You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
101 lines
2.9 KiB
101 lines
2.9 KiB
// Copyright 2026 Axel Waggershauser |
|
// SPDX-License-Identifier: Apache-2.0 |
|
|
|
#include "ReedSolomon.h" |
|
#include "Version.h" |
|
#include "ZXAlgorithms.h" |
|
|
|
#include "librscpp/encode.h" |
|
#include "librscpp/decode.h" |
|
|
|
#include <algorithm> |
|
#include <type_traits> |
|
#include <stdexcept> |
|
#include <utility> |
|
|
|
namespace ZXing { |
|
|
|
namespace rs = librscpp; |
|
|
|
using GF2nI = rs::GF2n<>; |
|
|
|
const GF2nI& GetGF2n(RSField field) |
|
{ |
|
static GF2nI gf2n_4_1(0x0013, 1); // x^4 + x + 1 |
|
static GF2nI gf2n_6_1(0x0043, 1); // x^6 + x + 1 |
|
static GF2nI gf2n_8_5_3_2(0x012D, 1); // x^8 + x^5 + x^3 + x^2 + 1 : DataMatrix |
|
static GF2nI gf2n_8_4_3_2(0x011D, 0); // x^8 + x^4 + x^3 + x^2 + 1 : QRCode |
|
static GF2nI gf2n_10_3(0x0409, 1); // x^10 + x^3 + 1 |
|
static GF2nI gf2n_12_6_5_3(0x1069, 1); // x^12 + x^6 + x^5 + x^3 + 1 |
|
|
|
switch (field) { |
|
case RSField::Aztec4: return gf2n_4_1; |
|
case RSField::Aztec6: return gf2n_6_1; |
|
case RSField::Aztec8: return gf2n_8_5_3_2; |
|
case RSField::Aztec10: return gf2n_10_3; |
|
case RSField::Aztec12: return gf2n_12_6_5_3; |
|
case RSField::DataMatrix: return gf2n_8_5_3_2; |
|
case RSField::MaxiCode: return gf2n_6_1; |
|
case RSField::QRCode: return gf2n_8_4_3_2; |
|
default: throw std::invalid_argument("Unsupported RSField"); |
|
} |
|
} |
|
|
|
const rs::GFp<>& GetGFPDF417() |
|
{ |
|
static rs::GFp<> gf929_3(929, 3, 1); |
|
return gf929_3; |
|
} |
|
|
|
// See ISO/IEC 15415:2024 7.5.9 |
|
static std::optional<double> UEC(std::optional<int> usedECC, int numECC) |
|
{ |
|
return usedECC ? std::optional(std::clamp(1.0 - static_cast<double>(*usedECC) / numECC, 0.0, 1.0)) : std::nullopt; |
|
} |
|
|
|
#ifdef ZXING_READERS |
|
std::optional<double> ReedSolomonDecode(RSField field, std::span<uint8_t> codeword, int numECC, std::span<const int> erasures) |
|
{ |
|
return UEC(rs::decode(GetGF2n(field), codeword, numECC, erasures), numECC); |
|
} |
|
|
|
std::optional<double> ReedSolomonDecode(RSField field, std::span<int> codeword, int numECC, std::span<const int> erasures) |
|
{ |
|
// The number of erasures may at most be numECC. |
|
// Note that leaves 0 parity symbols to error correction (or even detection) but the final syndrome verification in rs::decode will |
|
// still catch any errors in that case. |
|
if (Size(erasures) > numECC) |
|
return {}; |
|
|
|
#if ZXING_ENABLE_PDF417 |
|
if (field == RSField::PDF417) |
|
return UEC(rs::decode(GetGFPDF417(), codeword, numECC, erasures), numECC); |
|
else |
|
#endif |
|
return UEC(rs::decode(GetGF2n(field), codeword, numECC, erasures), numECC); |
|
} |
|
#endif |
|
|
|
#ifdef ZXING_WRITERS |
|
void ReedSolomonEncode(RSField field, std::span<const uint8_t> data, std::span<uint8_t> parity) |
|
{ |
|
rs::encode(GetGF2n(field), data, parity); |
|
} |
|
|
|
void ReedSolomonEncode(RSField field, std::span<uint8_t> codeword, int numECC) |
|
{ |
|
rs::encode_inplace(GetGF2n(field), codeword, numECC); |
|
} |
|
|
|
void ReedSolomonEncode(RSField field, std::span<int> codeword, int numECC) |
|
{ |
|
#if ZXING_ENABLE_PDF417 |
|
if (field == RSField::PDF417) |
|
return rs::encode_inplace(GetGFPDF417(), codeword, numECC); |
|
else |
|
#endif |
|
rs::encode_inplace(GetGF2n(field), codeword, numECC); |
|
} |
|
#endif |
|
|
|
} // namespace ZXing
|
|
|