draco/core/bit_coder_test.cc
2017-01-12 16:50:49 -08:00

114 lines
3.4 KiB
C++

// Copyright 2016 The Draco Authors.
//
// 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 "core/bit_coder.h"
#include "core/draco_test_base.h"
namespace draco {
class BitDecoderTest : public ::testing::Test {};
class BitEncoderTest : public ::testing::Test {};
TEST_F(BitDecoderTest, TestBitCodersByteAligned) {
constexpr int buffer_size = 32;
char buffer[buffer_size];
BitEncoder encoder(buffer);
const uint8_t data[] = {0x76, 0x54, 0x32, 0x10, 0x76, 0x54, 0x32, 0x10};
const int bytes_to_encode = sizeof(data);
for (int i = 0; i < bytes_to_encode; ++i) {
encoder.PutBits(data[i], sizeof(data[i]) * 8);
ASSERT_EQ((i + 1) * sizeof(data[i]) * 8, encoder.Bits());
}
BitDecoder decoder;
decoder.reset(static_cast<const void *>(buffer), bytes_to_encode);
for (int i = 0; i < bytes_to_encode; ++i) {
uint32_t x = 0;
ASSERT_TRUE(decoder.GetBits(8, &x));
ASSERT_EQ(x, data[i]);
}
ASSERT_EQ(bytes_to_encode * 8u, decoder.BitsDecoded());
}
TEST_F(BitDecoderTest, TestBitCodersNonByte) {
constexpr int buffer_size = 32;
char buffer[buffer_size];
BitEncoder encoder(buffer);
const uint8_t data[] = {0x76, 0x54, 0x32, 0x10, 0x76, 0x54, 0x32, 0x10};
const uint32_t bits_to_encode = 51;
const int bytes_to_encode = (bits_to_encode / 8) + 1;
for (int i = 0; i < bytes_to_encode; ++i) {
const int num_bits = (encoder.Bits() + 8 <= bits_to_encode)
? 8
: bits_to_encode - encoder.Bits();
encoder.PutBits(data[i], num_bits);
}
BitDecoder decoder;
decoder.reset(static_cast<const void *>(buffer), bytes_to_encode);
int64_t bits_to_decode = encoder.Bits();
for (int i = 0; i < bytes_to_encode; ++i) {
uint32_t x = 0;
const int num_bits = (bits_to_decode > 8) ? 8 : bits_to_decode;
ASSERT_TRUE(decoder.GetBits(num_bits, &x));
const int bits_to_shift = 8 - num_bits;
const uint8_t test_byte =
((data[i] << bits_to_shift) & 0xff) >> bits_to_shift;
ASSERT_EQ(x, test_byte);
bits_to_decode -= 8;
}
ASSERT_EQ(bits_to_encode, decoder.BitsDecoded());
}
TEST_F(BitDecoderTest, TestSingleBits) {
const int data = 0xaaaa;
BitDecoder decoder;
decoder.reset(static_cast<const void *>(&data), sizeof(data));
for (uint32_t i = 0; i < 16; ++i) {
uint32_t x = 0;
ASSERT_TRUE(decoder.GetBits(1, &x));
ASSERT_EQ(x, (i % 2));
}
ASSERT_EQ(16u, decoder.BitsDecoded());
}
TEST_F(BitDecoderTest, TestMultipleBits) {
const uint8_t data[] = {0x76, 0x54, 0x32, 0x10, 0x76, 0x54, 0x32, 0x10};
BitDecoder decoder;
decoder.reset(static_cast<const void *>(data), sizeof(data));
uint32_t x = 0;
for (uint32_t i = 0; i < 2; ++i) {
ASSERT_TRUE(decoder.GetBits(16, &x));
ASSERT_EQ(x, 0x5476u);
ASSERT_EQ(16 + (i * 32), decoder.BitsDecoded());
ASSERT_TRUE(decoder.GetBits(16, &x));
ASSERT_EQ(x, 0x1032u);
ASSERT_EQ(32 + (i * 32), decoder.BitsDecoded());
}
}
} // namespace draco