ref: daefbf2a6f5a2a9334355845396fa5f2fdccbaa5
dir: /vp8/common/loopfilter_filters.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.
*/
#include <stdlib.h>
#include "loopfilter.h"
#include "onyxc_int.h"
typedef unsigned char uc;
static signed char vp8_signed_char_clamp(int t) {
t = (t < -128 ? -128 : t);
t = (t > 127 ? 127 : t);
return (signed char)t;
}
/* should we apply any filter at all ( 11111111 yes, 00000000 no) */
static signed char vp8_filter_mask(uc limit, uc blimit, uc p3, uc p2, uc p1,
uc p0, uc q0, uc q1, uc q2, uc q3) {
signed char mask = 0;
mask |= (abs(p3 - p2) > limit);
mask |= (abs(p2 - p1) > limit);
mask |= (abs(p1 - p0) > limit);
mask |= (abs(q1 - q0) > limit);
mask |= (abs(q2 - q1) > limit);
mask |= (abs(q3 - q2) > limit);
mask |= (abs(p0 - q0) * 2 + abs(p1 - q1) / 2 > blimit);
return mask - 1;
}
/* is there high variance internal edge ( 11111111 yes, 00000000 no) */
static signed char vp8_hevmask(uc thresh, uc p1, uc p0, uc q0, uc q1) {
signed char hev = 0;
hev |= (abs(p1 - p0) > thresh) * -1;
hev |= (abs(q1 - q0) > thresh) * -1;
return hev;
}
static void vp8_filter(signed char mask, uc hev, uc *op1, uc *op0, uc *oq0,
uc *oq1) {
signed char ps0, qs0;
signed char ps1, qs1;
signed char filter_value, Filter1, Filter2;
signed char u;
ps1 = (signed char)*op1 ^ 0x80;
ps0 = (signed char)*op0 ^ 0x80;
qs0 = (signed char)*oq0 ^ 0x80;
qs1 = (signed char)*oq1 ^ 0x80;
/* add outer taps if we have high edge variance */
filter_value = vp8_signed_char_clamp(ps1 - qs1);
filter_value &= hev;
/* inner taps */
filter_value = vp8_signed_char_clamp(filter_value + 3 * (qs0 - ps0));
filter_value &= mask;
/* save bottom 3 bits so that we round one side +4 and the other +3
* if it equals 4 we'll set it to adjust by -1 to account for the fact
* we'd round it by 3 the other way
*/
Filter1 = vp8_signed_char_clamp(filter_value + 4);
Filter2 = vp8_signed_char_clamp(filter_value + 3);
Filter1 >>= 3;
Filter2 >>= 3;
u = vp8_signed_char_clamp(qs0 - Filter1);
*oq0 = u ^ 0x80;
u = vp8_signed_char_clamp(ps0 + Filter2);
*op0 = u ^ 0x80;
filter_value = Filter1;
/* outer tap adjustments */
filter_value += 1;
filter_value >>= 1;
filter_value &= ~hev;
u = vp8_signed_char_clamp(qs1 - filter_value);
*oq1 = u ^ 0x80;
u = vp8_signed_char_clamp(ps1 + filter_value);
*op1 = u ^ 0x80;
}
static void loop_filter_horizontal_edge_c(unsigned char *s, int p, /* pitch */
const unsigned char *blimit,
const unsigned char *limit,
const unsigned char *thresh,
int count) {
int hev = 0; /* high edge variance */
signed char mask = 0;
int i = 0;
/* loop filter designed to work using chars so that we can make maximum use
* of 8 bit simd instructions.
*/
do {
mask = vp8_filter_mask(limit[0], blimit[0], s[-4 * p], s[-3 * p], s[-2 * p],
s[-1 * p], s[0 * p], s[1 * p], s[2 * p], s[3 * p]);
hev = vp8_hevmask(thresh[0], s[-2 * p], s[-1 * p], s[0 * p], s[1 * p]);
vp8_filter(mask, hev, s - 2 * p, s - 1 * p, s, s + 1 * p);
++s;
} while (++i < count * 8);
}
static void loop_filter_vertical_edge_c(unsigned char *s, int p,
const unsigned char *blimit,
const unsigned char *limit,
const unsigned char *thresh,
int count) {
int hev = 0; /* high edge variance */
signed char mask = 0;
int i = 0;
/* loop filter designed to work using chars so that we can make maximum use
* of 8 bit simd instructions.
*/
do {
mask = vp8_filter_mask(limit[0], blimit[0], s[-4], s[-3], s[-2], s[-1],
s[0], s[1], s[2], s[3]);
hev = vp8_hevmask(thresh[0], s[-2], s[-1], s[0], s[1]);
vp8_filter(mask, hev, s - 2, s - 1, s, s + 1);
s += p;
} while (++i < count * 8);
}
static void vp8_mbfilter(signed char mask, uc hev, uc *op2, uc *op1, uc *op0,
uc *oq0, uc *oq1, uc *oq2) {
signed char s, u;
signed char filter_value, Filter1, Filter2;
signed char ps2 = (signed char)*op2 ^ 0x80;
signed char ps1 = (signed char)*op1 ^ 0x80;
signed char ps0 = (signed char)*op0 ^ 0x80;
signed char qs0 = (signed char)*oq0 ^ 0x80;
signed char qs1 = (signed char)*oq1 ^ 0x80;
signed char qs2 = (signed char)*oq2 ^ 0x80;
/* add outer taps if we have high edge variance */
filter_value = vp8_signed_char_clamp(ps1 - qs1);
filter_value = vp8_signed_char_clamp(filter_value + 3 * (qs0 - ps0));
filter_value &= mask;
Filter2 = filter_value;
Filter2 &= hev;
/* save bottom 3 bits so that we round one side +4 and the other +3 */
Filter1 = vp8_signed_char_clamp(Filter2 + 4);
Filter2 = vp8_signed_char_clamp(Filter2 + 3);
Filter1 >>= 3;
Filter2 >>= 3;
qs0 = vp8_signed_char_clamp(qs0 - Filter1);
ps0 = vp8_signed_char_clamp(ps0 + Filter2);
/* only apply wider filter if not high edge variance */
filter_value &= ~hev;
Filter2 = filter_value;
/* roughly 3/7th difference across boundary */
u = vp8_signed_char_clamp((63 + Filter2 * 27) >> 7);
s = vp8_signed_char_clamp(qs0 - u);
*oq0 = s ^ 0x80;
s = vp8_signed_char_clamp(ps0 + u);
*op0 = s ^ 0x80;
/* roughly 2/7th difference across boundary */
u = vp8_signed_char_clamp((63 + Filter2 * 18) >> 7);
s = vp8_signed_char_clamp(qs1 - u);
*oq1 = s ^ 0x80;
s = vp8_signed_char_clamp(ps1 + u);
*op1 = s ^ 0x80;
/* roughly 1/7th difference across boundary */
u = vp8_signed_char_clamp((63 + Filter2 * 9) >> 7);
s = vp8_signed_char_clamp(qs2 - u);
*oq2 = s ^ 0x80;
s = vp8_signed_char_clamp(ps2 + u);
*op2 = s ^ 0x80;
}
static void mbloop_filter_horizontal_edge_c(unsigned char *s, int p,
const unsigned char *blimit,
const unsigned char *limit,
const unsigned char *thresh,
int count) {
signed char hev = 0; /* high edge variance */
signed char mask = 0;
int i = 0;
/* loop filter designed to work using chars so that we can make maximum use
* of 8 bit simd instructions.
*/
do {
mask = vp8_filter_mask(limit[0], blimit[0], s[-4 * p], s[-3 * p], s[-2 * p],
s[-1 * p], s[0 * p], s[1 * p], s[2 * p], s[3 * p]);
hev = vp8_hevmask(thresh[0], s[-2 * p], s[-1 * p], s[0 * p], s[1 * p]);
vp8_mbfilter(mask, hev, s - 3 * p, s - 2 * p, s - 1 * p, s, s + 1 * p,
s + 2 * p);
++s;
} while (++i < count * 8);
}
static void mbloop_filter_vertical_edge_c(unsigned char *s, int p,
const unsigned char *blimit,
const unsigned char *limit,
const unsigned char *thresh,
int count) {
signed char hev = 0; /* high edge variance */
signed char mask = 0;
int i = 0;
do {
mask = vp8_filter_mask(limit[0], blimit[0], s[-4], s[-3], s[-2], s[-1],
s[0], s[1], s[2], s[3]);
hev = vp8_hevmask(thresh[0], s[-2], s[-1], s[0], s[1]);
vp8_mbfilter(mask, hev, s - 3, s - 2, s - 1, s, s + 1, s + 2);
s += p;
} while (++i < count * 8);
}
/* should we apply any filter at all ( 11111111 yes, 00000000 no) */
static signed char vp8_simple_filter_mask(uc blimit, uc p1, uc p0, uc q0,
uc q1) {
/* Why does this cause problems for win32?
* error C2143: syntax error : missing ';' before 'type'
* (void) limit;
*/
signed char mask = (abs(p0 - q0) * 2 + abs(p1 - q1) / 2 <= blimit) * -1;
return mask;
}
static void vp8_simple_filter(signed char mask, uc *op1, uc *op0, uc *oq0,
uc *oq1) {
signed char filter_value, Filter1, Filter2;
signed char p1 = (signed char)*op1 ^ 0x80;
signed char p0 = (signed char)*op0 ^ 0x80;
signed char q0 = (signed char)*oq0 ^ 0x80;
signed char q1 = (signed char)*oq1 ^ 0x80;
signed char u;
filter_value = vp8_signed_char_clamp(p1 - q1);
filter_value = vp8_signed_char_clamp(filter_value + 3 * (q0 - p0));
filter_value &= mask;
/* save bottom 3 bits so that we round one side +4 and the other +3 */
Filter1 = vp8_signed_char_clamp(filter_value + 4);
Filter1 >>= 3;
u = vp8_signed_char_clamp(q0 - Filter1);
*oq0 = u ^ 0x80;
Filter2 = vp8_signed_char_clamp(filter_value + 3);
Filter2 >>= 3;
u = vp8_signed_char_clamp(p0 + Filter2);
*op0 = u ^ 0x80;
}
void vp8_loop_filter_simple_horizontal_edge_c(unsigned char *y_ptr,
int y_stride,
const unsigned char *blimit) {
signed char mask = 0;
int i = 0;
do {
mask = vp8_simple_filter_mask(blimit[0], y_ptr[-2 * y_stride],
y_ptr[-1 * y_stride], y_ptr[0 * y_stride],
y_ptr[1 * y_stride]);
vp8_simple_filter(mask, y_ptr - 2 * y_stride, y_ptr - 1 * y_stride, y_ptr,
y_ptr + 1 * y_stride);
++y_ptr;
} while (++i < 16);
}
void vp8_loop_filter_simple_vertical_edge_c(unsigned char *y_ptr, int y_stride,
const unsigned char *blimit) {
signed char mask = 0;
int i = 0;
do {
mask = vp8_simple_filter_mask(blimit[0], y_ptr[-2], y_ptr[-1], y_ptr[0],
y_ptr[1]);
vp8_simple_filter(mask, y_ptr - 2, y_ptr - 1, y_ptr, y_ptr + 1);
y_ptr += y_stride;
} while (++i < 16);
}
/* Horizontal MB filtering */
void vp8_loop_filter_mbh_c(unsigned char *y_ptr, unsigned char *u_ptr,
unsigned char *v_ptr, int y_stride, int uv_stride,
loop_filter_info *lfi) {
mbloop_filter_horizontal_edge_c(y_ptr, y_stride, lfi->mblim, lfi->lim,
lfi->hev_thr, 2);
if (u_ptr) {
mbloop_filter_horizontal_edge_c(u_ptr, uv_stride, lfi->mblim, lfi->lim,
lfi->hev_thr, 1);
}
if (v_ptr) {
mbloop_filter_horizontal_edge_c(v_ptr, uv_stride, lfi->mblim, lfi->lim,
lfi->hev_thr, 1);
}
}
/* Vertical MB Filtering */
void vp8_loop_filter_mbv_c(unsigned char *y_ptr, unsigned char *u_ptr,
unsigned char *v_ptr, int y_stride, int uv_stride,
loop_filter_info *lfi) {
mbloop_filter_vertical_edge_c(y_ptr, y_stride, lfi->mblim, lfi->lim,
lfi->hev_thr, 2);
if (u_ptr) {
mbloop_filter_vertical_edge_c(u_ptr, uv_stride, lfi->mblim, lfi->lim,
lfi->hev_thr, 1);
}
if (v_ptr) {
mbloop_filter_vertical_edge_c(v_ptr, uv_stride, lfi->mblim, lfi->lim,
lfi->hev_thr, 1);
}
}
/* Horizontal B Filtering */
void vp8_loop_filter_bh_c(unsigned char *y_ptr, unsigned char *u_ptr,
unsigned char *v_ptr, int y_stride, int uv_stride,
loop_filter_info *lfi) {
loop_filter_horizontal_edge_c(y_ptr + 4 * y_stride, y_stride, lfi->blim,
lfi->lim, lfi->hev_thr, 2);
loop_filter_horizontal_edge_c(y_ptr + 8 * y_stride, y_stride, lfi->blim,
lfi->lim, lfi->hev_thr, 2);
loop_filter_horizontal_edge_c(y_ptr + 12 * y_stride, y_stride, lfi->blim,
lfi->lim, lfi->hev_thr, 2);
if (u_ptr) {
loop_filter_horizontal_edge_c(u_ptr + 4 * uv_stride, uv_stride, lfi->blim,
lfi->lim, lfi->hev_thr, 1);
}
if (v_ptr) {
loop_filter_horizontal_edge_c(v_ptr + 4 * uv_stride, uv_stride, lfi->blim,
lfi->lim, lfi->hev_thr, 1);
}
}
void vp8_loop_filter_bhs_c(unsigned char *y_ptr, int y_stride,
const unsigned char *blimit) {
vp8_loop_filter_simple_horizontal_edge_c(y_ptr + 4 * y_stride, y_stride,
blimit);
vp8_loop_filter_simple_horizontal_edge_c(y_ptr + 8 * y_stride, y_stride,
blimit);
vp8_loop_filter_simple_horizontal_edge_c(y_ptr + 12 * y_stride, y_stride,
blimit);
}
/* Vertical B Filtering */
void vp8_loop_filter_bv_c(unsigned char *y_ptr, unsigned char *u_ptr,
unsigned char *v_ptr, int y_stride, int uv_stride,
loop_filter_info *lfi) {
loop_filter_vertical_edge_c(y_ptr + 4, y_stride, lfi->blim, lfi->lim,
lfi->hev_thr, 2);
loop_filter_vertical_edge_c(y_ptr + 8, y_stride, lfi->blim, lfi->lim,
lfi->hev_thr, 2);
loop_filter_vertical_edge_c(y_ptr + 12, y_stride, lfi->blim, lfi->lim,
lfi->hev_thr, 2);
if (u_ptr) {
loop_filter_vertical_edge_c(u_ptr + 4, uv_stride, lfi->blim, lfi->lim,
lfi->hev_thr, 1);
}
if (v_ptr) {
loop_filter_vertical_edge_c(v_ptr + 4, uv_stride, lfi->blim, lfi->lim,
lfi->hev_thr, 1);
}
}
void vp8_loop_filter_bvs_c(unsigned char *y_ptr, int y_stride,
const unsigned char *blimit) {
vp8_loop_filter_simple_vertical_edge_c(y_ptr + 4, y_stride, blimit);
vp8_loop_filter_simple_vertical_edge_c(y_ptr + 8, y_stride, blimit);
vp8_loop_filter_simple_vertical_edge_c(y_ptr + 12, y_stride, blimit);
}