ref: a7f8bd451b82f52fb9bb5d9e7926f4d09cc66831
dir: /vpx_dsp/arm/subpel_variance_neon.c/
/*
* Copyright (c) 2014 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 <arm_neon.h>
#include "./vpx_dsp_rtcd.h"
#include "./vpx_config.h"
#include "vpx_ports/mem.h"
#include "vpx/vpx_integer.h"
#include "vpx_dsp/variance.h"
static const uint8_t bilinear_filters[8][2] = {
{ 128, 0 }, { 112, 16 }, { 96, 32 }, { 80, 48 },
{ 64, 64 }, { 48, 80 }, { 32, 96 }, { 16, 112 },
};
// Process a block exactly 8 wide and any height.
static void var_filter_block2d_bil_w8(const uint8_t *src_ptr,
uint8_t *output_ptr,
unsigned int src_pixels_per_line,
int pixel_step,
unsigned int output_height,
const uint8_t *filter) {
const uint8x8_t f0 = vmov_n_u8(filter[0]);
const uint8x8_t f1 = vmov_n_u8(filter[1]);
unsigned int i;
for (i = 0; i < output_height; ++i) {
const uint8x8_t src_0 = vld1_u8(&src_ptr[0]);
const uint8x8_t src_1 = vld1_u8(&src_ptr[pixel_step]);
const uint16x8_t a = vmull_u8(src_0, f0);
const uint16x8_t b = vmlal_u8(a, src_1, f1);
const uint8x8_t out = vrshrn_n_u16(b, FILTER_BITS);
vst1_u8(&output_ptr[0], out);
// Next row...
src_ptr += src_pixels_per_line;
output_ptr += 8;
}
}
// Process a block which is a mutiple of 16 wide and any height.
static void var_filter_block2d_bil_w16(const uint8_t *src_ptr,
uint8_t *output_ptr,
unsigned int src_pixels_per_line,
int pixel_step,
unsigned int output_height,
unsigned int output_width,
const uint8_t *filter) {
const uint8x8_t f0 = vmov_n_u8(filter[0]);
const uint8x8_t f1 = vmov_n_u8(filter[1]);
unsigned int i, j;
for (i = 0; i < output_height; ++i) {
for (j = 0; j < output_width; j += 16) {
const uint8x16_t src_0 = vld1q_u8(&src_ptr[j]);
const uint8x16_t src_1 = vld1q_u8(&src_ptr[j + pixel_step]);
const uint16x8_t a = vmull_u8(vget_low_u8(src_0), f0);
const uint16x8_t b = vmlal_u8(a, vget_low_u8(src_1), f1);
const uint8x8_t out_lo = vrshrn_n_u16(b, FILTER_BITS);
const uint16x8_t c = vmull_u8(vget_high_u8(src_0), f0);
const uint16x8_t d = vmlal_u8(c, vget_high_u8(src_1), f1);
const uint8x8_t out_hi = vrshrn_n_u16(d, FILTER_BITS);
vst1q_u8(&output_ptr[j], vcombine_u8(out_lo, out_hi));
}
// Next row...
src_ptr += src_pixels_per_line;
output_ptr += output_width;
}
}
// TODO(johannkoenig): support 4xM block sizes.
#define sub_pixel_varianceNxM(n, m) \
unsigned int vpx_sub_pixel_variance##n##x##m##_neon( \
const uint8_t *src, int src_stride, int xoffset, int yoffset, \
const uint8_t *dst, int dst_stride, unsigned int *sse) { \
DECLARE_ALIGNED(16, uint8_t, fdata3[n * (m + 1)]); \
DECLARE_ALIGNED(16, uint8_t, temp2[n * m]); \
\
if (n == 8) { \
var_filter_block2d_bil_w8(src, fdata3, src_stride, 1, (m + 1), \
bilinear_filters[xoffset]); \
var_filter_block2d_bil_w8(fdata3, temp2, n, n, m, \
bilinear_filters[yoffset]); \
} else { \
var_filter_block2d_bil_w16(src, fdata3, src_stride, 1, (m + 1), n, \
bilinear_filters[xoffset]); \
var_filter_block2d_bil_w16(fdata3, temp2, n, n, m, n, \
bilinear_filters[yoffset]); \
} \
return vpx_variance##n##x##m(temp2, n, dst, dst_stride, sse); \
}
sub_pixel_varianceNxM(8, 4);
sub_pixel_varianceNxM(8, 8);
sub_pixel_varianceNxM(8, 16);
sub_pixel_varianceNxM(16, 8);
sub_pixel_varianceNxM(16, 16);
sub_pixel_varianceNxM(16, 32);
sub_pixel_varianceNxM(32, 16);
sub_pixel_varianceNxM(32, 32);
sub_pixel_varianceNxM(32, 64);
sub_pixel_varianceNxM(64, 32);
sub_pixel_varianceNxM(64, 64);