ref: 896b6a9b5744f666c4658effc591f1e48e402748
dir: /vp8/common/idctllm.c/
/*
* 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"
#include <math.h>
static const int cospi8sqrt2minus1 = 20091;
static const int sinpi8sqrt2 = 35468;
static const int rounding = 0;
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;
}