/* * 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. */ #ifndef AOM_TEST_ACM_RANDOM_H_ #define AOM_TEST_ACM_RANDOM_H_ #include "third_party/googletest/src/googletest/include/gtest/gtest.h" #include "aom/aom_integer.h" namespace libaom_test { class ACMRandom { public: ACMRandom() : random_(DeterministicSeed()) {} explicit ACMRandom(int seed) : random_(seed) {} void Reset(int seed) { random_.Reseed(seed); } uint32_t Rand31(void) { return random_.Generate(testing::internal::Random::kMaxRange); } uint16_t Rand16(void) { const uint32_t value = random_.Generate(testing::internal::Random::kMaxRange); return (value >> 15) & 0xffff; } int16_t Rand15Signed(void) { const uint32_t value = random_.Generate(testing::internal::Random::kMaxRange); return (value >> 17) & 0xffff; } uint16_t Rand12(void) { const uint32_t value = random_.Generate(testing::internal::Random::kMaxRange); // There's a bit more entropy in the upper bits of this implementation. return (value >> 19) & 0xfff; } int16_t Rand9Signed(void) { // Use 9 bits: values between 255 (0x0FF) and -256 (0x100). const uint32_t value = random_.Generate(512); return static_cast<int16_t>(value) - 256; } uint8_t Rand8(void) { const uint32_t value = random_.Generate(testing::internal::Random::kMaxRange); // There's a bit more entropy in the upper bits of this implementation. return (value >> 23) & 0xff; } uint8_t Rand8Extremes(void) { // Returns a random value near 0 or near 255, to better exercise // saturation behavior. const uint8_t r = Rand8(); return r < 128 ? r << 4 : r >> 4; } int PseudoUniform(int range) { return random_.Generate(range); } int operator()(int n) { return PseudoUniform(n); } static int DeterministicSeed(void) { return 0xbaba; } private: testing::internal::Random random_; }; } // namespace libaom_test #endif // AOM_TEST_ACM_RANDOM_H_