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// 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.
//
// File provides basic classes and functions for rANS coding.
#ifndef DRACO_COMPRESSION_BIT_CODERS_RANS_BIT_DECODER_H_
#define DRACO_COMPRESSION_BIT_CODERS_RANS_BIT_DECODER_H_
#include <vector>
#include "draco/draco_features.h"
#include "draco/compression/entropy/ans.h"
#include "draco/core/decoder_buffer.h"
namespace draco {
// Class for decoding a sequence of bits that were encoded with RAnsBitEncoder.
class RAnsBitDecoder {
public:
RAnsBitDecoder();
~RAnsBitDecoder();
// Sets |source_buffer| as the buffer to decode bits from.
// Returns false when the data is invalid.
bool StartDecoding(DecoderBuffer *source_buffer);
// Decode one bit. Returns true if the bit is a 1, otherwise false.
bool DecodeNextBit();
// Decode the next |nbits| and return the sequence in |value|. |nbits| must be
// > 0 and <= 32.
void DecodeLeastSignificantBits32(int nbits, uint32_t *value);
void EndDecoding() {}
private:
void Clear();
AnsDecoder ans_decoder_;
uint8_t prob_zero_;
};
} // namespace draco
#endif // DRACO_COMPRESSION_BIT_CODERS_RANS_BIT_DECODER_H_
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