www.pudn.com > p64dir.rar > transform.c
/*************************************************************
Copyright (C) 1990, 1991, 1993 Andy C. Hung, all rights reserved.
PUBLIC DOMAIN LICENSE: Stanford University Portable Video Research
Group. If you use this software, you agree to the following: This
program package is purely experimental, and is licensed "as is".
Permission is granted to use, modify, and distribute this program
without charge for any purpose, provided this license/ disclaimer
notice appears in the copies. No warranty or maintenance is given,
either expressed or implied. In no event shall the author(s) be
liable to you or a third party for any special, incidental,
consequential, or other damages, arising out of the use or inability
to use the program for any purpose (or the loss of data), even if we
have been advised of such possibilities. Any public reference or
advertisement of this source code should refer to it as the Portable
Video Research Group (PVRG) code, and not by any author(s) (or
Stanford University) name.
*************************************************************/
/*
************************************************************
transform.c
This file contains the reference DCT, the zig-zag and quantization
algorithms.
************************************************************
*/
/*LABEL transform.c */
#include "globals.h"
#include "dct.h"
#include
/*PUBLIC*/
extern void ReferenceDct();
extern void ReferenceIDct();
extern void TransposeMatrix();
extern void CCITTQuantize();
extern void CCITTFlatQuantize();
extern void ICCITTFlatQuantize();
extern void ICCITTQuantize();
extern void BoundDctMatrix();
extern void BoundIDctMatrix();
extern void FlatBoundQuantizeMatrix();
extern void ZigzagMatrix();
extern void IZigzagMatrix();
extern void PrintMatrix();
extern void ClearMatrix();
static void DoubleReferenceDct1D();
static void DoubleReferenceIDct1D();
static void DoubleTransposeMatrix();
/*PRIVATE*/
static int transpose_index[] =
{0, 8, 16, 24, 32, 40, 48, 56,
1, 9, 17, 25, 33, 41, 49, 57,
2, 10, 18, 26, 34, 42, 50, 58,
3, 11, 19, 27, 35, 43, 51, 59,
4, 12, 20, 28, 36, 44, 52, 60,
5, 13, 21, 29, 37, 45, 53, 61,
6, 14, 22, 30, 38, 46, 54, 62,
7, 15, 23, 31, 39, 47, 55, 63};
static int zigzag_index[] =
{0, 1, 5, 6, 14, 15, 27, 28,
2, 4, 7, 13, 16, 26, 29, 42,
3, 8, 12, 17, 25, 30, 41, 43,
9, 11, 18, 24, 31, 40, 44, 53,
10, 19, 23, 32, 39, 45, 52, 54,
20, 22, 33, 38, 46, 51, 55, 60,
21, 34, 37, 47, 50, 56, 59, 61,
35, 36, 48, 49, 57, 58, 62, 63};
#define MakeMatrix() (int *) calloc(BLOCKSIZE,sizeof(int))
#define FixedMultiply(s,x,y) x = ((x * y) >> s);
#define DCT_OFFSET 128
/*START*/
/*BFUNC
ReferenceDct() does a reference DCT on the input (matrix) and output
(new matrix).
EFUNC*/
void ReferenceDct(matrix,newmatrix)
int *matrix;
int *newmatrix;
{
BEGIN("ReferenceDct");
int *mptr;
double *sptr,*dptr;
double sourcematrix[BLOCKSIZE],destmatrix[BLOCKSIZE];
for(sptr=sourcematrix,mptr=matrix;mptr 0 ? (*(sptr)+0.5):(*(sptr)-0.5));
}
}
/*BFUNC
DoubleReferenceDCT1D() does a 8 point dct on an array of double
input and places the result in a double output.
EFUNC*/
static void DoubleReferenceDct1D(ivect,ovect)
double *ivect;
double *ovect;
{
BEGIN("DoubleReferenceDct1D");
double *mptr,*iptr,*optr;
for(mptr=DctMatrix,optr=ovect;optr 0 ? (*(sptr)+0.5):(*(sptr)-0.5));
}
}
/*BFUNC
DoubleReferenceIDct1D() does an 8 point inverse dct on ivect and
puts the output in ovect.
EFUNC*/
static void DoubleReferenceIDct1D(ivect,ovect)
double *ivect;
double *ovect;
{
BEGIN("DoubleReferenceIDct1D");
double *mptr,*iptr,*optr;
for(mptr = IDctMatrix,optr=ovect;optr0)
*matrix= (*matrix+1)/(dcqfact<<1);
else
*matrix= (*matrix-1)/(dcqfact<<1);
}
if (acqfact&1) /* Odd */
{
acqfact<<=1;
for(mptr=matrix+1;mptr0)
*mptr = (*mptr+1) / acqfact;
else
*mptr = (*mptr-1) / acqfact;
}
}
#endif
}
/*BFUNC
CCITTFlatQuantize() quantizes the input matrix by a dc factor (flat)
and an acqfactor (thresholded).
EFUNC*/
void CCITTFlatQuantize(matrix,dcqfact,acqfact)
int *matrix;
int dcqfact;
int acqfact;
{
BEGIN("CCITTFlatQuantize");
int *mptr;
if (*matrix > 0) {*matrix = (*matrix + dcqfact/2)/ dcqfact;}
else {*matrix = (*matrix - dcqfact/2)/ dcqfact;}
#ifdef VERSION_1.0
acqfact++;
acqfact <<=1;
for(mptr=matrix+1;mptr0)
*mptr = (*mptr+1) / acqfact;
else
*mptr = (*mptr-1) / acqfact;
}
}
#endif
}
/*BFUNC
ICCITTFlatQuantize() does an inverse flat quantize on the dc element
and an inverse thresholded quantize on the ac elements of the input
matrix.
EFUNC*/
void ICCITTFlatQuantize(matrix,dcqfact,acqfact)
int *matrix;
int dcqfact;
int acqfact;
{
BEGIN("ICCITTFlatQuantize");
int *mptr;
*matrix = *matrix*dcqfact;
#ifdef VERSION_1.0
acqfact++;
for(mptr=matrix+1;mptr0) {*mptr = ((*mptr<<1) + 1)*acqfact;}
else if (*mptr<0) {*mptr = ((*mptr<<1) - 1)*acqfact;}
}
#else
if (acqfact&1) /* Odd */
{
for(mptr=matrix+1;mptr0) {*mptr = ((*mptr<<1) + 1)*acqfact;}
else if (*mptr<0) {*mptr = ((*mptr<<1) - 1)*acqfact;}
}
}
else
{
for(mptr=matrix+1;mptr0) {*mptr = (((*mptr<<1) + 1)*acqfact)-1;}
else if (*mptr<0) {*mptr = (((*mptr<<1) - 1)*acqfact)+1;}
}
}
#endif
}
/*BFUNC
ICCITTQuantize() does an inverse quantize on the dc element and the ac
element with their selective q values, respectively.
EFUNC*/
void ICCITTQuantize(matrix,dcqfact,acqfact)
int *matrix;
int dcqfact;
int acqfact;
{
BEGIN("ICCITTQuantize");
int *mptr;
#ifdef VERSION_1.0
dcqfact++;
acqfact++;
if (*matrix>0) {*matrix = (2* *matrix + 1)*dcqfact;}
else if (*matrix<0) {*matrix = (2* *matrix - 1)*dcqfact;}
for(mptr=matrix+1;mptr0) {*mptr = (2* *mptr + 1)*acqfact;}
else if (*mptr<0) {*mptr = (2* *mptr - 1)*acqfact;}
}
#else
if (dcqfact&1)
{
if (*matrix>0) {*matrix = ((*matrix<<1) + 1)*dcqfact;}
else if (*matrix<0) {*matrix = ((*matrix<<1) - 1)*dcqfact;}
}
else
{
if (*matrix>0) {*matrix = (((*matrix<<1) + 1)*dcqfact)-1;}
else if (*matrix<0) {*matrix = (((*matrix<<1) - 1)*dcqfact)+1;}
}
if (acqfact&1) /* Odd */
{
for(mptr=matrix+1;mptr0) {*mptr = ((*mptr<<1) + 1)*acqfact;}
else if (*mptr<0) {*mptr = ((*mptr<<1) - 1)*acqfact;}
}
}
else
{
for(mptr=matrix+1;mptr0) {*mptr = (((*mptr<<1) + 1)*acqfact)-1;}
else if (*mptr<0) {*mptr = (((*mptr<<1) - 1)*acqfact)+1;}
}
}
#endif
}
/*BFUNC
BoundDctMatrix() clips the Dct matrix such that it is no larger than
a 10 bit word.
EFUNC*/
void BoundDctMatrix(matrix)
int *matrix;
{
BEGIN("BoundDctMatrix");
int *mptr;
if (*matrix > 2047) {*matrix = 2047;}
for(mptr=matrix+1;mptr 1023) {*mptr = 1023;}
}
}
/*BFUNC
BoundIDctMatrix bounds the inverse dct matrix so that no pixel has a
value greater than 255 or less than 0.
EFUNC*/
void BoundIDctMatrix(matrix)
int *matrix;
{
BEGIN("BoundIDctMatrix");
int *mptr;
for(mptr=matrix;mptr 255) {*mptr = 255;}
}
}
/*BFUNC
FlatBoundQuantizeMatrix() bounds a quantized matrix generated by
CCITTFlatQuantize().
EFUNC*/
void FlatBoundQuantizeMatrix(matrix)
int *matrix;
{
BEGIN("FlatBoundQuantizeMatrix");
int *mptr;
if (*matrix > 254) {*matrix = 254;}
else if (*matrix < 1) {*matrix = 1;}
for(mptr=matrix+1;mptr 127) {*mptr = 127;}
}
}
/*BFUNC
BoundQuantizeMatrix() bounds a quantized matrix generated by
CCITTQuantize().
EFUNC*/
void BoundQuantizeMatrix(matrix)
int *matrix;
{
BEGIN("BoundQuantizeMatrix");
int *mptr;
for(mptr=matrix;mptr 127) {*mptr = 127;}
}
}
/*BFUNC
IZigzagMatrix() performs an inverse zig-zag translation on the
input imatrix and places the output in omatrix.
EFUNC*/
void IZigzagMatrix(imatrix,omatrix)
int *imatrix;
int *omatrix;
{
BEGIN("IZigzagMatrix");
int *tptr;
for(tptr=zigzag_index;tptr