| /* |
| * Copyright (C) 2018 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include <array> |
| #include <climits> |
| #include <math.h> |
| |
| #include <audio_utils/sample.h> |
| #include <gtest/gtest.h> |
| |
| static_assert(sizeof(sample_minifloat_t) == sizeof(uint16_t), |
| "sizeof(sample_minifloat_t != sizeof(uint16_t"); |
| |
| static constexpr int signum(float f) |
| { |
| return (f > 0) - (f < 0); |
| } |
| |
| TEST(audio_utils_sample, Convert) |
| { |
| std::vector<float> fvec; |
| // verify minifloat <-> float is a bijection, and monotonic as float |
| for (int i = 0; i <= 0xFFFF; i++) { |
| // construct floats in order |
| const int val = i < 0x8000 ? 0xFFFF - i : i ^ 0x8000; |
| // TODO shouldn't depend on representation in order to skip negative zero |
| if (val == 0x8000) { |
| // This is an undefined value and so we won't test its behavior |
| continue; |
| } |
| // TODO reinterpret_cast<sample_minifloat_t>(val) fails |
| const sample_minifloat_t in = (sample_minifloat_t) val; |
| const float f = float_from_sample(in); |
| const sample_minifloat_t out = sample_from_float(f); |
| ASSERT_EQ(in, out); |
| fvec.push_back(f); |
| } |
| // no longer needed since we construct floats in order |
| // #include <algorithm> |
| // std::sort(fvec.begin(), fvec.end()); |
| float prev = -2.0f; |
| for (auto curr : fvec) { |
| // LT instead of LE because no negative zero |
| ASSERT_LT(prev, curr); |
| int signum_prev = signum(prev); |
| int signum_curr = signum(curr); |
| ASSERT_LE(signum_prev, signum_curr); |
| if (signum_prev == signum_curr) { |
| // confirm ratio between adjacent values (3:45 of "Will it float?" video) |
| float ratio = curr / prev; |
| float lower, upper; |
| // normal |
| if (fabsf(curr) >= 0.001f) { |
| upper = 1.005f; |
| lower = 0.995f; |
| // denormal |
| } else { |
| upper = 2.0f; |
| lower = 0.5f; |
| } |
| ASSERT_GE(ratio, lower) << "prev " << prev << " curr " << curr; |
| ASSERT_LE(ratio, upper) << "prev " << prev << " curr " << curr; |
| } |
| prev = curr; |
| } |
| ASSERT_LT(prev, 2.0f); |
| } |