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https://github.com/RGBCube/serenity
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2e31b9cf7c
The VP9 specification requires a special decoding process to parse a lot of the data read from a frame, so this BitStream wrapper implements that behavior. These processes are defined in section 9 of the VP9 spec.
50 lines
957 B
C++
50 lines
957 B
C++
/*
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* Copyright (c) 2021, Hunter Salyer <thefalsehonesty@gmail.com>
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#pragma once
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#include <AK/Optional.h>
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#include <AK/Types.h>
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namespace Video::VP9 {
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class BitStream {
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public:
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BitStream(const u8* data, size_t size)
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: m_data_ptr(data)
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, m_bytes_remaining(size)
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{
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}
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u8 read_byte();
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bool read_bit();
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u8 read_f(size_t n);
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i8 read_s(size_t n);
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u8 read_f8();
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u16 read_f16();
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u8 read_literal(size_t n);
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u64 get_position();
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size_t bytes_remaining();
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size_t bits_remaining();
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bool init_bool(size_t bytes);
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bool read_bool(u8 probability);
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bool exit_bool();
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private:
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const u8* m_data_ptr { nullptr };
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size_t m_bytes_remaining { 0 };
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Optional<u8> m_current_byte;
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i8 m_current_bit_position { 0 };
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u64 m_bytes_read { 0 };
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u8 m_bool_value { 0 };
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u8 m_bool_range { 0 };
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u64 m_bool_max_bits { 0 };
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};
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}
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