| /* |
| * Copyright (c) 2021, Alliance for Open Media. All rights reserved |
| * |
| * This source code is subject to the terms of the BSD 3-Clause Clear License |
| * and the Alliance for Open Media Patent License 1.0. If the BSD 3-Clause Clear |
| * License was not distributed with this source code in the LICENSE file, you |
| * can obtain it at aomedia.org/license/software-license/bsd-3-c-c/. 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 |
| * aomedia.org/license/patent-license/. |
| */ |
| |
| #include <math.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| #include "third_party/googletest/src/googletest/include/gtest/gtest.h" |
| |
| #include "test/acm_random.h" |
| #include "aom/aom_integer.h" |
| #include "aom_dsp/bitreader.h" |
| #include "aom_dsp/bitwriter.h" |
| |
| using libaom_test::ACMRandom; |
| |
| namespace { |
| const int num_tests = 10; |
| } // namespace |
| |
| TEST(AV1, TestBitIO) { |
| ACMRandom rnd(ACMRandom::DeterministicSeed()); |
| for (int n = 0; n < num_tests; ++n) { |
| for (int method = 0; method <= 7; ++method) { // we generate various proba |
| const int kBitsToTest = 1000; |
| uint8_t probas[kBitsToTest]; |
| |
| for (int i = 0; i < kBitsToTest; ++i) { |
| const int parity = i & 1; |
| /* clang-format off */ |
| probas[i] = |
| (method == 0) ? 0 : (method == 1) ? 255 : |
| (method == 2) ? 128 : |
| (method == 3) ? rnd.Rand8() : |
| (method == 4) ? (parity ? 0 : 255) : |
| // alternate between low and high proba: |
| (method == 5) ? (parity ? rnd(128) : 255 - rnd(128)) : |
| (method == 6) ? |
| (parity ? rnd(64) : 255 - rnd(64)) : |
| (parity ? rnd(32) : 255 - rnd(32)); |
| /* clang-format on */ |
| } |
| for (int bit_method = 0; bit_method <= 3; ++bit_method) { |
| const int random_seed = 6432; |
| const int kBufferSize = 10000; |
| ACMRandom bit_rnd(random_seed); |
| aom_writer bw; |
| uint8_t bw_buffer[kBufferSize]; |
| aom_start_encode(&bw, bw_buffer); |
| |
| int bit = (bit_method == 0) ? 0 : (bit_method == 1) ? 1 : 0; |
| for (int i = 0; i < kBitsToTest; ++i) { |
| if (bit_method == 2) { |
| bit = (i & 1); |
| } else if (bit_method == 3) { |
| bit = bit_rnd(2); |
| } |
| aom_write(&bw, bit, static_cast<int>(probas[i])); |
| } |
| |
| aom_stop_encode(&bw); |
| |
| aom_reader br; |
| aom_reader_init(&br, bw_buffer, bw.pos); |
| bit_rnd.Reset(random_seed); |
| for (int i = 0; i < kBitsToTest; ++i) { |
| if (bit_method == 2) { |
| bit = (i & 1); |
| } else if (bit_method == 3) { |
| bit = bit_rnd(2); |
| } |
| GTEST_ASSERT_EQ(aom_read(&br, probas[i], NULL), bit) |
| << "pos: " << i << " / " << kBitsToTest |
| << " bit_method: " << bit_method << " method: " << method; |
| } |
| } |
| } |
| } |
| } |
| |
| #define FRAC_DIFF_TOTAL_ERROR 0.18 |
| |
| TEST(AV1, TestTell) { |
| const int kBufferSize = 10000; |
| aom_writer bw; |
| uint8_t bw_buffer[kBufferSize]; |
| const int kSymbols = 1024; |
| // Coders are noisier at low probabilities, so we start at p = 4. |
| for (int p = 4; p < 256; p++) { |
| double probability = p / 256.; |
| aom_start_encode(&bw, bw_buffer); |
| for (int i = 0; i < kSymbols; i++) { |
| aom_write(&bw, 0, p); |
| } |
| aom_stop_encode(&bw); |
| aom_reader br; |
| aom_reader_init(&br, bw_buffer, bw.pos); |
| uint32_t last_tell = aom_reader_tell(&br); |
| uint32_t last_tell_frac = aom_reader_tell_frac(&br); |
| double frac_diff_total = 0; |
| GTEST_ASSERT_GE(aom_reader_tell(&br), 0u); |
| GTEST_ASSERT_LE(aom_reader_tell(&br), 1u); |
| ASSERT_FALSE(aom_reader_has_overflowed(&br)); |
| for (int i = 0; i < kSymbols; i++) { |
| aom_read(&br, p, NULL); |
| uint32_t tell = aom_reader_tell(&br); |
| uint32_t tell_frac = aom_reader_tell_frac(&br); |
| GTEST_ASSERT_GE(tell, last_tell) |
| << "tell: " << tell << ", last_tell: " << last_tell; |
| GTEST_ASSERT_GE(tell_frac, last_tell_frac) |
| << "tell_frac: " << tell_frac |
| << ", last_tell_frac: " << last_tell_frac; |
| // Frac tell should round up to tell. |
| GTEST_ASSERT_EQ(tell, (tell_frac + 7) >> 3); |
| last_tell = tell; |
| frac_diff_total += |
| fabs(((tell_frac - last_tell_frac) / 8.0) + log2(probability)); |
| last_tell_frac = tell_frac; |
| } |
| const uint32_t expected = (uint32_t)(-kSymbols * log2(probability)); |
| // Last tell should be close to the expected value. |
| GTEST_ASSERT_LE(last_tell, expected + 20) << " last_tell: " << last_tell; |
| // The average frac_diff error should be pretty small. |
| GTEST_ASSERT_LE(frac_diff_total / kSymbols, FRAC_DIFF_TOTAL_ERROR) |
| << " frac_diff_total: " << frac_diff_total; |
| ASSERT_FALSE(aom_reader_has_overflowed(&br)); |
| } |
| } |
| |
| TEST(AV1, TestHasOverflowed) { |
| const int kBufferSize = 10000; |
| aom_writer bw; |
| uint8_t bw_buffer[kBufferSize]; |
| const int kSymbols = 1024; |
| // Coders are noisier at low probabilities, so we start at p = 4. |
| for (int p = 4; p < 256; p++) { |
| aom_start_encode(&bw, bw_buffer); |
| for (int i = 0; i < kSymbols; i++) { |
| aom_write(&bw, 1, p); |
| } |
| aom_stop_encode(&bw); |
| aom_reader br; |
| aom_reader_init(&br, bw_buffer, bw.pos); |
| ASSERT_FALSE(aom_reader_has_overflowed(&br)); |
| for (int i = 0; i < kSymbols; i++) { |
| GTEST_ASSERT_EQ(aom_read(&br, p, NULL), 1); |
| ASSERT_FALSE(aom_reader_has_overflowed(&br)); |
| } |
| // In the worst case, the encoder uses just a tiny fraction of the last |
| // byte in the buffer. So to guarantee that aom_reader_has_overflowed() |
| // returns true, we have to consume very nearly 8 additional bits of data. |
| // In the worse case, one of the bits in that byte will be 1, and the rest |
| // will be zero. Once we are past that 1 bit, when the probability of |
| // reading zero symbol from aom_read() is high, each additional symbol read |
| // will consume very little additional data (in the case that p == 255, |
| // approximately -log_2(255/256) ~= 0.0056 bits). In that case it would |
| // take around 178 calls to consume more than 8 bits. That is only an upper |
| // bound. In practice we are not guaranteed to hit the worse case and can |
| // get away with 174 calls. |
| for (int i = 0; i < 174; i++) { |
| aom_read(&br, p, NULL); |
| } |
| ASSERT_TRUE(aom_reader_has_overflowed(&br)); |
| } |
| } |