ref: c91dd55eda7717d7a5f9726977138fb430cbbcfb
dir: /test/vp8_fdct4x4_test.cc/
/*
* Copyright (c) 2013 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 <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include "third_party/googletest/src/include/gtest/gtest.h"
#include "./vp8_rtcd.h"
#include "test/acm_random.h"
#include "vpx/vpx_integer.h"
namespace {
const int cospi8sqrt2minus1 = 20091;
const int sinpi8sqrt2 = 35468;
void reference_idct4x4(const int16_t *input, int16_t *output) {
const int16_t *ip = input;
int16_t *op = output;
for (int i = 0; i < 4; ++i) {
const int a1 = ip[0] + ip[8];
const int b1 = ip[0] - ip[8];
const int temp1 = (ip[4] * sinpi8sqrt2) >> 16;
const int temp2 = ip[12] + ((ip[12] * cospi8sqrt2minus1) >> 16);
const int c1 = temp1 - temp2;
const int temp3 = ip[4] + ((ip[4] * cospi8sqrt2minus1) >> 16);
const int temp4 = (ip[12] * sinpi8sqrt2) >> 16;
const int d1 = temp3 + temp4;
op[0] = a1 + d1;
op[12] = a1 - d1;
op[4] = b1 + c1;
op[8] = b1 - c1;
++ip;
++op;
}
ip = output;
op = output;
for (int i = 0; i < 4; ++i) {
const int a1 = ip[0] + ip[2];
const int b1 = ip[0] - ip[2];
const int temp1 = (ip[1] * sinpi8sqrt2) >> 16;
const int temp2 = ip[3] + ((ip[3] * cospi8sqrt2minus1) >> 16);
const int c1 = temp1 - temp2;
const int temp3 = ip[1] + ((ip[1] * cospi8sqrt2minus1) >> 16);
const int temp4 = (ip[3] * sinpi8sqrt2) >> 16;
const int d1 = temp3 + temp4;
op[0] = (a1 + d1 + 4) >> 3;
op[3] = (a1 - d1 + 4) >> 3;
op[1] = (b1 + c1 + 4) >> 3;
op[2] = (b1 - c1 + 4) >> 3;
ip += 4;
op += 4;
}
}
using libvpx_test::ACMRandom;
TEST(VP8FdctTest, SignBiasCheck) {
ACMRandom rnd(ACMRandom::DeterministicSeed());
int16_t test_input_block[16];
int16_t test_output_block[16];
const int pitch = 8;
int count_sign_block[16][2];
const int count_test_block = 1000000;
memset(count_sign_block, 0, sizeof(count_sign_block));
for (int i = 0; i < count_test_block; ++i) {
// Initialize a test block with input range [-255, 255].
for (int j = 0; j < 16; ++j)
test_input_block[j] = rnd.Rand8() - rnd.Rand8();
vp8_short_fdct4x4_c(test_input_block, test_output_block, pitch);
for (int j = 0; j < 16; ++j) {
if (test_output_block[j] < 0)
++count_sign_block[j][0];
else if (test_output_block[j] > 0)
++count_sign_block[j][1];
}
}
bool bias_acceptable = true;
for (int j = 0; j < 16; ++j)
bias_acceptable = bias_acceptable &&
(abs(count_sign_block[j][0] - count_sign_block[j][1]) < 10000);
EXPECT_EQ(true, bias_acceptable)
<< "Error: 4x4 FDCT has a sign bias > 1% for input range [-255, 255]";
memset(count_sign_block, 0, sizeof(count_sign_block));
for (int i = 0; i < count_test_block; ++i) {
// Initialize a test block with input range [-15, 15].
for (int j = 0; j < 16; ++j)
test_input_block[j] = (rnd.Rand8() >> 4) - (rnd.Rand8() >> 4);
vp8_short_fdct4x4_c(test_input_block, test_output_block, pitch);
for (int j = 0; j < 16; ++j) {
if (test_output_block[j] < 0)
++count_sign_block[j][0];
else if (test_output_block[j] > 0)
++count_sign_block[j][1];
}
}
bias_acceptable = true;
for (int j = 0; j < 16; ++j)
bias_acceptable = bias_acceptable &&
(abs(count_sign_block[j][0] - count_sign_block[j][1]) < 100000);
EXPECT_EQ(true, bias_acceptable)
<< "Error: 4x4 FDCT has a sign bias > 10% for input range [-15, 15]";
};
TEST(VP8FdctTest, RoundTripErrorCheck) {
ACMRandom rnd(ACMRandom::DeterministicSeed());
int max_error = 0;
double total_error = 0;
const int count_test_block = 1000000;
for (int i = 0; i < count_test_block; ++i) {
int16_t test_input_block[16];
int16_t test_temp_block[16];
int16_t test_output_block[16];
// Initialize a test block with input range [-255, 255].
for (int j = 0; j < 16; ++j)
test_input_block[j] = rnd.Rand8() - rnd.Rand8();
const int pitch = 8;
vp8_short_fdct4x4_c(test_input_block, test_temp_block, pitch);
reference_idct4x4(test_temp_block, test_output_block);
for (int j = 0; j < 16; ++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: FDCT/IDCT has an individual roundtrip error > 1";
EXPECT_GE(count_test_block, total_error)
<< "Error: FDCT/IDCT has average roundtrip error > 1 per block";
};
} // namespace