reedsolomon.h File Reference

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Macros
#define	MM   8 /* Symbol size in bits */
#define	KK   207 /* Number of data symbols per block */
#define	B0   1 /* First root of generator polynomial, alpha form */
#define	PRIM   1 /* power of alpha used to generate roots of generator poly */
#define	STANDARD_ORDER
#define	NN   ((1 << MM) - 1)

Typedefs
typedef unsigned char	dtype

Functions
int	encode_rs (dtype data[], dtype bb[])
	Encodes data using Reed-Solomon error correction.
int	eras_dec_rs (dtype data[], int eras_pos[], int no_eras)
	Performs ERRORS+ERASURES decoding of Reed-Solomon codes.

Detailed Description

Global definitions for Reed-Solomon encoder/decoder, by Phil Karn (karn@.nosp@m.ka9q.nosp@m..ampr.nosp@m..org) September 1996 Copyright 1999 Phil Karn, KA9Q

Wireshark - Network traffic analyzer By Gerald Combs geral.nosp@m.d@wi.nosp@m.resha.nosp@m.rk.o.nosp@m.rg Copyright 1998 Gerald Combs

SPDX-License-Identifier: GPL-2.0-or-later

Function Documentation

encode_rs()

int encode_rs	(	dtype	data[],
		dtype	bb[]
	)

Encodes data using Reed-Solomon error correction.

Reed-Solomon encoding data[] is the input block, parity symbols are placed in bb[] bb[] may lie past the end of the data, e.g., for (255,223): encode_rs(&data[0],&data[223]);

Parameters

data	Input data array to be encoded.
bb	Output buffer for the encoded data.

Returns

Number of corrected symbols if successful, -1 otherwise.

eras_dec_rs()

int eras_dec_rs	(	dtype	data[],
		int	eras_pos[],
		int	no_eras
	)

Performs ERRORS+ERASURES decoding of Reed-Solomon codes.

Reed-Solomon erasures-and-errors decoding The received block goes into data[], and a list of zero-origin erasure positions, if any, goes in eras_pos[] with a count in no_eras.

The decoder corrects the symbols in place, if possible and returns the number of corrected symbols. If the codeword is illegal or uncorrectable, the data array is unchanged and -1 is returned

Parameters

data	Pointer to the input and output data array.
eras_pos	Array containing the positions of known erased symbols.
no_eras	Number of known erased symbols.

Returns

Number of symbols corrected, or -1 if codeword is illegal or uncorrectable.