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DMR SB/RC Additions; Cap+ LC/CSBK; RAS;

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lwvmobile
2023-01-17 23:58:52 -05:00
parent 1d49481f2d
commit ec7d7c24a5
11 changed files with 383 additions and 38 deletions
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101
src/dmr_utils.c
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@@ -4,7 +4,7 @@
//Original Source - https://github.com/LouisErigHerve/dsd
//Additional Functions
//Hamming17123, crc8, crc8ok functions
//Hamming17123, crc7, crc8, crc8ok functions
//Original Souce - https://github.com/boatbod/op25
#include "dsd.h"
@@ -121,6 +121,31 @@ bool crc8_ok(uint8_t bits[], unsigned int len)
return (crc == crc8(bits,len));
}
uint8_t crc7(uint8_t bits[], unsigned int len)
{
uint8_t crc=0;
unsigned int K = 7;
//G7(x) = x7 + x5 + x2 + x + 1 check poly below for correct (dmr rc crc7)
uint8_t poly[8] = {1,0,1,0,0,1,1,1}; // crc7 poly
uint8_t buf[256];
if (len+K > sizeof(buf)) {
// fprintf (stderr, "crc8: buffer length %u exceeds maximum %lu\n", len+K, sizeof(buf));
return 0;
}
memset (buf, 0, sizeof(buf));
for (unsigned int i=0; i<len; i++){
buf[i] = bits[i];
}
for (unsigned int i=0; i<len; i++)
if (buf[i])
for (unsigned int j=0; j<K+1; j++)
buf[i+j] ^= poly[j];
for (unsigned int i=0; i<K; i++){
crc = (crc << 1) + buf[len + i];
}
return crc;
}
/*
* @brief : This function compute the CRC-CCITT of the DMR data
* by using the polynomial x^16 + x^12 + x^5 + 1
@@ -329,4 +354,76 @@ uint32_t ConvertBitIntoBytes(uint8_t * BufferIn, uint32_t BitLength)
* Rate 1 coded confirmed (22 data octets): 176 bit sequence (176 bytes)
*
* @return The 9 bit CRC
*/
*/
uint16_t ComputeCrc9Bit(uint8_t * DMRData, uint32_t NbData)
{
uint32_t i;
uint16_t CRC = 0x0000; /* Initialization value = 0x0000 */
/* Polynomial x^9 + x^6 + x^4 + x^3 + 1
* Normal = 0x059
* Reciprocal = 0x134
* Reversed reciprocal = 0x12C */
uint16_t Polynome = 0x059;
for(i = 0; i < NbData; i++)
{
if(((CRC >> 8) & 1) ^ (DMRData[i] & 1))
{
CRC = (CRC << 1) ^ Polynome;
}
else
{
CRC <<= 1;
}
}
/* Conserve only the 9 LSBs */
CRC &= 0x01FF;
/* Invert the CRC */
CRC ^= 0x01FF;
/* Return the CRC */
return CRC;
} /* End ComputeCrc9Bit() */
/*
* @brief : This function compute the CRC-32 of the DMR data
* by using the polynomial x^32 + x^26 + x^23 + x^22 + x^16 + x^12 + x^11 + x^10 + x^8 + x^7 + x^5 + x^4 + x^2 + x + 1
*
* @param Input : A buffer pointer of the DMR data (80 bytes)
* Rate 1/2 coded confirmed (10 data octets): 80 bit sequence (80 bytes)
* Rate 3/4 coded confirmed (16 data octets): 128 bit sequence (120 bytes)
* Rate 1 coded confirmed (22 data octets): 176 bit sequence (176 bytes)
*
* @param NbData : The number of bit to compute
* Rate 1/2 coded confirmed (10 data octets): 80 bit sequence (80 bytes)
* Rate 3/4 coded confirmed (16 data octets): 128 bit sequence (120 bytes)
* Rate 1 coded confirmed (22 data octets): 176 bit sequence (176 bytes)
*
* @return The 32 bit CRC
*/
uint32_t ComputeCrc32Bit(uint8_t * DMRData, uint32_t NbData)
{
uint32_t i;
uint32_t CRC = 0x00000000; /* Initialization value = 0x00000000 */
/* Polynomial x^32 + x^26 + x^23 + x^22 + x^16 + x^12 + x^11 + x^10 + x^8 + x^7 + x^5 + x^4 + x^2 + x + 1
* Normal = 0x04C11DB7
* Reversed = 0xEDB88320
* Reciprocal = 0xDB710641
* Reversed reciprocal = 0x82608EDB */
uint32_t Polynome = 0x04C11DB7;
for(i = 0; i < NbData; i++)
{
if(((CRC >> 31) & 1) ^ (DMRData[i] & 1))
{
CRC = (CRC << 1) ^ Polynome;
}
else
{
CRC <<= 1;
}
}
/* Return the CRC */
return CRC;
} /* End ComputeCrc32Bit() */