diff options
Diffstat (limited to 'xfa/src/fxbarcode/common/reedsolomon/BC_ReedSolomonDecoder.cpp')
| -rw-r--r-- | xfa/src/fxbarcode/common/reedsolomon/BC_ReedSolomonDecoder.cpp | 373 |
1 files changed, 194 insertions, 179 deletions
diff --git a/xfa/src/fxbarcode/common/reedsolomon/BC_ReedSolomonDecoder.cpp b/xfa/src/fxbarcode/common/reedsolomon/BC_ReedSolomonDecoder.cpp index f0e87b8e40..d57efe1408 100644 --- a/xfa/src/fxbarcode/common/reedsolomon/BC_ReedSolomonDecoder.cpp +++ b/xfa/src/fxbarcode/common/reedsolomon/BC_ReedSolomonDecoder.cpp @@ -24,201 +24,216 @@ #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(CBC_ReedSolomonGF256* field) {
+ m_field = field;
}
-CBC_ReedSolomonDecoder::~CBC_ReedSolomonDecoder()
-{
-}
-void CBC_ReedSolomonDecoder::Decode(CFX_Int32Array* received, int32_t twoS, int32_t &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 (int32_t i = 0; i < twoS; i++) {
- int32_t eval = poly.EvaluateAt(m_field->Exp(dataMatrix ? i + 1 : i));
- syndromeCoefficients[twoS - 1 - i] = eval;
- if (eval != 0) {
- noError = FALSE;
- }
+CBC_ReedSolomonDecoder::~CBC_ReedSolomonDecoder() {}
+void CBC_ReedSolomonDecoder::Decode(CFX_Int32Array* received,
+ int32_t twoS,
+ int32_t& 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 (int32_t i = 0; i < twoS; i++) {
+ int32_t 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);
+ }
+ 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 (int32_t k = 0; k < errorLocations->GetSize(); k++) {
+ int32_t position =
+ received->GetSize() - 1 - m_field->Log((*errorLocations)[k], 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 (int32_t k = 0; k < errorLocations->GetSize(); k++) {
- int32_t 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]);
+ 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, int32_t R, int32_t &e)
-{
- if (a->GetDegree() < b->GetDegree()) {
- CBC_ReedSolomonGF256Poly* temp = a;
- a = b;
- b = temp;
+CFX_PtrArray* CBC_ReedSolomonDecoder::RunEuclideanAlgorithm(
+ CBC_ReedSolomonGF256Poly* a,
+ CBC_ReedSolomonGF256Poly* b,
+ int32_t R,
+ int32_t& 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* rsg1 = a->Clone(e);
- BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
- CBC_AutoPtr<CBC_ReedSolomonGF256Poly> rLast(rsg1);
- CBC_ReedSolomonGF256Poly* rsg2 = b->Clone(e);
+ CBC_ReedSolomonGF256Poly* rsg7 = rLastLast->Clone(e);
BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
- CBC_AutoPtr<CBC_ReedSolomonGF256Poly> r(rsg2);
- CBC_ReedSolomonGF256Poly* rsg3 = m_field->GetOne()->Clone(e);
+ 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> sLast(rsg3);
- CBC_ReedSolomonGF256Poly* rsg4 = m_field->GetZero()->Clone(e);
+ CBC_AutoPtr<CBC_ReedSolomonGF256Poly> q(rsg8);
+ int32_t denominatorLeadingTerm = rLast->GetCoefficients(rLast->GetDegree());
+ int32_t dltInverse = m_field->Inverse(denominatorLeadingTerm, e);
BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
- CBC_AutoPtr<CBC_ReedSolomonGF256Poly> s(rsg4);
- CBC_ReedSolomonGF256Poly* rsg5 = m_field->GetZero()->Clone(e);
+ while (r->GetDegree() >= rLast->GetDegree() && !(r->IsZero())) {
+ int32_t degreeDiff = r->GetDegree() - rLast->GetDegree();
+ int32_t 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> tLast(rsg5);
- CBC_ReedSolomonGF256Poly* rsg6 = m_field->GetOne()->Clone(e);
+ CBC_AutoPtr<CBC_ReedSolomonGF256Poly> temp1(rsg9);
+ CBC_ReedSolomonGF256Poly* rsg10 = temp1->AddOrSubtract(sLastLast.get(), 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);
- int32_t denominatorLeadingTerm = rLast->GetCoefficients(rLast->GetDegree());
- int32_t dltInverse = m_field->Inverse(denominatorLeadingTerm, e);
- BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
- while (r->GetDegree() >= rLast->GetDegree() && !(r->IsZero())) {
- int32_t degreeDiff = r->GetDegree() - rLast->GetDegree();
- int32_t 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;
- }
- int32_t sigmaTildeAtZero = t->GetCoefficients(0);
- if (sigmaTildeAtZero == 0) {
- e = BCExceptionIsZero;
- BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
- }
- int32_t inverse = m_field->Inverse(sigmaTildeAtZero, e);
+ CBC_AutoPtr<CBC_ReedSolomonGF256Poly> temp2(rsg10);
+ s = temp2;
+ CBC_ReedSolomonGF256Poly* rsg11 = q->Multiply(tLast.get(), e);
BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
- CBC_ReedSolomonGF256Poly* rsg13 = t->Multiply(inverse, e);
+ CBC_AutoPtr<CBC_ReedSolomonGF256Poly> temp5(rsg11);
+ CBC_ReedSolomonGF256Poly* rsg12 = temp5->AddOrSubtract(tLastlast.get(), e);
BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
- CBC_AutoPtr<CBC_ReedSolomonGF256Poly> sigma(rsg13);
- CBC_ReedSolomonGF256Poly* rsg14 = r->Multiply(inverse, e);
+ CBC_AutoPtr<CBC_ReedSolomonGF256Poly> temp6(rsg12);
+ t = temp6;
+ }
+ int32_t sigmaTildeAtZero = t->GetCoefficients(0);
+ if (sigmaTildeAtZero == 0) {
+ e = BCExceptionIsZero;
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;
+ }
+ int32_t 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, int32_t &e)
-{
- int32_t 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);
- int32_t ie = 0;
- for (int32_t 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++;
- }
+CFX_Int32Array* CBC_ReedSolomonDecoder::FindErrorLocations(
+ CBC_ReedSolomonGF256Poly* errorLocator,
+ int32_t& e) {
+ int32_t 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);
+ int32_t ie = 0;
+ for (int32_t 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();
+ }
+ 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, int32_t &e)
-{
- int32_t s = errorLocations->GetSize();
- CFX_Int32Array * temp = FX_NEW CFX_Int32Array;
- temp->SetSize(s);
- CBC_AutoPtr<CFX_Int32Array > result(temp);
- for (int32_t i = 0; i < s; i++) {
- int32_t xiInverse = m_field->Inverse(errorLocations->operator [](i), e);
- BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
- int32_t denominator = 1;
- for(int32_t j = 0; j < s; j++) {
- if(i != j) {
- denominator = m_field->Multiply(denominator,
- CBC_ReedSolomonGF256::AddOrSubtract(1, m_field->Multiply(errorLocations->operator [](j), xiInverse)));
- }
- }
- int32_t temp = m_field->Inverse(denominator, temp);
- BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
- (*result)[i] = m_field->Multiply(errorEvaluator->EvaluateAt(xiInverse),
- temp);
+CFX_Int32Array* CBC_ReedSolomonDecoder::FindErrorMagnitudes(
+ CBC_ReedSolomonGF256Poly* errorEvaluator,
+ CFX_Int32Array* errorLocations,
+ FX_BOOL dataMatrix,
+ int32_t& e) {
+ int32_t s = errorLocations->GetSize();
+ CFX_Int32Array* temp = FX_NEW CFX_Int32Array;
+ temp->SetSize(s);
+ CBC_AutoPtr<CFX_Int32Array> result(temp);
+ for (int32_t i = 0; i < s; i++) {
+ int32_t xiInverse = m_field->Inverse(errorLocations->operator[](i), e);
+ BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+ int32_t denominator = 1;
+ for (int32_t j = 0; j < s; j++) {
+ if (i != j) {
+ denominator = m_field->Multiply(
+ denominator, CBC_ReedSolomonGF256::AddOrSubtract(
+ 1, m_field->Multiply(errorLocations->operator[](j),
+ xiInverse)));
+ }
}
- return result.release();
+ int32_t temp = m_field->Inverse(denominator, temp);
+ BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+ (*result)[i] =
+ m_field->Multiply(errorEvaluator->EvaluateAt(xiInverse), temp);
+ }
+ return result.release();
}
|