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73bb3c8530
- Improved compression for triangular meshes (~10%) - Added WebAssembly decoder - Code cleanup + robustness fixes
39 lines
1.5 KiB
C++
39 lines
1.5 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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#ifndef DRACO_CORE_SHANNON_ENTROPY_H_
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#define DRACO_CORE_SHANNON_ENTROPY_H_
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#include <stdint.h>
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namespace draco {
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// Computes an approximate Shannon entropy of symbols stored in the provided
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// input array |symbols|. The entropy corresponds to the number of bits that is
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// required to represent/store all the symbols using an optimal entropy coding
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// algorithm. See for example "A mathematical theory of communication" by
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// Shannon'48 (http://ieeexplore.ieee.org/document/6773024/).
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//
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// |max_value| is a required input that define the maximum value in the input
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// |symbols| array.
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//
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// |out_num_unique_symbols| is an optional output argument that stores the
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// number of unique symbols contained within the |symbols| array.
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int64_t ComputeShannonEntropy(const uint32_t *symbols, int num_symbols,
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int max_value, int *out_num_unique_symbols);
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} // namespace draco
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#endif // DRACO_CORE_SHANNON_ENTROPY_H_
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