1/*
2 *  Copyright (c) 2014 The WebM project authors. All Rights Reserved.
3 *
4 *  Use of this source code is governed by a BSD-style license
5 *  that can be found in the LICENSE file in the root of the source
6 *  tree. An additional intellectual property rights grant can be found
7 *  in the file PATENTS.  All contributing project authors may
8 *  be found in the AUTHORS file in the root of the source tree.
9 */
10
11#include <arm_neon.h>
12#include "./vpx_dsp_rtcd.h"
13#include "./vpx_config.h"
14
15#include "vpx_ports/mem.h"
16#include "vpx/vpx_integer.h"
17
18#include "vpx_dsp/variance.h"
19
20static const uint8_t bilinear_filters[8][2] = {
21  { 128, 0 }, { 112, 16 }, { 96, 32 }, { 80, 48 },
22  { 64, 64 }, { 48, 80 },  { 32, 96 }, { 16, 112 },
23};
24
25// Process a block exactly 8 wide and any height.
26static void var_filter_block2d_bil_w8(const uint8_t *src_ptr,
27                                      uint8_t *output_ptr,
28                                      unsigned int src_pixels_per_line,
29                                      int pixel_step,
30                                      unsigned int output_height,
31                                      const uint8_t *filter) {
32  const uint8x8_t f0 = vmov_n_u8(filter[0]);
33  const uint8x8_t f1 = vmov_n_u8(filter[1]);
34  unsigned int i;
35  for (i = 0; i < output_height; ++i) {
36    const uint8x8_t src_0 = vld1_u8(&src_ptr[0]);
37    const uint8x8_t src_1 = vld1_u8(&src_ptr[pixel_step]);
38    const uint16x8_t a = vmull_u8(src_0, f0);
39    const uint16x8_t b = vmlal_u8(a, src_1, f1);
40    const uint8x8_t out = vrshrn_n_u16(b, FILTER_BITS);
41    vst1_u8(&output_ptr[0], out);
42    // Next row...
43    src_ptr += src_pixels_per_line;
44    output_ptr += 8;
45  }
46}
47
48// Process a block which is a mutiple of 16 wide and any height.
49static void var_filter_block2d_bil_w16(const uint8_t *src_ptr,
50                                       uint8_t *output_ptr,
51                                       unsigned int src_pixels_per_line,
52                                       int pixel_step,
53                                       unsigned int output_height,
54                                       unsigned int output_width,
55                                       const uint8_t *filter) {
56  const uint8x8_t f0 = vmov_n_u8(filter[0]);
57  const uint8x8_t f1 = vmov_n_u8(filter[1]);
58  unsigned int i, j;
59  for (i = 0; i < output_height; ++i) {
60    for (j = 0; j < output_width; j += 16) {
61      const uint8x16_t src_0 = vld1q_u8(&src_ptr[j]);
62      const uint8x16_t src_1 = vld1q_u8(&src_ptr[j + pixel_step]);
63      const uint16x8_t a = vmull_u8(vget_low_u8(src_0), f0);
64      const uint16x8_t b = vmlal_u8(a, vget_low_u8(src_1), f1);
65      const uint8x8_t out_lo = vrshrn_n_u16(b, FILTER_BITS);
66      const uint16x8_t c = vmull_u8(vget_high_u8(src_0), f0);
67      const uint16x8_t d = vmlal_u8(c, vget_high_u8(src_1), f1);
68      const uint8x8_t out_hi = vrshrn_n_u16(d, FILTER_BITS);
69      vst1q_u8(&output_ptr[j], vcombine_u8(out_lo, out_hi));
70    }
71    // Next row...
72    src_ptr += src_pixels_per_line;
73    output_ptr += output_width;
74  }
75}
76
77// TODO(johannkoenig): support 4xM block sizes.
78#define sub_pixel_varianceNxM(n, m)                                      \
79  unsigned int vpx_sub_pixel_variance##n##x##m##_neon(                   \
80      const uint8_t *src, int src_stride, int xoffset, int yoffset,      \
81      const uint8_t *dst, int dst_stride, unsigned int *sse) {           \
82    DECLARE_ALIGNED(16, uint8_t, fdata3[n * (m + 1)]);                   \
83    DECLARE_ALIGNED(16, uint8_t, temp2[n * m]);                          \
84                                                                         \
85    if (n == 8) {                                                        \
86      var_filter_block2d_bil_w8(src, fdata3, src_stride, 1, (m + 1),     \
87                                bilinear_filters[xoffset]);              \
88      var_filter_block2d_bil_w8(fdata3, temp2, n, n, m,                  \
89                                bilinear_filters[yoffset]);              \
90    } else {                                                             \
91      var_filter_block2d_bil_w16(src, fdata3, src_stride, 1, (m + 1), n, \
92                                 bilinear_filters[xoffset]);             \
93      var_filter_block2d_bil_w16(fdata3, temp2, n, n, m, n,              \
94                                 bilinear_filters[yoffset]);             \
95    }                                                                    \
96    return vpx_variance##n##x##m(temp2, n, dst, dst_stride, sse);        \
97  }
98
99sub_pixel_varianceNxM(8, 4);
100sub_pixel_varianceNxM(8, 8);
101sub_pixel_varianceNxM(8, 16);
102sub_pixel_varianceNxM(16, 8);
103sub_pixel_varianceNxM(16, 16);
104sub_pixel_varianceNxM(16, 32);
105sub_pixel_varianceNxM(32, 16);
106sub_pixel_varianceNxM(32, 32);
107sub_pixel_varianceNxM(32, 64);
108sub_pixel_varianceNxM(64, 32);
109sub_pixel_varianceNxM(64, 64);
110