gflib.h

GFLIB - C Procedures for Galois Field Arithmetic and Reed-Solomon Coding. 该函数库广泛用在网络编码和信道编码中。

/*
Procedures and Programs for Galois-Field Arithmetic and Reed-Solomon Coding.  
Copyright (C) 2003 James S. Plank

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

---------------------------------------------------------------------------
Please see http://www.cs.utk.edu/~plank/plank/gflib
for instruction on how to use this library.

Jim Plank
[e-mail]
http://www.cs.utk.edu/~plank

Associate Professor
Department of Computer Science
University of Tennessee
203 Claxton Complex
1122 Volunteer Blvd.
Knoxville, TN 37996-3450

     865-974-4397
Fax: [phone]

$Revision: 1.2 $
*/

#include <stdio.h>

#ifdef W_8
  typedef unsigned char unit;
#elif W_16
  typedef unsigned short unit;
#endif

typedef struct {
  int *condensed_matrix;   /* The n*n dispersal matrix with rows deleted */
  int *row_identities;     /* A nx1 vector of the original row identities of the cond_matrix */
} Condensed_Matrix;

extern void gf_modar_setup();
extern int gf_single_multiply(int a, int b);
extern int gf_single_divide(int a, int b);
extern void gf_fprint_matrix(FILE *f, int *m, int rows, int cols);
extern void gf_fast_add_parity(void *to_add, void *to_modify, int size);
extern void gf_add_parity(void *to_add, void *to_modify, int size);
extern void gf_mult_region(void *region, int size, int factor);
extern int gf_log(int value);
extern int *gf_make_vandermonde(int rows, int cols);
extern int *gf_make_dispersal_matrix(int rows, int cols);
extern Condensed_Matrix *gf_condense_dispersal_matrix(
                        int *disp,          /* The rows*cols dispersal matrix */
                        int *existing_rows, /* A 0/1 column vector -- 1 if the row still exists */
                        int rows, 
                        int  cols);
extern int *gf_invert_matrix(int *mat, int rows);
extern int *gf_matrix_multiply(int *a, int *b, int rows);  /* Must be square */
extern void gf_write_matrix(FILE *f, int *a, int rows, int cols);
extern int *gf_read_matrix(FILE *f, int *rows, int *cols);