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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 "dsputil.h"
#include "simple_idct.h"
//#define ARCH_ALPHA
#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
#ifdef ARCH_ALPHA
#define FAST_64BIT
#endif
#if defined(ARCH_POWERPC_405)
/* signed 16x16 -> 32 multiply add accumulate */
#define MAC16(rt, ra, rb) \
asm ("maclhw %0, %2, %3" : "=r" (rt) : "0" (rt), "r" (ra), "r" (rb));
/* signed 16x16 -> 32 multiply */
#define MUL16(rt, ra, rb) \
asm ("mullhw %0, %1, %2" : "=r" (rt) : "r" (ra), "r" (rb));
#else
/* signed 16x16 -> 32 multiply add accumulate */
#define MAC16(rt, ra, rb) rt += (ra) * (rb)
/* signed 16x16 -> 32 multiply */
#define MUL16(rt, ra, rb) rt = (ra) * (rb)
#endif
#ifdef ARCH_ALPHA
/* 0: all entries 0, 1: only first entry nonzero, 2: otherwise */
static inline int 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;
#if 1 //is ok if |a0| < 1024 than theres an +-1 error (for the *W4 case for W4=16383 !!!)
a0 = row[0]<<3;
#else
a0 = W4 * row[0];
a0 += 1 << (ROW_SHIFT - 1);
a0 >>= ROW_SHIFT;
#endif
v = (uint16_t) a0;
v += v << 16;
v += v << 32;
lrow[0] = v;
lrow[1] = v;
return 1;
}
}
a0 = (W4 * row[0]) + (1 << (ROW_SHIFT - 1));
a1 = a0;
a2 = a0;
a3 = a0;
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];
}
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;
}
inline static void idctSparseCol2(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];
}
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;
}
#else /* not ARCH_ALPHA */
static inline void idctRowCondDC (int16_t * row)
{
int a0, a1, a2, a3, b0, b1, b2, b3;
#ifdef FAST_64BIT
uint64_t temp;
#else
uint32_t temp;
#endif
#ifdef FAST_64BIT
#ifdef WORDS_BIGENDIAN
#define ROW0_MASK 0xffff000000000000LL
#else
#define ROW0_MASK 0xffffLL
#endif
if ( ((((uint64_t *)row)[0] & ~ROW0_MASK) |
((uint64_t *)row)[1]) == 0) {
temp = (row[0] << 3) & 0xffff;
temp += temp << 16;
temp += temp << 32;
((uint64_t *)row)[0] = temp;
((uint64_t *)row)[1] = temp;
return;
}
#else
if (!(((uint32_t*)row)[1] |
((uint32_t*)row)[2] |
((uint32_t*)row)[3] |
row[1])) {
temp = (row[0] << 3) & 0xffff;
temp += temp << 16;
((uint32_t*)row)[0]=((uint32_t*)row)[1] =
((uint32_t*)row)[2]=((uint32_t*)row)[3] = temp;
return;
}
#endif
a0 = (W4 * row[0]) + (1 << (ROW_SHIFT - 1));
a1 = a0;
a2 = a0;
a3 = a0;
/* no need to optimize : gcc does it */
a0 += W2 * row[2];
a1 += W6 * row[2];
a2 -= W6 * row[2];
a3 -= W2 * row[2];
MUL16(b0, W1, row[1]);
MAC16(b0, W3, row[3]);
MUL16(b1, W3, row[1]);
MAC16(b1, -W7, row[3]);
MUL16(b2, W5, row[1]);
MAC16(b2, -W1, row[3]);
MUL16(b3, W7, row[1]);
MAC16(b3, -W5, row[3]);
#ifdef FAST_64BIT
temp = ((uint64_t*)row)[1];
#else
temp = ((uint32_t*)row)[2] | ((uint32_t*)row)[3];
#endif
if (temp != 0) {
a0 += W4*row[4] + W6*row[6];
a1 += - W4*row[4] - W2*row[6];
a2 += - W4*row[4] + W2*row[6];
a3 += W4*row[4] - W6*row[6];
MAC16(b0, W5, row[5]);
MAC16(b0, W7, row[7]);
MAC16(b1, -W1, row[5]);
MAC16(b1, -W5, row[7]);
MAC16(b2, W7, row[5]);
MAC16(b2, W3, row[7]);
MAC16(b3, W3, row[5]);
MAC16(b3, -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;
}
#endif /* not ARCH_ALPHA */
static inline void idctSparseColPut (UINT8 *dest, int line_size,
int16_t * col)
{
int a0, a1, a2, a3, b0, b1, b2, b3;
UINT8 *cm = cropTbl + MAX_NEG_CROP;
/* XXX: I did that only to give same values as previous code */
a0 = W4 * (col[8*0] + ((1<<(COL_SHIFT-1))/W4));
a1 = a0;
a2 = a0;
a3 = a0;
a0 += + W2*col[8*2];
a1 += + W6*col[8*2];
a2 += - W6*col[8*2];
a3 += - W2*col[8*2];
MUL16(b0, W1, col[8*1]);
MUL16(b1, W3, col[8*1]);
MUL16(b2, W5, col[8*1]);
MUL16(b3, W7, col[8*1]);
MAC16(b0, + W3, col[8*3]);
MAC16(b1, - W7, col[8*3]);
MAC16(b2, - W1, col[8*3]);
MAC16(b3, - W5, col[8*3]);
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*5]) {
MAC16(b0, + W5, col[8*5]);
MAC16(b1, - W1, col[8*5]);
MAC16(b2, + W7, col[8*5]);
MAC16(b3, + W3, col[8*5]);
}
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*7]) {
MAC16(b0, + W7, col[8*7]);
MAC16(b1, - W5, col[8*7]);
MAC16(b2, + W3, col[8*7]);
MAC16(b3, - W1, col[8*7]);
}
dest[0] = cm[(a0 + b0) >> COL_SHIFT];
dest += line_size;
dest[0] = cm[(a1 + b1) >> COL_SHIFT];
dest += line_size;
dest[0] = cm[(a2 + b2) >> COL_SHIFT];
dest += line_size;
dest[0] = cm[(a3 + b3) >> COL_SHIFT];
dest += line_size;
dest[0] = cm[(a3 - b3) >> COL_SHIFT];
dest += line_size;
dest[0] = cm[(a2 - b2) >> COL_SHIFT];
dest += line_size;
dest[0] = cm[(a1 - b1) >> COL_SHIFT];
dest += line_size;
dest[0] = cm[(a0 - b0) >> COL_SHIFT];
}
static inline void idctSparseColAdd (UINT8 *dest, int line_size,
int16_t * col)
{
int a0, a1, a2, a3, b0, b1, b2, b3;
UINT8 *cm = cropTbl + MAX_NEG_CROP;
/* XXX: I did that only to give same values as previous code */
a0 = W4 * (col[8*0] + ((1<<(COL_SHIFT-1))/W4));
a1 = a0;
a2 = a0;
a3 = a0;
a0 += + W2*col[8*2];
a1 += + W6*col[8*2];
a2 += - W6*col[8*2];
a3 += - W2*col[8*2];
MUL16(b0, W1, col[8*1]);
MUL16(b1, W3, col[8*1]);
MUL16(b2, W5, col[8*1]);
MUL16(b3, W7, col[8*1]);
MAC16(b0, + W3, col[8*3]);
MAC16(b1, - W7, col[8*3]);
MAC16(b2, - W1, col[8*3]);
MAC16(b3, - W5, col[8*3]);
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*5]) {
MAC16(b0, + W5, col[8*5]);
MAC16(b1, - W1, col[8*5]);
MAC16(b2, + W7, col[8*5]);
MAC16(b3, + W3, col[8*5]);
}
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*7]) {
MAC16(b0, + W7, col[8*7]);
MAC16(b1, - W5, col[8*7]);
MAC16(b2, + W3, col[8*7]);
MAC16(b3, - W1, col[8*7]);
}
dest[0] = cm[dest[0] + ((a0 + b0) >> COL_SHIFT)];
dest += line_size;
dest[0] = cm[dest[0] + ((a1 + b1) >> COL_SHIFT)];
dest += line_size;
dest[0] = cm[dest[0] + ((a2 + b2) >> COL_SHIFT)];
dest += line_size;
dest[0] = cm[dest[0] + ((a3 + b3) >> COL_SHIFT)];
dest += line_size;
dest[0] = cm[dest[0] + ((a3 - b3) >> COL_SHIFT)];
dest += line_size;
dest[0] = cm[dest[0] + ((a2 - b2) >> COL_SHIFT)];
dest += line_size;
dest[0] = cm[dest[0] + ((a1 - b1) >> COL_SHIFT)];
dest += line_size;
dest[0] = cm[dest[0] + ((a0 - b0) >> COL_SHIFT)];
}
static inline void idctSparseCol (int16_t * col)
{
int a0, a1, a2, a3, b0, b1, b2, b3;
/* XXX: I did that only to give same values as previous code */
a0 = W4 * (col[8*0] + ((1<<(COL_SHIFT-1))/W4));
a1 = a0;
a2 = a0;
a3 = a0;
a0 += + W2*col[8*2];
a1 += + W6*col[8*2];
a2 += - W6*col[8*2];
a3 += - W2*col[8*2];
MUL16(b0, W1, col[8*1]);
MUL16(b1, W3, col[8*1]);
MUL16(b2, W5, col[8*1]);
MUL16(b3, W7, col[8*1]);
MAC16(b0, + W3, col[8*3]);
MAC16(b1, - W7, col[8*3]);
MAC16(b2, - W1, col[8*3]);
MAC16(b3, - W5, col[8*3]);
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*5]) {
MAC16(b0, + W5, col[8*5]);
MAC16(b1, - W1, col[8*5]);
MAC16(b2, + W7, col[8*5]);
MAC16(b3, + W3, col[8*5]);
}
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*7]) {
MAC16(b0, + W7, col[8*7]);
MAC16(b1, - W5, col[8*7]);
MAC16(b2, + W3, col[8*7]);
MAC16(b3, - W1, col[8*7]);
}
col[0 ] = ((a0 + b0) >> COL_SHIFT);
col[8 ] = ((a1 + b1) >> COL_SHIFT);
col[16] = ((a2 + b2) >> COL_SHIFT);
col[24] = ((a3 + b3) >> COL_SHIFT);
col[32] = ((a3 - b3) >> COL_SHIFT);
col[40] = ((a2 - b2) >> COL_SHIFT);
col[48] = ((a1 - b1) >> COL_SHIFT);
col[56] = ((a0 - b0) >> 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;
}
void simple_idct (short *block)
{
int i;
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;
idctSparseCol2(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++)
idctSparseCol2(block + i);
}
}
/* XXX: suppress this mess */
void simple_idct_put(UINT8 *dest, int line_size, DCTELEM *block)
{
simple_idct(block);
put_pixels_clamped(block, dest, line_size);
}
void simple_idct_add(UINT8 *dest, int line_size, DCTELEM *block)
{
simple_idct(block);
add_pixels_clamped(block, dest, line_size);
}
#else
void simple_idct_put(UINT8 *dest, int line_size, INT16 *block)
{
int i;
for(i=0; i<8; i++)
idctRowCondDC(block + i*8);
for(i=0; i<8; i++)
idctSparseColPut(dest + i, line_size, block + i);
}
void simple_idct_add(UINT8 *dest, int line_size, INT16 *block)
{
int i;
for(i=0; i<8; i++)
idctRowCondDC(block + i*8);
for(i=0; i<8; i++)
idctSparseColAdd(dest + i, line_size, block + i);
}
void simple_idct(INT16 *block)
{
int i;
for(i=0; i<8; i++)
idctRowCondDC(block + i*8);
for(i=0; i<8; i++)
idctSparseCol(block + i);
}
#endif
/* 2x4x8 idct */
#define CN_SHIFT 12
#define C_FIX(x) ((int)((x) * (1 << CN_SHIFT) + 0.5))
#define C1 C_FIX(0.6532814824)
#define C2 C_FIX(0.2705980501)
/* row idct is multiple by 16 * sqrt(2.0), col idct4 is normalized,
and the butterfly must be multiplied by 0.5 * sqrt(2.0) */
#define C_SHIFT (4+1+12)
static inline void idct4col(UINT8 *dest, int line_size, const INT16 *col)
{
int c0, c1, c2, c3, a0, a1, a2, a3;
const UINT8 *cm = cropTbl + MAX_NEG_CROP;
a0 = col[8*0];
a1 = col[8*2];
a2 = col[8*4];
a3 = col[8*6];
c0 = ((a0 + a2) << (CN_SHIFT - 1)) + (1 << (C_SHIFT - 1));
c2 = ((a0 - a2) << (CN_SHIFT - 1)) + (1 << (C_SHIFT - 1));
c1 = a1 * C1 + a3 * C2;
c3 = a1 * C2 - a3 * C1;
dest[0] = cm[(c0 + c1) >> C_SHIFT];
dest += line_size;
dest[0] = cm[(c2 + c3) >> C_SHIFT];
dest += line_size;
dest[0] = cm[(c2 - c3) >> C_SHIFT];
dest += line_size;
dest[0] = cm[(c0 - c1) >> C_SHIFT];
}
#define BF(k) \
{\
int a0, a1;\
a0 = ptr[k];\
a1 = ptr[8 + k];\
ptr[k] = a0 + a1;\
ptr[8 + k] = a0 - a1;\
}
/* only used by DV codec. The input must be interlaced. 128 is added
to the pixels before clamping to avoid systematic error
(1024*sqrt(2)) offset would be needed otherwise. */
/* XXX: I think a 1.0/sqrt(2) normalization should be needed to
compensate the extra butterfly stage - I don't have the full DV
specification */
void simple_idct248_put(UINT8 *dest, int line_size, INT16 *block)
{
int i;
INT16 *ptr;
/* butterfly */
ptr = block;
for(i=0;i<4;i++) {
BF(0);
BF(1);
BF(2);
BF(3);
BF(4);
BF(5);
BF(6);
BF(7);
ptr += 2 * 8;
}
/* IDCT8 on each line */
for(i=0; i<8; i++) {
idctRowCondDC(block + i*8);
}
/* IDCT4 and store */
for(i=0;i<8;i++) {
idct4col(dest + i, 2 * line_size, block + i);
idct4col(dest + line_size + i, 2 * line_size, block + 8 + i);
}
}
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