2020-08-18 22:01:00 +00:00
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extends Reference
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2020-08-07 05:13:04 +00:00
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class LSB_LZWBitUnpacker:
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var chunk_stream: PoolByteArray
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var bit_index: int = 0
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var byte: int
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var byte_index: int = 0
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func _init(_chunk_stream: PoolByteArray):
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chunk_stream = _chunk_stream
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self.get_byte()
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func get_bit(value: int, index: int) -> int:
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return (value >> index) & 1
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func set_bit(value: int, index: int) -> int:
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return value | (1 << index)
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func get_byte():
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byte = chunk_stream[byte_index]
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byte_index += 1
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bit_index = 0
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func read_bits(bits_count: int) -> int:
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var result: int = 0
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var result_bit_index: int = 0
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for _i in range(bits_count):
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if self.get_bit(byte, bit_index) == 1:
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result = self.set_bit(result, result_bit_index)
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result_bit_index += 1
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bit_index += 1
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if bit_index == 8:
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self.get_byte()
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return result
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func remove_bits(bits_count: int) -> void:
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self.read_bits(bits_count)
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