/*
* Copyright (c) 2020, Alliance for Open Media. All rights reserved.
*
* This source code is subject to the terms of the BSD 2 Clause License and
* the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
* was not distributed with this source code in the LICENSE file, you can
* obtain it at www.aomedia.org/license/software. If the Alliance for Open
* Media Patent License 1.0 was not distributed with this source code in the
* PATENTS file, you can obtain it at www.aomedia.org/license/patent.
*/
#include <assert.h>
#include <arm_neon.h>
#include "av1/encoder/rdopt.h"
#include "config/aom_config.h"
#include "config/av1_rtcd.h"
// Process horizontal and vertical correlations in a 4x4 block of pixels.
// We actually use the 4x4 pixels to calculate correlations corresponding to
// the top-left 3x3 pixels, so this function must be called with 1x1 overlap,
// moving the window along/down by 3 pixels at a time.
static inline void horver_correlation_4x4(
const int16_t *diff,
int stride,
int32x4_t *xy_sum_32,
int32x4_t *xz_sum_32,
int32x4_t *x_sum_32,
int32x4_t *x2_sum_32) {
// Pixels in this 4x4 [ a b c d ]
// are referred to as: [ e f g h ]
// [ i j k l ]
// [ m n o p ]
const int16x4_t pixelsa_2_lo = vld1_s16(diff + (0 * stride));
const int16x4_t pixelsa_2_sli =
vreinterpret_s16_s64(vshl_n_s64(vreinterpret_s64_s16(pixelsa_2_lo), 16));
const int16x4_t pixelsb_2_lo = vld1_s16(diff + (1 * stride));
const int16x4_t pixelsb_2_sli =
vreinterpret_s16_s64(vshl_n_s64(vreinterpret_s64_s16(pixelsb_2_lo), 16));
const int16x4_t pixelsa_1_lo = vld1_s16(diff + (2 * stride));
const int16x4_t pixelsa_1_sli =
vreinterpret_s16_s64(vshl_n_s64(vreinterpret_s64_s16(pixelsa_1_lo), 16));
const int16x4_t pixelsb_1_lo = vld1_s16(diff + (3 * stride));
const int16x4_t pixelsb_1_sli =
vreinterpret_s16_s64(vshl_n_s64(vreinterpret_s64_s16(pixelsb_1_lo), 16));
const int16x8_t slli_a = vcombine_s16(pixelsa_1_sli, pixelsa_2_sli);
*xy_sum_32 = vmlal_s16(*xy_sum_32, pixelsa_1_lo, pixelsa_1_sli);
*xy_sum_32 = vmlal_s16(*xy_sum_32, pixelsa_2_lo, pixelsa_2_sli);
*xy_sum_32 = vmlal_s16(*xy_sum_32, pixelsb_2_lo, pixelsb_2_sli);
*xz_sum_32 = vmlal_s16(*xz_sum_32, pixelsa_1_sli, pixelsb_1_sli);
*xz_sum_32 = vmlal_s16(*xz_sum_32, pixelsa_2_sli, pixelsb_2_sli);
*xz_sum_32 = vmlal_s16(*xz_sum_32, pixelsa_1_sli, pixelsb_2_sli);
// Now calculate the straight sums, x_sum += a+b+c+e+f+g+i+j+k
// (sum up every element in slli_a and swap_b)
*x_sum_32 = vpadalq_s16(*x_sum_32, slli_a);
*x_sum_32 = vaddw_s16(*x_sum_32, pixelsb_2_sli);
// Also sum their squares
*x2_sum_32 = vmlal_s16(*x2_sum_32, pixelsa_1_sli, pixelsa_1_sli);
*x2_sum_32 = vmlal_s16(*x2_sum_32, pixelsa_2_sli, pixelsa_2_sli);
*x2_sum_32 = vmlal_s16(*x2_sum_32, pixelsb_2_sli, pixelsb_2_sli);
}
void av1_get_horver_correlation_full_neon(
const int16_t *diff,
int stride,
int width,
int height,
float *hcorr,
float *vcorr) {
// The following notation is used:
// x - current pixel
// y - right neighbour pixel
// z - below neighbour pixel
// w - down-right neighbour pixel
int64_t xy_sum = 0, xz_sum = 0;
int64_t x_sum = 0, x2_sum = 0;
int32x4_t zero = vdupq_n_s32(0);
int64x2_t v_x_sum = vreinterpretq_s64_s32(zero);
int64x2_t v_xy_sum = vreinterpretq_s64_s32(zero);
int64x2_t v_xz_sum = vreinterpretq_s64_s32(zero);
int64x2_t v_x2_sum = vreinterpretq_s64_s32(zero);
// Process horizontal and vertical correlations through the body in 4x4
// blocks. This excludes the final row and column and possibly one extra
// column depending how 3 divides into width and height
for (
int i = 0; i <= height - 4; i += 3) {
int32x4_t xy_sum_32 = zero;
int32x4_t xz_sum_32 = zero;
int32x4_t x_sum_32 = zero;
int32x4_t x2_sum_32 = zero;
for (
int j = 0; j <= width - 4; j += 3) {
horver_correlation_4x4(&diff[i * stride + j], stride, &xy_sum_32,
&xz_sum_32, &x_sum_32, &x2_sum_32);
}
v_xy_sum = vpadalq_s32(v_xy_sum, xy_sum_32);
v_xz_sum = vpadalq_s32(v_xz_sum, xz_sum_32);
v_x_sum = vpadalq_s32(v_x_sum, x_sum_32);
v_x2_sum = vpadalq_s32(v_x2_sum, x2_sum_32);
}
#if AOM_ARCH_AARCH64
xy_sum = vaddvq_s64(v_xy_sum);
xz_sum = vaddvq_s64(v_xz_sum);
x2_sum = vaddvq_s64(v_x2_sum);
x_sum = vaddvq_s64(v_x_sum);
#else
xy_sum = vget_lane_s64(
vadd_s64(vget_low_s64(v_xy_sum), vget_high_s64(v_xy_sum)), 0);
xz_sum = vget_lane_s64(
vadd_s64(vget_low_s64(v_xz_sum), vget_high_s64(v_xz_sum)), 0);
x2_sum = vget_lane_s64(
vadd_s64(vget_low_s64(v_x2_sum), vget_high_s64(v_x2_sum)), 0);
x_sum =
vget_lane_s64(vadd_s64(vget_low_s64(v_x_sum), vget_high_s64(v_x_sum)), 0);
#endif
// x_sum now covers every pixel except the final 1-2 rows and 1-2 cols
int64_t x_finalrow = 0, x_finalcol = 0, x2_finalrow = 0, x2_finalcol = 0;
// Do we have 2 rows remaining or just the one? Note that width and height
// are powers of 2, so each modulo 3 must be 1 or 2.
if (height % 3 == 1) {
// Just horiz corrs on the final row
const int16_t x0 = diff[(height - 1) * stride];
x_sum += x0;
x_finalrow += x0;
x2_sum += x0 * x0;
x2_finalrow += x0 * x0;
if (width >= 8) {
int32x4_t v_y_sum = zero;
int32x4_t v_y2_sum = zero;
int32x4_t v_xy_sum_a = zero;
int k = width - 1;
int j = 0;
while ((k - 8) > 0) {
const int16x8_t v_x = vld1q_s16(&diff[(height - 1) * stride + j]);
const int16x8_t v_y = vld1q_s16(&diff[(height - 1) * stride + j + 1]);
const int16x4_t v_x_lo = vget_low_s16(v_x);
const int16x4_t v_x_hi = vget_high_s16(v_x);
const int16x4_t v_y_lo = vget_low_s16(v_y);
const int16x4_t v_y_hi = vget_high_s16(v_y);
v_xy_sum_a = vmlal_s16(v_xy_sum_a, v_x_lo, v_y_lo);
v_xy_sum_a = vmlal_s16(v_xy_sum_a, v_x_hi, v_y_hi);
v_y2_sum = vmlal_s16(v_y2_sum, v_y_lo, v_y_lo);
v_y2_sum = vmlal_s16(v_y2_sum, v_y_hi, v_y_hi);
v_y_sum = vpadalq_s16(v_y_sum, v_y);
k -= 8;
j += 8;
}
const int16x8_t v_l = vld1q_s16(&diff[(height - 1) * stride] + j);
const int16x8_t v_x =
vextq_s16(vextq_s16(vreinterpretq_s16_s32(zero), v_l, 7),
vreinterpretq_s16_s32(zero), 1);
const int16x8_t v_y = vextq_s16(v_l, vreinterpretq_s16_s32(zero), 1);
const int16x4_t v_x_lo = vget_low_s16(v_x);
const int16x4_t v_x_hi = vget_high_s16(v_x);
const int16x4_t v_y_lo = vget_low_s16(v_y);
const int16x4_t v_y_hi = vget_high_s16(v_y);
v_xy_sum_a = vmlal_s16(v_xy_sum_a, v_x_lo, v_y_lo);
v_xy_sum_a = vmlal_s16(v_xy_sum_a, v_x_hi, v_y_hi);
v_y2_sum = vmlal_s16(v_y2_sum, v_y_lo, v_y_lo);
v_y2_sum = vmlal_s16(v_y2_sum, v_y_hi, v_y_hi);
const int32x4_t v_y_sum_a = vpadalq_s16(v_y_sum, v_y);
const int64x2_t v_xy_sum2 = vpaddlq_s32(v_xy_sum_a);
#if AOM_ARCH_AARCH64
const int64x2_t v_y2_sum_a = vpaddlq_s32(v_y2_sum);
xy_sum += vaddvq_s64(v_xy_sum2);
const int32_t y = vaddvq_s32(v_y_sum_a);
const int64_t y2 = vaddvq_s64(v_y2_sum_a);
#else
xy_sum += vget_lane_s64(
vadd_s64(vget_low_s64(v_xy_sum2), vget_high_s64(v_xy_sum2)), 0);
const int64x2_t v_y_a = vpaddlq_s32(v_y_sum_a);
const int64_t y =
vget_lane_s64(vadd_s64(vget_low_s64(v_y_a), vget_high_s64(v_y_a)), 0);
const int64x2_t v_y2_sum_b = vpaddlq_s32(v_y2_sum);
int64_t y2 = vget_lane_s64(
vadd_s64(vget_low_s64(v_y2_sum_b), vget_high_s64(v_y2_sum_b)), 0);
#endif
x_sum += y;
x2_sum += y2;
x_finalrow += y;
x2_finalrow += y2;
}
else {
for (
int j = 0; j < width - 1; ++j) {
const int16_t x = diff[(height - 1) * stride + j];
const int16_t y = diff[(height - 1) * stride + j + 1];
xy_sum += x * y;
x_sum += y;
x2_sum += y * y;
x_finalrow += y;
x2_finalrow += y * y;
}
}
}
else {
// Two rows remaining to do
const int16_t x0 = diff[(height - 2) * stride];
const int16_t z0 = diff[(height - 1) * stride];
x_sum += x0 + z0;
x2_sum += x0 * x0 + z0 * z0;
x_finalrow += z0;
x2_finalrow += z0 * z0;
if (width >= 8) {
int32x4_t v_y2_sum = zero;
int32x4_t v_w2_sum = zero;
int32x4_t v_xy_sum_a = zero;
int32x4_t v_xz_sum_a = zero;
int32x4_t v_x_sum_a = zero;
int32x4_t v_w_sum = zero;
int k = width - 1;
int j = 0;
while ((k - 8) > 0) {
const int16x8_t v_x = vld1q_s16(&diff[(height - 2) * stride + j]);
const int16x8_t v_y = vld1q_s16(&diff[(height - 2) * stride + j + 1]);
const int16x8_t v_z = vld1q_s16(&diff[(height - 1) * stride + j]);
const int16x8_t v_w = vld1q_s16(&diff[(height - 1) * stride + j + 1]);
const int16x4_t v_x_lo = vget_low_s16(v_x);
const int16x4_t v_y_lo = vget_low_s16(v_y);
const int16x4_t v_z_lo = vget_low_s16(v_z);
const int16x4_t v_w_lo = vget_low_s16(v_w);
const int16x4_t v_x_hi = vget_high_s16(v_x);
const int16x4_t v_y_hi = vget_high_s16(v_y);
const int16x4_t v_z_hi = vget_high_s16(v_z);
const int16x4_t v_w_hi = vget_high_s16(v_w);
v_xy_sum_a = vmlal_s16(v_xy_sum_a, v_x_lo, v_y_lo);
v_xy_sum_a = vmlal_s16(v_xy_sum_a, v_x_hi, v_y_hi);
v_xy_sum_a = vmlal_s16(v_xy_sum_a, v_z_lo, v_w_lo);
v_xy_sum_a = vmlal_s16(v_xy_sum_a, v_z_hi, v_w_hi);
v_xz_sum_a = vmlal_s16(v_xz_sum_a, v_x_lo, v_z_lo);
v_xz_sum_a = vmlal_s16(v_xz_sum_a, v_x_hi, v_z_hi);
v_w2_sum = vmlal_s16(v_w2_sum, v_w_lo, v_w_lo);
v_w2_sum = vmlal_s16(v_w2_sum, v_w_hi, v_w_hi);
v_y2_sum = vmlal_s16(v_y2_sum, v_y_lo, v_y_lo);
v_y2_sum = vmlal_s16(v_y2_sum, v_y_hi, v_y_hi);
v_w_sum = vpadalq_s16(v_w_sum, v_w);
v_x_sum_a = vpadalq_s16(v_x_sum_a, v_y);
v_x_sum_a = vpadalq_s16(v_x_sum_a, v_w);
k -= 8;
j += 8;
}
const int16x8_t v_l = vld1q_s16(&diff[(height - 2) * stride] + j);
const int16x8_t v_x =
vextq_s16(vextq_s16(vreinterpretq_s16_s32(zero), v_l, 7),
vreinterpretq_s16_s32(zero), 1);
const int16x8_t v_y = vextq_s16(v_l, vreinterpretq_s16_s32(zero), 1);
const int16x8_t v_l_2 = vld1q_s16(&diff[(height - 1) * stride] + j);
const int16x8_t v_z =
vextq_s16(vextq_s16(vreinterpretq_s16_s32(zero), v_l_2, 7),
vreinterpretq_s16_s32(zero), 1);
const int16x8_t v_w = vextq_s16(v_l_2, vreinterpretq_s16_s32(zero), 1);
const int16x4_t v_x_lo = vget_low_s16(v_x);
const int16x4_t v_y_lo = vget_low_s16(v_y);
const int16x4_t v_z_lo = vget_low_s16(v_z);
const int16x4_t v_w_lo = vget_low_s16(v_w);
const int16x4_t v_x_hi = vget_high_s16(v_x);
const int16x4_t v_y_hi = vget_high_s16(v_y);
const int16x4_t v_z_hi = vget_high_s16(v_z);
const int16x4_t v_w_hi = vget_high_s16(v_w);
v_xy_sum_a = vmlal_s16(v_xy_sum_a, v_x_lo, v_y_lo);
v_xy_sum_a = vmlal_s16(v_xy_sum_a, v_x_hi, v_y_hi);
v_xy_sum_a = vmlal_s16(v_xy_sum_a, v_z_lo, v_w_lo);
v_xy_sum_a = vmlal_s16(v_xy_sum_a, v_z_hi, v_w_hi);
v_xz_sum_a = vmlal_s16(v_xz_sum_a, v_x_lo, v_z_lo);
v_xz_sum_a = vmlal_s16(v_xz_sum_a, v_x_hi, v_z_hi);
v_w2_sum = vmlal_s16(v_w2_sum, v_w_lo, v_w_lo);
v_w2_sum = vmlal_s16(v_w2_sum, v_w_hi, v_w_hi);
v_y2_sum = vmlal_s16(v_y2_sum, v_y_lo, v_y_lo);
v_y2_sum = vmlal_s16(v_y2_sum, v_y_hi, v_y_hi);
v_w_sum = vpadalq_s16(v_w_sum, v_w);
v_x_sum_a = vpadalq_s16(v_x_sum_a, v_y);
v_x_sum_a = vpadalq_s16(v_x_sum_a, v_w);
#if AOM_ARCH_AARCH64
xy_sum += vaddvq_s64(vpaddlq_s32(v_xy_sum_a));
xz_sum += vaddvq_s64(vpaddlq_s32(v_xz_sum_a));
x_sum += vaddvq_s32(v_x_sum_a);
x_finalrow += vaddvq_s32(v_w_sum);
int64_t y2 = vaddvq_s64(vpaddlq_s32(v_y2_sum));
int64_t w2 = vaddvq_s64(vpaddlq_s32(v_w2_sum));
#else
const int64x2_t v_xy_sum2 = vpaddlq_s32(v_xy_sum_a);
xy_sum += vget_lane_s64(
vadd_s64(vget_low_s64(v_xy_sum2), vget_high_s64(v_xy_sum2)), 0);
const int64x2_t v_xz_sum2 = vpaddlq_s32(v_xz_sum_a);
xz_sum += vget_lane_s64(
vadd_s64(vget_low_s64(v_xz_sum2), vget_high_s64(v_xz_sum2)), 0);
const int64x2_t v_x_sum2 = vpaddlq_s32(v_x_sum_a);
x_sum += vget_lane_s64(
vadd_s64(vget_low_s64(v_x_sum2), vget_high_s64(v_x_sum2)), 0);
const int64x2_t v_w_sum_a = vpaddlq_s32(v_w_sum);
x_finalrow += vget_lane_s64(
vadd_s64(vget_low_s64(v_w_sum_a), vget_high_s64(v_w_sum_a)), 0);
const int64x2_t v_y2_sum_a = vpaddlq_s32(v_y2_sum);
int64_t y2 = vget_lane_s64(
vadd_s64(vget_low_s64(v_y2_sum_a), vget_high_s64(v_y2_sum_a)), 0);
const int64x2_t v_w2_sum_a = vpaddlq_s32(v_w2_sum);
int64_t w2 = vget_lane_s64(
vadd_s64(vget_low_s64(v_w2_sum_a), vget_high_s64(v_w2_sum_a)), 0);
#endif
x2_sum += y2 + w2;
x2_finalrow += w2;
}
else {
for (
int j = 0; j < width - 1; ++j) {
const int16_t x = diff[(height - 2) * stride + j];
const int16_t y = diff[(height - 2) * stride + j + 1];
const int16_t z = diff[(height - 1) * stride + j];
const int16_t w = diff[(height - 1) * stride + j + 1];
// Horizontal and vertical correlations for the penultimate row:
xy_sum += x * y;
xz_sum += x * z;
// Now just horizontal correlations for the final row:
xy_sum += z * w;
x_sum += y + w;
x2_sum += y * y + w * w;
x_finalrow += w;
x2_finalrow += w * w;
}
}
}
// Do we have 2 columns remaining or just the one?
if (width % 3 == 1) {
// Just vert corrs on the final col
const int16_t x0 = diff[width - 1];
x_sum += x0;
x_finalcol += x0;
x2_sum += x0 * x0;
x2_finalcol += x0 * x0;
for (
int i = 0; i < height - 1; ++i) {
const int16_t x = diff[i * stride + width - 1];
const int16_t z = diff[(i + 1) * stride + width - 1];
xz_sum += x * z;
x_finalcol += z;
x2_finalcol += z * z;
// So the bottom-right elements don't get counted twice:
if (i < height - (height % 3 == 1 ? 2 : 3)) {
x_sum += z;
x2_sum += z * z;
}
}
}
else {
// Two cols remaining
const int16_t x0 = diff[width - 2];
const int16_t y0 = diff[width - 1];
x_sum += x0 + y0;
x2_sum += x0 * x0 + y0 * y0;
x_finalcol += y0;
x2_finalcol += y0 * y0;
for (
int i = 0; i < height - 1; ++i) {
const int16_t x = diff[i * stride + width - 2];
const int16_t y = diff[i * stride + width - 1];
const int16_t z = diff[(i + 1) * stride + width - 2];
const int16_t w = diff[(i + 1) * stride + width - 1];
// Horizontal and vertical correlations for the penultimate col:
// Skip these on the last iteration of this loop if we also had two
// rows remaining, otherwise the final horizontal and vertical correlation
// get erroneously processed twice
if (i < height - 2 || height % 3 == 1) {
xy_sum += x * y;
xz_sum += x * z;
}
x_finalcol += w;
x2_finalcol += w * w;
// So the bottom-right elements don't get counted twice:
if (i < height - (height % 3 == 1 ? 2 : 3)) {
x_sum += z + w;
x2_sum += z * z + w * w;
}
// Now just vertical correlations for the final column:
xz_sum += y * w;
}
}
// Calculate the simple sums and squared-sums
int64_t x_firstrow = 0, x_firstcol = 0;
int64_t x2_firstrow = 0, x2_firstcol = 0;
if (width >= 8) {
int32x4_t v_x_firstrow = zero;
int32x4_t v_x2_firstrow = zero;
for (
int j = 0; j < width; j += 8) {
const int16x8_t v_diff = vld1q_s16(diff + j);
const int16x4_t v_diff_lo = vget_low_s16(v_diff);
const int16x4_t v_diff_hi = vget_high_s16(v_diff);
v_x_firstrow = vpadalq_s16(v_x_firstrow, v_diff);
v_x2_firstrow = vmlal_s16(v_x2_firstrow, v_diff_lo, v_diff_lo);
v_x2_firstrow = vmlal_s16(v_x2_firstrow, v_diff_hi, v_diff_hi);
}
#if AOM_ARCH_AARCH64
x_firstrow += vaddvq_s32(v_x_firstrow);
x2_firstrow += vaddvq_s32(v_x2_firstrow);
#else
const int64x2_t v_x_firstrow_64 = vpaddlq_s32(v_x_firstrow);
x_firstrow += vget_lane_s64(
vadd_s64(vget_low_s64(v_x_firstrow_64), vget_high_s64(v_x_firstrow_64)),
0);
const int64x2_t v_x2_firstrow_64 = vpaddlq_s32(v_x2_firstrow);
x2_firstrow += vget_lane_s64(vadd_s64(vget_low_s64(v_x2_firstrow_64),
vget_high_s64(v_x2_firstrow_64)),
0);
#endif
}
else {
for (
int j = 0; j < width; ++j) {
x_firstrow += diff[j];
x2_firstrow += diff[j] * diff[j];
}
}
for (
int i = 0; i < height; ++i) {
x_firstcol += diff[i * stride];
x2_firstcol += diff[i * stride] * diff[i * stride];
}
int64_t xhor_sum = x_sum - x_finalcol;
int64_t xver_sum = x_sum - x_finalrow;
int64_t y_sum = x_sum - x_firstcol;
int64_t z_sum = x_sum - x_firstrow;
int64_t x2hor_sum = x2_sum - x2_finalcol;
int64_t x2ver_sum = x2_sum - x2_finalrow;
int64_t y2_sum = x2_sum - x2_firstcol;
int64_t z2_sum = x2_sum - x2_firstrow;
const float num_hor = (
float)(height * (width - 1));
const float num_ver = (
float)((height - 1) * width);
const float xhor_var_n = x2hor_sum - (xhor_sum * xhor_sum) / num_hor;
const float xver_var_n = x2ver_sum - (xver_sum * xver_sum) / num_ver;
const float y_var_n = y2_sum - (y_sum * y_sum) / num_hor;
const float z_var_n = z2_sum - (z_sum * z_sum) / num_ver;
const float xy_var_n = xy_sum - (xhor_sum * y_sum) / num_hor;
const float xz_var_n = xz_sum - (xver_sum * z_sum) / num_ver;
if (xhor_var_n > 0 && y_var_n > 0) {
*hcorr = xy_var_n / sqrtf(xhor_var_n * y_var_n);
*hcorr = *hcorr < 0 ? 0 : *hcorr;
}
else {
*hcorr = 1.0;
}
if (xver_var_n > 0 && z_var_n > 0) {
*vcorr = xz_var_n / sqrtf(xver_var_n * z_var_n);
*vcorr = *vcorr < 0 ? 0 : *vcorr;
}
else {
*vcorr = 1.0;
}
}
