test/idct8x8_test.cc

   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
  21 using libvpx_test::ACMRandom;
  22
  23 namespace {
  24
  25 #ifdef _MSC_VER
  26 static int round(double x) {
  27   if (x < 0)
  28     return static_cast<int>(ceil(x - 0.5));
  29   else
  30     return static_cast<int>(floor(x + 0.5));
  31 }
  32 #endif
  33
  34 void reference_dct_1d(double input[8], double output[8]) {
  35   const double kPi = 3.141592653589793238462643383279502884;
  36   const double kInvSqrt2 = 0.707106781186547524400844362104;
  37   for (int k = 0; k < 8; k++) {
  38     output[k] = 0.0;
  39     for (int n = 0; n < 8; n++)
  40       output[k] += input[n]*cos(kPi*(2*n+1)*k/16.0);
  41     if (k == 0)
  42       output[k] = output[k]*kInvSqrt2;
  43   }
  44 }
  45
  46 void reference_dct_2d(int16_t input[64], double output[64]) {
  47   // First transform columns
  48   for (int i = 0; i < 8; ++i) {
  49     double temp_in[8], temp_out[8];
  50     for (int j = 0; j < 8; ++j)
  51       temp_in[j] = input[j*8 + i];
  52     reference_dct_1d(temp_in, temp_out);
  53     for (int j = 0; j < 8; ++j)
  54       output[j*8 + i] = temp_out[j];
  55   }
  56   // Then transform rows
  57   for (int i = 0; i < 8; ++i) {
  58     double temp_in[8], temp_out[8];
  59     for (int j = 0; j < 8; ++j)
  60       temp_in[j] = output[j + i*8];
  61     reference_dct_1d(temp_in, temp_out);
  62     for (int j = 0; j < 8; ++j)
  63       output[j + i*8] = temp_out[j];
  64   }
  65   // Scale by some magic number
  66   for (int i = 0; i < 64; ++i)
  67     output[i] *= 2;
  68 }
  69
  70 TEST(VP9Idct8x8Test, AccuracyCheck) {
  71   ACMRandom rnd(ACMRandom::DeterministicSeed());
  72   const int count_test_block = 10000;
  73   for (int i = 0; i < count_test_block; ++i) {
  74     int16_t input[64];
  75     tran_low_t coeff[64];
  76     double output_r[64];
  77     uint8_t dst[64], src[64];
  78
  79     for (int j = 0; j < 64; ++j) {
  80       src[j] = rnd.Rand8();
  81       dst[j] = rnd.Rand8();
  82     }
  83     // Initialize a test block with input range [-255, 255].
  84     for (int j = 0; j < 64; ++j)
  85       input[j] = src[j] - dst[j];
  86
  87     reference_dct_2d(input, output_r);
  88     for (int j = 0; j < 64; ++j)
  89       coeff[j] = round(output_r[j]);
  90     vpx_idct8x8_64_add_c(coeff, dst, 8);
  91     for (int j = 0; j < 64; ++j) {
  92       const int diff = dst[j] - src[j];
  93       const int error = diff * diff;
  94       EXPECT_GE(1, error)
  95           << "Error: 8x8 FDCT/IDCT has error " << error
  96           << " at index " << j;
  97     }
  98   }
  99 }
 100
 101 }  // namespace