public Decoder() { rsDecoder = new ReedSolomonDecoder(GF256.DATA_MATRIX_FIELD); }
runEuclideanAlgorithm(field.buildMonomial(twoS, 1), syndrome, twoS); GF256Poly sigma = sigmaOmega[0]; GF256Poly omega = sigmaOmega[1]; int[] errorLocations = findErrorLocations(sigma); int[] errorMagnitudes = findErrorMagnitudes(omega, errorLocations, dataMatrix); for (int i = 0; i < errorLocations.length; i++) { int position = received.length - 1 - field.log(errorLocations[i]);
/** * <p>Given data and error-correction codewords received, possibly corrupted by errors, attempts to * correct the errors in-place using Reed-Solomon error correction.</p> * * @param codewordBytes data and error correction codewords * @param numDataCodewords number of codewords that are data bytes * @throws ChecksumException if error correction fails */ private void correctErrors(byte[] codewordBytes, int numDataCodewords) throws ChecksumException { int numCodewords = codewordBytes.length; // First read into an array of ints int[] codewordsInts = new int[numCodewords]; for (int i = 0; i < numCodewords; i++) { codewordsInts[i] = codewordBytes[i] & 0xFF; } int numECCodewords = codewordBytes.length - numDataCodewords; try { rsDecoder.decode(codewordsInts, numECCodewords); } catch (ReedSolomonException rse) { throw ChecksumException.getChecksumInstance(); } // Copy back into array of bytes -- only need to worry about the bytes that were data // We don't care about errors in the error-correction codewords for (int i = 0; i < numDataCodewords; i++) { codewordBytes[i] = (byte) codewordsInts[i]; } }
runEuclideanAlgorithm(field.buildMonomial(twoS, 1), syndrome, twoS); GenericGFPoly sigma = sigmaOmega[0]; GenericGFPoly omega = sigmaOmega[1]; int[] errorLocations = findErrorLocations(sigma); int[] errorMagnitudes = findErrorMagnitudes(omega, errorLocations); for (int i = 0; i < errorLocations.length; i++) { int position = received.length - 1 - field.log(errorLocations[i]);
/** * <p>Given data and error-correction codewords received, possibly corrupted by errors, attempts to * correct the errors in-place using Reed-Solomon error correction.</p> * * @param codewordBytes data and error correction codewords * @param numDataCodewords number of codewords that are data bytes * @throws ChecksumException if error correction fails */ private void correctErrors(byte[] codewordBytes, int numDataCodewords) throws ChecksumException { int numCodewords = codewordBytes.length; // First read into an array of ints int[] codewordsInts = new int[numCodewords]; for (int i = 0; i < numCodewords; i++) { codewordsInts[i] = codewordBytes[i] & 0xFF; } try { rsDecoder.decode(codewordsInts, codewordBytes.length - numDataCodewords); } catch (ReedSolomonException ignored) { throw ChecksumException.getChecksumInstance(); } // Copy back into array of bytes -- only need to worry about the bytes that were data // We don't care about errors in the error-correction codewords for (int i = 0; i < numDataCodewords; i++) { codewordBytes[i] = (byte) codewordsInts[i]; } }
runEuclideanAlgorithm(field.buildMonomial(twoS, 1), syndrome, twoS); GenericGFPoly sigma = sigmaOmega[0]; GenericGFPoly omega = sigmaOmega[1]; int[] errorLocations = findErrorLocations(sigma); int[] errorMagnitudes = findErrorMagnitudes(omega, errorLocations); for (int i = 0; i < errorLocations.length; i++) { int position = received.length - 1 - field.log(errorLocations[i]);
public Decoder() { rsDecoder = new ReedSolomonDecoder(GenericGF.QR_CODE_FIELD_256); }
/** * <p>Given data and error-correction codewords received, possibly corrupted by errors, attempts to * correct the errors in-place using Reed-Solomon error correction.</p> * * @param codewordBytes data and error correction codewords * @param numDataCodewords number of codewords that are data bytes * @throws ChecksumException if error correction fails */ private void correctErrors(byte[] codewordBytes, int numDataCodewords) throws ChecksumException { int numCodewords = codewordBytes.length; // First read into an array of ints int[] codewordsInts = new int[numCodewords]; for (int i = 0; i < numCodewords; i++) { codewordsInts[i] = codewordBytes[i] & 0xFF; } try { rsDecoder.decode(codewordsInts, codewordBytes.length - numDataCodewords); } catch (ReedSolomonException ignored) { throw ChecksumException.getChecksumInstance(); } // Copy back into array of bytes -- only need to worry about the bytes that were data // We don't care about errors in the error-correction codewords for (int i = 0; i < numDataCodewords; i++) { codewordBytes[i] = (byte) codewordsInts[i]; } }
public Decoder() { rsDecoder = new ReedSolomonDecoder(GenericGF.QR_CODE_FIELD_256); }
/** * <p>Given data and error-correction codewords received, possibly corrupted by errors, attempts to * correct the errors in-place using Reed-Solomon error correction.</p> * * @param codewordBytes data and error correction codewords * @param numDataCodewords number of codewords that are data bytes * @throws ChecksumException if error correction fails */ private void correctErrors(byte[] codewordBytes, int numDataCodewords) throws ChecksumException { int numCodewords = codewordBytes.length; // First read into an array of ints int[] codewordsInts = new int[numCodewords]; for (int i = 0; i < numCodewords; i++) { codewordsInts[i] = codewordBytes[i] & 0xFF; } int numECCodewords = codewordBytes.length - numDataCodewords; try { rsDecoder.decode(codewordsInts, numECCodewords); } catch (ReedSolomonException rse) { throw ChecksumException.getChecksumInstance(); } // Copy back into array of bytes -- only need to worry about the bytes that were data // We don't care about errors in the error-correction codewords for (int i = 0; i < numDataCodewords; i++) { codewordBytes[i] = (byte) codewordsInts[i]; } }
public Decoder() { rsDecoder = new ReedSolomonDecoder(GF256.QR_CODE_FIELD); }