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M17_Implementations/SP5WWP/m17-decoder/m17-decoder-sym.c

880 wiersze
30 KiB
C
Czysty Bezpośredni odnośnik Wina Historia

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <time.h>
//libm17
#include "../../libm17/m17.h"
//micro-ecc
#include "../../micro-ecc/uECC.h"
//tinier-aes
#include "../../tinier-aes/aes.h"
//TODO: Load Signature Private and Public Keys from file
//settings
uint8_t decode_callsigns=0;
uint8_t show_viterbi_errs=0;
uint8_t show_meta=0;
uint8_t show_lsf_crc=0;
float dist_thresh=2.0; //distance threshold for the L2 metric (for syncword detection), default: 2.0
float sample; //last raw sample from the stdin
float last[8]; //look-back buffer for finding syncwords
float dist; //Euclidean distance for finding syncwords in the symbol stream
float pld[SYM_PER_PLD]; //raw frame symbols
uint16_t soft_bit[2*SYM_PER_PLD]; //raw frame soft bits
uint16_t d_soft_bit[2*SYM_PER_PLD]; //deinterleaved soft bits
uint8_t lsf[30+1]; //complete LSF (one byte extra needed for the Viterbi decoder)
uint16_t lich_chunk[96]; //raw, soft LSF chunk extracted from the LICH
uint8_t lich_b[6]; //48-bit decoded LICH
uint8_t lich_cnt; //LICH_CNT
uint8_t lich_chunks_rcvd=0; //flags set for each LSF chunk received
uint16_t expected_next_fn=0; //frame number of the next frame expected to arrive
uint16_t enc_data[272]; //raw frame data soft bits
uint8_t frame_data[19]; //decoded frame data, 144 bits (16+128), plus 4 flushing bits
uint8_t syncd=0; //syncword found?
uint8_t fl=0; //Frame=0 of LSF=1
uint8_t pushed; //counter for pushed symbols
//used for signatures
uint8_t digest[16]={0}; //16-byte field for the stream digest
uint8_t signed_str=0; //is the stream signed?
uint8_t pub_key[64]={0}; //public key
uint8_t sig[64]={0}; //ECDSA signature
//encryption
typedef enum
{
ENCR_NONE,
ENCR_SCRAM,
ENCR_AES,
ENCR_RES //reserved
} encr_t;
encr_t encryption=ENCR_NONE;
//AES
typedef enum
{
AES128,
AES192,
AES256
} aes_t;
uint8_t key[32];
uint8_t iv[16];
time_t epoch = 1577836800L; //Jan 1, 2020, 00:00:00 UTC
//Scrambler
uint8_t scr_bytes[16];
uint8_t scrambler_pn[128];
uint32_t scrambler_key=0; //keep set to initial value for seed calculation function
uint32_t scrambler_seed=0;
int8_t scrambler_subtype = -1;
//debug mode
uint8_t debug_mode=0; //TODO: Remove lines looking at this
//this is generating a correct seed value based on the fn value,
//ideally, we would only want to run this under poor signal, frame skips, etc
//Note: Running this every frame will lag if high fn values (observed with test file)
uint32_t scrambler_seed_calculation(int8_t subtype, uint32_t key, int fn)
{
int i;
uint32_t lfsr, bit;
lfsr = key; bit = 0;
for (i = 0; i < 128*fn; i++)
{
//get feedback bit with specified taps, depending on the subtype
if (subtype == 0)
bit = (lfsr >> 7) ^ (lfsr >> 5) ^ (lfsr >> 4) ^ (lfsr >> 3);
else if (subtype == 1)
bit = (lfsr >> 15) ^ (lfsr >> 14) ^ (lfsr >> 12) ^ (lfsr >> 3);
else if (subtype == 2)
bit = (lfsr >> 23) ^ (lfsr >> 22) ^ (lfsr >> 21) ^ (lfsr >> 16);
else bit = 0; //should never get here, but just in case
bit &= 1; //truncate bit to 1 bit
lfsr = (lfsr << 1) | bit; //shift LFSR left once and OR bit onto LFSR's LSB
lfsr &= 0xFFFFFF; //truncate lfsr to 24-bit
}
//truncate seed so subtype will continue to set properly on subsequent passes
if (scrambler_subtype == 0) scrambler_seed &= 0xFF;
else if (scrambler_subtype == 1) scrambler_seed &= 0xFFFF;
else if (scrambler_subtype == 2) scrambler_seed &= 0xFFFFFF;
//debug
//fprintf (stderr, "\nScrambler Key: 0x%06X; Seed: 0x%06X; Subtype: %02d; FN: %05d; ", key, lfsr, subtype, fn);
return lfsr;
}
//scrambler pn sequence generation
void scrambler_sequence_generator()
{
int i = 0;
uint32_t lfsr, bit;
lfsr = scrambler_seed;
//only set if not initially set (first run), it is possible (and observed) that the scrambler_subtype can
//change on subsequent passes if the current SEED for the LFSR falls below one of these thresholds
if (scrambler_subtype == -1)
{
if (lfsr > 0 && lfsr <= 0xFF) scrambler_subtype = 0; // 8-bit key
else if (lfsr > 0xFF && lfsr <= 0xFFFF) scrambler_subtype = 1; //16-bit key
else if (lfsr > 0xFFFF && lfsr <= 0xFFFFFF) scrambler_subtype = 2; //24-bit key
else scrambler_subtype = 0; // 8-bit key (default)
}
//TODO: Set Frame Type based on scrambler_subtype value
if (debug_mode>1)
{
fprintf(stderr, "\nScrambler Key: 0x%06X; Seed: 0x%06X; Subtype: %02d;", scrambler_seed, lfsr, scrambler_subtype);
fprintf(stderr, "\n pN: ");
}
//run pN sequence with taps specified
for (i = 0; i < 128; i++)
{
//get feedback bit with specified taps, depending on the scrambler_subtype
if (scrambler_subtype == 0)
bit = (lfsr >> 7) ^ (lfsr >> 5) ^ (lfsr >> 4) ^ (lfsr >> 3);
else if (scrambler_subtype == 1)
bit = (lfsr >> 15) ^ (lfsr >> 14) ^ (lfsr >> 12) ^ (lfsr >> 3);
else if (scrambler_subtype == 2)
bit = (lfsr >> 23) ^ (lfsr >> 22) ^ (lfsr >> 21) ^ (lfsr >> 16);
else bit = 0; //should never get here, but just in case
bit &= 1; //truncate bit to 1 bit (required since I didn't do it above)
lfsr = (lfsr << 1) | bit; //shift LFSR left once and OR bit onto LFSR's LSB
lfsr &= 0xFFFFFF; //truncate lfsr to 24-bit (really doesn't matter)
scrambler_pn[i] = bit;
}
//pack bit array into byte array for easy data XOR
pack_bit_array_into_byte_array(scrambler_pn, scr_bytes, 16);
//save scrambler seed for next round
scrambler_seed = lfsr;
//truncate seed so subtype will continue to set properly on subsequent passes
if (scrambler_subtype == 0) scrambler_seed &= 0xFF;
else if (scrambler_subtype == 1) scrambler_seed &= 0xFFFF;
else if (scrambler_subtype == 2) scrambler_seed &= 0xFFFFFF;
if (debug_mode > 1)
{
//debug packed bytes
for (i = 0; i < 16; i++)
fprintf (stderr, " %02X", scr_bytes[i]);
fprintf (stderr, "\n");
}
}
void usage(void)
{
fprintf(stderr, "Usage:\n");
fprintf(stderr, "-c - Display decoded callsigns,\n");
fprintf(stderr, "-v - Display Viterbi error metrics,\n");
fprintf(stderr, "-m - Display META fields,\n");
fprintf(stderr, "-l - Display LSF CRC checks,\n");
fprintf(stderr, "-d - Set syncword detection threshold (decimal value),\n");
fprintf(stderr, "-s - Public key for ECDSA signature, 64 bytes (-s [hex_string|key_file]),\n");
fprintf(stderr, "-K - AES encryption key (-K [hex_string|text_file]),\n");
fprintf(stderr, "-k - Scrambler encryption seed value (-k [hex_string]),\n");
fprintf(stderr, "-h - help / print usage\n");
}
//convert a user string (as hex octets) into a uint8_t array for key
void parse_raw_key_string(uint8_t* dest, const char* inp)
{
uint16_t len = strlen(inp);
if(len==0) return; //return silently and pretend nothing happened
memset(dest, 0, len/2); //one character represents half of a byte
if(!(len%2)) //length even?
{
for(uint8_t i=0; i<len; i+=2)
{
if(inp[i]>='a')
dest[i/2]|=(inp[i]-'a'+10)*0x10;
else if(inp[i]>='A')
dest[i/2]|=(inp[i]-'A'+10)*0x10;
else if(inp[i]>='0')
dest[i/2]|=(inp[i]-'0')*0x10;
if(inp[i+1]>='a')
dest[i/2]|=inp[i+1]-'a'+10;
else if(inp[i+1]>='A')
dest[i/2]|=inp[i+1]-'A'+10;
else if(inp[i+1]>='0')
dest[i/2]|=inp[i+1]-'0';
}
}
else
{
if(inp[0]>='a')
dest[0]|=inp[0]-'a'+10;
else if(inp[0]>='A')
dest[0]|=inp[0]-'A'+10;
else if(inp[0]>='0')
dest[0]|=inp[0]-'0';
for(uint8_t i=1; i<len-1; i+=2)
{
if(inp[i]>='a')
dest[i/2+1]|=(inp[i]-'a'+10)*0x10;
else if(inp[i]>='A')
dest[i/2+1]|=(inp[i]-'A'+10)*0x10;
else if(inp[i]>='0')
dest[i/2+1]|=(inp[i]-'0')*0x10;
if(inp[i+1]>='a')
dest[i/2+1]|=inp[i+1]-'a'+10;
else if(inp[i+1]>='A')
dest[i/2+1]|=inp[i+1]-'A'+10;
else if(inp[i+1]>='0')
dest[i/2+1]|=inp[i+1]-'0';
}
}
}
int main(int argc, char* argv[])
{
if(argc>1) //arg scanning: not foolproof at all
{
for(uint8_t i=1; i<argc; i++)
{
if(!strcmp(argv[i], "-c"))
{
decode_callsigns=1;
printf("Decode callsigns: ON\n");
}
if(!strcmp(argv[i], "-v"))
{
show_viterbi_errs=1;
printf("Show Viterbi errors: ON\n");
}
if(!strcmp(argv[i], "-m"))
{
show_meta=1;
printf("Show META field: ON\n");
}
if(!strcmp(argv[i], "-d"))
{
dist_thresh=atof(argv[i+1]);
if(dist_thresh>=0)
printf("Syncword detection threshold: %1.2f\n", dist_thresh);
else
{
printf("Invalid syncword detection threshold, setting to default (2.0)\n");
dist_thresh=2.0f;
}
i++;
}
if(!strcmp(argv[i], "-s"))
{
if(strstr(argv[i+1], ".")) //if the next arg contains a dot - read key from a text file
{
if(strlen(argv[i+1])<3)
{
fprintf(stderr, "Invalid filename. Exiting...\n");
return -1;
}
FILE* fp;
char source_str[64*2];
fp = fopen(argv[i+1], "r");
if(!fp)
{
fprintf(stderr, "Failed to load file %s.\n", argv[i+1]);
return -1;
}
//size check
size_t len = fread(source_str, 1, 64*2, fp);
fclose(fp);
if(len!=64*2) //for secp256r1
{
fprintf(stderr, "Invalid public key length. Exiting...\n");
return -1;
}
parse_raw_key_string(pub_key, source_str);
}
else
{
uint16_t len=strlen(argv[i+1]);
if(len!=64*2) //for secp256r1
{
fprintf(stderr, "Invalid public key length. Exiting...\n");
return -1;
}
parse_raw_key_string(pub_key, argv[i+1]);
}
i++;
}
if(argv[i][1]=='K') //-K - AES Encryption
{
if(strstr(argv[i+1], ".")) //if the next arg contains a dot - read key from a text file
{
if(strlen(argv[i+1])<3)
{
fprintf(stderr, "Invalid filename. Exiting...\n");
return -1;
}
FILE* fp;
char source_str[64];
fp = fopen(argv[i+1], "r");
if(!fp)
{
fprintf(stderr, "Failed to load file %s.\n", argv[i+1]);
return -1;
}
//size check
size_t len = fread(source_str, 1, 64, fp);
fclose(fp);
if(len==256/4)
fprintf(stderr, "AES256");
else if(len==192/4)
fprintf(stderr, "AES192");
else if(len==128/4)
fprintf(stderr, "AES128");
else
{
fprintf(stderr, "Invalid key length.\n");
return -1;
}
parse_raw_key_string(key, source_str);
fprintf(stderr, " key:");
for(uint8_t i=0; i<len/2; i++)
{
if(i==16)
fprintf(stderr, "\n ");
fprintf(stderr, " %02X", key[i]);
}
fprintf(stderr, "\n");
}
else
{
//size check
size_t len = strlen(argv[i+1]);
if(len==256/4)
fprintf(stderr, "AES256");
else if(len==192/4)
fprintf(stderr, "AES192");
else if(len==128/4)
fprintf(stderr, "AES128");
else
{
fprintf(stderr, "Invalid key length.\n");
return -1;
}
parse_raw_key_string(key, argv[i+1]);
fprintf(stderr, " key:");
for(uint8_t i=0; i<len/2; i++)
{
if(i==16)
fprintf(stderr, "\n ");
fprintf(stderr, " %02X", key[i]);
}
fprintf(stderr, "\n");
}
encryption=ENCR_AES; //AES key was passed
i++;
}
if(argv[i][1]=='k') //-k - Scrambler Encryption
{
//length check
uint8_t length=strlen(argv[i+1]);
if(length==0 || length>24/4) //24-bit is the largest seed value
{
fprintf(stderr, "Invalid key length.\n");
return -1;
}
parse_raw_key_string(key, argv[i+1]);
scrambler_key = (key[0] << 16) | (key[1] << 8) | (key[2] << 0);
if(length<=2)
{
scrambler_key = scrambler_key >> 16;
fprintf(stderr, "Scrambler key: 0x%02X (8-bit)\n", scrambler_key);
}
else if(length<=4)
{
scrambler_key = scrambler_key >> 8;
fprintf(stderr, "Scrambler key: 0x%04X (16-bit)\n", scrambler_key);
}
else
fprintf(stderr, "Scrambler key: 0x%06X (24-bit)\n", scrambler_key);
encryption=ENCR_SCRAM; //Scrambler key was passed
scrambler_seed = scrambler_key; //set initial seed value to key value
}
if(!strcmp(argv[i], "-l"))
{
show_lsf_crc=1;
printf("Show LSF CRC: ON\n");
}
if(!strcmp(argv[i], "-h"))
{
usage();
return 0;
}
}
}
printf("Awaiting samples...\n");
const struct uECC_Curve_t* curve = uECC_secp256r1();
while(1)
{
//wait for another symbol
if(fread((uint8_t*)&sample, 4, 1, stdin)<1) break;
if(!syncd)
{
//push new symbol
for(uint8_t i=0; i<7; i++)
{
last[i]=last[i+1];
}
last[7]=sample;
//calculate euclidean norm
dist = eucl_norm(last, str_sync_symbols, 8);
if(dist<dist_thresh) //frame syncword detected
{
//fprintf(stderr, "str_sync dist: %3.5f\n", dist);
syncd=1;
pushed=0;
fl=0;
}
else
{
//calculate euclidean norm again, this time against LSF syncword
dist = eucl_norm(last, lsf_sync_symbols, 8);
if(dist<dist_thresh) //LSF syncword
{
//fprintf(stderr, "lsf_sync dist: %3.5f\n", dist);
syncd=1;
pushed=0;
fl=1;
}
}
}
else
{
pld[pushed++]=sample;
if(pushed==SYM_PER_PLD)
{
//common operations for all frame types
//slice symbols to soft dibits
slice_symbols(soft_bit, pld);
//derandomize
randomize_soft_bits(soft_bit);
//deinterleave
reorder_soft_bits(d_soft_bit, soft_bit);
//if it is a frame
if(!fl)
{
//extract data
for(uint16_t i=0; i<272; i++)
{
enc_data[i]=d_soft_bit[96+i];
}
//decode
uint32_t e=viterbi_decode_punctured(frame_data, enc_data, puncture_pattern_2, 272, 12);
uint16_t fn = (frame_data[1] << 8) | frame_data[2];
uint16_t type=(uint16_t)lsf[12]*0x100+lsf[13]; //big-endian
signed_str=(type>>11)&1;
///if the stream is signed (process before decryption)
if(signed_str && fn<0x7FFC)
{
if(fn==0)
memset(digest, 0, sizeof(digest));
for(uint8_t i=0; i<sizeof(digest); i++)
digest[i]^=frame_data[3+i];
uint8_t tmp=digest[0];
for(uint8_t i=0; i<sizeof(digest)-1; i++)
digest[i]=digest[i+1];
digest[sizeof(digest)-1]=tmp;
}
//NOTE: Don't attempt decryption when a signed stream is >= 0x7FFC
//The Signature is not encrypted
//AES
if(encryption==ENCR_AES)
{
memcpy(iv, lsf+14, 14);
iv[14] = frame_data[1] & 0x7F;
iv[15] = frame_data[2] & 0xFF;
if(signed_str && (fn % 0x8000)<0x7FFC) //signed stream
aes_ctr_bytewise_payload_crypt(iv, key, frame_data+3, AES128); //hardcoded for now
else if(!signed_str) //non-signed stream
aes_ctr_bytewise_payload_crypt(iv, key, frame_data+3, AES128); //hardcoded for now
}
//Scrambler
if(encryption==ENCR_SCRAM)
{
if(fn != 0 && (fn % 0x8000)!=expected_next_fn) //frame skip, etc
scrambler_seed = scrambler_seed_calculation(scrambler_subtype, scrambler_key, fn&0x7FFF);
else if(fn == 0) scrambler_seed = scrambler_key; //reset back to key value
if(signed_str && (fn % 0x8000)<0x7FFC) //signed stream
scrambler_sequence_generator();
else if(!signed_str) //non-signed stream
scrambler_sequence_generator();
for(uint8_t i=0; i<16; i++)
{
frame_data[i+3] ^= scr_bytes[i];
}
}
//dump data - first byte is empty
printf("FN: %04X PLD: ", fn);
for(uint8_t i=3; i<19; i++)
{
printf("%02X", frame_data[i]);
}
if(show_viterbi_errs)
printf(" e=%1.1f\n", (float)e/0xFFFF);
printf("\n");
//send codec2 stream to stdout
//fwrite(&frame_data[3], 16, 1, stdout);
//extract LICH
for(uint16_t i=0; i<96; i++)
{
lich_chunk[i]=d_soft_bit[i];
}
//Golay decoder
decode_LICH(lich_b, lich_chunk);
lich_cnt=lich_b[5]>>5;
//If we're at the start of a superframe, or we missed a frame, reset the LICH state
if((lich_cnt==0) || ((fn % 0x8000)!=expected_next_fn && fn<0x7FFC))
lich_chunks_rcvd=0;
lich_chunks_rcvd|=(1<<lich_cnt);
memcpy(&lsf[lich_cnt*5], lich_b, 5);
//debug - dump LICH
if(lich_chunks_rcvd==0x3F) //all 6 chunks received?
{
if(decode_callsigns)
{
uint8_t d_dst[12], d_src[12]; //decoded strings
decode_callsign_bytes(d_dst, &lsf[0]);
decode_callsign_bytes(d_src, &lsf[6]);
//DST
printf("DST: %-9s ", d_dst);
//SRC
printf("SRC: %-9s ", d_src);
}
else
{
//DST
printf("DST: ");
for(uint8_t i=0; i<6; i++)
printf("%02X", lsf[i]);
printf(" ");
//SRC
printf("SRC: ");
for(uint8_t i=0; i<6; i++)
printf("%02X", lsf[6+i]);
printf(" ");
}
//TYPE
printf("TYPE: %04X (", type);
if(type&&1)
printf("STREAM: ");
else
printf("PACKET: "); //shouldn't happen
if(((type>>1)&3)==1)
printf("DATA, ");
else if(((type>>1)&3)==2)
printf("VOICE, ");
else if(((type>>1)&3)==3)
printf("VOICE+DATA, ");
printf("ENCR: ");
if(((type>>3)&3)==0)
printf("PLAIN, ");
else if(((type>>3)&3)==1)
{
printf("SCRAM ");
if(((type>>5)&3)==0)
printf("8-bit, ");
else if(((type>>5)&3)==1)
printf("16-bit, ");
else if(((type>>5)&3)==2)
printf("24-bit, ");
}
else if(((type>>3)&3)==2)
{
printf("AES");
if(((type>>5)&3)==0)
printf("128");
else if(((type>>5)&3)==1)
printf("192");
else if(((type>>5)&3)==2)
printf("256");
printf(", ");
}
else
printf("UNK, ");
printf("CAN: %d", (type>>7)&0xF);
if(signed_str)
{
printf(", SIGNED");
}
printf(") ");
//META
if(show_meta)
{
printf("META: ");
for(uint8_t i=0; i<14; i++)
printf("%02X", lsf[14+i]);
printf(" ");
}
//CRC
if(show_lsf_crc)
{
//printf("CRC: ");
//for(uint8_t i=0; i<2; i++)
//printf("%02X", lsf[28+i]);
if(CRC_M17(lsf, 30))
printf("LSF_CRC_ERR");
else
printf("LSF_CRC_OK");
}
printf("\n");
}
//if the contents of the payload is now digital signature, not data/voice
if(fn>=0x7FFC && signed_str)
{
memcpy(&sig[((fn&0x7FFF)-0x7FFC)*16], &frame_data[3], 16);
if(fn==(0x7FFF|0x8000))
{
//dump data
/*printf("DEC-Digest: ");
for(uint8_t i=0; i<sizeof(digest); i++)
printf("%02X", digest[i]);
printf("\n");
printf("Key: ");
for(uint8_t i=0; i<sizeof(pub_key); i++)
printf("%02X", pub_key[i]);
printf("\n");
printf("Signature: ");
for(uint8_t i=0; i<sizeof(sig); i++)
printf("%02X", sig[i]);
printf("\n");*/
if(uECC_verify(pub_key, digest, sizeof(digest), sig, curve))
{
printf("Signature OK\n");
}
else
{
printf("Signature invalid\n");
}
}
}
expected_next_fn = (fn + 1) % 0x8000;
}
else //lsf
{
printf("{LSF} ");
//decode
uint32_t e=viterbi_decode_punctured(lsf, d_soft_bit, puncture_pattern_1, 2*SYM_PER_PLD, 61);
//shift the buffer 1 position left - get rid of the encoded flushing bits
for(uint8_t i=0; i<30; i++)
lsf[i]=lsf[i+1];
//dump data
if(decode_callsigns)
{
uint8_t d_dst[12], d_src[12]; //decoded strings
decode_callsign_bytes(d_dst, &lsf[0]);
decode_callsign_bytes(d_src, &lsf[6]);
//DST
printf("DST: %-9s ", d_dst);
//SRC
printf("SRC: %-9s ", d_src);
}
else
{
//DST
printf("DST: ");
for(uint8_t i=0; i<6; i++)
printf("%02X", lsf[i]);
printf(" ");
//SRC
printf("SRC: ");
for(uint8_t i=0; i<6; i++)
printf("%02X", lsf[6+i]);
printf(" ");
}
//TYPE
uint16_t type=(uint16_t)lsf[12]*0x100+lsf[13]; //big-endian
printf("TYPE: %04X (", type);
if(type&&1)
printf("STREAM: ");
else
printf("PACKET: "); //shouldn't happen
if(((type>>1)&3)==1)
printf("DATA, ");
else if(((type>>1)&3)==2)
printf("VOICE, ");
else if(((type>>1)&3)==3)
printf("VOICE+DATA, ");
printf("ENCR: ");
if(((type>>3)&3)==0)
printf("PLAIN, ");
else if(((type>>3)&3)==1)
{
printf("SCRAM ");
if(((type>>5)&3)==0)
printf("8-bit, ");
else if(((type>>5)&3)==1)
printf("16-bit, ");
else if(((type>>5)&3)==2)
printf("24-bit, ");
}
else if(((type>>3)&3)==2)
{
printf("AES");
if(((type>>5)&3)==0)
printf("128");
else if(((type>>5)&3)==1)
printf("192");
else if(((type>>5)&3)==2)
printf("256");
printf(", ");
}
else
printf("UNK, ");
printf("CAN: %d", (type>>7)&0xF);
if((type>>11)&1)
{
printf(", SIGNED");
signed_str=1;
}
else
signed_str=0;
printf(") ");
//META
if(show_meta)
{
printf("META: ");
for(uint8_t i=0; i<14; i++)
printf("%02X", lsf[14+i]);
printf(" ");
}
//CRC
if(show_lsf_crc)
{
//printf("CRC: ");
//for(uint8_t i=0; i<2; i++)
//printf("%02X", lsf[28+i]);
if(CRC_M17(lsf, 30))
printf("LSF_CRC_ERR");
else
printf("LSF_CRC_OK");
printf(" ");
}
//Viterbi decoder errors
if(show_viterbi_errs)
printf("e=%1.1f\n", (float)e/0xFFFF);
printf("\n");
}
//job done
syncd=0;
pushed=0;
for(uint8_t i=0; i<8; i++)
last[i]=0.0;
}
}
}
return 0;
}
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