| // Copyright 2014 PDFium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com |
| // Original code is licensed as follows: |
| /* |
| * Copyright 2013 ZXing 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. |
| */ |
| |
| #include <limits> |
| |
| #include "xfa/fxbarcode/pdf417/BC_PDF417CodewordDecoder.h" |
| #include "xfa/fxbarcode/pdf417/BC_PDF417Common.h" |
| |
| #define SYMBOL_TABLE_Length 2787 |
| |
| namespace { |
| |
| FX_FLOAT RATIOS_TABLE[SYMBOL_TABLE_Length][8] = {{0}}; |
| |
| } // namespace |
| |
| CBC_PDF417CodewordDecoder::CBC_PDF417CodewordDecoder() {} |
| CBC_PDF417CodewordDecoder::~CBC_PDF417CodewordDecoder() {} |
| void CBC_PDF417CodewordDecoder::Initialize() { |
| for (int32_t i = 0; i < SYMBOL_TABLE_Length; i++) { |
| int32_t currentSymbol = CBC_PDF417Common::SYMBOL_TABLE[i]; |
| int32_t currentBit = currentSymbol & 0x1; |
| for (int32_t j = 0; j < CBC_PDF417Common::BARS_IN_MODULE; j++) { |
| FX_FLOAT size = 0.0f; |
| while ((currentSymbol & 0x1) == currentBit) { |
| size += 1.0f; |
| currentSymbol >>= 1; |
| } |
| currentBit = currentSymbol & 0x1; |
| RATIOS_TABLE[i][CBC_PDF417Common::BARS_IN_MODULE - j - 1] = |
| size / CBC_PDF417Common::MODULES_IN_CODEWORD; |
| } |
| } |
| } |
| void CBC_PDF417CodewordDecoder::Finalize() {} |
| int32_t CBC_PDF417CodewordDecoder::getDecodedValue( |
| CFX_Int32Array& moduleBitCount) { |
| CFX_Int32Array* array = sampleBitCounts(moduleBitCount); |
| int32_t decodedValue = getDecodedCodewordValue(*array); |
| delete array; |
| if (decodedValue != -1) { |
| return decodedValue; |
| } |
| return getClosestDecodedValue(moduleBitCount); |
| } |
| CFX_Int32Array* CBC_PDF417CodewordDecoder::sampleBitCounts( |
| CFX_Int32Array& moduleBitCount) { |
| FX_FLOAT bitCountSum = |
| (FX_FLOAT)CBC_PDF417Common::getBitCountSum(moduleBitCount); |
| CFX_Int32Array* bitCount = new CFX_Int32Array(); |
| bitCount->SetSize(CBC_PDF417Common::BARS_IN_MODULE); |
| int32_t bitCountIndex = 0; |
| int32_t sumPreviousBits = 0; |
| for (int32_t i = 0; i < CBC_PDF417Common::MODULES_IN_CODEWORD; i++) { |
| FX_FLOAT sampleIndex = |
| bitCountSum / (2 * CBC_PDF417Common::MODULES_IN_CODEWORD) + |
| (i * bitCountSum) / CBC_PDF417Common::MODULES_IN_CODEWORD; |
| if (sumPreviousBits + moduleBitCount.GetAt(bitCountIndex) <= sampleIndex) { |
| sumPreviousBits += moduleBitCount.GetAt(bitCountIndex); |
| bitCountIndex++; |
| } |
| bitCount->SetAt(bitCountIndex, bitCount->GetAt(bitCountIndex) + 1); |
| } |
| return bitCount; |
| } |
| int32_t CBC_PDF417CodewordDecoder::getDecodedCodewordValue( |
| CFX_Int32Array& moduleBitCount) { |
| int32_t decodedValue = getBitValue(moduleBitCount); |
| return CBC_PDF417Common::getCodeword(decodedValue) == -1 ? -1 : decodedValue; |
| } |
| int32_t CBC_PDF417CodewordDecoder::getBitValue(CFX_Int32Array& moduleBitCount) { |
| int64_t result = 0; |
| for (int32_t i = 0; i < moduleBitCount.GetSize(); i++) { |
| for (int32_t bit = 0; bit < moduleBitCount.GetAt(i); bit++) { |
| result = (result << 1) | (i % 2 == 0 ? 1 : 0); |
| } |
| } |
| return (int32_t)result; |
| } |
| int32_t CBC_PDF417CodewordDecoder::getClosestDecodedValue( |
| CFX_Int32Array& moduleBitCount) { |
| int32_t bitCountSum = CBC_PDF417Common::getBitCountSum(moduleBitCount); |
| CFX_FloatArray bitCountRatios; |
| bitCountRatios.SetSize(CBC_PDF417Common::BARS_IN_MODULE); |
| for (int32_t i = 0; i < bitCountRatios.GetSize(); i++) { |
| bitCountRatios[i] = moduleBitCount.GetAt(i) / (FX_FLOAT)bitCountSum; |
| } |
| FX_FLOAT bestMatchError = std::numeric_limits<int32_t>::max(); |
| int32_t bestMatch = -1; |
| for (int32_t j = 0; j < SYMBOL_TABLE_Length; j++) { |
| FX_FLOAT error = 0.0f; |
| for (int32_t k = 0; k < CBC_PDF417Common::BARS_IN_MODULE; k++) { |
| FX_FLOAT diff = RATIOS_TABLE[j][k] - bitCountRatios[k]; |
| error += diff * diff; |
| } |
| if (error < bestMatchError) { |
| bestMatchError = error; |
| bestMatch = CBC_PDF417Common::SYMBOL_TABLE[j]; |
| } |
| } |
| return bestMatch; |
| } |