ref: b0e3ca126189123ddec27ebba6aa62290e64adb6
dir: /test/dct16x16_test.cc/
/*
* Copyright (c) 2012 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 <math.h>
#include <stdlib.h>
#include <string.h>
#include "third_party/googletest/src/include/gtest/gtest.h"
extern "C" {
#include "vp8/common/entropy.h"
#include "vp8/common/idct.h"
#include "vp8/encoder/dct.h"
}
#include "acm_random.h"
#include "vpx/vpx_integer.h"
using libvpx_test::ACMRandom;
namespace {
const double PI = 3.1415926535898;
void reference2_16x16_idct_2d(double *input, double *output) {
double x;
for (int l = 0; l < 16; ++l) {
for (int k = 0; k < 16; ++k) {
double s = 0;
for (int i = 0; i < 16; ++i) {
for (int j = 0; j < 16; ++j) {
x=cos(PI*j*(l+0.5)/16.0)*cos(PI*i*(k+0.5)/16.0)*input[i*16+j]/256;
if (i != 0)
x *= sqrt(2.0);
if (j != 0)
x *= sqrt(2.0);
s += x;
}
}
output[k*16+l] = s;
}
}
}
static const double C1 = 0.995184726672197;
static const double C2 = 0.98078528040323;
static const double C3 = 0.956940335732209;
static const double C4 = 0.923879532511287;
static const double C5 = 0.881921264348355;
static const double C6 = 0.831469612302545;
static const double C7 = 0.773010453362737;
static const double C8 = 0.707106781186548;
static const double C9 = 0.634393284163646;
static const double C10 = 0.555570233019602;
static const double C11 = 0.471396736825998;
static const double C12 = 0.38268343236509;
static const double C13 = 0.290284677254462;
static const double C14 = 0.195090322016128;
static const double C15 = 0.098017140329561;
static void butterfly_16x16_dct_1d(double input[16], double output[16]) {
double step[16];
double intermediate[16];
double temp1, temp2;
// step 1
step[ 0] = input[0] + input[15];
step[ 1] = input[1] + input[14];
step[ 2] = input[2] + input[13];
step[ 3] = input[3] + input[12];
step[ 4] = input[4] + input[11];
step[ 5] = input[5] + input[10];
step[ 6] = input[6] + input[ 9];
step[ 7] = input[7] + input[ 8];
step[ 8] = input[7] - input[ 8];
step[ 9] = input[6] - input[ 9];
step[10] = input[5] - input[10];
step[11] = input[4] - input[11];
step[12] = input[3] - input[12];
step[13] = input[2] - input[13];
step[14] = input[1] - input[14];
step[15] = input[0] - input[15];
// step 2
output[0] = step[0] + step[7];
output[1] = step[1] + step[6];
output[2] = step[2] + step[5];
output[3] = step[3] + step[4];
output[4] = step[3] - step[4];
output[5] = step[2] - step[5];
output[6] = step[1] - step[6];
output[7] = step[0] - step[7];
temp1 = step[ 8]*C7;
temp2 = step[15]*C9;
output[ 8] = temp1 + temp2;
temp1 = step[ 9]*C11;
temp2 = step[14]*C5;
output[ 9] = temp1 - temp2;
temp1 = step[10]*C3;
temp2 = step[13]*C13;
output[10] = temp1 + temp2;
temp1 = step[11]*C15;
temp2 = step[12]*C1;
output[11] = temp1 - temp2;
temp1 = step[11]*C1;
temp2 = step[12]*C15;
output[12] = temp2 + temp1;
temp1 = step[10]*C13;
temp2 = step[13]*C3;
output[13] = temp2 - temp1;
temp1 = step[ 9]*C5;
temp2 = step[14]*C11;
output[14] = temp2 + temp1;
temp1 = step[ 8]*C9;
temp2 = step[15]*C7;
output[15] = temp2 - temp1;
// step 3
step[ 0] = output[0] + output[3];
step[ 1] = output[1] + output[2];
step[ 2] = output[1] - output[2];
step[ 3] = output[0] - output[3];
temp1 = output[4]*C14;
temp2 = output[7]*C2;
step[ 4] = temp1 + temp2;
temp1 = output[5]*C10;
temp2 = output[6]*C6;
step[ 5] = temp1 + temp2;
temp1 = output[5]*C6;
temp2 = output[6]*C10;
step[ 6] = temp2 - temp1;
temp1 = output[4]*C2;
temp2 = output[7]*C14;
step[ 7] = temp2 - temp1;
step[ 8] = output[ 8] + output[11];
step[ 9] = output[ 9] + output[10];
step[10] = output[ 9] - output[10];
step[11] = output[ 8] - output[11];
step[12] = output[12] + output[15];
step[13] = output[13] + output[14];
step[14] = output[13] - output[14];
step[15] = output[12] - output[15];
// step 4
output[ 0] = (step[ 0] + step[ 1]);
output[ 8] = (step[ 0] - step[ 1]);
temp1 = step[2]*C12;
temp2 = step[3]*C4;
temp1 = temp1 + temp2;
output[ 4] = 2*(temp1*C8);
temp1 = step[2]*C4;
temp2 = step[3]*C12;
temp1 = temp2 - temp1;
output[12] = 2*(temp1*C8);
output[ 2] = 2*((step[4] + step[ 5])*C8);
output[14] = 2*((step[7] - step[ 6])*C8);
temp1 = step[4] - step[5];
temp2 = step[6] + step[7];
output[ 6] = (temp1 + temp2);
output[10] = (temp1 - temp2);
intermediate[8] = step[8] + step[14];
intermediate[9] = step[9] + step[15];
temp1 = intermediate[8]*C12;
temp2 = intermediate[9]*C4;
temp1 = temp1 - temp2;
output[3] = 2*(temp1*C8);
temp1 = intermediate[8]*C4;
temp2 = intermediate[9]*C12;
temp1 = temp2 + temp1;
output[13] = 2*(temp1*C8);
output[ 9] = 2*((step[10] + step[11])*C8);
intermediate[11] = step[10] - step[11];
intermediate[12] = step[12] + step[13];
intermediate[13] = step[12] - step[13];
intermediate[14] = step[ 8] - step[14];
intermediate[15] = step[ 9] - step[15];
output[15] = (intermediate[11] + intermediate[12]);
output[ 1] = -(intermediate[11] - intermediate[12]);
output[ 7] = 2*(intermediate[13]*C8);
temp1 = intermediate[14]*C12;
temp2 = intermediate[15]*C4;
temp1 = temp1 - temp2;
output[11] = -2*(temp1*C8);
temp1 = intermediate[14]*C4;
temp2 = intermediate[15]*C12;
temp1 = temp2 + temp1;
output[ 5] = 2*(temp1*C8);
}
static void reference_16x16_dct_1d(double in[16], double out[16]) {
const double kPi = 3.141592653589793238462643383279502884;
const double kInvSqrt2 = 0.707106781186547524400844362104;
for (int k = 0; k < 16; k++) {
out[k] = 0.0;
for (int n = 0; n < 16; n++)
out[k] += in[n]*cos(kPi*(2*n+1)*k/32.0);
if (k == 0)
out[k] = out[k]*kInvSqrt2;
}
}
void reference_16x16_dct_2d(int16_t input[16*16], double output[16*16]) {
// First transform columns
for (int i = 0; i < 16; ++i) {
double temp_in[16], temp_out[16];
for (int j = 0; j < 16; ++j)
temp_in[j] = input[j*16 + i];
butterfly_16x16_dct_1d(temp_in, temp_out);
for (int j = 0; j < 16; ++j)
output[j*16 + i] = temp_out[j];
}
// Then transform rows
for (int i = 0; i < 16; ++i) {
double temp_in[16], temp_out[16];
for (int j = 0; j < 16; ++j)
temp_in[j] = output[j + i*16];
butterfly_16x16_dct_1d(temp_in, temp_out);
// Scale by some magic number
for (int j = 0; j < 16; ++j)
output[j + i*16] = temp_out[j]/2;
}
}
TEST(VP8Idct16x16Test, AccuracyCheck) {
ACMRandom rnd(ACMRandom::DeterministicSeed());
const int count_test_block = 1000;
for (int i = 0; i < count_test_block; ++i) {
int16_t in[256], coeff[256];
int16_t out_c[256];
double out_r[256];
// Initialize a test block with input range [-255, 255].
for (int j = 0; j < 256; ++j)
in[j] = rnd.Rand8() - rnd.Rand8();
reference_16x16_dct_2d(in, out_r);
for (int j = 0; j < 256; j++)
coeff[j] = round(out_r[j]);
vp8_short_idct16x16_c(coeff, out_c, 32);
for (int j = 0; j < 256; ++j) {
const int diff = out_c[j] - in[j];
const int error = diff * diff;
EXPECT_GE(1, error)
<< "Error: 16x16 IDCT has error " << error
<< " at index " << j;
}
vp8_short_fdct16x16_c(in, out_c, 32);
for (int j = 0; j < 256; ++j) {
const double diff = coeff[j] - out_c[j];
const double error = diff * diff;
EXPECT_GE(1.0, error)
<< "Error: 16x16 FDCT has error " << error
<< " at index " << j;
}
}
}
TEST(VP8Fdct16x16Test, AccuracyCheck) {
ACMRandom rnd(ACMRandom::DeterministicSeed());
int max_error = 0;
double total_error = 0;
const int count_test_block = 1000;
for (int i = 0; i < count_test_block; ++i) {
int16_t test_input_block[256];
int16_t test_temp_block[256];
int16_t test_output_block[256];
// Initialize a test block with input range [-255, 255].
for (int j = 0; j < 256; ++j)
test_input_block[j] = rnd.Rand8() - rnd.Rand8();
const int pitch = 32;
vp8_short_fdct16x16_c(test_input_block, test_temp_block, pitch);
vp8_short_idct16x16_c(test_temp_block, test_output_block, pitch);
for (int j = 0; j < 256; ++j) {
const int diff = test_input_block[j] - test_output_block[j];
const int error = diff * diff;
if (max_error < error)
max_error = error;
total_error += error;
}
}
EXPECT_GE(1, max_error)
<< "Error: 16x16 FDCT/IDCT has an individual roundtrip error > 1";
EXPECT_GE(count_test_block/10, total_error)
<< "Error: 16x16 FDCT/IDCT has average roundtrip error > 1/10 per block";
}
TEST(VP8Fdct16x16Test, CoeffSizeCheck) {
ACMRandom rnd(ACMRandom::DeterministicSeed());
const int count_test_block = 1000;
for (int i = 0; i < count_test_block; ++i) {
int16_t input_block[256], input_extreme_block[256];
int16_t output_block[256], output_extreme_block[256];
// Initialize a test block with input range [-255, 255].
for (int j = 0; j < 256; ++j) {
input_block[j] = rnd.Rand8() - rnd.Rand8();
input_extreme_block[j] = rnd.Rand8() % 2 ? 255 : -255;
}
if (i == 0)
for (int j = 0; j < 256; ++j)
input_extreme_block[j] = 255;
const int pitch = 32;
vp8_short_fdct16x16_c(input_block, output_block, pitch);
vp8_short_fdct16x16_c(input_extreme_block, output_extreme_block, pitch);
// The minimum quant value is 4.
for (int j = 0; j < 256; ++j) {
EXPECT_GE(4*DCT_MAX_VALUE, abs(output_block[j]))
<< "Error: 16x16 FDCT has coefficient larger than 4*DCT_MAX_VALUE";
EXPECT_GE(4*DCT_MAX_VALUE, abs(output_extreme_block[j]))
<< "Error: 16x16 FDCT extreme has coefficient larger than 4*DCT_MAX_VALUE";
}
}
}
} // namespace