bitwriter_buffer_test.cc (2873B)
1 /* 2 * Copyright (c) 2025, Alliance for Open Media. All rights reserved. 3 * 4 * This source code is subject to the terms of the BSD 2 Clause License and 5 * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License 6 * was not distributed with this source code in the LICENSE file, you can 7 * obtain it at www.aomedia.org/license/software. If the Alliance for Open 8 * Media Patent License 1.0 was not distributed with this source code in the 9 * PATENTS file, you can obtain it at www.aomedia.org/license/patent. 10 */ 11 12 #include <cstdint> 13 14 #include "gtest/gtest.h" 15 16 #include "aom_dsp/bitwriter_buffer.h" 17 18 namespace { 19 20 // Test the examples in Table 25 in ITU-T H.274 (V3) (09/2023) and a few more. 21 // 22 // Bit string codeNum 23 // 1 0 24 // 010 1 25 // 011 2 26 // 00100 3 27 // 00101 4 28 // 00110 5 29 // 00111 6 30 // 0001000 7 31 // 0001001 8 32 // 0001010 9 33 // 0001011 10 34 // 0001100 11 35 // 0001101 12 36 // 0001110 13 37 // 0001111 14 38 TEST(BitwriterBufferTest, UvlcOneByte) { 39 static constexpr struct { 40 uint32_t bit_offset; 41 uint8_t byte; 42 } kExpected[] = { 43 { 1, 0x80 }, // 0 44 { 3, 0x40 }, // 1 45 { 3, 0x60 }, // 2 46 { 5, 0x20 }, // 3 47 { 5, 0x28 }, // 4 48 { 5, 0x30 }, // 5 49 { 5, 0x38 }, // 6 50 { 7, 0x10 }, // 7 51 { 7, 0x12 }, // 8 52 { 7, 0x14 }, // 9 53 { 7, 0x16 }, // 10 54 { 7, 0x18 }, // 11 55 { 7, 0x1a }, // 12 56 { 7, 0x1c }, // 13 57 { 7, 0x1e }, // 14 58 }; 59 uint8_t dst[1]; 60 61 for (int i = 0; i < 15; i++) { 62 struct aom_write_bit_buffer wb = { dst, 0 }; 63 aom_wb_write_uvlc(&wb, i); 64 ASSERT_EQ(wb.bit_offset, kExpected[i].bit_offset); 65 EXPECT_EQ(wb.bit_buffer[0], kExpected[i].byte); 66 } 67 } 68 69 // Tests two values with the maximum number (31) of leading zero bits. 70 TEST(BitwriterBufferTest, Uvlc31LeadingZeros) { 71 uint8_t dst[8]; 72 73 // 2^31 - 1 74 { 75 struct aom_write_bit_buffer wb = { dst, 0 }; 76 aom_wb_write_uvlc(&wb, 0x7fffffff); 77 ASSERT_EQ(wb.bit_offset, 63u); 78 EXPECT_EQ(wb.bit_buffer[0], 0x00); 79 EXPECT_EQ(wb.bit_buffer[1], 0x00); 80 EXPECT_EQ(wb.bit_buffer[2], 0x00); 81 EXPECT_EQ(wb.bit_buffer[3], 0x01); 82 EXPECT_EQ(wb.bit_buffer[4], 0x00); 83 EXPECT_EQ(wb.bit_buffer[5], 0x00); 84 EXPECT_EQ(wb.bit_buffer[6], 0x00); 85 EXPECT_EQ(wb.bit_buffer[7], 0x00); 86 } 87 88 // 2^32 - 2 89 { 90 struct aom_write_bit_buffer wb = { dst, 0 }; 91 aom_wb_write_uvlc(&wb, 0xfffffffe); 92 ASSERT_EQ(wb.bit_offset, 63u); 93 EXPECT_EQ(wb.bit_buffer[0], 0x00); 94 EXPECT_EQ(wb.bit_buffer[1], 0x00); 95 EXPECT_EQ(wb.bit_buffer[2], 0x00); 96 EXPECT_EQ(wb.bit_buffer[3], 0x01); 97 EXPECT_EQ(wb.bit_buffer[4], 0xff); 98 EXPECT_EQ(wb.bit_buffer[5], 0xff); 99 EXPECT_EQ(wb.bit_buffer[6], 0xff); 100 EXPECT_EQ(wb.bit_buffer[7], 0xfe); 101 } 102 } 103 104 } // namespace