffers Modified:
min_ptr points to the found minimum value in the square block of
size BLKSIZE contained in 2D block of data.
max_ptr points to the found maximum value in the square block of
size BLKSIZE contained in 2D block of data.
Local Stores Modified:
None
Global Stores Modified:
None
------------------------------------------------------------------------------
FUNCTION DESCRIPTION
This function finds the maximum and the minimum values in a square block of
data of size BLKSIZE * BLKSIZE. The data is contained in the buffer which
represents a 2D block of data that is larger than BLKSIZE * BLKSIZE.
This is illustrated below.
mem loc x + 00h -> o o o o o o o o o o o o o o o o
mem loc x + 10h -> o o o o o X X X X X X X X o o o
mem loc x + 20h -> o o o o o X X X X X X X X o o o
mem loc x + 30h -> o o o o o X X X X X X X X o o o
mem loc x + 40h -> o o o o o X X X X X X X X o o o
mem loc x + 50h -> o o o o o X X X X X X X X o o o
mem loc x + 60h -> o o o o o X X X X X X X X o o o
mem loc x + 70h -> o o o o o X X X X X X X X o o o
mem loc x + 80h -> o o o o o X X X X X X X X o o o
mem loc x + 90h -> o o o o o o o o o o o o o o o o
mem loc x + A0h -> o o o o o o o o o o o o o o o o
mem loc x + B0h -> o o o o o o o o o o o o o o o o
For illustration purposes, the diagram assumes that BLKSIZE is equal to 8
but this is not a requirement. In this diagram, the buffer starts at
location x but the input pointer, input_ptr, passed into this function
would be the first row of data to be searched which is at x + 15h. The
value of incr passed onto this function represents the amount the input_ptr
needs to be incremented to point to the next row of data.
This function compares each value in a row to the current maximum and
minimum. After each row, input_ptr is incremented to point to the next row.
This is repeated until all rows have been processed. When the search is
complete the location pointed to by min_ptr contains the minimum value
found and the location pointed to by max_ptr contains the maximum value found.
------------------------------------------------------------------------------
*/
/*----------------------------------------------------------------------------
; INCLUDES
----------------------------------------------------------------------------*/
#include "mp4dec_lib.h"
#include "post_proc.h"
/*----------------------------------------------------------------------------
; MACROS
; Define module specific macros here
----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------
; DEFINES
; Include all pre-processor statements here. Include conditional
; compile variables also.
----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------
; LOCAL FUNCTION DEFINITIONS
; Function Prototype declaration
----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------
; LOCAL STORE/BUFFER/POINTER DEFINITIONS
; Variable declaration - defined here and used outside this module
----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------
; EXTERNAL FUNCTION REFERENCES
; Declare functions defined elsewhere and referenced in this module
----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------
; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES
; Declare variables used in this module but defined elsewhere
----------------------------------------------------------------------------*/
#ifdef PV_POSTPROC_ON
/*----------------------------------------------------------------------------
; FUNCTION CODE
----------------------------------------------------------------------------*/
void FindMaxMin(
uint8 *input_ptr,
int *min_ptr,
int *max_ptr,
int incr)
{
/*----------------------------------------------------------------------------
; Define all local variables
----------------------------------------------------------------------------*/
uint i, j;
int min, max;
/*----------------------------------------------------------------------------
; Function body here
----------------------------------------------------------------------------*/
max = min = *input_ptr;
/* incr = incr - BLKSIZE; */ /* 09/06/2001, already passed in as width - BLKSIZE */
for (i = BLKSIZE; i > 0; i--)
{
for (j = BLKSIZE; j > 0; j--)
{
if (*input_ptr > max)
{
max = *input_ptr;
}
else if (*input_ptr < min)
{
min = *input_ptr;
}
input_ptr += 1;
}
/* set pointer to the beginning of the next row*/
input_ptr += incr;
}
*max_ptr = max;
*min_ptr = min;
/*----------------------------------------------------------------------------
; Return nothing or data or data pointer
----------------------------------------------------------------------------*/
return;
}
#endif
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