Commit 042e70e4 authored by Yaowu Xu's avatar Yaowu Xu
Browse files

Changed to use a new variant of WHT

The commit changed to use a new variant of Walsh-Hadamard Transform
by Tim Terriberry. This new variant has the best compression among a
number of variants that developed by Tim.

Change-Id: Icb3a88515463cfc644b17ca046fcd139db2557e9
parent 5e97862a
......@@ -32,20 +32,17 @@ void vp9_short_iwalsh4x4_add_c(int16_t *input, uint8_t *dest, int dest_stride) {
c1 = ip[1] >> WHT_UPSCALE_FACTOR;
d1 = ip[2] >> WHT_UPSCALE_FACTOR;
b1 = ip[3] >> WHT_UPSCALE_FACTOR;
c1 = a1 - c1;
b1 += d1;
e1 = (c1 - b1) >> 1;
a1 -= e1;
d1 += e1;
b1 = a1 - b1;
c1 -= d1;
a1 += c1;
d1 -= b1;
e1 = (a1 - d1) >> 1;
b1 = e1 - b1;
c1 = e1 - c1;
a1 -= b1;
d1 += c1;
op[0] = a1;
op[1] = b1;
op[2] = c1;
op[3] = d1;
ip += 4;
op += 4;
}
......@@ -56,15 +53,13 @@ void vp9_short_iwalsh4x4_add_c(int16_t *input, uint8_t *dest, int dest_stride) {
c1 = ip[4 * 1];
d1 = ip[4 * 2];
b1 = ip[4 * 3];
c1 = a1 - c1;
b1 += d1;
e1 = (c1 - b1) >> 1;
a1 -= e1;
d1 += e1;
b1 = a1 - b1;
c1 -= d1;
a1 += c1;
d1 -= b1;
e1 = (a1 - d1) >> 1;
b1 = e1 - b1;
c1 = e1 - c1;
a1 -= b1;
d1 += c1;
dest[dest_stride * 0] = clip_pixel(dest[dest_stride * 0] + a1);
dest[dest_stride * 1] = clip_pixel(dest[dest_stride * 1] + b1);
dest[dest_stride * 2] = clip_pixel(dest[dest_stride * 2] + c1);
......@@ -84,16 +79,17 @@ void vp9_short_iwalsh4x4_1_add_c(int16_t *in, uint8_t *dest, int dest_stride) {
a1 = ip[0] >> WHT_UPSCALE_FACTOR;
e1 = a1 >> 1;
op[0] = op[1] = op[2] = a1 - e1;
op[3] = e1;
a1 -= e1;
op[0] = a1;
op[1] = op[2] = op[3] = e1;
ip = tmp;
for (i = 0; i < 4; i++) {
e1 = ip[0] >> 1;
a1 = ip[0] - e1;
dest[dest_stride * 0] = clip_pixel(dest[dest_stride * 0] + a1);
dest[dest_stride * 1] = clip_pixel(dest[dest_stride * 1] + a1);
dest[dest_stride * 2] = clip_pixel(dest[dest_stride * 2] + a1);
dest[dest_stride * 1] = clip_pixel(dest[dest_stride * 1] + e1);
dest[dest_stride * 2] = clip_pixel(dest[dest_stride * 2] + e1);
dest[dest_stride * 3] = clip_pixel(dest[dest_stride * 3] + e1);
ip++;
dest++;
......
......@@ -17,6 +17,7 @@
#include "vpx/vpx_integer.h"
#include "vp9/common/vp9_common.h"
// Constants and Macros used by all idct/dct functions
#define DCT_CONST_BITS 14
#define DCT_CONST_ROUNDING (1 << (DCT_CONST_BITS - 1))
......
......@@ -606,14 +606,13 @@ void vp9_short_walsh4x4_c(short *input, short *output, int pitch) {
c1 = ip[2 * pitch_short];
d1 = ip[3 * pitch_short];
b1 = a1 - b1;
c1 += d1;
e1 = (c1 - b1) >> 1;
a1 += e1;
d1 -= e1;
c1 = a1 - c1;
b1 -= d1;
a1 += b1;
d1 = d1 - c1;
e1 = (a1 - d1) >> 1;
b1 = e1 - b1;
c1 = e1 - c1;
a1 -= c1;
d1 += b1;
op[0] = a1;
op[4] = c1;
op[8] = d1;
......@@ -631,14 +630,13 @@ void vp9_short_walsh4x4_c(short *input, short *output, int pitch) {
c1 = ip[2];
d1 = ip[3];
b1 = a1 - b1;
c1 += d1;
e1 = (c1 - b1) >> 1;
a1 += e1;
d1 -= e1;
c1 = a1 - c1;
b1 -= d1;
a1 += b1;
d1 -= c1;
e1 = (a1 - d1) >> 1;
b1 = e1 - b1;
c1 = e1 - c1;
a1 -= c1;
d1 += b1;
op[0] = a1 << WHT_UPSCALE_FACTOR;
op[1] = c1 << WHT_UPSCALE_FACTOR;
op[2] = d1 << WHT_UPSCALE_FACTOR;
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment