com.google.zxing.common.reedsolomon

Class ReedSolomonDecoder

java.lang.Object

com.google.zxing.common.reedsolomon.ReedSolomonDecoder

public final class ReedSolomonDecoder
extends Object

Implements Reed-Solomon decoding, as the name implies.

The algorithm will not be explained here, but the following references were helpful in creating this implementation:

• Bruce Maggs. "Decoding Reed-Solomon Codes" (see discussion of Forney's Formula)
• J.I. Hall. "Chapter 5. Generalized Reed-Solomon Codes" (see discussion of Euclidean algorithm)

Much credit is due to William Rucklidge since portions of this code are an indirect port of his C++ Reed-Solomon implementation.

Author:

Sean Owen, William Rucklidge, sanfordsquires

Constructor Summary

Constructors

Constructor and Description
ReedSolomonDecoder(GenericGF field)

Method Summary

Modifier and Type	Method and Description
void	decode(int[] received, int twoS) Decodes given set of received codewords, which include both data and error-correction codewords.
int	decodeWithECCount(int[] received, int twoS) Decodes given set of received codewords, which include both data and error-correction codewords.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ReedSolomonDecoder

public ReedSolomonDecoder(GenericGF field)

Method Detail

decode

public void decode(int[] received,
                   int twoS)
            throws ReedSolomonException

Decodes given set of received codewords, which include both data and error-correction codewords. Really, this means it uses Reed-Solomon to detect and correct errors, in-place, in the input.

Parameters:

received - data and error-correction codewords

twoS - number of error-correction codewords available

Throws:

ReedSolomonException - if decoding fails for any reason

decodeWithECCount

public int decodeWithECCount(int[] received,
                             int twoS)
                      throws ReedSolomonException

Decodes given set of received codewords, which include both data and error-correction codewords. Really, this means it uses Reed-Solomon to detect and correct errors, in-place, in the input.

Parameters:

received - data and error-correction codewords

twoS - number of error-correction codewords available

Returns:

the number of errors corrected

Throws:

ReedSolomonException - if decoding fails for any reason