diff options
Diffstat (limited to 'xfa/src/fxbarcode/common/reedsolomon/BC_ReedSolomonDecoder.cpp')
| -rw-r--r-- | xfa/src/fxbarcode/common/reedsolomon/BC_ReedSolomonDecoder.cpp | 224 |
1 files changed, 224 insertions, 0 deletions
diff --git a/xfa/src/fxbarcode/common/reedsolomon/BC_ReedSolomonDecoder.cpp b/xfa/src/fxbarcode/common/reedsolomon/BC_ReedSolomonDecoder.cpp new file mode 100644 index 0000000000..3cb5e7762f --- /dev/null +++ b/xfa/src/fxbarcode/common/reedsolomon/BC_ReedSolomonDecoder.cpp @@ -0,0 +1,224 @@ +// 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 2007 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 "../../barcode.h"
+#include "BC_ReedSolomonGF256.h"
+#include "BC_ReedSolomonGF256Poly.h"
+#include "BC_ReedSolomonDecoder.h"
+CBC_ReedSolomonDecoder::CBC_ReedSolomonDecoder(CBC_ReedSolomonGF256* field)
+{
+ m_field = field;
+}
+CBC_ReedSolomonDecoder::~CBC_ReedSolomonDecoder()
+{
+}
+void CBC_ReedSolomonDecoder::Decode(CFX_Int32Array* received, FX_INT32 twoS, FX_INT32 &e)
+{
+ CBC_ReedSolomonGF256Poly poly;
+ poly.Init(m_field, received, e);
+ BC_EXCEPTION_CHECK_ReturnVoid(e);
+ CFX_Int32Array syndromeCoefficients;
+ syndromeCoefficients.SetSize(twoS);
+ FX_BOOL dataMatrix = FALSE;
+ FX_BOOL noError = TRUE;
+ for (FX_INT32 i = 0; i < twoS; i++) {
+ FX_INT32 eval = poly.EvaluateAt(m_field->Exp(dataMatrix ? i + 1 : i));
+ syndromeCoefficients[twoS - 1 - i] = eval;
+ if (eval != 0) {
+ noError = FALSE;
+ }
+ }
+ if(noError) {
+ return;
+ }
+ CBC_ReedSolomonGF256Poly syndrome;
+ syndrome.Init(m_field, &syndromeCoefficients, e);
+ BC_EXCEPTION_CHECK_ReturnVoid(e);
+ CBC_ReedSolomonGF256Poly* rsg = m_field->BuildMonomial(twoS, 1, e);
+ BC_EXCEPTION_CHECK_ReturnVoid(e);
+ CBC_AutoPtr<CBC_ReedSolomonGF256Poly> temp(rsg);
+ CFX_PtrArray* pa = RunEuclideanAlgorithm(temp.get(), &syndrome, twoS, e);
+ BC_EXCEPTION_CHECK_ReturnVoid(e);
+ CBC_AutoPtr<CFX_PtrArray > sigmaOmega(pa);
+ CBC_AutoPtr<CBC_ReedSolomonGF256Poly> sigma((CBC_ReedSolomonGF256Poly*)(*sigmaOmega)[0]);
+ CBC_AutoPtr<CBC_ReedSolomonGF256Poly> omega((CBC_ReedSolomonGF256Poly*)(*sigmaOmega)[1]);
+ CFX_Int32Array* ia1 = FindErrorLocations(sigma.get(), e);
+ BC_EXCEPTION_CHECK_ReturnVoid(e);
+ CBC_AutoPtr<CFX_Int32Array > errorLocations(ia1);
+ CFX_Int32Array* ia2 = FindErrorMagnitudes(omega.get(), errorLocations.get(), dataMatrix, e);
+ BC_EXCEPTION_CHECK_ReturnVoid(e);
+ CBC_AutoPtr<CFX_Int32Array > errorMagnitudes(ia2);
+ for (FX_INT32 k = 0; k < errorLocations->GetSize(); k++) {
+ FX_INT32 position = received->GetSize() - 1 - m_field->Log((*errorLocations)[k], e);
+ BC_EXCEPTION_CHECK_ReturnVoid(e);
+ if(position < 0) {
+ e = BCExceptionBadErrorLocation;
+ BC_EXCEPTION_CHECK_ReturnVoid(e);
+ }
+ (*received)[position] = CBC_ReedSolomonGF256::AddOrSubtract((*received)[position], (*errorMagnitudes)[k]);
+ }
+}
+CFX_PtrArray *CBC_ReedSolomonDecoder::RunEuclideanAlgorithm(CBC_ReedSolomonGF256Poly* a, CBC_ReedSolomonGF256Poly* b, FX_INT32 R, FX_INT32 &e)
+{
+ if (a->GetDegree() < b->GetDegree()) {
+ CBC_ReedSolomonGF256Poly* temp = a;
+ a = b;
+ b = temp;
+ }
+ CBC_ReedSolomonGF256Poly* rsg1 = a->Clone(e);
+ BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+ CBC_AutoPtr<CBC_ReedSolomonGF256Poly> rLast(rsg1);
+ CBC_ReedSolomonGF256Poly* rsg2 = b->Clone(e);
+ BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+ CBC_AutoPtr<CBC_ReedSolomonGF256Poly> r(rsg2);
+ CBC_ReedSolomonGF256Poly* rsg3 = m_field->GetOne()->Clone(e);
+ BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+ CBC_AutoPtr<CBC_ReedSolomonGF256Poly> sLast(rsg3);
+ CBC_ReedSolomonGF256Poly* rsg4 = m_field->GetZero()->Clone(e);
+ BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+ CBC_AutoPtr<CBC_ReedSolomonGF256Poly> s(rsg4);
+ CBC_ReedSolomonGF256Poly* rsg5 = m_field->GetZero()->Clone(e);
+ BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+ CBC_AutoPtr<CBC_ReedSolomonGF256Poly> tLast(rsg5);
+ CBC_ReedSolomonGF256Poly* rsg6 = m_field->GetOne()->Clone(e);
+ BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+ CBC_AutoPtr<CBC_ReedSolomonGF256Poly> t(rsg6);
+ while (r->GetDegree() >= R / 2) {
+ CBC_AutoPtr<CBC_ReedSolomonGF256Poly> rLastLast = rLast;
+ CBC_AutoPtr<CBC_ReedSolomonGF256Poly> sLastLast = sLast;
+ CBC_AutoPtr<CBC_ReedSolomonGF256Poly> tLastlast = tLast;
+ rLast = r;
+ sLast = s;
+ tLast = t;
+ if (rLast->IsZero()) {
+ e = BCExceptionR_I_1IsZero;
+ BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+ }
+ CBC_ReedSolomonGF256Poly* rsg7 = rLastLast->Clone(e);
+ BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+ CBC_AutoPtr<CBC_ReedSolomonGF256Poly> rTemp(rsg7);
+ r = rTemp;
+ CBC_ReedSolomonGF256Poly* rsg8 = m_field->GetZero()->Clone(e);
+ BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+ CBC_AutoPtr<CBC_ReedSolomonGF256Poly> q(rsg8);
+ FX_INT32 denominatorLeadingTerm = rLast->GetCoefficients(rLast->GetDegree());
+ FX_INT32 dltInverse = m_field->Inverse(denominatorLeadingTerm, e);
+ BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+ while (r->GetDegree() >= rLast->GetDegree() && !(r->IsZero())) {
+ FX_INT32 degreeDiff = r->GetDegree() - rLast->GetDegree();
+ FX_INT32 scale = m_field->Multiply(r->GetCoefficients(r->GetDegree()), dltInverse);
+ CBC_ReedSolomonGF256Poly* rsgp1 = m_field->BuildMonomial(degreeDiff, scale, e);
+ BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+ CBC_AutoPtr<CBC_ReedSolomonGF256Poly> build(rsgp1);
+ CBC_ReedSolomonGF256Poly* rsgp2 = q->AddOrSubtract(build.get(), e);
+ BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+ CBC_AutoPtr<CBC_ReedSolomonGF256Poly> temp(rsgp2);
+ q = temp;
+ CBC_ReedSolomonGF256Poly* rsgp3 = rLast->MultiplyByMonomial(degreeDiff, scale, e);
+ BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+ CBC_AutoPtr<CBC_ReedSolomonGF256Poly> multiply(rsgp3);
+ CBC_ReedSolomonGF256Poly* rsgp4 = r->AddOrSubtract(multiply.get(), e);
+ BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+ CBC_AutoPtr<CBC_ReedSolomonGF256Poly> temp3(rsgp4);
+ r = temp3;
+ }
+ CBC_ReedSolomonGF256Poly* rsg9 = q->Multiply(sLast.get(), e);
+ BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+ CBC_AutoPtr<CBC_ReedSolomonGF256Poly> temp1(rsg9);
+ CBC_ReedSolomonGF256Poly* rsg10 = temp1->AddOrSubtract(sLastLast.get(), e);
+ BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+ CBC_AutoPtr<CBC_ReedSolomonGF256Poly> temp2(rsg10);
+ s = temp2;
+ CBC_ReedSolomonGF256Poly* rsg11 = q->Multiply(tLast.get(), e);
+ BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+ CBC_AutoPtr<CBC_ReedSolomonGF256Poly> temp5(rsg11);
+ CBC_ReedSolomonGF256Poly* rsg12 = temp5->AddOrSubtract(tLastlast.get(), e);
+ BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+ CBC_AutoPtr<CBC_ReedSolomonGF256Poly> temp6(rsg12);
+ t = temp6;
+ }
+ FX_INT32 sigmaTildeAtZero = t->GetCoefficients(0);
+ if (sigmaTildeAtZero == 0) {
+ e = BCExceptionIsZero;
+ BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+ }
+ FX_INT32 inverse = m_field->Inverse(sigmaTildeAtZero, e);
+ BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+ CBC_ReedSolomonGF256Poly* rsg13 = t->Multiply(inverse, e);
+ BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+ CBC_AutoPtr<CBC_ReedSolomonGF256Poly> sigma(rsg13);
+ CBC_ReedSolomonGF256Poly* rsg14 = r->Multiply(inverse, e);
+ BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+ CBC_AutoPtr<CBC_ReedSolomonGF256Poly> omega(rsg14);
+ CFX_PtrArray *temp = FX_NEW CFX_PtrArray;
+ temp->Add(sigma.release());
+ temp->Add(omega.release());
+ return temp;
+}
+CFX_Int32Array *CBC_ReedSolomonDecoder::FindErrorLocations(CBC_ReedSolomonGF256Poly* errorLocator, FX_INT32 &e)
+{
+ FX_INT32 numErrors = errorLocator->GetDegree();
+ if (numErrors == 1) {
+ CBC_AutoPtr<CFX_Int32Array > temp(FX_NEW CFX_Int32Array);
+ temp->Add(errorLocator->GetCoefficients(1));
+ return temp.release();
+ }
+ CFX_Int32Array *tempT = FX_NEW CFX_Int32Array;
+ tempT->SetSize(numErrors);
+ CBC_AutoPtr<CFX_Int32Array > result(tempT);
+ FX_INT32 ie = 0;
+ for (FX_INT32 i = 1; i < 256 && ie < numErrors; i++) {
+ if(errorLocator->EvaluateAt(i) == 0) {
+ (*result)[ie] = m_field->Inverse(i, ie);
+ BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+ ie++;
+ }
+ }
+ if (ie != numErrors) {
+ e = BCExceptionDegreeNotMatchRoots;
+ BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+ }
+ return result.release();
+}
+CFX_Int32Array *CBC_ReedSolomonDecoder::FindErrorMagnitudes(CBC_ReedSolomonGF256Poly* errorEvaluator, CFX_Int32Array* errorLocations, FX_BOOL dataMatrix, FX_INT32 &e)
+{
+ FX_INT32 s = errorLocations->GetSize();
+ CFX_Int32Array * temp = FX_NEW CFX_Int32Array;
+ temp->SetSize(s);
+ CBC_AutoPtr<CFX_Int32Array > result(temp);
+ for (FX_INT32 i = 0; i < s; i++) {
+ FX_INT32 xiInverse = m_field->Inverse(errorLocations->operator [](i), e);
+ BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+ FX_INT32 denominator = 1;
+ for(FX_INT32 j = 0; j < s; j++) {
+ if(i != j) {
+ denominator = m_field->Multiply(denominator,
+ CBC_ReedSolomonGF256::AddOrSubtract(1, m_field->Multiply(errorLocations->operator [](j), xiInverse)));
+ }
+ }
+ FX_INT32 temp = m_field->Inverse(denominator, temp);
+ BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+ (*result)[i] = m_field->Multiply(errorEvaluator->EvaluateAt(xiInverse),
+ temp);
+ }
+ return result.release();
+}
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