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66f440f1ee
vpx/vp8/common/idctllm.c
Jingning Han 66f440f1ee Refactoring hybrid transform coding 
The forward and inverse hybrid transforms are now performed using
single function modules, where the dimension is sent as argument.

Added an inline function clip8b to clip the reconstruction pixels
into range of 0-255.

Change-Id: Id7d870b3e1aefc092721c80c0af6f641eb5f3747
2012-08-06 17:26:21 -07:00

970 lines
26 KiB
C
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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 void butterfly_16x16_idct_1d(double input[16], double output[16]) {
double step[16];
double intermediate[16];
double temp1, temp2;
const double PI = M_PI;
const double C1 = cos(1*PI/(double)32);
const double C2 = cos(2*PI/(double)32);
const double C3 = cos(3*PI/(double)32);
const double C4 = cos(4*PI/(double)32);
const double C5 = cos(5*PI/(double)32);
const double C6 = cos(6*PI/(double)32);
const double C7 = cos(7*PI/(double)32);
const double C8 = cos(8*PI/(double)32);
const double C9 = cos(9*PI/(double)32);
const double C10 = cos(10*PI/(double)32);
const double C11 = cos(11*PI/(double)32);
const double C12 = cos(12*PI/(double)32);
const double C13 = cos(13*PI/(double)32);
const double C14 = cos(14*PI/(double)32);
const double C15 = cos(15*PI/(double)32);
// 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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