mirror of
https://github.com/godotengine/godot
synced 2024-09-16 05:07:49 +00:00
696346f4cc
Co-authored-by: Gordon A Macpherson <gordon.a.macpherson@gmail.com> Co-authored-by: Rémi Verschelde <rverschelde@gmail.com>
740 lines
22 KiB
C++
740 lines
22 KiB
C++
// SPDX-License-Identifier: Apache-2.0
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// ----------------------------------------------------------------------------
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// Copyright 2011-2021 Arm Limited
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//
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// Licensed under the Apache License, Version 2.0 (the "License"); you may not
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// use this file except in compliance with the License. You may obtain a copy
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// 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, WITHOUT
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// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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// License for the specific language governing permissions and limitations
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// under the License.
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// ----------------------------------------------------------------------------
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/**
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* @brief Functions for encoding/decoding Bounded Integer Sequence Encoding.
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*/
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#include "astcenc_internal.h"
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#include <array>
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/** @brief Unpacked quint triplets <low,middle,high> for each packed value */
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// TODO: Bitpack these into a uint16_t?
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static const uint8_t quints_of_integer[128][3] {
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{0, 0, 0}, {1, 0, 0}, {2, 0, 0}, {3, 0, 0},
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{4, 0, 0}, {0, 4, 0}, {4, 4, 0}, {4, 4, 4},
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{0, 1, 0}, {1, 1, 0}, {2, 1, 0}, {3, 1, 0},
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{4, 1, 0}, {1, 4, 0}, {4, 4, 1}, {4, 4, 4},
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{0, 2, 0}, {1, 2, 0}, {2, 2, 0}, {3, 2, 0},
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{4, 2, 0}, {2, 4, 0}, {4, 4, 2}, {4, 4, 4},
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{0, 3, 0}, {1, 3, 0}, {2, 3, 0}, {3, 3, 0},
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{4, 3, 0}, {3, 4, 0}, {4, 4, 3}, {4, 4, 4},
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{0, 0, 1}, {1, 0, 1}, {2, 0, 1}, {3, 0, 1},
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{4, 0, 1}, {0, 4, 1}, {4, 0, 4}, {0, 4, 4},
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{0, 1, 1}, {1, 1, 1}, {2, 1, 1}, {3, 1, 1},
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{4, 1, 1}, {1, 4, 1}, {4, 1, 4}, {1, 4, 4},
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{0, 2, 1}, {1, 2, 1}, {2, 2, 1}, {3, 2, 1},
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{4, 2, 1}, {2, 4, 1}, {4, 2, 4}, {2, 4, 4},
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{0, 3, 1}, {1, 3, 1}, {2, 3, 1}, {3, 3, 1},
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{4, 3, 1}, {3, 4, 1}, {4, 3, 4}, {3, 4, 4},
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{0, 0, 2}, {1, 0, 2}, {2, 0, 2}, {3, 0, 2},
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{4, 0, 2}, {0, 4, 2}, {2, 0, 4}, {3, 0, 4},
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{0, 1, 2}, {1, 1, 2}, {2, 1, 2}, {3, 1, 2},
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{4, 1, 2}, {1, 4, 2}, {2, 1, 4}, {3, 1, 4},
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{0, 2, 2}, {1, 2, 2}, {2, 2, 2}, {3, 2, 2},
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{4, 2, 2}, {2, 4, 2}, {2, 2, 4}, {3, 2, 4},
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{0, 3, 2}, {1, 3, 2}, {2, 3, 2}, {3, 3, 2},
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{4, 3, 2}, {3, 4, 2}, {2, 3, 4}, {3, 3, 4},
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{0, 0, 3}, {1, 0, 3}, {2, 0, 3}, {3, 0, 3},
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{4, 0, 3}, {0, 4, 3}, {0, 0, 4}, {1, 0, 4},
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{0, 1, 3}, {1, 1, 3}, {2, 1, 3}, {3, 1, 3},
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{4, 1, 3}, {1, 4, 3}, {0, 1, 4}, {1, 1, 4},
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{0, 2, 3}, {1, 2, 3}, {2, 2, 3}, {3, 2, 3},
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{4, 2, 3}, {2, 4, 3}, {0, 2, 4}, {1, 2, 4},
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{0, 3, 3}, {1, 3, 3}, {2, 3, 3}, {3, 3, 3},
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{4, 3, 3}, {3, 4, 3}, {0, 3, 4}, {1, 3, 4}
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};
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/** @brief Packed quint values for each unpacked value, indexed [hi][mid][lo]. */
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static const uint8_t integer_of_quints[5][5][5] {
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{
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{0, 1, 2, 3, 4},
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{8, 9, 10, 11, 12},
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{16, 17, 18, 19, 20},
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{24, 25, 26, 27, 28},
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{5, 13, 21, 29, 6}
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},
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{
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{32, 33, 34, 35, 36},
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{40, 41, 42, 43, 44},
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{48, 49, 50, 51, 52},
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{56, 57, 58, 59, 60},
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{37, 45, 53, 61, 14}
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},
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{
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{64, 65, 66, 67, 68},
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{72, 73, 74, 75, 76},
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{80, 81, 82, 83, 84},
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{88, 89, 90, 91, 92},
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{69, 77, 85, 93, 22}
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},
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{
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{96, 97, 98, 99, 100},
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{104, 105, 106, 107, 108},
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{112, 113, 114, 115, 116},
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{120, 121, 122, 123, 124},
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{101, 109, 117, 125, 30}
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},
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{
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{102, 103, 70, 71, 38},
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{110, 111, 78, 79, 46},
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{118, 119, 86, 87, 54},
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{126, 127, 94, 95, 62},
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{39, 47, 55, 63, 31}
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}
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};
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/** @brief Unpacked trit quintuplets <low,...,high> for each packed value */
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// TODO: Bitpack these into a uint16_t?
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static const uint8_t trits_of_integer[256][5] {
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{0, 0, 0, 0, 0}, {1, 0, 0, 0, 0}, {2, 0, 0, 0, 0}, {0, 0, 2, 0, 0},
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{0, 1, 0, 0, 0}, {1, 1, 0, 0, 0}, {2, 1, 0, 0, 0}, {1, 0, 2, 0, 0},
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{0, 2, 0, 0, 0}, {1, 2, 0, 0, 0}, {2, 2, 0, 0, 0}, {2, 0, 2, 0, 0},
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{0, 2, 2, 0, 0}, {1, 2, 2, 0, 0}, {2, 2, 2, 0, 0}, {2, 0, 2, 0, 0},
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{0, 0, 1, 0, 0}, {1, 0, 1, 0, 0}, {2, 0, 1, 0, 0}, {0, 1, 2, 0, 0},
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{0, 1, 1, 0, 0}, {1, 1, 1, 0, 0}, {2, 1, 1, 0, 0}, {1, 1, 2, 0, 0},
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{0, 2, 1, 0, 0}, {1, 2, 1, 0, 0}, {2, 2, 1, 0, 0}, {2, 1, 2, 0, 0},
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{0, 0, 0, 2, 2}, {1, 0, 0, 2, 2}, {2, 0, 0, 2, 2}, {0, 0, 2, 2, 2},
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{0, 0, 0, 1, 0}, {1, 0, 0, 1, 0}, {2, 0, 0, 1, 0}, {0, 0, 2, 1, 0},
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{0, 1, 0, 1, 0}, {1, 1, 0, 1, 0}, {2, 1, 0, 1, 0}, {1, 0, 2, 1, 0},
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{0, 2, 0, 1, 0}, {1, 2, 0, 1, 0}, {2, 2, 0, 1, 0}, {2, 0, 2, 1, 0},
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{0, 2, 2, 1, 0}, {1, 2, 2, 1, 0}, {2, 2, 2, 1, 0}, {2, 0, 2, 1, 0},
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{0, 0, 1, 1, 0}, {1, 0, 1, 1, 0}, {2, 0, 1, 1, 0}, {0, 1, 2, 1, 0},
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{0, 1, 1, 1, 0}, {1, 1, 1, 1, 0}, {2, 1, 1, 1, 0}, {1, 1, 2, 1, 0},
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{0, 2, 1, 1, 0}, {1, 2, 1, 1, 0}, {2, 2, 1, 1, 0}, {2, 1, 2, 1, 0},
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{0, 1, 0, 2, 2}, {1, 1, 0, 2, 2}, {2, 1, 0, 2, 2}, {1, 0, 2, 2, 2},
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{0, 0, 0, 2, 0}, {1, 0, 0, 2, 0}, {2, 0, 0, 2, 0}, {0, 0, 2, 2, 0},
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{0, 1, 0, 2, 0}, {1, 1, 0, 2, 0}, {2, 1, 0, 2, 0}, {1, 0, 2, 2, 0},
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{0, 2, 0, 2, 0}, {1, 2, 0, 2, 0}, {2, 2, 0, 2, 0}, {2, 0, 2, 2, 0},
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{0, 2, 2, 2, 0}, {1, 2, 2, 2, 0}, {2, 2, 2, 2, 0}, {2, 0, 2, 2, 0},
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{0, 0, 1, 2, 0}, {1, 0, 1, 2, 0}, {2, 0, 1, 2, 0}, {0, 1, 2, 2, 0},
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{0, 1, 1, 2, 0}, {1, 1, 1, 2, 0}, {2, 1, 1, 2, 0}, {1, 1, 2, 2, 0},
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{0, 2, 1, 2, 0}, {1, 2, 1, 2, 0}, {2, 2, 1, 2, 0}, {2, 1, 2, 2, 0},
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{0, 2, 0, 2, 2}, {1, 2, 0, 2, 2}, {2, 2, 0, 2, 2}, {2, 0, 2, 2, 2},
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{0, 0, 0, 0, 2}, {1, 0, 0, 0, 2}, {2, 0, 0, 0, 2}, {0, 0, 2, 0, 2},
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{0, 1, 0, 0, 2}, {1, 1, 0, 0, 2}, {2, 1, 0, 0, 2}, {1, 0, 2, 0, 2},
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{0, 2, 0, 0, 2}, {1, 2, 0, 0, 2}, {2, 2, 0, 0, 2}, {2, 0, 2, 0, 2},
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{0, 2, 2, 0, 2}, {1, 2, 2, 0, 2}, {2, 2, 2, 0, 2}, {2, 0, 2, 0, 2},
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{0, 0, 1, 0, 2}, {1, 0, 1, 0, 2}, {2, 0, 1, 0, 2}, {0, 1, 2, 0, 2},
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{0, 1, 1, 0, 2}, {1, 1, 1, 0, 2}, {2, 1, 1, 0, 2}, {1, 1, 2, 0, 2},
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{0, 2, 1, 0, 2}, {1, 2, 1, 0, 2}, {2, 2, 1, 0, 2}, {2, 1, 2, 0, 2},
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{0, 2, 2, 2, 2}, {1, 2, 2, 2, 2}, {2, 2, 2, 2, 2}, {2, 0, 2, 2, 2},
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{0, 0, 0, 0, 1}, {1, 0, 0, 0, 1}, {2, 0, 0, 0, 1}, {0, 0, 2, 0, 1},
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{0, 1, 0, 0, 1}, {1, 1, 0, 0, 1}, {2, 1, 0, 0, 1}, {1, 0, 2, 0, 1},
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{0, 2, 0, 0, 1}, {1, 2, 0, 0, 1}, {2, 2, 0, 0, 1}, {2, 0, 2, 0, 1},
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{0, 2, 2, 0, 1}, {1, 2, 2, 0, 1}, {2, 2, 2, 0, 1}, {2, 0, 2, 0, 1},
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{0, 0, 1, 0, 1}, {1, 0, 1, 0, 1}, {2, 0, 1, 0, 1}, {0, 1, 2, 0, 1},
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{0, 1, 1, 0, 1}, {1, 1, 1, 0, 1}, {2, 1, 1, 0, 1}, {1, 1, 2, 0, 1},
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{0, 2, 1, 0, 1}, {1, 2, 1, 0, 1}, {2, 2, 1, 0, 1}, {2, 1, 2, 0, 1},
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{0, 0, 1, 2, 2}, {1, 0, 1, 2, 2}, {2, 0, 1, 2, 2}, {0, 1, 2, 2, 2},
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{0, 0, 0, 1, 1}, {1, 0, 0, 1, 1}, {2, 0, 0, 1, 1}, {0, 0, 2, 1, 1},
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{0, 1, 0, 1, 1}, {1, 1, 0, 1, 1}, {2, 1, 0, 1, 1}, {1, 0, 2, 1, 1},
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{0, 2, 0, 1, 1}, {1, 2, 0, 1, 1}, {2, 2, 0, 1, 1}, {2, 0, 2, 1, 1},
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{0, 2, 2, 1, 1}, {1, 2, 2, 1, 1}, {2, 2, 2, 1, 1}, {2, 0, 2, 1, 1},
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{0, 0, 1, 1, 1}, {1, 0, 1, 1, 1}, {2, 0, 1, 1, 1}, {0, 1, 2, 1, 1},
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{0, 1, 1, 1, 1}, {1, 1, 1, 1, 1}, {2, 1, 1, 1, 1}, {1, 1, 2, 1, 1},
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{0, 2, 1, 1, 1}, {1, 2, 1, 1, 1}, {2, 2, 1, 1, 1}, {2, 1, 2, 1, 1},
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{0, 1, 1, 2, 2}, {1, 1, 1, 2, 2}, {2, 1, 1, 2, 2}, {1, 1, 2, 2, 2},
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{0, 0, 0, 2, 1}, {1, 0, 0, 2, 1}, {2, 0, 0, 2, 1}, {0, 0, 2, 2, 1},
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{0, 1, 0, 2, 1}, {1, 1, 0, 2, 1}, {2, 1, 0, 2, 1}, {1, 0, 2, 2, 1},
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{0, 2, 0, 2, 1}, {1, 2, 0, 2, 1}, {2, 2, 0, 2, 1}, {2, 0, 2, 2, 1},
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{0, 2, 2, 2, 1}, {1, 2, 2, 2, 1}, {2, 2, 2, 2, 1}, {2, 0, 2, 2, 1},
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{0, 0, 1, 2, 1}, {1, 0, 1, 2, 1}, {2, 0, 1, 2, 1}, {0, 1, 2, 2, 1},
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{0, 1, 1, 2, 1}, {1, 1, 1, 2, 1}, {2, 1, 1, 2, 1}, {1, 1, 2, 2, 1},
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{0, 2, 1, 2, 1}, {1, 2, 1, 2, 1}, {2, 2, 1, 2, 1}, {2, 1, 2, 2, 1},
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{0, 2, 1, 2, 2}, {1, 2, 1, 2, 2}, {2, 2, 1, 2, 2}, {2, 1, 2, 2, 2},
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{0, 0, 0, 1, 2}, {1, 0, 0, 1, 2}, {2, 0, 0, 1, 2}, {0, 0, 2, 1, 2},
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{0, 1, 0, 1, 2}, {1, 1, 0, 1, 2}, {2, 1, 0, 1, 2}, {1, 0, 2, 1, 2},
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{0, 2, 0, 1, 2}, {1, 2, 0, 1, 2}, {2, 2, 0, 1, 2}, {2, 0, 2, 1, 2},
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{0, 2, 2, 1, 2}, {1, 2, 2, 1, 2}, {2, 2, 2, 1, 2}, {2, 0, 2, 1, 2},
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{0, 0, 1, 1, 2}, {1, 0, 1, 1, 2}, {2, 0, 1, 1, 2}, {0, 1, 2, 1, 2},
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{0, 1, 1, 1, 2}, {1, 1, 1, 1, 2}, {2, 1, 1, 1, 2}, {1, 1, 2, 1, 2},
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{0, 2, 1, 1, 2}, {1, 2, 1, 1, 2}, {2, 2, 1, 1, 2}, {2, 1, 2, 1, 2},
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{0, 2, 2, 2, 2}, {1, 2, 2, 2, 2}, {2, 2, 2, 2, 2}, {2, 1, 2, 2, 2}
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};
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/** @brief Packed trit values for each unpacked value, indexed [hi][][][][lo]. */
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static const uint8_t integer_of_trits[3][3][3][3][3] {
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{
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{
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{
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{0, 1, 2},
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{4, 5, 6},
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{8, 9, 10}
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},
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{
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{16, 17, 18},
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{20, 21, 22},
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{24, 25, 26}
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},
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{
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{3, 7, 15},
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{19, 23, 27},
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{12, 13, 14}
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}
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},
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{
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{
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{32, 33, 34},
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{36, 37, 38},
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{40, 41, 42}
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},
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{
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{48, 49, 50},
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{52, 53, 54},
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{56, 57, 58}
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},
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{
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{35, 39, 47},
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{51, 55, 59},
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{44, 45, 46}
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}
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},
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{
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{
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{64, 65, 66},
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{68, 69, 70},
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{72, 73, 74}
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},
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{
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{80, 81, 82},
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{84, 85, 86},
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{88, 89, 90}
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},
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{
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{67, 71, 79},
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{83, 87, 91},
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{76, 77, 78}
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}
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}
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},
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{
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{
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{
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{128, 129, 130},
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{132, 133, 134},
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{136, 137, 138}
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},
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{
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{144, 145, 146},
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{148, 149, 150},
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{152, 153, 154}
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},
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{
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{131, 135, 143},
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{147, 151, 155},
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{140, 141, 142}
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}
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},
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{
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{
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{160, 161, 162},
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{164, 165, 166},
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{168, 169, 170}
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},
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{
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{176, 177, 178},
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{180, 181, 182},
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{184, 185, 186}
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},
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{
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{163, 167, 175},
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{179, 183, 187},
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{172, 173, 174}
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}
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},
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{
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{
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{192, 193, 194},
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{196, 197, 198},
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{200, 201, 202}
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},
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{
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{208, 209, 210},
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{212, 213, 214},
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{216, 217, 218}
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},
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{
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{195, 199, 207},
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{211, 215, 219},
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{204, 205, 206}
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}
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}
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},
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{
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{
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{
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{96, 97, 98},
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{100, 101, 102},
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{104, 105, 106}
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},
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{
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{112, 113, 114},
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{116, 117, 118},
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{120, 121, 122}
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},
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{
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{99, 103, 111},
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{115, 119, 123},
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{108, 109, 110}
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}
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},
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{
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{
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{224, 225, 226},
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{228, 229, 230},
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{232, 233, 234}
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},
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{
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{240, 241, 242},
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{244, 245, 246},
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{248, 249, 250}
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},
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{
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{227, 231, 239},
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{243, 247, 251},
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{236, 237, 238}
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}
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},
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{
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{
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{28, 29, 30},
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{60, 61, 62},
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{92, 93, 94}
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},
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{
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{156, 157, 158},
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{188, 189, 190},
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{220, 221, 222}
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},
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{
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{31, 63, 127},
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{159, 191, 255},
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{252, 253, 254}
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}
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}
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}
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};
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/**
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* @brief The number of bits, trits, and quints needed for a quant level.
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*/
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struct btq_count
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{
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/** @brief The number of bits. */
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uint8_t bits:6;
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/** @brief The number of trits. */
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uint8_t trits:1;
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/** @brief The number of quints. */
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uint8_t quints:1;
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};
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/**
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* @brief The table of bits, trits, and quints needed for a quant encode.
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*/
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static const std::array<btq_count, 21> btq_counts {{
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{ 1, 0, 0 }, // QUANT_2
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{ 0, 1, 0 }, // QUANT_3
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{ 2, 0, 0 }, // QUANT_4
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{ 0, 0, 1 }, // QUANT_5
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{ 1, 1, 0 }, // QUANT_6
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{ 3, 0, 0 }, // QUANT_8
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{ 1, 0, 1 }, // QUANT_10
|
|
{ 2, 1, 0 }, // QUANT_12
|
|
{ 4, 0, 0 }, // QUANT_16
|
|
{ 2, 0, 1 }, // QUANT_20
|
|
{ 3, 1, 0 }, // QUANT_24
|
|
{ 5, 0, 0 }, // QUANT_32
|
|
{ 3, 0, 1 }, // QUANT_40
|
|
{ 4, 1, 0 }, // QUANT_48
|
|
{ 6, 0, 0 }, // QUANT_64
|
|
{ 4, 0, 1 }, // QUANT_80
|
|
{ 5, 1, 0 }, // QUANT_96
|
|
{ 7, 0, 0 }, // QUANT_128
|
|
{ 5, 0, 1 }, // QUANT_160
|
|
{ 6, 1, 0 }, // QUANT_192
|
|
{ 8, 0, 0 } // QUANT_256
|
|
}};
|
|
|
|
/**
|
|
* @brief The sequence scale, round, and divisors needed to compute sizing.
|
|
*
|
|
* The length of a quantized sequence in bits is:
|
|
* (scale * <sequence_len> + round) / divisor
|
|
*/
|
|
struct ise_size
|
|
{
|
|
/** @brief The scaling parameter. */
|
|
uint8_t scale:6;
|
|
|
|
/** @brief The divisor parameter. */
|
|
uint8_t divisor:2;
|
|
};
|
|
|
|
/**
|
|
* @brief The table of scale, round, and divisors needed for quant sizing.
|
|
*/
|
|
static const std::array<ise_size, 21> ise_sizes {{
|
|
{ 1, 0 }, // QUANT_2
|
|
{ 8, 2 }, // QUANT_3
|
|
{ 2, 0 }, // QUANT_4
|
|
{ 7, 1 }, // QUANT_5
|
|
{ 13, 2 }, // QUANT_6
|
|
{ 3, 0 }, // QUANT_8
|
|
{ 10, 1 }, // QUANT_10
|
|
{ 18, 2 }, // QUANT_12
|
|
{ 4, 0 }, // QUANT_16
|
|
{ 13, 1 }, // QUANT_20
|
|
{ 23, 2 }, // QUANT_24
|
|
{ 5, 0 }, // QUANT_32
|
|
{ 16, 1 }, // QUANT_40
|
|
{ 28, 2 }, // QUANT_48
|
|
{ 6, 0 }, // QUANT_64
|
|
{ 19, 1 }, // QUANT_80
|
|
{ 33, 2 }, // QUANT_96
|
|
{ 7, 0 }, // QUANT_128
|
|
{ 22, 1 }, // QUANT_160
|
|
{ 38, 2 }, // QUANT_192
|
|
{ 8, 0 } // QUANT_256
|
|
}};
|
|
|
|
/* See header for documentation. */
|
|
unsigned int get_ise_sequence_bitcount(
|
|
unsigned int character_count,
|
|
quant_method quant_level
|
|
) {
|
|
// Cope with out-of bounds values - input might be invalid
|
|
if (static_cast<size_t>(quant_level) >= ise_sizes.size())
|
|
{
|
|
// Arbitrary large number that's more than an ASTC block can hold
|
|
return 1024;
|
|
}
|
|
|
|
auto& entry = ise_sizes[quant_level];
|
|
unsigned int divisor = (entry.divisor << 1) + 1;
|
|
return (entry.scale * character_count + divisor - 1) / divisor;
|
|
}
|
|
|
|
/**
|
|
* @brief Write up to 8 bits at an arbitrary bit offset.
|
|
*
|
|
* The stored value is at most 8 bits, but can be stored at an offset of between 0 and 7 bits so may
|
|
* span two separate bytes in memory.
|
|
*
|
|
* @param value The value to write.
|
|
* @param bitcount The number of bits to write, starting from LSB.
|
|
* @param bitoffset The bit offset to store at, between 0 and 7.
|
|
* @param[in,out] ptr The data pointer to write to.
|
|
*/
|
|
static inline void write_bits(
|
|
unsigned int value,
|
|
unsigned int bitcount,
|
|
unsigned int bitoffset,
|
|
uint8_t ptr[2]
|
|
) {
|
|
unsigned int mask = (1 << bitcount) - 1;
|
|
value &= mask;
|
|
ptr += bitoffset >> 3;
|
|
bitoffset &= 7;
|
|
value <<= bitoffset;
|
|
mask <<= bitoffset;
|
|
mask = ~mask;
|
|
|
|
ptr[0] &= mask;
|
|
ptr[0] |= value;
|
|
ptr[1] &= mask >> 8;
|
|
ptr[1] |= value >> 8;
|
|
}
|
|
|
|
/**
|
|
* @brief Read up to 8 bits at an arbitrary bit offset.
|
|
*
|
|
* The stored value is at most 8 bits, but can be stored at an offset of between 0 and 7 bits so may
|
|
* span two separate bytes in memory.
|
|
*
|
|
* @param bitcount The number of bits to read.
|
|
* @param bitoffset The bit offset to read from, between 0 and 7.
|
|
* @param[in,out] ptr The data pointer to read from.
|
|
*
|
|
* @return The read value.
|
|
*/
|
|
static inline unsigned int read_bits(
|
|
unsigned int bitcount,
|
|
unsigned int bitoffset,
|
|
const uint8_t* ptr
|
|
) {
|
|
unsigned int mask = (1 << bitcount) - 1;
|
|
ptr += bitoffset >> 3;
|
|
bitoffset &= 7;
|
|
unsigned int value = ptr[0] | (ptr[1] << 8);
|
|
value >>= bitoffset;
|
|
value &= mask;
|
|
return value;
|
|
}
|
|
|
|
/* See header for documentation. */
|
|
void encode_ise(
|
|
quant_method quant_level,
|
|
unsigned int character_count,
|
|
const uint8_t* input_data,
|
|
uint8_t* output_data,
|
|
unsigned int bit_offset
|
|
) {
|
|
promise(character_count > 0);
|
|
|
|
unsigned int bits = btq_counts[quant_level].bits;
|
|
unsigned int trits = btq_counts[quant_level].trits;
|
|
unsigned int quints = btq_counts[quant_level].quints;
|
|
unsigned int mask = (1 << bits) - 1;
|
|
|
|
// Write out trits and bits
|
|
if (trits)
|
|
{
|
|
unsigned int i = 0;
|
|
unsigned int full_trit_blocks = character_count / 5;
|
|
|
|
for (unsigned int j = 0; j < full_trit_blocks; j++)
|
|
{
|
|
unsigned int i4 = input_data[i + 4] >> bits;
|
|
unsigned int i3 = input_data[i + 3] >> bits;
|
|
unsigned int i2 = input_data[i + 2] >> bits;
|
|
unsigned int i1 = input_data[i + 1] >> bits;
|
|
unsigned int i0 = input_data[i + 0] >> bits;
|
|
|
|
uint8_t T = integer_of_trits[i4][i3][i2][i1][i0];
|
|
|
|
// The max size of a trit bit count is 6, so we can always safely
|
|
// pack a single MX value with the following 1 or 2 T bits.
|
|
uint8_t pack;
|
|
|
|
// Element 0 + T0 + T1
|
|
pack = (input_data[i++] & mask) | (((T >> 0) & 0x3) << bits);
|
|
write_bits(pack, bits + 2, bit_offset, output_data);
|
|
bit_offset += bits + 2;
|
|
|
|
// Element 1 + T2 + T3
|
|
pack = (input_data[i++] & mask) | (((T >> 2) & 0x3) << bits);
|
|
write_bits(pack, bits + 2, bit_offset, output_data);
|
|
bit_offset += bits + 2;
|
|
|
|
// Element 2 + T4
|
|
pack = (input_data[i++] & mask) | (((T >> 4) & 0x1) << bits);
|
|
write_bits(pack, bits + 1, bit_offset, output_data);
|
|
bit_offset += bits + 1;
|
|
|
|
// Element 3 + T5 + T6
|
|
pack = (input_data[i++] & mask) | (((T >> 5) & 0x3) << bits);
|
|
write_bits(pack, bits + 2, bit_offset, output_data);
|
|
bit_offset += bits + 2;
|
|
|
|
// Element 4 + T7
|
|
pack = (input_data[i++] & mask) | (((T >> 7) & 0x1) << bits);
|
|
write_bits(pack, bits + 1, bit_offset, output_data);
|
|
bit_offset += bits + 1;
|
|
}
|
|
|
|
// Loop tail for a partial block
|
|
if (i != character_count)
|
|
{
|
|
// i4 cannot be present - we know the block is partial
|
|
// i0 must be present - we know the block isn't empty
|
|
unsigned int i4 = 0;
|
|
unsigned int i3 = i + 3 >= character_count ? 0 : input_data[i + 3] >> bits;
|
|
unsigned int i2 = i + 2 >= character_count ? 0 : input_data[i + 2] >> bits;
|
|
unsigned int i1 = i + 1 >= character_count ? 0 : input_data[i + 1] >> bits;
|
|
unsigned int i0 = input_data[i + 0] >> bits;
|
|
|
|
uint8_t T = integer_of_trits[i4][i3][i2][i1][i0];
|
|
|
|
for (unsigned int j = 0; i < character_count; i++, j++)
|
|
{
|
|
// Truncated table as this iteration is always partital
|
|
static const uint8_t tbits[4] { 2, 2, 1, 2 };
|
|
static const uint8_t tshift[4] { 0, 2, 4, 5 };
|
|
|
|
uint8_t pack = (input_data[i] & mask) |
|
|
(((T >> tshift[j]) & ((1 << tbits[j]) - 1)) << bits);
|
|
|
|
write_bits(pack, bits + tbits[j], bit_offset, output_data);
|
|
bit_offset += bits + tbits[j];
|
|
}
|
|
}
|
|
}
|
|
// Write out quints and bits
|
|
else if (quints)
|
|
{
|
|
unsigned int i = 0;
|
|
unsigned int full_quint_blocks = character_count / 3;
|
|
|
|
for (unsigned int j = 0; j < full_quint_blocks; j++)
|
|
{
|
|
unsigned int i2 = input_data[i + 2] >> bits;
|
|
unsigned int i1 = input_data[i + 1] >> bits;
|
|
unsigned int i0 = input_data[i + 0] >> bits;
|
|
|
|
uint8_t T = integer_of_quints[i2][i1][i0];
|
|
|
|
// The max size of a quint bit count is 5, so we can always safely
|
|
// pack a single M value with the following 2 or 3 T bits.
|
|
uint8_t pack;
|
|
|
|
// Element 0
|
|
pack = (input_data[i++] & mask) | (((T >> 0) & 0x7) << bits);
|
|
write_bits(pack, bits + 3, bit_offset, output_data);
|
|
bit_offset += bits + 3;
|
|
|
|
// Element 1
|
|
pack = (input_data[i++] & mask) | (((T >> 3) & 0x3) << bits);
|
|
write_bits(pack, bits + 2, bit_offset, output_data);
|
|
bit_offset += bits + 2;
|
|
|
|
// Element 2
|
|
pack = (input_data[i++] & mask) | (((T >> 5) & 0x3) << bits);
|
|
write_bits(pack, bits + 2, bit_offset, output_data);
|
|
bit_offset += bits + 2;
|
|
}
|
|
|
|
// Loop tail for a partial block
|
|
if (i != character_count)
|
|
{
|
|
// i2 cannot be present - we know the block is partial
|
|
// i0 must be present - we know the block isn't empty
|
|
unsigned int i2 = 0;
|
|
unsigned int i1 = i + 1 >= character_count ? 0 : input_data[i + 1] >> bits;
|
|
unsigned int i0 = input_data[i + 0] >> bits;
|
|
|
|
uint8_t T = integer_of_quints[i2][i1][i0];
|
|
|
|
for (unsigned int j = 0; i < character_count; i++, j++)
|
|
{
|
|
// Truncated table as this iteration is always partital
|
|
static const uint8_t tbits[2] { 3, 2 };
|
|
static const uint8_t tshift[2] { 0, 3 };
|
|
|
|
uint8_t pack = (input_data[i] & mask) |
|
|
(((T >> tshift[j]) & ((1 << tbits[j]) - 1)) << bits);
|
|
|
|
write_bits(pack, bits + tbits[j], bit_offset, output_data);
|
|
bit_offset += bits + tbits[j];
|
|
}
|
|
}
|
|
}
|
|
// Write out just bits
|
|
else
|
|
{
|
|
for (unsigned int i = 0; i < character_count; i++)
|
|
{
|
|
write_bits(input_data[i], bits, bit_offset, output_data);
|
|
bit_offset += bits;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* See header for documentation. */
|
|
void decode_ise(
|
|
quant_method quant_level,
|
|
unsigned int character_count,
|
|
const uint8_t* input_data,
|
|
uint8_t* output_data,
|
|
unsigned int bit_offset
|
|
) {
|
|
promise(character_count > 0);
|
|
|
|
// Note: due to how the trit/quint-block unpacking is done in this function, we may write more
|
|
// temporary results than the number of outputs. The maximum actual number of results is 64 bit,
|
|
// but we keep 4 additional character_count of padding.
|
|
uint8_t results[68];
|
|
uint8_t tq_blocks[22] { 0 }; // Trit-blocks or quint-blocks, must be zeroed
|
|
|
|
unsigned int bits = btq_counts[quant_level].bits;
|
|
unsigned int trits = btq_counts[quant_level].trits;
|
|
unsigned int quints = btq_counts[quant_level].quints;
|
|
|
|
unsigned int lcounter = 0;
|
|
unsigned int hcounter = 0;
|
|
|
|
// Collect bits for each element, as well as bits for any trit-blocks and quint-blocks.
|
|
for (unsigned int i = 0; i < character_count; i++)
|
|
{
|
|
results[i] = static_cast<uint8_t>(read_bits(bits, bit_offset, input_data));
|
|
bit_offset += bits;
|
|
|
|
if (trits)
|
|
{
|
|
static const uint8_t bits_to_read[5] { 2, 2, 1, 2, 1 };
|
|
static const uint8_t block_shift[5] { 0, 2, 4, 5, 7 };
|
|
static const uint8_t next_lcounter[5] { 1, 2, 3, 4, 0 };
|
|
static const uint8_t hcounter_incr[5] { 0, 0, 0, 0, 1 };
|
|
unsigned int tdata = read_bits(bits_to_read[lcounter], bit_offset, input_data);
|
|
bit_offset += bits_to_read[lcounter];
|
|
tq_blocks[hcounter] |= tdata << block_shift[lcounter];
|
|
hcounter += hcounter_incr[lcounter];
|
|
lcounter = next_lcounter[lcounter];
|
|
}
|
|
|
|
if (quints)
|
|
{
|
|
static const uint8_t bits_to_read[3] { 3, 2, 2 };
|
|
static const uint8_t block_shift[3] { 0, 3, 5 };
|
|
static const uint8_t next_lcounter[3] { 1, 2, 0 };
|
|
static const uint8_t hcounter_incr[3] { 0, 0, 1 };
|
|
unsigned int tdata = read_bits(bits_to_read[lcounter], bit_offset, input_data);
|
|
bit_offset += bits_to_read[lcounter];
|
|
tq_blocks[hcounter] |= tdata << block_shift[lcounter];
|
|
hcounter += hcounter_incr[lcounter];
|
|
lcounter = next_lcounter[lcounter];
|
|
}
|
|
}
|
|
|
|
// Unpack trit-blocks or quint-blocks as needed
|
|
if (trits)
|
|
{
|
|
unsigned int trit_blocks = (character_count + 4) / 5;
|
|
promise(trit_blocks > 0);
|
|
for (unsigned int i = 0; i < trit_blocks; i++)
|
|
{
|
|
const uint8_t *tritptr = trits_of_integer[tq_blocks[i]];
|
|
results[5 * i ] |= tritptr[0] << bits;
|
|
results[5 * i + 1] |= tritptr[1] << bits;
|
|
results[5 * i + 2] |= tritptr[2] << bits;
|
|
results[5 * i + 3] |= tritptr[3] << bits;
|
|
results[5 * i + 4] |= tritptr[4] << bits;
|
|
}
|
|
}
|
|
|
|
if (quints)
|
|
{
|
|
unsigned int quint_blocks = (character_count + 2) / 3;
|
|
promise(quint_blocks > 0);
|
|
for (unsigned int i = 0; i < quint_blocks; i++)
|
|
{
|
|
const uint8_t *quintptr = quints_of_integer[tq_blocks[i]];
|
|
results[3 * i ] |= quintptr[0] << bits;
|
|
results[3 * i + 1] |= quintptr[1] << bits;
|
|
results[3 * i + 2] |= quintptr[2] << bits;
|
|
}
|
|
}
|
|
|
|
for (unsigned int i = 0; i < character_count; i++)
|
|
{
|
|
output_data[i] = results[i];
|
|
}
|
|
}
|