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ffmpeg/libavcodec/simple_idct.c

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/*
* Simple IDCT
*
* Copyright (c) 2001 Michael Niedermayer <michaelni@gmx.at>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
based upon some outcommented c code from mpeg2dec (idct_mmx.c
written by Aaron Holtzman <aholtzma@ess.engr.uvic.ca>)
*/
#include "avcodec.h"
#include "simple_idct.h"
#if 0
#define W1 2841 /* 2048*sqrt (2)*cos (1*pi/16) */
#define W2 2676 /* 2048*sqrt (2)*cos (2*pi/16) */
#define W3 2408 /* 2048*sqrt (2)*cos (3*pi/16) */
#define W4 2048 /* 2048*sqrt (2)*cos (4*pi/16) */
#define W5 1609 /* 2048*sqrt (2)*cos (5*pi/16) */
#define W6 1108 /* 2048*sqrt (2)*cos (6*pi/16) */
#define W7 565 /* 2048*sqrt (2)*cos (7*pi/16) */
#define ROW_SHIFT 8
#define COL_SHIFT 17
#else
#define W1 22725 //cos(i*M_PI/16)*sqrt(2)*(1<<14) + 0.5
#define W2 21407 //cos(i*M_PI/16)*sqrt(2)*(1<<14) + 0.5
#define W3 19266 //cos(i*M_PI/16)*sqrt(2)*(1<<14) + 0.5
#define W4 16383 //cos(i*M_PI/16)*sqrt(2)*(1<<14) + 0.5
#define W5 12873 //cos(i*M_PI/16)*sqrt(2)*(1<<14) + 0.5
#define W6 8867 //cos(i*M_PI/16)*sqrt(2)*(1<<14) + 0.5
#define W7 4520 //cos(i*M_PI/16)*sqrt(2)*(1<<14) + 0.5
#define ROW_SHIFT 11
#define COL_SHIFT 20 // 6
#endif
/* 8x8 Matrix used to do a trivial (slow) 8 point IDCT */
static int coeff[64]={
W4, W4, W4, W4, W4, W4, W4, W4,
W1, W3, W5, W7,-W7,-W5,-W3,-W1,
W2, W6,-W6,-W2,-W2,-W6, W6, W2,
W3,-W7,-W1,-W5, W5, W1, W7,-W3,
W4,-W4,-W4, W4, W4,-W4,-W4, W4,
W5,-W1, W7, W3,-W3,-W7, W1,-W5,
W6,-W2, W2,-W6,-W6, W2,-W2, W6,
W7,-W5, W3,-W1, W1,-W3, W5,-W7
};
static int inline idctRowCondZ (int16_t * row)
{
int a0, a1, a2, a3, b0, b1, b2, b3;
if( !( ((uint32_t*)row)[0]|((uint32_t*)row)[1] |((uint32_t*)row)[2] |((uint32_t*)row)[3])) {
/* row[0] = row[1] = row[2] = row[3] = row[4] =
row[5] = row[6] = row[7] = 0;*/
return 0;
}
if(!( ((uint32_t*)row)[2] |((uint32_t*)row)[3] )){
a0 = W4*row[0] + W2*row[2] + (1<<(ROW_SHIFT-1));
a1 = W4*row[0] + W6*row[2] + (1<<(ROW_SHIFT-1));
a2 = W4*row[0] - W6*row[2] + (1<<(ROW_SHIFT-1));
a3 = W4*row[0] - W2*row[2] + (1<<(ROW_SHIFT-1));
b0 = W1*row[1] + W3*row[3];
b1 = W3*row[1] - W7*row[3];
b2 = W5*row[1] - W1*row[3];
b3 = W7*row[1] - W5*row[3];
}else{
a0 = W4*row[0] + W2*row[2] + W4*row[4] + W6*row[6] + (1<<(ROW_SHIFT-1));
a1 = W4*row[0] + W6*row[2] - W4*row[4] - W2*row[6] + (1<<(ROW_SHIFT-1));
a2 = W4*row[0] - W6*row[2] - W4*row[4] + W2*row[6] + (1<<(ROW_SHIFT-1));
a3 = W4*row[0] - W2*row[2] + W4*row[4] - W6*row[6] + (1<<(ROW_SHIFT-1));
b0 = W1*row[1] + W3*row[3] + W5*row[5] + W7*row[7];
b1 = W3*row[1] - W7*row[3] - W1*row[5] - W5*row[7];
b2 = W5*row[1] - W1*row[3] + W7*row[5] + W3*row[7];
b3 = W7*row[1] - W5*row[3] + W3*row[5] - W1*row[7];
}
row[0] = (a0 + b0) >> ROW_SHIFT;
row[1] = (a1 + b1) >> ROW_SHIFT;
row[2] = (a2 + b2) >> ROW_SHIFT;
row[3] = (a3 + b3) >> ROW_SHIFT;
row[4] = (a3 - b3) >> ROW_SHIFT;
row[5] = (a2 - b2) >> ROW_SHIFT;
row[6] = (a1 - b1) >> ROW_SHIFT;
row[7] = (a0 - b0) >> ROW_SHIFT;
return 1;
}
#ifdef ARCH_ALPHA
/* 0: all entries 0, 1: only first entry nonzero, 2: otherwise */
static int inline idctRowCondDC(int16_t *row)
{
int_fast32_t a0, a1, a2, a3, b0, b1, b2, b3;
uint64_t *lrow = (uint64_t *) row;
if (lrow[1] == 0) {
if (lrow[0] == 0)
return 0;
if ((lrow[0] & ~0xffffULL) == 0) {
uint64_t v;
a0 = W4 * row[0];
a0 += 1 << (ROW_SHIFT - 1);
a0 >>= ROW_SHIFT;
v = (uint16_t) a0;
v += v << 16;
v += v << 32;
lrow[0] = v;
lrow[1] = v;
return 1;
}
}
a0 = W4 * row[0];
a1 = W4 * row[0];
a2 = W4 * row[0];
a3 = W4 * row[0];
if (row[2]) {
a0 += W2 * row[2];
a1 += W6 * row[2];
a2 -= W6 * row[2];
a3 -= W2 * row[2];
}
if (row[4]) {
a0 += W4 * row[4];
a1 -= W4 * row[4];
a2 -= W4 * row[4];
a3 += W4 * row[4];
}
if (row[6]) {
a0 += W6 * row[6];
a1 -= W2 * row[6];
a2 += W2 * row[6];
a3 -= W6 * row[6];
}
a0 += 1 << (ROW_SHIFT - 1);
a1 += 1 << (ROW_SHIFT - 1);
a2 += 1 << (ROW_SHIFT - 1);
a3 += 1 << (ROW_SHIFT - 1);
if (row[1]) {
b0 = W1 * row[1];
b1 = W3 * row[1];
b2 = W5 * row[1];
b3 = W7 * row[1];
} else {
b0 = 0;
b1 = 0;
b2 = 0;
b3 = 0;
}
if (row[3]) {
b0 += W3 * row[3];
b1 -= W7 * row[3];
b2 -= W1 * row[3];
b3 -= W5 * row[3];
}
if (row[5]) {
b0 += W5 * row[5];
b1 -= W1 * row[5];
b2 += W7 * row[5];
b3 += W3 * row[5];
}
if (row[7]) {
b0 += W7 * row[7];
b1 -= W5 * row[7];
b2 += W3 * row[7];
b3 -= W1 * row[7];
}
row[0] = (a0 + b0) >> ROW_SHIFT;
row[1] = (a1 + b1) >> ROW_SHIFT;
row[2] = (a2 + b2) >> ROW_SHIFT;
row[3] = (a3 + b3) >> ROW_SHIFT;
row[4] = (a3 - b3) >> ROW_SHIFT;
row[5] = (a2 - b2) >> ROW_SHIFT;
row[6] = (a1 - b1) >> ROW_SHIFT;
row[7] = (a0 - b0) >> ROW_SHIFT;
return 2;
}
#else /* not ARCH_ALPHA */
static int inline idctRowCondDC (int16_t * row)
{
int a0, a1, a2, a3, b0, b1, b2, b3;
if( !( ((uint32_t*)row)[1] |((uint32_t*)row)[2] |((uint32_t*)row)[3]| row[1])) {
// row[0] = row[1] = row[2] = row[3] = row[4] = row[5] = row[6] = row[7] = row[0]<<3;
uint16_t temp= row[0]<<3;
((uint32_t*)row)[0]=((uint32_t*)row)[1]=
((uint32_t*)row)[2]=((uint32_t*)row)[3]= temp + (temp<<16);
return 0;
}
if(!( ((uint32_t*)row)[2] |((uint32_t*)row)[3] )){
a0 = W4*row[0] + W2*row[2] + (1<<(ROW_SHIFT-1));
a1 = W4*row[0] + W6*row[2] + (1<<(ROW_SHIFT-1));
a2 = W4*row[0] - W6*row[2] + (1<<(ROW_SHIFT-1));
a3 = W4*row[0] - W2*row[2] + (1<<(ROW_SHIFT-1));
b0 = W1*row[1] + W3*row[3];
b1 = W3*row[1] - W7*row[3];
b2 = W5*row[1] - W1*row[3];
b3 = W7*row[1] - W5*row[3];
}else{
a0 = W4*row[0] + W2*row[2] + W4*row[4] + W6*row[6] + (1<<(ROW_SHIFT-1));
a1 = W4*row[0] + W6*row[2] - W4*row[4] - W2*row[6] + (1<<(ROW_SHIFT-1));
a2 = W4*row[0] - W6*row[2] - W4*row[4] + W2*row[6] + (1<<(ROW_SHIFT-1));
a3 = W4*row[0] - W2*row[2] + W4*row[4] - W6*row[6] + (1<<(ROW_SHIFT-1));
b0 = W1*row[1] + W3*row[3] + W5*row[5] + W7*row[7];
b1 = W3*row[1] - W7*row[3] - W1*row[5] - W5*row[7];
b2 = W5*row[1] - W1*row[3] + W7*row[5] + W3*row[7];
b3 = W7*row[1] - W5*row[3] + W3*row[5] - W1*row[7];
}
row[0] = (a0 + b0) >> ROW_SHIFT;
row[7] = (a0 - b0) >> ROW_SHIFT;
row[1] = (a1 + b1) >> ROW_SHIFT;
row[6] = (a1 - b1) >> ROW_SHIFT;
row[2] = (a2 + b2) >> ROW_SHIFT;
row[5] = (a2 - b2) >> ROW_SHIFT;
row[3] = (a3 + b3) >> ROW_SHIFT;
row[4] = (a3 - b3) >> ROW_SHIFT;
return 1;
}
#endif /* not ARCH_ALPHA */
static void inline idctCol (int16_t * col)
{
/*
if( !(col[8*1] | col[8*2] |col[8*3] |col[8*4] |col[8*5] |col[8*6] | col[8*7])) {
col[8*0] = col[8*1] = col[8*2] = col[8*3] = col[8*4] =
col[8*5] = col[8*6] = col[8*7] = col[8*0]<<3;
return;
}*/
int a0, a1, a2, a3, b0, b1, b2, b3;
col[0] += (1<<(COL_SHIFT-1))/W4;
a0 = W4*col[8*0] + W2*col[8*2] + W4*col[8*4] + W6*col[8*6];
a1 = W4*col[8*0] + W6*col[8*2] - W4*col[8*4] - W2*col[8*6];
a2 = W4*col[8*0] - W6*col[8*2] - W4*col[8*4] + W2*col[8*6];
a3 = W4*col[8*0] - W2*col[8*2] + W4*col[8*4] - W6*col[8*6];
b0 = W1*col[8*1] + W3*col[8*3] + W5*col[8*5] + W7*col[8*7];
b1 = W3*col[8*1] - W7*col[8*3] - W1*col[8*5] - W5*col[8*7];
b2 = W5*col[8*1] - W1*col[8*3] + W7*col[8*5] + W3*col[8*7];
b3 = W7*col[8*1] - W5*col[8*3] + W3*col[8*5] - W1*col[8*7];
col[8*0] = (a0 + b0) >> COL_SHIFT;
col[8*7] = (a0 - b0) >> COL_SHIFT;
col[8*1] = (a1 + b1) >> COL_SHIFT;
col[8*6] = (a1 - b1) >> COL_SHIFT;
col[8*2] = (a2 + b2) >> COL_SHIFT;
col[8*5] = (a2 - b2) >> COL_SHIFT;
col[8*3] = (a3 + b3) >> COL_SHIFT;
col[8*4] = (a3 - b3) >> COL_SHIFT;
}
static void inline idctSparseCol (int16_t * col)
{
int a0, a1, a2, a3, b0, b1, b2, b3;
col[0] += (1<<(COL_SHIFT-1))/W4;
a0 = W4*col[8*0];
a1 = W4*col[8*0];
a2 = W4*col[8*0];
a3 = W4*col[8*0];
if(col[8*2]){
a0 += + W2*col[8*2];
a1 += + W6*col[8*2];
a2 += - W6*col[8*2];
a3 += - W2*col[8*2];
}
if(col[8*4]){
a0 += + W4*col[8*4];
a1 += - W4*col[8*4];
a2 += - W4*col[8*4];
a3 += + W4*col[8*4];
}
if(col[8*6]){
a0 += + W6*col[8*6];
a1 += - W2*col[8*6];
a2 += + W2*col[8*6];
a3 += - W6*col[8*6];
}
if(col[8*1]){
b0 = W1*col[8*1];
b1 = W3*col[8*1];
b2 = W5*col[8*1];
b3 = W7*col[8*1];
}else{
b0 =
b1 =
b2 =
b3 = 0;
}
if(col[8*3]){
b0 += + W3*col[8*3];
b1 += - W7*col[8*3];
b2 += - W1*col[8*3];
b3 += - W5*col[8*3];
}
if(col[8*5]){
b0 += + W5*col[8*5];
b1 += - W1*col[8*5];
b2 += + W7*col[8*5];
b3 += + W3*col[8*5];
}
if(col[8*7]){
b0 += + W7*col[8*7];
b1 += - W5*col[8*7];
b2 += + W3*col[8*7];
b3 += - W1*col[8*7];
}
#ifndef ARCH_ALPHA
if(!(b0|b1|b2|b3)){
col[8*0] = (a0) >> COL_SHIFT;
col[8*7] = (a0) >> COL_SHIFT;
col[8*1] = (a1) >> COL_SHIFT;
col[8*6] = (a1) >> COL_SHIFT;
col[8*2] = (a2) >> COL_SHIFT;
col[8*5] = (a2) >> COL_SHIFT;
col[8*3] = (a3) >> COL_SHIFT;
col[8*4] = (a3) >> COL_SHIFT;
}else{
#endif
col[8*0] = (a0 + b0) >> COL_SHIFT;
col[8*7] = (a0 - b0) >> COL_SHIFT;
col[8*1] = (a1 + b1) >> COL_SHIFT;
col[8*6] = (a1 - b1) >> COL_SHIFT;
col[8*2] = (a2 + b2) >> COL_SHIFT;
col[8*5] = (a2 - b2) >> COL_SHIFT;
col[8*3] = (a3 + b3) >> COL_SHIFT;
col[8*4] = (a3 - b3) >> COL_SHIFT;
#ifndef ARCH_ALPHA
}
#endif
}
static void inline idctSparse2Col (int16_t * col)
{
int a0, a1, a2, a3, b0, b1, b2, b3;
col[0] += (1<<(COL_SHIFT-1))/W4;
a0 = W4*col[8*0];
a1 = W4*col[8*0];
a2 = W4*col[8*0];
a3 = W4*col[8*0];
if(col[8*2]){
a0 += + W2*col[8*2];
a1 += + W6*col[8*2];
a2 += - W6*col[8*2];
a3 += - W2*col[8*2];
}
if(col[8*4]){
a0 += + W4*col[8*4];
a1 += - W4*col[8*4];
a2 += - W4*col[8*4];
a3 += + W4*col[8*4];
}
if(col[8*6]){
a0 += + W6*col[8*6];
a1 += - W2*col[8*6];
a2 += + W2*col[8*6];
a3 += - W6*col[8*6];
}
if(col[8*1] || 1){
b0 = W1*col[8*1];
b1 = W3*col[8*1];
b2 = W5*col[8*1];
b3 = W7*col[8*1];
}else{
b0 =
b1 =
b2 =
b3 = 0;
}
if(col[8*3]){
b0 += + W3*col[8*3];
b1 += - W7*col[8*3];
b2 += - W1*col[8*3];
b3 += - W5*col[8*3];
}
if(col[8*5]){
b0 += + W5*col[8*5];
b1 += - W1*col[8*5];
b2 += + W7*col[8*5];
b3 += + W3*col[8*5];
}
if(col[8*7]){
b0 += + W7*col[8*7];
b1 += - W5*col[8*7];
b2 += + W3*col[8*7];
b3 += - W1*col[8*7];
}
col[8*0] = (a0 + b0) >> COL_SHIFT;
col[8*7] = (a0 - b0) >> COL_SHIFT;
col[8*1] = (a1 + b1) >> COL_SHIFT;
col[8*6] = (a1 - b1) >> COL_SHIFT;
col[8*2] = (a2 + b2) >> COL_SHIFT;
col[8*5] = (a2 - b2) >> COL_SHIFT;
col[8*3] = (a3 + b3) >> COL_SHIFT;
col[8*4] = (a3 - b3) >> COL_SHIFT;
}
#ifdef ARCH_ALPHA
/* If all rows but the first one are zero after row transformation,
all rows will be identical after column transformation. */
static inline void idctCol2(int16_t *col)
{
int i;
uint64_t l, r;
uint64_t *lcol = (uint64_t *) col;
for (i = 0; i < 8; ++i) {
int a0 = col[0] + (1 << (COL_SHIFT - 1)) / W4;
a0 *= W4;
col[0] = a0 >> COL_SHIFT;
++col;
}
l = lcol[0];
r = lcol[1];
lcol[ 2] = l; lcol[ 3] = r;
lcol[ 4] = l; lcol[ 5] = r;
lcol[ 6] = l; lcol[ 7] = r;
lcol[ 8] = l; lcol[ 9] = r;
lcol[10] = l; lcol[11] = r;
lcol[12] = l; lcol[13] = r;
lcol[14] = l; lcol[15] = r;
}
#endif
void simple_idct (short *block)
{
int i;
#if 0
int nonZero[8];
int buffer[64];
int nNonZero=0;
idctRowCondDC(block);
for(i=1; i<8; i++)
{
nonZero[nNonZero]=i;
nNonZero+= idctRowCondZ(block + i*8);
}
if(nNonZero==0)
{
for(i=0; i<8; i++)
{
block[i ]=
block[i+8 ]=
block[i+16]=
block[i+24]=
block[i+32]=
block[i+40]=
block[i+48]=
block[i+56]= (W4*block[i] + (1<<(COL_SHIFT-1))) >> COL_SHIFT;
}
}
else if(nNonZero==1)
{
int index= nonZero[0]*8;
for(i=0; i<8; i++)
{
int bias= W4*block[i] + (1<<(COL_SHIFT-1));
int c= block[i + index];
block[i ]= (c*coeff[index ] + bias) >> COL_SHIFT;
block[i+8 ]= (c*coeff[index+1] + bias) >> COL_SHIFT;
block[i+16]= (c*coeff[index+2] + bias) >> COL_SHIFT;
block[i+24]= (c*coeff[index+3] + bias) >> COL_SHIFT;
block[i+32]= (c*coeff[index+4] + bias) >> COL_SHIFT;
block[i+40]= (c*coeff[index+5] + bias) >> COL_SHIFT;
block[i+48]= (c*coeff[index+6] + bias) >> COL_SHIFT;
block[i+56]= (c*coeff[index+7] + bias) >> COL_SHIFT;
}
}
/* else if(nNonZero==2)
{
int index1= nonZero[0]*8;
int index2= nonZero[1]*8;
for(i=0; i<8; i++)
{
int bias= W4*block[i] + (1<<(COL_SHIFT-1));
int c1= block[i + index1];
int c2= block[i + index2];
block[i ]= (c1*coeff[index1 ] + c2*coeff[index2 ] + bias) >> COL_SHIFT;
block[i+8 ]= (c1*coeff[index1+1] + c2*coeff[index2+1] + bias) >> COL_SHIFT;
block[i+16]= (c1*coeff[index1+2] + c2*coeff[index2+2] + bias) >> COL_SHIFT;
block[i+24]= (c1*coeff[index1+3] + c2*coeff[index2+3] + bias) >> COL_SHIFT;
block[i+32]= (c1*coeff[index1+4] + c2*coeff[index2+4] + bias) >> COL_SHIFT;
block[i+40]= (c1*coeff[index1+5] + c2*coeff[index2+5] + bias) >> COL_SHIFT;
block[i+48]= (c1*coeff[index1+6] + c2*coeff[index2+6] + bias) >> COL_SHIFT;
block[i+56]= (c1*coeff[index1+7] + c2*coeff[index2+7] + bias) >> COL_SHIFT;
}
}*/
else
{
for(i=0; i<8; i++)
idctSparse2Col(block + i);
}
#elif defined(ARCH_ALPHA)
int rowsZero = 1; /* all rows except row 0 zero */
int rowsConstant = 1; /* all rows consist of a constant value */
for (i = 0; i < 8; i++) {
int sparseness = idctRowCondDC(block + 8 * i);
if (i > 0 && sparseness > 0)
rowsZero = 0;
if (sparseness == 2)
rowsConstant = 0;
}
if (rowsZero) {
idctCol2(block);
} else if (rowsConstant) {
uint64_t *lblock = (uint64_t *) block;
idctSparseCol(block);
for (i = 0; i < 8; i++) {
uint64_t v = (uint16_t) block[i * 8];
v += v << 16;
v += v << 32;
lblock[0] = v;
lblock[1] = v;
lblock += 2;
}
} else {
for (i = 0; i < 8; i++)
idctSparseCol(block + i);
}
#else
for(i=0; i<8; i++)
idctRowCondDC(block + i*8);
for(i=0; i<8; i++)
idctSparseCol(block + i);
#endif
}
#undef COL_SHIFT
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