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3682ca2801
1. Add 'use strict'to example Javascript. 2. Small fixes to README.md. 3. Fix Draco compiler flag tests. 4. Fixed issue when number of quantized bits was to large. 5. Changed StartDecoding to return a value. 6. Check that num of attributes are not less than 0. 7. Check that the number of attributes is a valid value.
89 lines
2.5 KiB
C++
89 lines
2.5 KiB
C++
// Copyright 2016 The Draco Authors.
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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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// File provides basic classes and functions for rANS coding.
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#ifndef DRACO_CORE_ADAPTIVE_RANS_CODING_H_
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#define DRACO_CORE_ADAPTIVE_RANS_CODING_H_
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#include <vector>
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#include "core/ans.h"
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#include "core/decoder_buffer.h"
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#include "core/encoder_buffer.h"
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namespace draco {
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// Class for adaptive encoding a sequence of bits using rANS.
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class AdaptiveRAnsBitEncoder {
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public:
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AdaptiveRAnsBitEncoder();
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~AdaptiveRAnsBitEncoder();
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// Must be called before any Encode* function is called.
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void StartEncoding();
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// Encode one bit. If |bit| is true encode a 1, otherwise encode a 0.
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void EncodeBit(bool bit) { bits_.push_back(bit); }
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// Encode |nibts| of |value|, starting from the least significant bit.
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// |nbits| must be > 0 and <= 32.
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void EncodeLeastSignificantBits32(int nbits, uint32_t value) {
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DCHECK_EQ(true, nbits <= 32);
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DCHECK_EQ(true, nbits > 0);
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uint32_t selector = (1 << (nbits - 1));
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while (selector) {
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EncodeBit(value & selector);
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selector = selector >> 1;
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}
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}
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// Ends the bit encoding and stores the result into the target_buffer.
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void EndEncoding(EncoderBuffer *target_buffer);
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private:
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void Clear();
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std::vector<bool> bits_;
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};
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// Class for decoding a sequence of bits that were encoded with
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// AdaptiveRAnsBitEncoder.
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class AdaptiveRAnsBitDecoder {
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public:
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AdaptiveRAnsBitDecoder();
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~AdaptiveRAnsBitDecoder();
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// Sets |source_buffer| as the buffer to decode bits from.
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bool StartDecoding(DecoderBuffer *source_buffer);
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// Decode one bit. Returns true if the bit is a 1, otherwsie false.
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bool DecodeNextBit();
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// Decode the next |nbits| and return the sequence in |value|. |nbits| must be
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// > 0 and <= 32.
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void DecodeLeastSignificantBits32(int nbits, uint32_t *value);
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void EndDecoding() {}
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private:
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void Clear();
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AnsDecoder ans_decoder_;
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double p0_f_;
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};
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} // namespace draco
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#endif // DRACO_CORE_ADAPTIVE_RANS_CODING_H_
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