SSB_HighSpeed_Modem/modem/fec_fast.c

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2020-10-27 11:41:16 -04:00
/*
* High Speed modem to transfer data in a 2,7kHz SSB channel
* =========================================================
* Author: DJ0ABR
*
* (c) DJ0ABR
* www.dj0abr.de
*
* 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; either version 2 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 for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include "qo100modem.h"
#include "liquid.h"
fec fecobjTX;
fec fecobjRX;
fec_scheme fs = LIQUID_FEC_SECDED3932; // error-correcting scheme
uint8_t encoded_message[UdpBlocklen];
uint8_t decoded_message[PayloadLen+framenumlen+CRClen];
uint8_t *cfec_Reconstruct(uint8_t *darr)
{
memset(decoded_message,0,(PayloadLen+framenumlen+CRClen));
fec_decode(fecobjRX, (PayloadLen+framenumlen+CRClen), darr, decoded_message);
return decoded_message;
}
uint8_t *GetFEC(uint8_t *txblock, int len)
{
if(len != (PayloadLen+framenumlen+CRClen))
{
printf("wrong FEC encode length, len:%d Payloadlen:%d\n",len,PayloadLen);
exit(0);
}
fec_encode(fecobjTX, len, txblock, encoded_message);
return encoded_message;
}
void initFEC()
{
int n_enc = fec_get_enc_msg_length(fs,(PayloadLen+framenumlen+CRClen));
if(n_enc != UdpBlocklen)
{
printf("wrong FEC init length\n");
exit(0);
}
fecobjTX = fec_create(fs,NULL);
fecobjRX = fec_create(fs,NULL);
}