www.pudn.com > av3dec_20050318.zip > intMDCT.c
/*
***********************************************************************
* COPYRIGHT AND WARRANTY INFORMATION
*
* Copyright 2004, Audio Video Coding Standard, Part III
*
* This software module was originally developed by
* edited by
*
* DISCLAIMER OF WARRANTY
*
* These software programs are available to the users without any
* license fee or royalty on an "as is" basis. The AVS disclaims
* any and all warranties, whether express, implied, or statutory,
* including any implied warranties of merchantability or of fitness
* for a particular purpose. In no event shall the contributors or
* the AVS be liable for any incidental, punitive, or consequential
* damages of any kind whatsoever arising from the use of this program.
*
* This disclaimer of warranty extends to the user of this program
* and user's customers, employees, agents, transferees, successors,
* and assigns.
*
* The AVS does not represent or warrant that the program furnished
* hereunder are free of infringement of any third-party patents.
* Commercial implementations of AVS, including shareware, may be
* subject to royalty fees to patent holders. Information regarding
* the AVS patent policy is available from the AVS Web site at
* http://www.avs.org.cn
*
* THIS IS NOT A GRANT OF PATENT RIGHTS - SEE THE AVS PATENT POLICY.
************************************************************************
*/
#include
#include
#include
#include "common.h"
#include "av3dec.h"
#include "intMDCT.h"
#ifdef _WIN32_WCE
#define assert(x)
#else
#include
#endif
int log2int(int x)
{
int m;
if (x<0)
x = -x;
for (m=0; x>1; x>>=1)
m++;
return (m);
}
int msbHeadroomINT32(int *x, int len)
{
int i,max;
max = 0;
for (i=0; i0)
for (i=0; i0)
for (i=0; i>(shift-1))+1)>>1);
}
int calPreShiftINT32(int *x, int len)
{
int m;
m = msbHeadroomINT32(x,len);
if (m>8)
return (m-6);
else
return (2);
}
int multiINT32 (int x, int y)
{
return ((int)((((__int64)x*y)>>(SHIFT-1))+1)>>1);
}
void hardamard(int* u0, int* u1, int* u2, int* u3)
{
*u2 = *u2 + *u0;
*u0 = -*u0;
*u3 = *u3 - *u1;
*u1 = -*u1;
*u0 = *u0 + ((*u2+*u3+1)>>1);
*u1 = *u1 + ((*u2-*u3+1)>>1);
*u2 = *u2 - *u1;
*u3 = *u3 - *u0;
*u0 = -*u0;
}
void dctII_4p(int *x)
{
int tmp;
hardamard(&x[0],&x[1],&x[2],&x[3]);
// Lifting rotation
// angle = pi/8
// | c -s | = | 1 0 | | 1 -s | | 1 0 |
// | s c | | t 1 | | 0 1 | | t 1 |
x[0] = x[0] + multiINT32(TAN_PI_16,x[1]);
x[1] = x[1] - multiINT32(SIN_PI_8,x[0]);
x[0] = x[0] + multiINT32(TAN_PI_16,x[1]);
tmp = x[0]; x[0] = x[2]; x[2] = x[3];
x[3] = x[1]; x[1] = tmp;
}
void dctII_8p(int *x)
{
int u[8];
int tmp,tmp1;
u[0] = x[0]; u[1] = x[7]; u[2] = x[3]; u[3] = x[4];
u[4] = x[1]; u[5] = x[6]; u[6] = x[2]; u[7] = x[5];
hardamard(&u[0],&u[1],&u[2],&u[3]);
hardamard(&u[4],&u[5],&u[6],&u[7]);
// Rotation A1
// sin(pi/4) * | 1 -1 |
// | 1 1 |
tmp = multiINT32((u[1]-u[3]),SIN_PI_4);
tmp1 = multiINT32((u[1]+u[3]),SIN_PI_4);
u[1] = tmp; u[3] = tmp1;
hardamard(&u[1],&u[7],&u[5],&u[3]);
// Rotation A2
// sin(pi/4) * | 1 1 |
// | 1 -1 |
x[0] = multiINT32((u[2]+u[6]),SIN_PI_4);
x[4] = multiINT32((u[2]-u[6]),SIN_PI_4);
// Lifting rotation B
// angle = pi/8
// | s c | = |-t 1 | |-1 s | | 1 0 |
// |-c s | | 1 0 | | 0 1 | | t 1 |
u[0] = u[0] + multiINT32(TAN_PI_16,u[4]);
x[6] = multiINT32(SIN_PI_8,u[0]) - u[4];
x[2] = u[0] - multiINT32(TAN_PI_16,x[6]);
// Lifting rotation C
// angle = 3pi/16
// | c -s | = | t 1 | |-1 -s | | 0 1 |
// |-s -c | | 1 0 | | 0 1 | | 1 -t |
u[5] = u[5] - multiINT32(TAN_3PI_32,u[1]);
x[7] = -u[1] - multiINT32(SIN_3PI_16,u[5]);
x[1] = u[5] + multiINT32(TAN_3PI_32,x[7]);
// Lifting rotation D
// angle = pi/16
// | c s | = |-t 1 | |-1 s | | 0 1 |
// | s -c | | 1 0 | | 0 1 | | 1 t |
u[3] = u[3] + multiINT32(TAN_PI_32,u[7]);
x[3] = multiINT32(SIN_PI_16,u[3]) - u[7];
x[5] = u[3] - multiINT32(TAN_PI_32,x[3]);
}
void flipud(int *u, int len)
{
int i,len1,tmp;
len1 = len>>1;
for (i=0; i>1;
for (i=0; i>1; len2 = len>>2;
for (i=0; i>1;
// Matrix T - Rotation
step = 1<<(LOG2_N_MDCT-logm);
for (i=0; i>1;
// Matrix P - alternative implementation
flipud(&u[m2],m2);
permute(u,logm,1);
// Transpose of matrix B
for (i=1; i>1;
// Matrix A2
for (i=0; i>1;
// Matrix J
flipud(&u[m2],m2);
// Matrix P - alternative implementation
flipud(&u[m2],m2);
permute(u,logm,1);
}
void MDCT_window(int *signal, int len, int dir)
{
int i,len1,step;
len1 = (len>>1);
if (len==N_MDCT)
step = 1; // Long block
else
step = 8; // Short block
// Sine window
for (i=0; i>1; len2 = len>>2;
for (i=0; i>1; len2 = len>>2;
for (i=0; i>1; len2 = len>>2;
if (len==N_MDCT)
step = 1; // Long block
else
step = 8; // Short block
v1 = &liftBuffer[len1]; v2 = &liftBuffer[len];
for (i=0; i>1; len2 = len>>2;
if (len==N_MDCT)
step = 1; // Long block
else
step = 8; // Short block
// Forward integer DCT-IV
// C4 = R1*R2*S*T1*T2*Peo
// Step(1) Even-odd permutation matrix Peo
permute(signal0,log2int(len),-1);
// Step(2) Lifting matrix T2
liftingStepT2(signal0,signal1,liftBuffer,len);
for (i=0; i>1; len2 = len>>2;
if (len==N_MDCT)
step = 1; // Long block
else
step = 8; // Short block
// Integer inverse DCT-IV
// Inv(C4) = Inv(R1*R2*S*T1*T2*Peo)
// Inverse step(6) Lifting matrix R1
for (i=0; i