59 lines
1.4 KiB
C++
59 lines
1.4 KiB
C++
/*
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* BitReader.cpp
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*
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* Copyright 2019 HIMSA II K/S - www.himsa.dk. Represented by EHIMA - www.ehima.com
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include "BitReader.hpp"
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namespace Lc3Dec
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{
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uint8_t read_bit(const uint8_t bytes[], uint16_t* bp, uint8_t* mask)
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{
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uint8_t bit;
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if (bytes[*bp] & *mask)
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{
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bit = 1;
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}
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else
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{
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bit = 0;
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}
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if (*mask == 0x80)
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{
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*mask = 1;
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*bp -= 1;
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}
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else
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{
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*mask <<= 1;
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}
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return bit;
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}
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uint16_t read_uint(const uint8_t bytes[], uint16_t* bp, uint8_t* mask, uint8_t numbits)
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{
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uint16_t value = read_bit(bytes, bp, mask);
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for (uint8_t i = 1; i < numbits; i++)
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{
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uint16_t bit = read_bit(bytes, bp, mask);
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value += bit << i;
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}
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return value;
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}
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}//namespace Lc3Dec
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