kopia lustrzana https://github.com/sq8vps/vp-digi
148 wiersze
3.3 KiB
C
148 wiersze
3.3 KiB
C
/*
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Copyright 2020-2023 Piotr Wilkon
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This file is part of VP-Digi.
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VP-Digi is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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VP-Digi is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with VP-Digi. If not, see <http://www.gnu.org/licenses/>.
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*/
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#ifdef ENABLE_FX25
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#include "fx25.h"
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#include <stddef.h>
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#include "rs.h"
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#define FX25_RS_FCR 1
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#define FX25_PREGENERATE_POLYS
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#define FX25_MAX_DISTANCE 10 //maximum Hamming distance when comparing tags
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const struct Fx25Mode Fx25ModeList[11] =
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{
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{.tag = 0xB74DB7DF8A532F3E, .K = 239, .T = 16},
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{.tag = 0x26FF60A600CC8FDE, .K = 128, .T = 16},
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{.tag = 0xC7DC0508F3D9B09E, .K = 64, .T = 16},
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{.tag = 0x8F056EB4369660EE, .K = 32, .T = 16},
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{.tag = 0x6E260B1AC5835FAE, .K = 223, .T = 32},
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{.tag = 0xFF94DC634F1CFF4E, .K = 128, .T = 32},
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{.tag = 0x1EB7B9CDBC09C00E, .K = 64, .T = 32},
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{.tag = 0xDBF869BD2DBB1776, .K = 32, .T = 32},
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{.tag = 0x3ADB0C13DEAE2836, .K = 191, .T = 64},
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{.tag = 0xAB69DB6A543188D6, .K = 128, .T = 64},
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{.tag = 0x4A4ABEC4A724B796, .K = 64, .T = 64}
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};
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const struct Fx25Mode* Fx25GetModeForTag(uint64_t tag)
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{
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for(uint8_t i = 0; i < sizeof(Fx25ModeList) / sizeof(*Fx25ModeList); i++)
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{
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if(__builtin_popcountll(tag ^ Fx25ModeList[i].tag) <= FX25_MAX_DISTANCE)
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return &Fx25ModeList[i];
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}
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return NULL;
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}
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const struct Fx25Mode* Fx25GetModeForSize(uint16_t size)
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{
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//use "UZ7HO Soundmodem standard" for choosing FX.25 mode
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if(size <= 32)
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return &Fx25ModeList[3];
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else if(size <= 64)
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return &Fx25ModeList[2];
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else if(size <= 128)
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return &Fx25ModeList[5];
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else if(size <= 191)
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return &Fx25ModeList[8];
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else if(size <= 223)
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return &Fx25ModeList[4];
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else if(size <= 239)
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return &Fx25ModeList[0];
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else
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return NULL; //frame too big, do not use FX.25
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}
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#ifdef FX25_PREGENERATE_POLYS
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static struct LwFecRS rs16, rs32, rs64;
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#else
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static struct LwFecRS rs;
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#endif
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void Fx25Encode(uint8_t *buffer, const struct Fx25Mode *mode)
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{
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#ifdef FX25_PREGENERATE_POLYS
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struct LwFecRS *rs = NULL;
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switch(mode->T)
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{
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case 16:
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rs = &rs16;
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break;
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case 32:
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rs = &rs32;
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break;
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case 64:
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rs = &rs64;
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break;
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default:
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rs = &rs16;
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break;
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}
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RsEncode(rs, buffer, mode->K);
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#else
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RsInit(&rs, mode->T, FX25_RS_FCR);
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RsEncode(&rs, buffer, mode->K);
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#endif
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}
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bool Fx25Decode(uint8_t *buffer, const struct Fx25Mode *mode, uint8_t *fixed)
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{
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#ifdef FX25_PREGENERATE_POLYS
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struct LwFecRS *rs = NULL;
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switch(mode->T)
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{
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case 16:
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rs = &rs16;
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break;
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case 32:
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rs = &rs32;
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break;
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case 64:
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rs = &rs64;
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break;
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default:
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rs = &rs16;
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break;
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}
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return RsDecode(rs, buffer, mode->K, fixed);
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#else
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RsInit(&rs, mode->T, FX25_RS_FCR);
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return RsDecode(&rs, buffer, mode->K, fixed);
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#endif
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}
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void Fx25Init(void)
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{
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#ifdef FX25_PREGENERATE_POLYS
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RsInit(&rs16, 16, FX25_RS_FCR);
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RsInit(&rs32, 32, FX25_RS_FCR);
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RsInit(&rs64, 64, FX25_RS_FCR);
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#else
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#endif
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}
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#endif
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