idct8x8_test.cc revision 7bc9febe8749e98a3812a0dc4380ceae75c29450 
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 "third_party/googletest/src/include/gtest/gtest.h"
16
17#include "./vpx_dsp_rtcd.h"
18#include "test/acm_random.h"
19#include "vpx/vpx_integer.h"
20#include "vpx_ports/msvc.h"  // for round()
21
22using libvpx_test::ACMRandom;
23
24namespace {
25
26void reference_dct_1d(double input[8], double output[8]) {
27  const double kPi = 3.141592653589793238462643383279502884;
28  const double kInvSqrt2 = 0.707106781186547524400844362104;
29  for (int k = 0; k < 8; k++) {
30    output[k] = 0.0;
31    for (int n = 0; n < 8; n++) {
32      output[k] += input[n] * cos(kPi * (2 * n + 1) * k / 16.0);
33    }
34    if (k == 0) output[k] = output[k] * kInvSqrt2;
35  }
36}
37
38void reference_dct_2d(int16_t input[64], double output[64]) {
39  // First transform columns
40  for (int i = 0; i < 8; ++i) {
41    double temp_in[8], temp_out[8];
42    for (int j = 0; j < 8; ++j) temp_in[j] = input[j * 8 + i];
43    reference_dct_1d(temp_in, temp_out);
44    for (int j = 0; j < 8; ++j) output[j * 8 + i] = temp_out[j];
45  }
46  // Then transform rows
47  for (int i = 0; i < 8; ++i) {
48    double temp_in[8], temp_out[8];
49    for (int j = 0; j < 8; ++j) temp_in[j] = output[j + i * 8];
50    reference_dct_1d(temp_in, temp_out);
51    for (int j = 0; j < 8; ++j) output[j + i * 8] = temp_out[j];
52  }
53  // Scale by some magic number
54  for (int i = 0; i < 64; ++i) output[i] *= 2;
55}
56
57TEST(VP9Idct8x8Test, AccuracyCheck) {
58  ACMRandom rnd(ACMRandom::DeterministicSeed());
59  const int count_test_block = 10000;
60  for (int i = 0; i < count_test_block; ++i) {
61    int16_t input[64];
62    tran_low_t coeff[64];
63    double output_r[64];
64    uint8_t dst[64], src[64];
65
66    for (int j = 0; j < 64; ++j) {
67      src[j] = rnd.Rand8();
68      dst[j] = rnd.Rand8();
69    }
70    // Initialize a test block with input range [-255, 255].
71    for (int j = 0; j < 64; ++j) input[j] = src[j] - dst[j];
72
73    reference_dct_2d(input, output_r);
74    for (int j = 0; j < 64; ++j) {
75      coeff[j] = static_cast<tran_low_t>(round(output_r[j]));
76    }
77    vpx_idct8x8_64_add_c(coeff, dst, 8);
78    for (int j = 0; j < 64; ++j) {
79      const int diff = dst[j] - src[j];
80      const int error = diff * diff;
81      EXPECT_GE(1, error) << "Error: 8x8 FDCT/IDCT has error " << error
82                          << " at index " << j;
83    }
84  }
85}
86
87}  // namespace
88