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sdrangel/sdrbase/util/crc.h
Jon Beniston 1a9b6d1763 Add ADS-B Demodulator plugin.
Add GS232 Rotator Controller feature plugin.
Add altitude and station name to My Positon.
Use QtDeploy to ensure all required Qt libraries are included (Should
fix OpenGL issues)
2020-10-27 16:22:10 +00:00

122 lines
3.5 KiB
C++

///////////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2020 Jon Beniston, M7RCE //
// //
// This program is free software; you can redistribute it and/or modify //
// it under the terms of the GNU General Public License as published by //
// the Free Software Foundation as version 3 of the License, or //
// (at your option) any later version. //
// //
// This program 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 General Public License V3 for more details. //
// //
// You should have received a copy of the GNU General Public License //
// along with this program. If not, see <http://www.gnu.org/licenses/>. //
///////////////////////////////////////////////////////////////////////////////////
#ifndef INCLUDE_CRC_H
#define INCLUDE_CRC_H
#include <stdint.h>
#include "export.h"
// Class to calculate arbitrary CRCs (up to 32-bits)
class SDRBASE_API crc
{
public:
// Create and initialise CRC with specified polynomial and parameters
crc(int poly_bits, uint32_t polynomial, bool msb_first, uint32_t init_value, uint32_t final_xor) :
m_poly_bits(poly_bits),
m_polynomial(polynomial),
m_msb_first(msb_first),
m_init_value(init_value),
m_final_xor(final_xor)
{
int shift;
shift = 32 - m_poly_bits;
m_polynomial_rev = reverse (m_polynomial << shift, 32);
init();
}
// Initialise CRC state
void init()
{
m_crc = m_init_value;
}
// Calculate CRC for supplied data
void calculate(uint32_t data, int data_bits);
void calculate(const uint8_t *data, int length);
// Get final CRC
uint32_t get()
{
uint32_t t;
t = m_final_xor ^ m_crc;
if (m_msb_first)
return reverse(t, m_poly_bits);
else
return t;
}
private:
static uint32_t reverse(uint32_t val, int bits);
uint32_t m_crc;
uint32_t m_polynomial;
uint32_t m_polynomial_rev;
uint32_t m_poly_bits;
bool m_msb_first;
uint32_t m_init_value;
uint32_t m_final_xor;
};
class SDRBASE_API crc16ansi : public crc
{
public:
crc16ansi() : crc(16, 0x8005, false, 0x0000, 0) {}
};
class SDRBASE_API crc16ccitt : public crc
{
public:
crc16ccitt() : crc(16, 0x1021, true, 0xffff, 0) {}
};
class SDRBASE_API crc16itut : public crc
{
public:
crc16itut() : crc(16, 0x1021, false, 0x0000, 0) {}
};
class SDRBASE_API crc16x25 : public crc
{
public:
crc16x25() : crc(16, 0x1021, false, 0xffff, 0xffff) {}
};
class SDRBASE_API crc32 : public crc
{
public:
crc32() : crc(32, 0x04C11DB7, false, 0xffffffff, 0xffffffff) {}
};
class SDRBASE_API crc32c : public crc
{
public:
crc32c() : crc(32, 0x1EDC6F41, false, 0xffffffff, 0) {}
};
// ADS-B - https://mode-s.org/decode/adsb/introduction.html
class SDRBASE_API crcadsb : public crc
{
public:
crcadsb() : crc(24, 0xfff409, true, 0, 0) {}
};
#endif