xref: /aosp_15_r20/external/libvpx/test/idct8x8_test.cc (revision fb1b10ab9aebc7c7068eedab379b749d7e3900be)
1 /*
2  *  Copyright (c) 2012 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 <math.h>
12 #include <stdlib.h>
13 #include <string.h>
14 
15 #include "gtest/gtest.h"
16 
17 #include "./vpx_dsp_rtcd.h"
18 #include "test/acm_random.h"
19 #include "vpx/vpx_integer.h"
20 
21 using libvpx_test::ACMRandom;
22 
23 namespace {
24 
reference_dct_1d(double input[8],double output[8])25 void reference_dct_1d(double input[8], double output[8]) {
26   const double kPi = 3.141592653589793238462643383279502884;
27   const double kInvSqrt2 = 0.707106781186547524400844362104;
28   for (int k = 0; k < 8; k++) {
29     output[k] = 0.0;
30     for (int n = 0; n < 8; n++) {
31       output[k] += input[n] * cos(kPi * (2 * n + 1) * k / 16.0);
32     }
33     if (k == 0) output[k] = output[k] * kInvSqrt2;
34   }
35 }
36 
reference_dct_2d(int16_t input[64],double output[64])37 void reference_dct_2d(int16_t input[64], double output[64]) {
38   // First transform columns
39   for (int i = 0; i < 8; ++i) {
40     double temp_in[8], temp_out[8];
41     for (int j = 0; j < 8; ++j) temp_in[j] = input[j * 8 + i];
42     reference_dct_1d(temp_in, temp_out);
43     for (int j = 0; j < 8; ++j) output[j * 8 + i] = temp_out[j];
44   }
45   // Then transform rows
46   for (int i = 0; i < 8; ++i) {
47     double temp_in[8], temp_out[8];
48     for (int j = 0; j < 8; ++j) temp_in[j] = output[j + i * 8];
49     reference_dct_1d(temp_in, temp_out);
50     for (int j = 0; j < 8; ++j) output[j + i * 8] = temp_out[j];
51   }
52   // Scale by some magic number
53   for (int i = 0; i < 64; ++i) output[i] *= 2;
54 }
55 
TEST(VP9Idct8x8Test,AccuracyCheck)56 TEST(VP9Idct8x8Test, AccuracyCheck) {
57   ACMRandom rnd(ACMRandom::DeterministicSeed());
58   const int count_test_block = 10000;
59   for (int i = 0; i < count_test_block; ++i) {
60     int16_t input[64];
61     tran_low_t coeff[64];
62     double output_r[64];
63     uint8_t dst[64], src[64];
64 
65     for (int j = 0; j < 64; ++j) {
66       src[j] = rnd.Rand8();
67       dst[j] = rnd.Rand8();
68     }
69     // Initialize a test block with input range [-255, 255].
70     for (int j = 0; j < 64; ++j) input[j] = src[j] - dst[j];
71 
72     reference_dct_2d(input, output_r);
73     for (int j = 0; j < 64; ++j) {
74       coeff[j] = static_cast<tran_low_t>(round(output_r[j]));
75     }
76     vpx_idct8x8_64_add_c(coeff, dst, 8);
77     for (int j = 0; j < 64; ++j) {
78       const int diff = dst[j] - src[j];
79       const int error = diff * diff;
80       EXPECT_GE(1, error) << "Error: 8x8 FDCT/IDCT has error " << error
81                           << " at index " << j;
82     }
83   }
84 }
85 
86 }  // namespace
87