rssoft::RS_Encoding Class Reference

Does the Reed-Solomon encoding of a message. his is the genuine, straightforward, non-systematic encoding that takes message symbols to build the successive coefficients of the encoding polynomial. Then this polynomial is evaluated at the evaluation points to make the codeword. More...

#include <RS_Encoding.h>

Collaboration diagram for rssoft::RS_Encoding:

List of all members.

Public Member Functions
	RS_Encoding (const gf::GFq &_gf, unsigned int k, const EvaluationValues &_evaluation_values)
	~RS_Encoding ()
void	run (const std::vector< gf::GFq_Symbol > &message, std::vector< gf::GFq_Symbol > &codeword) const
Protected Attributes
const gf::GFq &	gf
	Galois Field in use.
unsigned int	k
	k as in RS(n,k). n is the "size" of the Galois Field
const EvaluationValues &	evaluation_values
	Evaluation X,Y values of the code.

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Detailed Description

Does the Reed-Solomon encoding of a message. his is the genuine, straightforward, non-systematic encoding that takes message symbols to build the successive coefficients of the encoding polynomial. Then this polynomial is evaluated at the evaluation points to make the codeword.

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Constructor & Destructor Documentation

rssoft::RS_Encoding::RS_Encoding	(	const gf::GFq &	_gf,
		unsigned int	k,
		const EvaluationValues &	_evaluation_values
	)

Constructor

Parameters:

_gf	Galois Field in use
_k	k as in RS(n,k). n is the "size" of the Galois Field
_evaluation_values	Evaluation X,Y values of the code

                                                                                                      :
        gf(_gf),
        k(_k),
        evaluation_values(_evaluation_values)
{}

rssoft::RS_Encoding::~RS_Encoding

(

)

Destructor. Nothing special.

{}

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Member Function Documentation

void rssoft::RS_Encoding::run	(	const std::vector< gf::GFq_Symbol > &	message,
		std::vector< gf::GFq_Symbol > &	codeword
	)		const

Runs an encoding

Parameters:

message	Message symbols to be encoded
codeword	RS codeword in elements of GFq that will be built

{
        if (message.size() != k)
        {
                throw RSSoft_Exception("Invalid message length");
        }
        else
        {
                std::vector<gf::GFq_Symbol>::const_iterator s_it = message.begin();
                std::vector<gf::GFq_Element> encoding_coefficients;

                for(; s_it != message.end(); ++s_it)
                {
                        encoding_coefficients.push_back(gf::GFq_Element(gf, *s_it));
                }

                gf::GFq_Polynomial encoding_polynomial(gf, encoding_coefficients);
                codeword.clear();
                const std::vector<gf::GFq_Element>& evaluation_points = evaluation_values.get_evaluation_points();
                std::vector<gf::GFq_Element>::const_iterator evp_it = evaluation_points.begin();

                for (; evp_it != evaluation_points.end(); ++evp_it)
                {
                        codeword.push_back(encoding_polynomial(*evp_it).poly());
                }
        }
}

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Member Data Documentation

const EvaluationValues& rssoft::RS_Encoding::evaluation_values [protected]

Evaluation X,Y values of the code.

const gf::GFq& rssoft::RS_Encoding::gf [protected]

Galois Field in use.

unsigned int rssoft::RS_Encoding::k [protected]

k as in RS(n,k). n is the "size" of the Galois Field

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The documentation for this class was generated from the following files:

• /shared/development/google_code/rssoft/library/lib/RS_Encoding.h
• /shared/development/google_code/rssoft/library/lib/RS_Encoding.cpp