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vpx/vp8/common/idctllm.c
Yaowu Xu 0b17ea6f68 A bit of temporary relief on encoder slowness 
The commit replaces run-time initialization of cosine constants with
static constant values, which provides ~30% relief on slow speed. The
real solution, however will be to implement integer versions of those
functions that current use float/double.

Change-Id: Ie3ff1793509653d78dd1aeaf88cc6737da1bc55f
2012-08-07 14:06:11 -07:00

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/*
* Copyright (c) 2010 The WebM project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
/****************************************************************************
* Notes:
*
* This implementation makes use of 16 bit fixed point verio of two multiply
* constants:
* 1. sqrt(2) * cos (pi/8)
* 2. sqrt(2) * sin (pi/8)
* Becuase the first constant is bigger than 1, to maintain the same 16 bit
* fixed point precision as the second one, we use a trick of
* x * a = x + x*(a-1)
* so
* x * sqrt(2) * cos (pi/8) = x + x * (sqrt(2) *cos(pi/8)-1).
**************************************************************************/
#include "vpx_ports/config.h"
#include "vp8/common/idct.h"
#if CONFIG_HYBRIDTRANSFORM
#include "vp8/common/blockd.h"
#endif
#include <math.h>
static const int cospi8sqrt2minus1 = 20091;
static const int sinpi8sqrt2 = 35468;
static const int rounding = 0;
// TODO: these transforms can be further converted into integer forms
// for complexity optimization
#if CONFIG_HYBRIDTRANSFORM
float idct_4[16] = {
0.500000000000000, 0.653281482438188, 0.500000000000000, 0.270598050073099,
0.500000000000000, 0.270598050073099, -0.500000000000000, -0.653281482438188,
0.500000000000000, -0.270598050073099, -0.500000000000000, 0.653281482438188,
0.500000000000000, -0.653281482438188, 0.500000000000000, -0.270598050073099
};
float iadst_4[16] = {
0.228013428883779, 0.577350269189626, 0.656538502008139, 0.428525073124360,
0.428525073124360, 0.577350269189626, -0.228013428883779, -0.656538502008139,
0.577350269189626, 0, -0.577350269189626, 0.577350269189626,
0.656538502008139, -0.577350269189626, 0.428525073124359, -0.228013428883779
};
#endif
#if CONFIG_HYBRIDTRANSFORM8X8
float idct_8[64] = {
0.353553390593274, 0.490392640201615, 0.461939766255643, 0.415734806151273,
0.353553390593274, 0.277785116509801, 0.191341716182545, 0.097545161008064,
0.353553390593274, 0.415734806151273, 0.191341716182545, -0.097545161008064,
-0.353553390593274, -0.490392640201615, -0.461939766255643, -0.277785116509801,
0.353553390593274, 0.277785116509801, -0.191341716182545, -0.490392640201615,
-0.353553390593274, 0.097545161008064, 0.461939766255643, 0.415734806151273,
0.353553390593274, 0.097545161008064, -0.461939766255643, -0.277785116509801,
0.353553390593274, 0.415734806151273, -0.191341716182545, -0.490392640201615,
0.353553390593274, -0.097545161008064, -0.461939766255643, 0.277785116509801,
0.353553390593274, -0.415734806151273, -0.191341716182545, 0.490392640201615,
0.353553390593274, -0.277785116509801, -0.191341716182545, 0.490392640201615,
-0.353553390593274, -0.097545161008064, 0.461939766255643, -0.415734806151273,
0.353553390593274, -0.415734806151273, 0.191341716182545, 0.097545161008064,
-0.353553390593274, 0.490392640201615, -0.461939766255643, 0.277785116509801,
0.353553390593274, -0.490392640201615, 0.461939766255643, -0.415734806151273,
0.353553390593274, -0.277785116509801, 0.191341716182545, -0.097545161008064
};
float iadst_8[64] = {
0.089131608307533, 0.255357107325376, 0.387095214016349, 0.466553967085785,
0.483002021635509, 0.434217976756762, 0.326790388032145, 0.175227946595735,
0.175227946595735, 0.434217976756762, 0.466553967085785, 0.255357107325376,
-0.089131608307533, -0.387095214016348, -0.483002021635509, -0.326790388032145,
0.255357107325376, 0.483002021635509, 0.175227946595735, -0.326790388032145,
-0.466553967085785, -0.089131608307533, 0.387095214016349, 0.434217976756762,
0.326790388032145, 0.387095214016349, -0.255357107325376, -0.434217976756762,
0.175227946595735, 0.466553967085786, -0.089131608307534, -0.483002021635509,
0.387095214016349, 0.175227946595735, -0.483002021635509, 0.089131608307533,
0.434217976756762, -0.326790388032145, -0.255357107325377, 0.466553967085785,
0.434217976756762, -0.089131608307533, -0.326790388032145, 0.483002021635509,
-0.255357107325376, -0.175227946595735, 0.466553967085785, -0.387095214016348,
0.466553967085785, -0.326790388032145, 0.089131608307533, 0.175227946595735,
-0.387095214016348, 0.483002021635509, -0.434217976756762, 0.255357107325376,
0.483002021635509, -0.466553967085785, 0.434217976756762, -0.387095214016348,
0.326790388032145, -0.255357107325375, 0.175227946595736, -0.089131608307532
};
#endif
#if CONFIG_HYBRIDTRANSFORM8X8 || CONFIG_HYBRIDTRANSFORM
void vp8_ihtllm_c(short *input, short *output, int pitch,
TX_TYPE tx_type, int tx_dim) {
int i, j, k;
float bufa[64], bufb[64]; // buffers are for floating-point test purpose
// the implementation could be simplified in
// conjunction with integer transform
// further notice, since we are thinking to use one
// function for both 4x4 and 8x8 transforms, the
// temporary buffers are simply initialized with 64.
short *ip = input;
short *op = output;
int shortpitch = pitch >> 1;
float *pfa = &bufa[0];
float *pfb = &bufb[0];
// pointers to vertical and horizontal transforms
float *ptv, *pth;
// load and convert residual array into floating-point
for(j = 0; j < tx_dim; j++) {
for(i = 0; i < tx_dim; i++) {
pfa[i] = (float)ip[i];
}
pfa += tx_dim;
ip += tx_dim;
}
// vertical transformation
pfa = &bufa[0];
pfb = &bufb[0];
switch(tx_type) {
case ADST_ADST :
case ADST_DCT :
ptv = (tx_dim == 4) ? &iadst_4[0] : &iadst_8[0];
break;
default :
ptv = (tx_dim == 4) ? &idct_4[0] : &idct_8[0];
break;
}
for(j = 0; j < tx_dim; j++) {
for(i = 0; i < tx_dim; i++) {
pfb[i] = 0 ;
for(k = 0; k < tx_dim; k++) {
pfb[i] += ptv[k] * pfa[(k * tx_dim)];
}
pfa += 1;
}
pfb += tx_dim;
ptv += tx_dim;
pfa = &bufa[0];
}
// horizontal transformation
pfa = &bufa[0];
pfb = &bufb[0];
switch(tx_type) {
case ADST_ADST :
case DCT_ADST :
pth = (tx_dim == 4) ? &iadst_4[0] : &iadst_8[0];
break;
default :
pth = (tx_dim == 4) ? &idct_4[0] : &idct_8[0];
break;
}
for(j = 0; j < tx_dim; j++) {
for(i = 0; i < tx_dim; i++) {
pfa[i] = 0;
for(k = 0; k < tx_dim; k++) {
pfa[i] += pfb[k] * pth[k];
}
pth += tx_dim;
}
pfa += tx_dim;
pfb += tx_dim;
switch(tx_type) {
case ADST_ADST :
case DCT_ADST :
pth = (tx_dim == 4) ? &iadst_4[0] : &iadst_8[0];
break;
default :
pth = (tx_dim == 4) ? &idct_4[0] : &idct_8[0];
break;
}
}
// convert to short integer format and load BLOCKD buffer
op = output;
pfa = &bufa[0];
for(j = 0; j < tx_dim; j++) {
for(i = 0; i < tx_dim; i++) {
op[i] = (pfa[i] > 0 ) ? (short)( pfa[i] / 8 + 0.49) :
-(short)( - pfa[i] / 8 + 0.49);
}
op += shortpitch;
pfa += tx_dim;
}
}
#endif
void vp8_short_idct4x4llm_c(short *input, short *output, int pitch) {
int i;
int a1, b1, c1, d1;
short *ip = input;
short *op = output;
int temp1, temp2;
int shortpitch = pitch >> 1;
for (i = 0; i < 4; i++) {
a1 = ip[0] + ip[8];
b1 = ip[0] - ip[8];
temp1 = (ip[4] * sinpi8sqrt2 + rounding) >> 16;
temp2 = ip[12] + ((ip[12] * cospi8sqrt2minus1 + rounding) >> 16);
c1 = temp1 - temp2;
temp1 = ip[4] + ((ip[4] * cospi8sqrt2minus1 + rounding) >> 16);
temp2 = (ip[12] * sinpi8sqrt2 + rounding) >> 16;
d1 = temp1 + temp2;
op[shortpitch * 0] = a1 + d1;
op[shortpitch * 3] = a1 - d1;
op[shortpitch * 1] = b1 + c1;
op[shortpitch * 2] = b1 - c1;
ip++;
op++;
}
ip = output;
op = output;
for (i = 0; i < 4; i++) {
a1 = ip[0] + ip[2];
b1 = ip[0] - ip[2];
temp1 = (ip[1] * sinpi8sqrt2 + rounding) >> 16;
temp2 = ip[3] + ((ip[3] * cospi8sqrt2minus1 + rounding) >> 16);
c1 = temp1 - temp2;
temp1 = ip[1] + ((ip[1] * cospi8sqrt2minus1 + rounding) >> 16);
temp2 = (ip[3] * sinpi8sqrt2 + rounding) >> 16;
d1 = temp1 + temp2;
op[0] = (a1 + d1 + 16) >> 5;
op[3] = (a1 - d1 + 16) >> 5;
op[1] = (b1 + c1 + 16) >> 5;
op[2] = (b1 - c1 + 16) >> 5;
ip += shortpitch;
op += shortpitch;
}
}
void vp8_short_idct4x4llm_1_c(short *input, short *output, int pitch) {
int i;
int a1;
short *op = output;
int shortpitch = pitch >> 1;
a1 = ((input[0] + 16) >> 5);
for (i = 0; i < 4; i++) {
op[0] = a1;
op[1] = a1;
op[2] = a1;
op[3] = a1;
op += shortpitch;
}
}
void vp8_dc_only_idct_add_c(short input_dc, unsigned char *pred_ptr, unsigned char *dst_ptr, int pitch, int stride) {
int a1 = ((input_dc + 16) >> 5);
int r, c;
for (r = 0; r < 4; r++) {
for (c = 0; c < 4; c++) {
int a = a1 + pred_ptr[c];
if (a < 0)
a = 0;
if (a > 255)
a = 255;
dst_ptr[c] = (unsigned char) a;
}
dst_ptr += stride;
pred_ptr += pitch;
}
}
void vp8_short_inv_walsh4x4_c(short *input, short *output) {
int i;
int a1, b1, c1, d1;
short *ip = input;
short *op = output;
for (i = 0; i < 4; i++) {
a1 = ((ip[0] + ip[3]));
b1 = ((ip[1] + ip[2]));
c1 = ((ip[1] - ip[2]));
d1 = ((ip[0] - ip[3]));
op[0] = (a1 + b1 + 1) >> 1;
op[1] = (c1 + d1) >> 1;
op[2] = (a1 - b1) >> 1;
op[3] = (d1 - c1) >> 1;
ip += 4;
op += 4;
}
ip = output;
op = output;
for (i = 0; i < 4; i++) {
a1 = ip[0] + ip[12];
b1 = ip[4] + ip[8];
c1 = ip[4] - ip[8];
d1 = ip[0] - ip[12];
op[0] = (a1 + b1 + 1) >> 1;
op[4] = (c1 + d1) >> 1;
op[8] = (a1 - b1) >> 1;
op[12] = (d1 - c1) >> 1;
ip++;
op++;
}
}
void vp8_short_inv_walsh4x4_1_c(short *in, short *out) {
int i;
short tmp[4];
short *ip = in;
short *op = tmp;
op[0] = (ip[0] + 1) >> 1;
op[1] = op[2] = op[3] = (ip[0] >> 1);
ip = tmp;
op = out;
for (i = 0; i < 4; i++) {
op[0] = (ip[0] + 1) >> 1;
op[4] = op[8] = op[12] = (ip[0] >> 1);
ip++;
op++;
}
}
#if CONFIG_LOSSLESS
void vp8_short_inv_walsh4x4_lossless_c(short *input, short *output) {
int i;
int a1, b1, c1, d1;
short *ip = input;
short *op = output;
for (i = 0; i < 4; i++) {
a1 = ((ip[0] + ip[3])) >> Y2_WHT_UPSCALE_FACTOR;
b1 = ((ip[1] + ip[2])) >> Y2_WHT_UPSCALE_FACTOR;
c1 = ((ip[1] - ip[2])) >> Y2_WHT_UPSCALE_FACTOR;
d1 = ((ip[0] - ip[3])) >> Y2_WHT_UPSCALE_FACTOR;
op[0] = (a1 + b1 + 1) >> 1;
op[1] = (c1 + d1) >> 1;
op[2] = (a1 - b1) >> 1;
op[3] = (d1 - c1) >> 1;
ip += 4;
op += 4;
}
ip = output;
op = output;
for (i = 0; i < 4; i++) {
a1 = ip[0] + ip[12];
b1 = ip[4] + ip[8];
c1 = ip[4] - ip[8];
d1 = ip[0] - ip[12];
op[0] = ((a1 + b1 + 1) >> 1) << Y2_WHT_UPSCALE_FACTOR;
op[4] = ((c1 + d1) >> 1) << Y2_WHT_UPSCALE_FACTOR;
op[8] = ((a1 - b1) >> 1) << Y2_WHT_UPSCALE_FACTOR;
op[12] = ((d1 - c1) >> 1) << Y2_WHT_UPSCALE_FACTOR;
ip++;
op++;
}
}
void vp8_short_inv_walsh4x4_1_lossless_c(short *in, short *out) {
int i;
short tmp[4];
short *ip = in;
short *op = tmp;
op[0] = ((ip[0] >> Y2_WHT_UPSCALE_FACTOR) + 1) >> 1;
op[1] = op[2] = op[3] = ((ip[0] >> Y2_WHT_UPSCALE_FACTOR) >> 1);
ip = tmp;
op = out;
for (i = 0; i < 4; i++) {
op[0] = ((ip[0] + 1) >> 1) << Y2_WHT_UPSCALE_FACTOR;
op[4] = op[8] = op[12] = ((ip[0] >> 1)) << Y2_WHT_UPSCALE_FACTOR;
ip++;
op++;
}
}
void vp8_short_inv_walsh4x4_x8_c(short *input, short *output, int pitch) {
int i;
int a1, b1, c1, d1;
short *ip = input;
short *op = output;
int shortpitch = pitch >> 1;
for (i = 0; i < 4; i++) {
a1 = ((ip[0] + ip[3])) >> WHT_UPSCALE_FACTOR;
b1 = ((ip[1] + ip[2])) >> WHT_UPSCALE_FACTOR;
c1 = ((ip[1] - ip[2])) >> WHT_UPSCALE_FACTOR;
d1 = ((ip[0] - ip[3])) >> WHT_UPSCALE_FACTOR;
op[0] = (a1 + b1 + 1) >> 1;
op[1] = (c1 + d1) >> 1;
op[2] = (a1 - b1) >> 1;
op[3] = (d1 - c1) >> 1;
ip += 4;
op += shortpitch;
}
ip = output;
op = output;
for (i = 0; i < 4; i++) {
a1 = ip[shortpitch * 0] + ip[shortpitch * 3];
b1 = ip[shortpitch * 1] + ip[shortpitch * 2];
c1 = ip[shortpitch * 1] - ip[shortpitch * 2];
d1 = ip[shortpitch * 0] - ip[shortpitch * 3];
op[shortpitch * 0] = (a1 + b1 + 1) >> 1;
op[shortpitch * 1] = (c1 + d1) >> 1;
op[shortpitch * 2] = (a1 - b1) >> 1;
op[shortpitch * 3] = (d1 - c1) >> 1;
ip++;
op++;
}
}
void vp8_short_inv_walsh4x4_1_x8_c(short *in, short *out, int pitch) {
int i;
short tmp[4];
short *ip = in;
short *op = tmp;
int shortpitch = pitch >> 1;
op[0] = ((ip[0] >> WHT_UPSCALE_FACTOR) + 1) >> 1;
op[1] = op[2] = op[3] = ((ip[0] >> WHT_UPSCALE_FACTOR) >> 1);
ip = tmp;
op = out;
for (i = 0; i < 4; i++) {
op[shortpitch * 0] = (ip[0] + 1) >> 1;
op[shortpitch * 1] = op[shortpitch * 2] = op[shortpitch * 3] = ip[0] >> 1;
ip++;
op++;
}
}
void vp8_dc_only_inv_walsh_add_c(short input_dc, unsigned char *pred_ptr, unsigned char *dst_ptr, int pitch, int stride) {
int r, c;
short tmp[16];
vp8_short_inv_walsh4x4_1_x8_c(&input_dc, tmp, 4 << 1);
for (r = 0; r < 4; r++) {
for (c = 0; c < 4; c++) {
int a = tmp[r * 4 + c] + pred_ptr[c];
if (a < 0)
a = 0;
if (a > 255)
a = 255;
dst_ptr[c] = (unsigned char) a;
}
dst_ptr += stride;
pred_ptr += pitch;
}
}
#endif
void vp8_dc_only_idct_add_8x8_c(short input_dc,
unsigned char *pred_ptr,
unsigned char *dst_ptr,
int pitch, int stride) {
int a1 = ((input_dc + 16) >> 5);
int r, c, b;
unsigned char *orig_pred = pred_ptr;
unsigned char *orig_dst = dst_ptr;
for (b = 0; b < 4; b++) {
for (r = 0; r < 4; r++) {
for (c = 0; c < 4; c++) {
int a = a1 + pred_ptr[c];
if (a < 0)
a = 0;
if (a > 255)
a = 255;
dst_ptr[c] = (unsigned char) a;
}
dst_ptr += stride;
pred_ptr += pitch;
}
dst_ptr = orig_dst + (b + 1) % 2 * 4 + (b + 1) / 2 * 4 * stride;
pred_ptr = orig_pred + (b + 1) % 2 * 4 + (b + 1) / 2 * 4 * pitch;
}
}
#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 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) */
/* row (horizontal) IDCT
*
* 7 pi 1 dst[k] = sum c[l] * src[l] * cos( -- *
* ( k + - ) * l ) l=0 8 2
*
* where: c[0] = 128 c[1..7] = 128*sqrt(2) */
static void idctrow(int *blk) {
int x0, x1, x2, x3, x4, x5, x6, x7, x8;
/* shortcut */
if (!((x1 = blk[4] << 11) | (x2 = blk[6]) | (x3 = blk[2]) |
(x4 = blk[1]) | (x5 = blk[7]) | (x6 = blk[5]) | (x7 = blk[3]))) {
blk[0] = blk[1] = blk[2] = blk[3] = blk[4]
= blk[5] = blk[6] = blk[7] = blk[0] << 3;
return;
}
x0 = (blk[0] << 11) + 128; /* for proper rounding in the fourth stage */
/* first stage */
x8 = W7 * (x4 + x5);
x4 = x8 + (W1 - W7) * x4;
x5 = x8 - (W1 + W7) * x5;
x8 = W3 * (x6 + x7);
x6 = x8 - (W3 - W5) * x6;
x7 = x8 - (W3 + W5) * x7;
/* second stage */
x8 = x0 + x1;
x0 -= x1;
x1 = W6 * (x3 + x2);
x2 = x1 - (W2 + W6) * x2;
x3 = x1 + (W2 - W6) * x3;
x1 = x4 + x6;
x4 -= x6;
x6 = x5 + x7;
x5 -= x7;
/* third stage */
x7 = x8 + x3;
x8 -= x3;
x3 = x0 + x2;
x0 -= x2;
x2 = (181 * (x4 + x5) + 128) >> 8;
x4 = (181 * (x4 - x5) + 128) >> 8;
/* fourth stage */
blk[0] = (x7 + x1) >> 8;
blk[1] = (x3 + x2) >> 8;
blk[2] = (x0 + x4) >> 8;
blk[3] = (x8 + x6) >> 8;
blk[4] = (x8 - x6) >> 8;
blk[5] = (x0 - x4) >> 8;
blk[6] = (x3 - x2) >> 8;
blk[7] = (x7 - x1) >> 8;
}
/* column (vertical) IDCT
*
* 7 pi 1 dst[8*k] = sum c[l] * src[8*l] *
* cos( -- * ( k + - ) * l ) l=0 8 2
*
* where: c[0] = 1/1024 c[1..7] = (1/1024)*sqrt(2) */
static void idctcol(int *blk) {
int x0, x1, x2, x3, x4, x5, x6, x7, x8;
/* shortcut */
if (!((x1 = (blk[8 * 4] << 8)) | (x2 = blk[8 * 6]) | (x3 = blk[8 * 2]) |
(x4 = blk[8 * 1]) | (x5 = blk[8 * 7]) | (x6 = blk[8 * 5]) |
(x7 = blk[8 * 3]))) {
blk[8 * 0] = blk[8 * 1] = blk[8 * 2] = blk[8 * 3]
= blk[8 * 4] = blk[8 * 5] = blk[8 * 6]
= blk[8 * 7] = ((blk[8 * 0] + 32) >> 6);
return;
}
x0 = (blk[8 * 0] << 8) + 16384;
/* first stage */
x8 = W7 * (x4 + x5) + 4;
x4 = (x8 + (W1 - W7) * x4) >> 3;
x5 = (x8 - (W1 + W7) * x5) >> 3;
x8 = W3 * (x6 + x7) + 4;
x6 = (x8 - (W3 - W5) * x6) >> 3;
x7 = (x8 - (W3 + W5) * x7) >> 3;
/* second stage */
x8 = x0 + x1;
x0 -= x1;
x1 = W6 * (x3 + x2) + 4;
x2 = (x1 - (W2 + W6) * x2) >> 3;
x3 = (x1 + (W2 - W6) * x3) >> 3;
x1 = x4 + x6;
x4 -= x6;
x6 = x5 + x7;
x5 -= x7;
/* third stage */
x7 = x8 + x3;
x8 -= x3;
x3 = x0 + x2;
x0 -= x2;
x2 = (181 * (x4 + x5) + 128) >> 8;
x4 = (181 * (x4 - x5) + 128) >> 8;
/* fourth stage */
blk[8 * 0] = (x7 + x1) >> 14;
blk[8 * 1] = (x3 + x2) >> 14;
blk[8 * 2] = (x0 + x4) >> 14;
blk[8 * 3] = (x8 + x6) >> 14;
blk[8 * 4] = (x8 - x6) >> 14;
blk[8 * 5] = (x0 - x4) >> 14;
blk[8 * 6] = (x3 - x2) >> 14;
blk[8 * 7] = (x7 - x1) >> 14;
}
#define TX_DIM 8
void vp8_short_idct8x8_c(short *coefs, short *block, int pitch) {
int X[TX_DIM * TX_DIM];
int i, j;
int shortpitch = pitch >> 1;
for (i = 0; i < TX_DIM; i++) {
for (j = 0; j < TX_DIM; j++) {
X[i * TX_DIM + j] = (int)(coefs[i * TX_DIM + j] + 1
+ (coefs[i * TX_DIM + j] < 0)) >> 2;
}
}
for (i = 0; i < 8; i++)
idctrow(X + 8 * i);
for (i = 0; i < 8; i++)
idctcol(X + i);
for (i = 0; i < TX_DIM; i++) {
for (j = 0; j < TX_DIM; j++) {
block[i * shortpitch + j] = X[i * TX_DIM + j] >> 1;
}
}
}
void vp8_short_ihaar2x2_c(short *input, short *output, int pitch) {
int i;
short *ip = input; // 0,1, 4, 8
short *op = output;
for (i = 0; i < 16; i++) {
op[i] = 0;
}
op[0] = (ip[0] + ip[1] + ip[4] + ip[8] + 1) >> 1;
op[1] = (ip[0] - ip[1] + ip[4] - ip[8]) >> 1;
op[4] = (ip[0] + ip[1] - ip[4] - ip[8]) >> 1;
op[8] = (ip[0] - ip[1] - ip[4] + ip[8]) >> 1;
}
#if CONFIG_TX16X16
#if 0
// Keep a really bad float version as reference for now.
void vp8_short_idct16x16_c(short *input, short *output, int pitch) {
double x;
const int short_pitch = pitch >> 1;
int i, j, k, l;
for (l = 0; l < 16; ++l) {
for (k = 0; k < 16; ++k) {
double s = 0;
for (i = 0; i < 16; ++i) {
for (j = 0; j < 16; ++j) {
x=cos(PI*j*(l+0.5)/16.0)*cos(PI*i*(k+0.5)/16.0)*input[i*16+j]/32;
if (i != 0)
x *= sqrt(2.0);
if (j != 0)
x *= sqrt(2.0);
s += x;
}
}
output[k*short_pitch+l] = (short)round(s);
}
}
}
#endif
static const double C1 = 0.995184726672197;
static const double C2 = 0.98078528040323;
static const double C3 = 0.956940335732209;
static const double C4 = 0.923879532511287;
static const double C5 = 0.881921264348355;
static const double C6 = 0.831469612302545;
static const double C7 = 0.773010453362737;
static const double C8 = 0.707106781186548;
static const double C9 = 0.634393284163646;
static const double C10 = 0.555570233019602;
static const double C11 = 0.471396736825998;
static const double C12 = 0.38268343236509;
static const double C13 = 0.290284677254462;
static const double C14 = 0.195090322016128;
static const double C15 = 0.098017140329561;
static void butterfly_16x16_idct_1d(double input[16], double output[16]) {
double step[16];
double intermediate[16];
double temp1, temp2;
// step 1 and 2
step[ 0] = input[0] + input[8];
step[ 1] = input[0] - input[8];
temp1 = input[4]*C12;
temp2 = input[12]*C4;
temp1 -= temp2;
temp1 *= C8;
step[ 2] = 2*(temp1);
temp1 = input[4]*C4;
temp2 = input[12]*C12;
temp1 += temp2;
temp1 = (temp1);
temp1 *= C8;
step[ 3] = 2*(temp1);
temp1 = input[2]*C8;
temp1 = 2*(temp1);
temp2 = input[6] + input[10];
step[ 4] = temp1 + temp2;
step[ 5] = temp1 - temp2;
temp1 = input[14]*C8;
temp1 = 2*(temp1);
temp2 = input[6] - input[10];
step[ 6] = temp2 - temp1;
step[ 7] = temp2 + temp1;
// for odd input
temp1 = input[3]*C12;
temp2 = input[13]*C4;
temp1 += temp2;
temp1 = (temp1);
temp1 *= C8;
intermediate[ 8] = 2*(temp1);
temp1 = input[3]*C4;
temp2 = input[13]*C12;
temp2 -= temp1;
temp2 = (temp2);
temp2 *= C8;
intermediate[ 9] = 2*(temp2);
intermediate[10] = 2*(input[9]*C8);
intermediate[11] = input[15] - input[1];
intermediate[12] = input[15] + input[1];
intermediate[13] = 2*((input[7]*C8));
temp1 = input[11]*C12;
temp2 = input[5]*C4;
temp2 -= temp1;
temp2 = (temp2);
temp2 *= C8;
intermediate[14] = 2*(temp2);
temp1 = input[11]*C4;
temp2 = input[5]*C12;
temp1 += temp2;
temp1 = (temp1);
temp1 *= C8;
intermediate[15] = 2*(temp1);
step[ 8] = intermediate[ 8] + intermediate[14];
step[ 9] = intermediate[ 9] + intermediate[15];
step[10] = intermediate[10] + intermediate[11];
step[11] = intermediate[10] - intermediate[11];
step[12] = intermediate[12] + intermediate[13];
step[13] = intermediate[12] - intermediate[13];
step[14] = intermediate[ 8] - intermediate[14];
step[15] = intermediate[ 9] - intermediate[15];
// step 3
output[0] = step[ 0] + step[ 3];
output[1] = step[ 1] + step[ 2];
output[2] = step[ 1] - step[ 2];
output[3] = step[ 0] - step[ 3];
temp1 = step[ 4]*C14;
temp2 = step[ 7]*C2;
temp1 -= temp2;
output[4] = (temp1);
temp1 = step[ 4]*C2;
temp2 = step[ 7]*C14;
temp1 += temp2;
output[7] = (temp1);
temp1 = step[ 5]*C10;
temp2 = step[ 6]*C6;
temp1 -= temp2;
output[5] = (temp1);
temp1 = step[ 5]*C6;
temp2 = step[ 6]*C10;
temp1 += temp2;
output[6] = (temp1);
output[8] = step[ 8] + step[11];
output[9] = step[ 9] + step[10];
output[10] = step[ 9] - step[10];
output[11] = step[ 8] - step[11];
output[12] = step[12] + step[15];
output[13] = step[13] + step[14];
output[14] = step[13] - step[14];
output[15] = step[12] - step[15];
// output 4
step[ 0] = output[0] + output[7];
step[ 1] = output[1] + output[6];
step[ 2] = output[2] + output[5];
step[ 3] = output[3] + output[4];
step[ 4] = output[3] - output[4];
step[ 5] = output[2] - output[5];
step[ 6] = output[1] - output[6];
step[ 7] = output[0] - output[7];
temp1 = output[8]*C7;
temp2 = output[15]*C9;
temp1 -= temp2;
step[ 8] = (temp1);
temp1 = output[9]*C11;
temp2 = output[14]*C5;
temp1 += temp2;
step[ 9] = (temp1);
temp1 = output[10]*C3;
temp2 = output[13]*C13;
temp1 -= temp2;
step[10] = (temp1);
temp1 = output[11]*C15;
temp2 = output[12]*C1;
temp1 += temp2;
step[11] = (temp1);
temp1 = output[11]*C1;
temp2 = output[12]*C15;
temp2 -= temp1;
step[12] = (temp2);
temp1 = output[10]*C13;
temp2 = output[13]*C3;
temp1 += temp2;
step[13] = (temp1);
temp1 = output[9]*C5;
temp2 = output[14]*C11;
temp2 -= temp1;
step[14] = (temp2);
temp1 = output[8]*C9;
temp2 = output[15]*C7;
temp1 += temp2;
step[15] = (temp1);
// step 5
output[0] = (step[0] + step[15]);
output[1] = (step[1] + step[14]);
output[2] = (step[2] + step[13]);
output[3] = (step[3] + step[12]);
output[4] = (step[4] + step[11]);
output[5] = (step[5] + step[10]);
output[6] = (step[6] + step[ 9]);
output[7] = (step[7] + step[ 8]);
output[15] = (step[0] - step[15]);
output[14] = (step[1] - step[14]);
output[13] = (step[2] - step[13]);
output[12] = (step[3] - step[12]);
output[11] = (step[4] - step[11]);
output[10] = (step[5] - step[10]);
output[9] = (step[6] - step[ 9]);
output[8] = (step[7] - step[ 8]);
}
// Remove once an int version of iDCT is written
#if 0
void reference_16x16_idct_1d(double input[16], double output[16]) {
const double kPi = 3.141592653589793238462643383279502884;
const double kSqrt2 = 1.414213562373095048801688724209698;
for (int k = 0; k < 16; k++) {
output[k] = 0.0;
for (int n = 0; n < 16; n++) {
output[k] += input[n]*cos(kPi*(2*k+1)*n/32.0);
if (n == 0)
output[k] = output[k]/kSqrt2;
}
}
}
#endif
void vp8_short_idct16x16_c(short *input, short *output, int pitch) {
double out[16*16], out2[16*16];
const int short_pitch = pitch >> 1;
int i, j;
// First transform rows
for (i = 0; i < 16; ++i) {
double temp_in[16], temp_out[16];
for (j = 0; j < 16; ++j)
temp_in[j] = input[j + i*short_pitch];
butterfly_16x16_idct_1d(temp_in, temp_out);
for (j = 0; j < 16; ++j)
out[j + i*16] = temp_out[j];
}
// Then transform columns
for (i = 0; i < 16; ++i) {
double temp_in[16], temp_out[16];
for (j = 0; j < 16; ++j)
temp_in[j] = out[j*16 + i];
butterfly_16x16_idct_1d(temp_in, temp_out);
for (j = 0; j < 16; ++j)
out2[j*16 + i] = temp_out[j];
}
for (i = 0; i < 16*16; ++i)
output[i] = round(out2[i]/128);
}
#endif
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