Ryo Hagimoto
ZBar bar code reader . http://zbar.sourceforge.net/ ZBar is licensed under the GNU LGPL 2.1 to enable development of both open source and commercial projects.
Dependents: GR-PEACH_Camera_in_barcode levkov_ov7670
LICENSE
The ZBar Bar Code Reader is Copyright (C) 2007-2009 Jeff Brown <spadix@users.sourceforge.net> The QR Code reader is Copyright (C) 1999-2009 Timothy B. Terriberry <tterribe@xiph.org>
You can redistribute this library 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
ISAAC is based on the public domain implementation by Robert J. Jenkins Jr., and is itself public domain.
Portions of the bit stream reader are copyright (C) The Xiph.Org Foundation 1994-2008, and are licensed under a BSD-style license.
The Reed-Solomon decoder is derived from an implementation (C) 1991-1995 Henry Minsky (hqm@ua.com, hqm@ai.mit.edu), and is licensed under the LGPL with permission.
zbar/qrcode/rs.h@1:500d42699c34, 2016-04-19 (annotated)
- Committer:
- RyoheiHagimoto
- Date:
- Tue Apr 19 02:19:39 2016 +0000
- Revision:
- 1:500d42699c34
- Parent:
- 0:56c5742b9e2b
Add copying.txt and license.txt
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| RyoheiHagimoto | 0:56c5742b9e2b | 1 | /*Copyright (C) 1991-1995 Henry Minsky (hqm@ua.com, hqm@ai.mit.edu) |
| RyoheiHagimoto | 0:56c5742b9e2b | 2 | Copyright (C) 2008-2009 Timothy B. Terriberry (tterribe@xiph.org) |
| RyoheiHagimoto | 0:56c5742b9e2b | 3 | You can redistribute this library and/or modify it under the terms of the |
| RyoheiHagimoto | 0:56c5742b9e2b | 4 | GNU Lesser General Public License as published by the Free Software |
| RyoheiHagimoto | 0:56c5742b9e2b | 5 | Foundation; either version 2.1 of the License, or (at your option) any later |
| RyoheiHagimoto | 0:56c5742b9e2b | 6 | version.*/ |
| RyoheiHagimoto | 0:56c5742b9e2b | 7 | #if !defined(_qrcode_rs_H) |
| RyoheiHagimoto | 0:56c5742b9e2b | 8 | # define _qrcode_rs_H (1) |
| RyoheiHagimoto | 0:56c5742b9e2b | 9 | |
| RyoheiHagimoto | 0:56c5742b9e2b | 10 | /*This is one of 16 irreducible primitive polynomials of degree 8: |
| RyoheiHagimoto | 0:56c5742b9e2b | 11 | x**8+x**4+x**3+x**2+1. |
| RyoheiHagimoto | 0:56c5742b9e2b | 12 | Under such a polynomial, x (i.e., 0x02) is a generator of GF(2**8). |
| RyoheiHagimoto | 0:56c5742b9e2b | 13 | The high order 1 bit is implicit. |
| RyoheiHagimoto | 0:56c5742b9e2b | 14 | From~\cite{MD88}, Ch. 5, p. 275 by Patel. |
| RyoheiHagimoto | 0:56c5742b9e2b | 15 | @BOOK{MD88, |
| RyoheiHagimoto | 0:56c5742b9e2b | 16 | author="C. Dennis Mee and Eric D. Daniel", |
| RyoheiHagimoto | 0:56c5742b9e2b | 17 | title="Video, Audio, and Instrumentation Recording", |
| RyoheiHagimoto | 0:56c5742b9e2b | 18 | series="Magnetic Recording", |
| RyoheiHagimoto | 0:56c5742b9e2b | 19 | volume=3, |
| RyoheiHagimoto | 0:56c5742b9e2b | 20 | publisher="McGraw-Hill Education", |
| RyoheiHagimoto | 0:56c5742b9e2b | 21 | address="Columbus, OH", |
| RyoheiHagimoto | 0:56c5742b9e2b | 22 | month=Jun, |
| RyoheiHagimoto | 0:56c5742b9e2b | 23 | year=1988 |
| RyoheiHagimoto | 0:56c5742b9e2b | 24 | }*/ |
| RyoheiHagimoto | 0:56c5742b9e2b | 25 | #define QR_PPOLY (0x1D) |
| RyoheiHagimoto | 0:56c5742b9e2b | 26 | |
| RyoheiHagimoto | 0:56c5742b9e2b | 27 | /*The index to start the generator polynomial from (0...254).*/ |
| RyoheiHagimoto | 0:56c5742b9e2b | 28 | #define QR_M0 (0) |
| RyoheiHagimoto | 0:56c5742b9e2b | 29 | |
| RyoheiHagimoto | 0:56c5742b9e2b | 30 | typedef struct rs_gf256 rs_gf256; |
| RyoheiHagimoto | 0:56c5742b9e2b | 31 | |
| RyoheiHagimoto | 0:56c5742b9e2b | 32 | struct rs_gf256{ |
| RyoheiHagimoto | 0:56c5742b9e2b | 33 | /*A logarithm table in GF(2**8).*/ |
| RyoheiHagimoto | 0:56c5742b9e2b | 34 | unsigned char log[256]; |
| RyoheiHagimoto | 0:56c5742b9e2b | 35 | /*An exponential table in GF(2**8): exp[i] contains x^i reduced modulo the |
| RyoheiHagimoto | 0:56c5742b9e2b | 36 | irreducible primitive polynomial used to define the field. |
| RyoheiHagimoto | 0:56c5742b9e2b | 37 | The extra 256 entries are used to do arithmetic mod 255, since some extra |
| RyoheiHagimoto | 0:56c5742b9e2b | 38 | table lookups are generally faster than doing the modulus.*/ |
| RyoheiHagimoto | 0:56c5742b9e2b | 39 | unsigned char exp[511]; |
| RyoheiHagimoto | 0:56c5742b9e2b | 40 | }; |
| RyoheiHagimoto | 0:56c5742b9e2b | 41 | |
| RyoheiHagimoto | 0:56c5742b9e2b | 42 | /*Initialize discrete logarithm tables for GF(2**8) using a given primitive |
| RyoheiHagimoto | 0:56c5742b9e2b | 43 | irreducible polynomial.*/ |
| RyoheiHagimoto | 0:56c5742b9e2b | 44 | void rs_gf256_init(rs_gf256 *_gf,unsigned _ppoly); |
| RyoheiHagimoto | 0:56c5742b9e2b | 45 | |
| RyoheiHagimoto | 0:56c5742b9e2b | 46 | /*Corrects a codeword with _ndata<256 bytes, of which the last _npar are parity |
| RyoheiHagimoto | 0:56c5742b9e2b | 47 | bytes. |
| RyoheiHagimoto | 0:56c5742b9e2b | 48 | Known locations of errors can be passed in the _erasures array. |
| RyoheiHagimoto | 0:56c5742b9e2b | 49 | Twice as many (up to _npar) errors with a known location can be corrected |
| RyoheiHagimoto | 0:56c5742b9e2b | 50 | compared to errors with an unknown location. |
| RyoheiHagimoto | 0:56c5742b9e2b | 51 | Returns the number of errors corrected if successful, or a negative number if |
| RyoheiHagimoto | 0:56c5742b9e2b | 52 | the message could not be corrected because too many errors were detected.*/ |
| RyoheiHagimoto | 0:56c5742b9e2b | 53 | int rs_correct(const rs_gf256 *_gf,int _m0,unsigned char *_data,int _ndata, |
| RyoheiHagimoto | 0:56c5742b9e2b | 54 | int _npar,const unsigned char *_erasures,int _nerasures); |
| RyoheiHagimoto | 0:56c5742b9e2b | 55 | |
| RyoheiHagimoto | 0:56c5742b9e2b | 56 | /*Create an _npar-coefficient generator polynomial for a Reed-Solomon code with |
| RyoheiHagimoto | 0:56c5742b9e2b | 57 | _npar<256 parity bytes.*/ |
| RyoheiHagimoto | 0:56c5742b9e2b | 58 | void rs_compute_genpoly(const rs_gf256 *_gf,int _m0, |
| RyoheiHagimoto | 0:56c5742b9e2b | 59 | unsigned char *_genpoly,int _npar); |
| RyoheiHagimoto | 0:56c5742b9e2b | 60 | |
| RyoheiHagimoto | 0:56c5742b9e2b | 61 | /*Adds _npar<=_ndata parity bytes to an _ndata-_npar byte message. |
| RyoheiHagimoto | 0:56c5742b9e2b | 62 | _data must contain room for _ndata<256 bytes.*/ |
| RyoheiHagimoto | 0:56c5742b9e2b | 63 | void rs_encode(const rs_gf256 *_gf,unsigned char *_data,int _ndata, |
| RyoheiHagimoto | 0:56c5742b9e2b | 64 | const unsigned char *_genpoly,int _npar); |
| RyoheiHagimoto | 0:56c5742b9e2b | 65 | |
| RyoheiHagimoto | 0:56c5742b9e2b | 66 | #endif |
| RyoheiHagimoto | 0:56c5742b9e2b | 67 |