aom/test/ans_test.cc

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5.3 KiB
C++

/*
* Copyright (c) 2016, Alliance for Open Media. All rights reserved
*
* This source code is subject to the terms of the BSD 2 Clause License and
* the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
* was not distributed with this source code in the LICENSE file, you can
* obtain it at www.aomedia.org/license/software. If the Alliance for Open
* Media Patent License 1.0 was not distributed with this source code in the
* PATENTS file, you can obtain it at www.aomedia.org/license/patent.
*/
#include <assert.h>
#include <math.h>
#include <stdio.h>
#include <ctime>
#include <utility>
#include <vector>
#include "third_party/googletest/src/include/gtest/gtest.h"
#include "test/acm_random.h"
#include "aom_dsp/ansreader.h"
#include "aom_dsp/answriter.h"
namespace {
typedef std::vector<std::pair<uint8_t, bool> > PvVec;
const int kPrintStats = 0;
PvVec abs_encode_build_vals(int iters) {
PvVec ret;
libaom_test::ACMRandom gen(0x30317076);
double entropy = 0;
for (int i = 0; i < iters; ++i) {
uint8_t p;
do {
p = gen.Rand8();
} while (p == 0); // zero is not a valid coding probability
bool b = gen.Rand8() < p;
ret.push_back(std::make_pair(static_cast<uint8_t>(p), b));
if (kPrintStats) {
double d = p / 256.;
entropy += -d * log2(d) - (1 - d) * log2(1 - d);
}
}
if (kPrintStats) printf("entropy %f\n", entropy);
return ret;
}
bool check_uabs(const PvVec &pv_vec, uint8_t *buf) {
AnsCoder a;
ans_write_init(&a, buf);
std::clock_t start = std::clock();
for (PvVec::const_reverse_iterator it = pv_vec.rbegin(); it != pv_vec.rend();
++it) {
uabs_write(&a, it->second, 256 - it->first);
}
std::clock_t enc_time = std::clock() - start;
int offset = ans_write_end(&a);
bool okay = true;
AnsDecoder d;
if (ans_read_init(&d, buf, offset)) return false;
start = std::clock();
for (PvVec::const_iterator it = pv_vec.begin(); it != pv_vec.end(); ++it) {
okay &= uabs_read(&d, 256 - it->first) == it->second;
}
std::clock_t dec_time = std::clock() - start;
if (!okay) return false;
if (kPrintStats)
printf("uABS size %d enc_time %f dec_time %f\n", offset,
static_cast<float>(enc_time) / CLOCKS_PER_SEC,
static_cast<float>(dec_time) / CLOCKS_PER_SEC);
return ans_read_end(&d);
}
const aom_cdf_prob spareto65[] = { 8320, 6018, 4402, 3254, 4259,
3919, 2057, 492, 45, 2 };
const int kRansSymbols =
static_cast<int>(sizeof(spareto65) / sizeof(spareto65[0]));
std::vector<int> ans_encode_build_vals(rans_sym *const tab, int iters) {
aom_cdf_prob sum = 0;
for (int i = 0; i < kRansSymbols; ++i) {
tab[i].cum_prob = sum;
tab[i].prob = spareto65[i];
sum += spareto65[i];
}
std::vector<int> p_to_sym;
for (int i = 0; i < kRansSymbols; ++i) {
p_to_sym.insert(p_to_sym.end(), tab[i].prob, i);
}
assert(p_to_sym.size() == RANS_PRECISION);
std::vector<int> ret;
libaom_test::ACMRandom gen(18543637);
for (int i = 0; i < iters; ++i) {
int sym =
p_to_sym[((gen.Rand8() << 8) + gen.Rand8()) & (RANS_PRECISION - 1)];
ret.push_back(sym);
}
return ret;
}
void rans_build_dec_tab(const struct rans_sym sym_tab[],
aom_cdf_prob *dec_tab) {
unsigned int sum = 0;
for (int i = 0; sum < RANS_PRECISION; ++i) {
dec_tab[i] = sum += sym_tab[i].prob;
}
}
bool check_rans(const std::vector<int> &sym_vec, const rans_sym *const tab,
uint8_t *buf) {
AnsCoder a;
ans_write_init(&a, buf);
aom_cdf_prob dec_tab[kRansSymbols];
rans_build_dec_tab(tab, dec_tab);
std::clock_t start = std::clock();
for (std::vector<int>::const_reverse_iterator it = sym_vec.rbegin();
it != sym_vec.rend(); ++it) {
rans_write(&a, &tab[*it]);
}
std::clock_t enc_time = std::clock() - start;
int offset = ans_write_end(&a);
bool okay = true;
AnsDecoder d;
if (ans_read_init(&d, buf, offset)) return false;
start = std::clock();
for (std::vector<int>::const_iterator it = sym_vec.begin();
it != sym_vec.end(); ++it) {
okay &= rans_read(&d, dec_tab) == *it;
}
std::clock_t dec_time = std::clock() - start;
if (!okay) return false;
if (kPrintStats)
printf("rANS size %d enc_time %f dec_time %f\n", offset,
static_cast<float>(enc_time) / CLOCKS_PER_SEC,
static_cast<float>(dec_time) / CLOCKS_PER_SEC);
return ans_read_end(&d);
}
class AbsTest : public ::testing::Test {
protected:
static void SetUpTestCase() { pv_vec_ = abs_encode_build_vals(kNumBools); }
virtual void SetUp() { buf_ = new uint8_t[kNumBools / 8]; }
virtual void TearDown() { delete[] buf_; }
static const int kNumBools = 100000000;
static PvVec pv_vec_;
uint8_t *buf_;
};
PvVec AbsTest::pv_vec_;
class AnsTest : public ::testing::Test {
protected:
static void SetUpTestCase() {
sym_vec_ = ans_encode_build_vals(rans_sym_tab_, kNumSyms);
}
virtual void SetUp() { buf_ = new uint8_t[kNumSyms / 2]; }
virtual void TearDown() { delete[] buf_; }
static const int kNumSyms = 25000000;
static std::vector<int> sym_vec_;
static rans_sym rans_sym_tab_[kRansSymbols];
uint8_t *buf_;
};
std::vector<int> AnsTest::sym_vec_;
rans_sym AnsTest::rans_sym_tab_[kRansSymbols];
TEST_F(AbsTest, Uabs) { EXPECT_TRUE(check_uabs(pv_vec_, buf_)); }
TEST_F(AnsTest, Rans) {
EXPECT_TRUE(check_rans(sym_vec_, rans_sym_tab_, buf_));
}
} // namespace