📄 simple_idct.c
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/*
* Simple IDCT
*
* Copyright (c) 2001 Michael Niedermayer <michaelni@gmx.at>
*
* This file is part of FFmpeg.
*
* FFmpeg 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 2.1 of the License, or (at your option) any later version.
*
* FFmpeg 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 FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file simple_idct.c
* simpleidct in C.
*/
/*
based upon some outcommented c code from mpeg2dec (idct_mmx.c
written by Aaron Holtzman <aholtzma@ess.engr.uvic.ca>)
*/
#include <assert.h>
#include "mem.h"
#include "common.h"
#include "rational.h"
#include "log.h"
#include "avutil.h"
#include "avcodec.h"
#include "dsputil.h"
#include "rectangle.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
#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
static void idctRowCondDC (DCTELEM * row)
{
int a0, a1, a2, a3, b0, b1, b2, b3;
#ifdef HAVE_FAST_64BIT
uint64_t temp;
#else
uint32_t temp;
#endif
#ifdef HAVE_FAST_64BIT
#ifdef WORDS_BIGENDIAN
#define ROW0_MASK 0xffff000000000000LL
#else
#define ROW0_MASK 0xffffLL
#endif
if(sizeof(DCTELEM)==2)
{
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 (!(row[1]|row[2]|row[3]|row[4]|row[5]|row[6]|row[7]))
{
row[0]=row[1]=row[2]=row[3]=row[4]=row[5]=row[6]=row[7]= row[0] << 3;
return;
}
}
#else
if(sizeof(DCTELEM)==2)
{
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;
}
}
else
{
if (!(row[1]|row[2]|row[3]|row[4]|row[5]|row[6]|row[7]))
{
row[0]=row[1]=row[2]=row[3]=row[4]=row[5]=row[6]=row[7]= row[0] << 3;
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 HAVE_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;
}
static void idctSparseColPut (uint8_t *dest, int line_size,
DCTELEM * col)
{
int a0, a1, a2, a3, b0, b1, b2, b3;
uint8_t *cm = ff_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 void idctSparseColAdd (uint8_t *dest, int line_size,
DCTELEM * col)
{
int a0, a1, a2, a3, b0, b1, b2, b3;
uint8_t *cm = ff_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]);
}
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