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Added field separation in FT8 message unpacking

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This commit is contained in:
Karlis Goba 2019-11-14 13:44:19 +02:00
parent b41916aebf
commit 0b8f6f8b48
3 changed files with 95 additions and 74 deletions
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11
decode_ft8.cpp
View file

@ -25,6 +25,7 @@ const int kMax_message_length = 25;
const int kFreq_osr = 2;
const int kTime_osr = 2;
const float kFSK_dev = 6.25f; // tone deviation in Hz and symbol rate
void usage() {
fprintf(stderr, "Decode a 15-second WAV file.\n");
@ -178,10 +179,8 @@ int main(int argc, char **argv) {
}
normalize_signal(signal, num_samples);
const float fsk_dev = 6.25f; // tone deviation in Hz and symbol rate
// Compute DSP parameters that depend on the sample rate
const int num_bins = (int)(sample_rate / (2 * fsk_dev));
const int num_bins = (int)(sample_rate / (2 * kFSK_dev));
const int block_size = 2 * num_bins;
const int subblock_size = block_size / kTime_osr;
const int nfft = block_size * kFreq_osr;
@ -211,8 +210,10 @@ int main(int argc, char **argv) {
int num_decoded = 0;
for (int idx = 0; idx < num_candidates; ++idx) {
ft8::Candidate &cand = candidate_list[idx];
float freq_hz = (cand.freq_offset + (float)cand.freq_sub / kFreq_osr) * fsk_dev;
float time_sec = (cand.time_offset + (float)cand.time_sub / kTime_osr) / fsk_dev;
if (cand.score < kMin_score) continue;
float freq_hz = (cand.freq_offset + (float)cand.freq_sub / kFreq_osr) * kFSK_dev;
float time_sec = (cand.time_offset + (float)cand.time_sub / kTime_osr) / kFSK_dev;
float log174[ft8::N];
ft8::extract_likelihood(&power, cand, ft8::kGray_map, log174);

149
ft8/unpack.cpp
View file

@ -51,10 +51,13 @@ int unpack28(uint32_t n28, uint8_t ip, uint8_t i3, char *result) {
n28 = n28 - NTOKENS;
if (n28 < MAX22) {
// This is a 22-bit hash of a result
//n22=n28
//call hash22(n22,c13) !Retrieve result from hash table
// TODO: implement
strcpy(result, "<...>");
// strcpy(result, "<...>");
result[0] = '<';
int_to_dd(result + 1, n28, 7);
result[8] = '>';
result[9] = '\0';
return 0;
}
@ -88,11 +91,12 @@ int unpack28(uint32_t n28, uint8_t ip, uint8_t i3, char *result) {
strcat(result, "/P");
}
}
return 0; // Success
}
int unpack_type1(const uint8_t *a77, uint8_t i3, char *message) {
int unpack_type1(const uint8_t *a77, uint8_t i3, char *field1, char *field2, char *field3) {
uint32_t n28a, n28b;
uint16_t igrid4;
uint8_t ir;
@ -115,76 +119,61 @@ int unpack_type1(const uint8_t *a77, uint8_t i3, char *message) {
igrid4 |= (a77[9] >> 6);
// Unpack both callsigns
char field_1[14];
char field_2[14];
if (unpack28(n28a >> 1, n28a & 0x01, i3, field_1) < 0) {
if (unpack28(n28a >> 1, n28a & 0x01, i3, field1) < 0) {
return -1;
}
if (unpack28(n28b >> 1, n28b & 0x01, i3, field_2) < 0) {
if (unpack28(n28b >> 1, n28b & 0x01, i3, field2) < 0) {
return -2;
}
// Fix "CQ_" to "CQ " -> already done in unpack28()
// if (starts_with(field_1, "CQ_")) {
// field_1[2] = ' ';
// }
// Append first two fields to the result
strcpy(message, field_1);
strcat(message, " ");
strcat(message, field_2);
// TODO: add to recent calls
// if (field_1[0] != '<' && strlen(field_1) >= 4) {
// save_hash_call(field_1)
// if (field1[0] != '<' && strlen(field1) >= 4) {
// save_hash_call(field1)
// }
// if (field_2[0] != '<' && strlen(field_2) >= 4) {
// save_hash_call(field_2)
// if (field2[0] != '<' && strlen(field2) >= 4) {
// save_hash_call(field2)
// }
char field_3[5];
if (igrid4 <= MAXGRID4) {
// Extract 4 symbol grid locator
field_3[4] = '\0';
char *dst = field3;
uint16_t n = igrid4;
field_3[3] = '0' + (n % 10);
n /= 10;
field_3[2] = '0' + (n % 10);
n /= 10;
field_3[1] = 'A' + (n % 18);
n /= 18;
field_3[0] = 'A' + (n % 18);
if (ir != 0) {
// In case of ir=1 add an " R " before grid
strcat(message, " R ");
if (ir > 0) {
// In case of ir=1 add an "R" before grid
dst = stpcpy(dst, "R ");
}
dst[4] = '\0';
dst[3] = '0' + (n % 10);
n /= 10;
dst[2] = '0' + (n % 10);
n /= 10;
dst[1] = 'A' + (n % 18);
n /= 18;
dst[0] = 'A' + (n % 18);
// if(msg(1:3).eq.'CQ ' .and. ir.eq.1) unpk77_success=.false.
// if (ir > 0 && strncmp(field1, "CQ", 2) == 0) return -1;
}
else {
// Extract report
int irpt = igrid4 - MAXGRID4;
// Check special cases first
if (irpt == 1) field_3[0] = '\0';
else if (irpt == 2) strcpy(field_3, "RRR");
else if (irpt == 3) strcpy(field_3, "RR73");
else if (irpt == 4) strcpy(field_3, "73");
if (irpt == 1) field3[0] = '\0';
else if (irpt == 2) strcpy(field3, "RRR");
else if (irpt == 3) strcpy(field3, "RR73");
else if (irpt == 4) strcpy(field3, "73");
else if (irpt >= 5) {
char *dst = field3;
// Extract signal report as a two digit number with a + or - sign
if (ir == 0) {
int_to_dd(field_3, irpt - 35, 2, true);
}
else {
field_3[0] = 'R';
int_to_dd(field_3 + 1, irpt - 35, 2, true);
if (ir > 0) {
*dst++ = 'R'; // Add "R" before report
}
int_to_dd(dst, irpt - 35, 2, true);
}
}
// Append the last field to the result
if (strlen(field_3) > 0) {
strcat(message, " ");
strcat(message, field_3);
// if(msg(1:3).eq.'CQ ' .and. irpt.ge.2) unpk77_success=.false.
// if (irpt >= 2 && strncmp(field1, "CQ", 2) == 0) return -1;
}
return 0; // Success
@ -246,7 +235,7 @@ int unpack_telemetry(const uint8_t *a71, char *telemetry) {
//none standard for wsjt-x 2.0
//by KD8CEC
int unpack_nonstandard(const uint8_t *a77, char *message)
int unpack_nonstandard(const uint8_t *a77, char *field1, char *field2, char *field3)
{
/*
wsjt-x 2.1.0 rc5
@ -283,41 +272,48 @@ int unpack_nonstandard(const uint8_t *a77, char *message)
char call_3[15];
// should replace with hash12(n12, call_3);
strcpy(call_3, "<...>");
// strcpy(call_3, "<...>");
call_3[0] = '<';
int_to_dd(call_3 + 1, n12, 4);
call_3[5] = '>';
call_3[6] = '\0';
char * call_1 = (iflip) ? c11 : call_3;
char * call_2 = (iflip) ? call_3 : c11;
//save_hash_call(c11_trimmed);
if (icq == 0) {
strcpy(message, trim(call_1));
strcat(message, " ");
strcat(message, trim(call_2));
strcpy(field1, trim(call_1));
if (nrpt == 1)
strcat(message, " RRR");
strcpy(field3, "RRR");
else if (nrpt == 2)
strcat(message, " RR73");
strcpy(field3, "RR73");
else if (nrpt == 3)
strcat(message, " 73");
strcpy(field3, "73");
else {
field3[0] = '\0';
}
} else {
strcpy(message, "CQ ");
strcat(message, trim(call_2));
strcpy(field1, "CQ");
field3[0] = '\0';
}
strcpy(field2, trim(call_2));
return 0;
}
int unpack77(const uint8_t *a77, char *message) {
int unpack77_fields(const uint8_t *a77, char *field1, char *field2, char *field3) {
uint8_t n3, i3;
// Extract n3 (bits 71..73) and i3 (bits 74..76)
n3 = ((a77[8] << 2) & 0x04) | ((a77[9] >> 6) & 0x03);
i3 = (a77[9] >> 3) & 0x07;
field1[0] = field2[0] = field3[0] = '\0';
if (i3 == 0 && n3 == 0) {
// 0.0 Free text
return unpack_text(a77, message);
return unpack_text(a77, field1);
}
// else if (i3 == 0 && n3 == 1) {
// // 0.1 K1ABC RR73; W9XYZ <KH1/KH7Z> -11 28 28 10 5 71 DXpedition Mode
@ -331,11 +327,11 @@ int unpack77(const uint8_t *a77, char *message) {
// }
else if (i3 == 0 && n3 == 5) {
// 0.5 0123456789abcdef01 71 71 Telemetry (18 hex)
return unpack_telemetry(a77, message);
return unpack_telemetry(a77, field1);
}
else if (i3 == 1 || i3 == 2) {
// Type 1 (standard message) or Type 2 ("/P" form for EU VHF contest)
return unpack_type1(a77, i3, message);
return unpack_type1(a77, i3, field1, field2, field3);
}
// else if (i3 == 3) {
// // Type 3: ARRL RTTY Contest
@ -344,15 +340,34 @@ int unpack77(const uint8_t *a77, char *message) {
// // Type 4: Nonstandard calls, e.g. <WA9XYZ> PJ4/KA1ABC RR73
// // One hashed call or "CQ"; one compound or nonstandard call with up
// // to 11 characters; and (if not "CQ") an optional RRR, RR73, or 73.
return unpack_nonstandard(a77, message);
return unpack_nonstandard(a77, field1, field2, field3);
}
// else if (i3 == 5) {
// // Type 5: TU; W9XYZ K1ABC R-09 FN 1 28 28 1 7 9 74 WWROF contest
// }
// unknown type, should never get here
message[0] = '\0';
return -1;
}
int unpack77(const uint8_t *a77, char *message) {
char field1[14];
char field2[14];
char field3[7];
int rc = unpack77_fields(a77, field1, field2, field3);
if (rc < 0) return rc;
char *dst = message;
// int msg_sz = strlen(field1) + strlen(field2) + strlen(field3) + 2;
dst = stpcpy(dst, field1);
*dst++ = ' ';
dst = stpcpy(dst, field2);
*dst++ = ' ';
dst = stpcpy(dst, field3);
*dst = '\0';
return 0;
}
} // namespace
} // namespace

9
ft8/unpack.h
View file

@ -4,7 +4,12 @@
namespace ft8 {
// message should have at least 19 bytes allocated (18 characters + zero terminator)
// field1 - at least 14 bytes
// field2 - at least 14 bytes
// field3 - at least 7 bytes
int unpack77_fields(const uint8_t *a77, char *field1, char *field2, char *field3);
// message should have at least 35 bytes allocated (34 characters + zero terminator)
int unpack77(const uint8_t *a77, char *message);
}
}