kgoba-ft8_lib/ft8/message.c

995 wiersze
30 KiB
C

#include "message.h"
#include "text.h"
#include <stdlib.h>
#include <string.h>
#define LOG_LEVEL LOG_WARN
#include "debug.h"
#define MAX22 ((uint32_t)4194304ul)
#define NTOKENS ((uint32_t)2063592ul)
#define MAXGRID4 ((uint16_t)32400ul)
////////////////////////////////////////////////////// Static function prototypes //////////////////////////////////////////////////////////////
static bool trim_brackets(char* result, const char* original, int length);
static void add_brackets(char* result, const char* original, int length);
/// Compute hash value for a callsign and save it in a hash table via the provided callsign hash interface.
/// @param[in] hash_if Callsign hash interface
/// @param[in] callsign Callsign (up to 11 characters, trimmed)
/// @param[out] n22_out Pointer to store 22-bit hash value (can be NULL)
/// @param[out] n12_out Pointer to store 12-bit hash value (can be NULL)
/// @param[out] n10_out Pointer to store 10-bit hash value (can be NULL)
/// @return True on success
static bool save_callsign(const ftx_callsign_hash_interface_t* hash_if, const char* callsign, uint32_t* n22_out, uint16_t* n12_out, uint16_t* n10_out);
static bool lookup_callsign(const ftx_callsign_hash_interface_t* hash_if, ftx_callsign_hash_type_t hash_type, uint32_t hash, char* callsign);
static int32_t pack_basecall(const char* callsign, int length);
/// Pack a special token, a 22-bit hash code, or a valid base call into a 29-bit integer.
static int32_t pack28(const char* callsign, const ftx_callsign_hash_interface_t* hash_if, uint8_t* ip);
/// Unpack a callsign from 28+1 bit field in the payload of the standard message (type 1 or type 2).
/// @param[in] n29 29-bit integer, e.g. n29a or n29b, containing encoded callsign, plus suffix flag (1 bit) as LSB
/// @param[in] i3 Payload type (3 bits), 1 or 2
/// @param[in] hash_if Callsign hash table interface (can be NULL)
/// @param[out] result Unpacked callsign (max size: 13 characters including the terminating \0)
static int unpack28(uint32_t n28, uint8_t ip, uint8_t i3, const ftx_callsign_hash_interface_t* hash_if, char* result);
/// Pack a non-standard base call into a 28-bit integer.
static bool pack58(const ftx_callsign_hash_interface_t* hash_if, const char* callsign, uint64_t* n58);
/// Unpack a non-standard base call from a 58-bit integer.
static bool unpack58(uint64_t n58, const ftx_callsign_hash_interface_t* hash_if, char* callsign);
static uint16_t packgrid(const char* grid4);
static int unpackgrid(uint16_t igrid4, uint8_t ir, char* extra);
/////////////////////////////////////////////////////////// Exported functions /////////////////////////////////////////////////////////////////
void ftx_message_init(ftx_message_t* msg)
{
memset((void*)msg, 0, sizeof(ftx_message_t));
}
uint8_t ftx_message_get_i3(const ftx_message_t* msg)
{
// Extract i3 (bits 74..76)
uint8_t i3 = (msg->payload[9] >> 3) & 0x07u;
return i3;
}
uint8_t ftx_message_get_n3(const ftx_message_t* msg)
{
// Extract n3 (bits 71..73)
uint8_t n3 = ((msg->payload[8] << 2) & 0x04u) | ((msg->payload[9] >> 6) & 0x03u);
return n3;
}
ftx_message_type_t ftx_message_get_type(const ftx_message_t* msg)
{
// Extract i3 (bits 74..76)
uint8_t i3 = (msg->payload[9] >> 3) & 0x07u;
switch (i3)
{
case 0: {
// Extract n3 (bits 71..73)
uint8_t n3 = ((msg->payload[8] << 2) & 0x04u) | ((msg->payload[9] >> 6) & 0x03u);
switch (n3)
{
case 0:
return FTX_MESSAGE_TYPE_FREE_TEXT;
case 1:
return FTX_MESSAGE_TYPE_DXPEDITION;
case 2:
return FTX_MESSAGE_TYPE_EU_VHF;
case 3:
case 4:
return FTX_MESSAGE_TYPE_ARRL_FD;
case 5:
return FTX_MESSAGE_TYPE_TELEMETRY;
default:
return FTX_MESSAGE_TYPE_UNKNOWN;
}
break;
}
case 1:
case 2:
return FTX_MESSAGE_TYPE_STANDARD;
break;
case 3:
return FTX_MESSAGE_TYPE_ARRL_RTTY;
break;
case 4:
return FTX_MESSAGE_TYPE_NONSTD_CALL;
break;
case 5:
return FTX_MESSAGE_TYPE_WWROF;
default:
return FTX_MESSAGE_TYPE_UNKNOWN;
}
}
ftx_message_rc_t ftx_message_encode(ftx_message_t* msg, ftx_callsign_hash_interface_t* hash_if, const char* message_text)
{
char call_to[12];
char call_de[12];
char extra[20];
const char* parse_position = message_text;
parse_position = copy_token(call_to, 12, parse_position);
parse_position = copy_token(call_de, 12, parse_position);
parse_position = copy_token(extra, 20, parse_position);
if (call_to[11] != '\0')
{
// token too long
return FTX_MESSAGE_RC_ERROR_CALLSIGN1;
}
if (call_de[11] != '\0')
{
// token too long
return FTX_MESSAGE_RC_ERROR_CALLSIGN2;
}
if (extra[19] != '\0')
{
// token too long
return FTX_MESSAGE_RC_ERROR_GRID;
}
ftx_message_rc_t rc;
rc = ftx_message_encode_std(msg, hash_if, call_to, call_de, extra);
if (rc == FTX_MESSAGE_RC_OK)
return rc;
rc = ftx_message_encode_nonstd(msg, hash_if, call_to, call_de, extra);
if (rc == FTX_MESSAGE_RC_OK)
return rc;
// rc = ftx_message_encode_telemetry_hex(msg, hash_if, call_to, call_de, extra);
return rc;
}
ftx_message_rc_t ftx_message_encode_std(ftx_message_t* msg, ftx_callsign_hash_interface_t* hash_if, const char* call_to, const char* call_de, const char* extra)
{
uint8_t ipa, ipb;
int32_t n28a = pack28(call_to, hash_if, &ipa);
int32_t n28b = pack28(call_de, hash_if, &ipb);
LOG(LOG_DEBUG, "n29a = %d, n29b = %d\n", n28a, n28b);
if (n28a < 0)
return FTX_MESSAGE_RC_ERROR_CALLSIGN1;
if (n28b < 0)
return FTX_MESSAGE_RC_ERROR_CALLSIGN2;
uint8_t i3 = 1; // No suffix or /R
if (ends_with(call_to, "/P") || ends_with(call_de, "/P"))
{
i3 = 2; // Suffix /P for EU VHF contest
if (ends_with(call_to, "/R") || ends_with(call_de, "/R"))
{
return FTX_MESSAGE_RC_ERROR_SUFFIX;
}
}
uint16_t igrid4 = packgrid(extra);
LOG(LOG_DEBUG, "igrid4 = %d\n", igrid4);
// Shift in ipa and ipb bits into n28a and n28b
uint32_t n29a = ((uint32_t)n28a << 1) | ipa;
uint32_t n29b = ((uint32_t)n28b << 1) | ipb;
// TODO: check for suffixes
if (ends_with(call_to, "/R"))
n29a |= 1; // ipa = 1
else if (ends_with(call_to, "/P"))
{
n29a |= 1; // ipa = 1
i3 = 2;
}
// Pack into (28 + 1) + (28 + 1) + (1 + 15) + 3 bits
msg->payload[0] = (uint8_t)(n29a >> 21);
msg->payload[1] = (uint8_t)(n29a >> 13);
msg->payload[2] = (uint8_t)(n29a >> 5);
msg->payload[3] = (uint8_t)(n29a << 3) | (uint8_t)(n29b >> 26);
msg->payload[4] = (uint8_t)(n29b >> 18);
msg->payload[5] = (uint8_t)(n29b >> 10);
msg->payload[6] = (uint8_t)(n29b >> 2);
msg->payload[7] = (uint8_t)(n29b << 6) | (uint8_t)(igrid4 >> 10);
msg->payload[8] = (uint8_t)(igrid4 >> 2);
msg->payload[9] = (uint8_t)(igrid4 << 6) | (uint8_t)(i3 << 3);
return FTX_MESSAGE_RC_OK;
}
ftx_message_rc_t ftx_message_encode_nonstd(ftx_message_t* msg, ftx_callsign_hash_interface_t* hash_if, const char* call_to, const char* call_de, const char* extra)
{
uint8_t i3 = 4;
uint8_t icq = (uint8_t)equals(call_to, "CQ");
int len_call_to = strlen(call_to);
int len_call_de = strlen(call_de);
// if ((icq != 0) || (pack_basecall(call_to, len_call_to) >= 0))
// {
// if (pack_basecall(call_de, len_call_de) >= 0)
// {
// // no need for encode_nonstd, should use encode_std
// return FTX_MESSAGE_RC_ERROR_CALLSIGN2;
// }
// }
if ((icq == 0) && ((len_call_to < 3)))
return FTX_MESSAGE_RC_ERROR_CALLSIGN1;
if ((len_call_de < 3))
return FTX_MESSAGE_RC_ERROR_CALLSIGN2;
uint8_t iflip;
uint16_t n12;
uint64_t n58;
uint8_t nrpt;
const char* call58;
if (icq == 0)
{
// choose which of the callsigns to encode as plain-text (58 bits) or hash (12 bits)
iflip = 0; // call_de will be sent plain-text
if (call_de[0] == '<' && call_de[len_call_to - 1] == '>')
{
iflip = 1;
}
const char* call12;
call12 = (iflip == 0) ? call_to : call_de;
call58 = (iflip == 0) ? call_de : call_to;
if (!save_callsign(hash_if, call12, NULL, &n12, NULL))
{
return FTX_MESSAGE_RC_ERROR_CALLSIGN1;
}
}
else
{
iflip = 0;
n12 = 0;
call58 = call_de;
}
if (!pack58(hash_if, call58, &n58))
{
return FTX_MESSAGE_RC_ERROR_CALLSIGN2;
}
if (icq != 0)
nrpt = 0;
else if (equals(extra, "RRR"))
nrpt = 1;
else if (equals(extra, "RR73"))
nrpt = 2;
else if (equals(extra, "73"))
nrpt = 3;
else
nrpt = 0;
// Pack into 12 + 58 + 1 + 2 + 1 + 3 == 77 bits
// write(c77,1010) n12,n58,iflip,nrpt,icq,i3
// format(b12.12,b58.58,b1,b2.2,b1,b3.3)
msg->payload[0] = (uint8_t)(n12 >> 4);
msg->payload[1] = (uint8_t)(n12 << 4) | (uint8_t)(n58 >> 54);
msg->payload[2] = (uint8_t)(n58 >> 46);
msg->payload[3] = (uint8_t)(n58 >> 38);
msg->payload[4] = (uint8_t)(n58 >> 30);
msg->payload[5] = (uint8_t)(n58 >> 22);
msg->payload[6] = (uint8_t)(n58 >> 14);
msg->payload[7] = (uint8_t)(n58 >> 6);
msg->payload[8] = (uint8_t)(n58 << 2) | (uint8_t)(iflip << 1) | (uint8_t)(nrpt >> 1);
msg->payload[9] = (uint8_t)(nrpt << 7) | (uint8_t)(icq << 6) | (uint8_t)(i3 << 3);
return FTX_MESSAGE_RC_OK;
}
ftx_message_rc_t ftx_message_decode(const ftx_message_t* msg, ftx_callsign_hash_interface_t* hash_if, char* message)
{
ftx_message_rc_t rc;
char buf[35]; // 13 + 13 + 6 (std/nonstd) / 14 (free text) / 19 (telemetry)
char* field1 = buf;
char* field2 = buf + 14;
char* field3 = buf + 14 + 14;
message[0] = '\0';
ftx_message_type_t msg_type = ftx_message_get_type(msg);
switch (msg_type)
{
case FTX_MESSAGE_TYPE_STANDARD:
rc = ftx_message_decode_std(msg, hash_if, field1, field2, field3);
break;
case FTX_MESSAGE_TYPE_NONSTD_CALL:
rc = ftx_message_decode_nonstd(msg, hash_if, field1, field2, field3);
break;
case FTX_MESSAGE_TYPE_FREE_TEXT:
ftx_message_decode_free(msg, field1);
field2 = NULL;
field3 = NULL;
rc = FTX_MESSAGE_RC_OK;
break;
case FTX_MESSAGE_TYPE_TELEMETRY:
ftx_message_decode_telemetry_hex(msg, field1);
field2 = NULL;
field3 = NULL;
rc = FTX_MESSAGE_RC_OK;
break;
default:
// not handled yet
field1 = NULL;
rc = FTX_MESSAGE_RC_ERROR_TYPE;
break;
}
if (field1 != NULL)
{
// TODO join fields via whitespace
message = append_string(message, field1);
if (field2 != NULL)
{
message = append_string(message, " ");
message = append_string(message, field2);
if (field3 != NULL)
{
message = append_string(message, " ");
message = append_string(message, field3);
}
}
}
return rc;
}
ftx_message_rc_t ftx_message_decode_std(const ftx_message_t* msg, ftx_callsign_hash_interface_t* hash_if, char* call_to, char* call_de, char* extra)
{
uint32_t n29a, n29b;
uint16_t igrid4;
uint8_t ir;
// Extract packed fields
n29a = (msg->payload[0] << 21);
n29a |= (msg->payload[1] << 13);
n29a |= (msg->payload[2] << 5);
n29a |= (msg->payload[3] >> 3);
n29b = ((msg->payload[3] & 0x07u) << 26);
n29b |= (msg->payload[4] << 18);
n29b |= (msg->payload[5] << 10);
n29b |= (msg->payload[6] << 2);
n29b |= (msg->payload[7] >> 6);
ir = ((msg->payload[7] & 0x20u) >> 5);
igrid4 = ((msg->payload[7] & 0x1Fu) << 10);
igrid4 |= (msg->payload[8] << 2);
igrid4 |= (msg->payload[9] >> 6);
// Extract i3 (bits 74..76)
uint8_t i3 = (msg->payload[9] >> 3) & 0x07u;
LOG(LOG_DEBUG, "decode_std() n28a=%d ipa=%d n28b=%d ipb=%d ir=%d igrid4=%d i3=%d\n", n29a >> 1, n29a & 1u, n29b >> 1, n29b & 1u, ir, igrid4, i3);
call_to[0] = call_de[0] = extra[0] = '\0';
// Unpack both callsigns
if (unpack28(n29a >> 1, n29a & 1u, i3, hash_if, call_to) < 0)
{
return FTX_MESSAGE_RC_ERROR_CALLSIGN1;
}
if (unpack28(n29b >> 1, n29b & 1u, i3, hash_if, call_de) < 0)
{
return FTX_MESSAGE_RC_ERROR_CALLSIGN2;
}
if (unpackgrid(igrid4, ir, extra) < 0)
{
return FTX_MESSAGE_RC_ERROR_GRID;
}
LOG(LOG_INFO, "Decoded standard (type %d) message [%s] [%s] [%s]\n", i3, call_to, call_de, extra);
return FTX_MESSAGE_RC_OK;
}
// non-standard messages, code originally by KD8CEC
ftx_message_rc_t ftx_message_decode_nonstd(const ftx_message_t* msg, ftx_callsign_hash_interface_t* hash_if, char* call_to, char* call_de, char* extra)
{
uint16_t n12, iflip, nrpt, icq;
uint64_t n58;
n12 = (msg->payload[0] << 4); // 11 ~ 4 : 8
n12 |= (msg->payload[1] >> 4); // 3 ~ 0 : 12
n58 = ((uint64_t)(msg->payload[1] & 0x0Fu) << 54); // 57 ~ 54 : 4
n58 |= ((uint64_t)msg->payload[2] << 46); // 53 ~ 46 : 12
n58 |= ((uint64_t)msg->payload[3] << 38); // 45 ~ 38 : 12
n58 |= ((uint64_t)msg->payload[4] << 30); // 37 ~ 30 : 12
n58 |= ((uint64_t)msg->payload[5] << 22); // 29 ~ 22 : 12
n58 |= ((uint64_t)msg->payload[6] << 14); // 21 ~ 14 : 12
n58 |= ((uint64_t)msg->payload[7] << 6); // 13 ~ 6 : 12
n58 |= ((uint64_t)msg->payload[8] >> 2); // 5 ~ 0 : 765432 10
iflip = (msg->payload[8] >> 1) & 0x01u; // 76543210
nrpt = ((msg->payload[8] & 0x01u) << 1);
nrpt |= (msg->payload[9] >> 7); // 76543210
icq = ((msg->payload[9] >> 6) & 0x01u);
// Extract i3 (bits 74..76)
uint8_t i3 = (msg->payload[9] >> 3) & 0x07u;
LOG(LOG_DEBUG, "decode_nonstd() n12=%04x n58=%08llx iflip=%d nrpt=%d icq=%d i3=%d\n", n12, n58, iflip, nrpt, icq, i3);
// Decode one of the calls from 58 bit encoded string
char call_decoded[14];
unpack58(n58, hash_if, call_decoded);
// Decode the other call from hash lookup table
char call_3[14];
lookup_callsign(hash_if, FTX_CALLSIGN_HASH_12_BITS, n12, call_3);
// Possibly flip them around
char* call_1 = (iflip) ? call_decoded : call_3;
char* call_2 = (iflip) ? call_3 : call_decoded;
if (icq == 0)
{
strcpy(call_to, call_1);
if (nrpt == 1)
strcpy(extra, "RRR");
else if (nrpt == 2)
strcpy(extra, "RR73");
else if (nrpt == 3)
strcpy(extra, "73");
else
extra[0] = '\0';
}
else
{
strcpy(call_to, "CQ");
extra[0] = '\0';
}
strcpy(call_de, call_2);
LOG(LOG_INFO, "Decoded non-standard (type %d) message [%s] [%s] [%s]\n", i3, call_to, call_de, extra);
return FTX_MESSAGE_RC_OK;
}
void ftx_message_decode_free(const ftx_message_t* msg, char* text)
{
uint8_t b71[9];
ftx_message_decode_telemetry(msg, b71);
char c14[14];
c14[13] = 0;
for (int idx = 12; idx >= 0; --idx)
{
// Divide the long integer in b71 by 42
uint16_t rem = 0;
for (int i = 0; i < 9; ++i)
{
rem = (rem << 8) | b71[i];
b71[i] = rem / 42;
rem = rem % 42;
}
c14[idx] = charn(rem, FT8_CHAR_TABLE_FULL);
}
strcpy(text, trim(c14));
}
void ftx_message_decode_telemetry_hex(const ftx_message_t* msg, char* telemetry_hex)
{
uint8_t b71[9];
ftx_message_decode_telemetry(msg, b71);
// Convert b71 to hexadecimal string
for (int i = 0; i < 9; ++i)
{
uint8_t nibble1 = (b71[i] >> 4);
uint8_t nibble2 = (b71[i] & 0x0Fu);
char c1 = (nibble1 > 9) ? (nibble1 - 10 + 'A') : nibble1 + '0';
char c2 = (nibble2 > 9) ? (nibble2 - 10 + 'A') : nibble2 + '0';
telemetry_hex[i * 2] = c1;
telemetry_hex[i * 2 + 1] = c2;
}
telemetry_hex[18] = '\0';
}
void ftx_message_decode_telemetry(const ftx_message_t* msg, uint8_t* telemetry)
{
// Shift bits in payload right by 1 bit to right-align the data
uint8_t carry = 0;
for (int i = 0; i < 9; ++i)
{
telemetry[i] = (carry << 7) | (msg->payload[i] >> 1);
carry = (msg->payload[i] & 0x01u);
}
}
#ifdef FTX_DEBUG_PRINT
#include <stdio.h>
void ftx_message_print(ftx_message_t* msg)
{
printf("[");
for (int i = 0; i < PAYLOAD_LENGTH_BYTES; ++i)
{
if (i > 0)
printf(" ");
printf("%02x", msg->payload[i]));
}
printf("]");
}
#endif
/////////////////////////////////////////////////////////// Static functions /////////////////////////////////////////////////////////////////
static bool trim_brackets(char* result, const char* original, int length)
{
if (original[0] == '<' && original[length - 1] == '>')
{
memcpy(result, original + 1, length - 2);
result[length - 2] = '\0';
return true;
}
else
{
memcpy(result, original, length);
result[length] = '\0';
return false;
}
}
static void add_brackets(char* result, const char* original, int length)
{
result[0] = '<';
memcpy(result + 1, original, length);
result[length + 1] = '>';
result[length + 2] = '\0';
}
static bool save_callsign(const ftx_callsign_hash_interface_t* hash_if, const char* callsign, uint32_t* n22_out, uint16_t* n12_out, uint16_t* n10_out)
{
uint64_t n58 = 0;
int i = 0;
while (callsign[i] != '\0' && i < 11)
{
int j = nchar(callsign[i], FT8_CHAR_TABLE_ALPHANUM_SPACE_SLASH);
if (j < 0)
return false; // hash error (wrong character set)
n58 = (38 * n58) + j;
i++;
}
// pretend to have trailing whitespace (with j=0, index of ' ')
while (i < 11)
{
n58 = (38 * n58);
i++;
}
uint32_t n22 = ((47055833459ull * n58) >> (64 - 22)) & (0x3FFFFFul);
uint32_t n12 = n22 >> 10;
uint32_t n10 = n22 >> 12;
LOG(LOG_DEBUG, "save_callsign('%s') = [n22=%d, n12=%d, n10=%d]\n", callsign, n22, n12, n10);
if (n22_out != NULL)
*n22_out = n22;
if (n12_out != NULL)
*n12_out = n12;
if (n10_out != NULL)
*n10_out = n10;
if (hash_if != NULL)
hash_if->save_hash(callsign, n22);
return true;
}
static bool lookup_callsign(const ftx_callsign_hash_interface_t* hash_if, ftx_callsign_hash_type_t hash_type, uint32_t hash, char* callsign)
{
char c11[12];
bool found;
if (hash_if != NULL)
found = hash_if->lookup_hash(hash_type, hash, c11);
else
found = false;
if (!found)
{
strcpy(callsign, "<...>");
}
else
{
add_brackets(callsign, c11, strlen(c11));
}
LOG(LOG_DEBUG, "lookup_callsign(n%s=%d) = '%s'\n", (hash_type == FTX_CALLSIGN_HASH_22_BITS ? "22" : (hash_type == FTX_CALLSIGN_HASH_12_BITS ? "12" : "10")), hash, callsign);
return found;
}
static int32_t pack_basecall(const char* callsign, int length)
{
if (length > 2)
{
// Attempt to pack a standard callsign, if fail, revert to hashed callsign
char c6[6] = { ' ', ' ', ' ', ' ', ' ', ' ' };
// Copy callsign to 6 character buffer
if (starts_with(callsign, "3DA0") && (length > 4) && (length <= 7))
{
// Work-around for Swaziland prefix: 3DA0XYZ -> 3D0XYZ
memcpy(c6, "3D0", 3);
memcpy(c6 + 3, callsign + 4, length - 4);
}
else if (starts_with(callsign, "3X") && is_letter(callsign[2]) && length <= 7)
{
// Work-around for Guinea prefixes: 3XA0XYZ -> QA0XYZ
memcpy(c6, "Q", 1);
memcpy(c6 + 1, callsign + 2, length - 2);
}
else
{
// Check the position of callsign digit and make a right-aligned copy into c6
if (is_digit(callsign[2]) && length <= 6)
{
// AB0XYZ
memcpy(c6, callsign, length);
}
else if (is_digit(callsign[1]) && length <= 5)
{
// A0XYZ -> " A0XYZ"
memcpy(c6 + 1, callsign, length);
}
}
// Check for standard callsign
int i0 = nchar(c6[0], FT8_CHAR_TABLE_ALPHANUM_SPACE);
int i1 = nchar(c6[1], FT8_CHAR_TABLE_ALPHANUM);
int i2 = nchar(c6[2], FT8_CHAR_TABLE_NUMERIC);
int i3 = nchar(c6[3], FT8_CHAR_TABLE_LETTERS_SPACE);
int i4 = nchar(c6[4], FT8_CHAR_TABLE_LETTERS_SPACE);
int i5 = nchar(c6[5], FT8_CHAR_TABLE_LETTERS_SPACE);
if ((i0 >= 0) && (i1 >= 0) && (i2 >= 0) && (i3 >= 0) && (i4 >= 0) && (i5 >= 0))
{
// This is a standard callsign
LOG(LOG_DEBUG, "Encoding basecall [%.6s]\n", c6);
int32_t n = i0;
n = n * 36 + i1;
n = n * 10 + i2;
n = n * 27 + i3;
n = n * 27 + i4;
n = n * 27 + i5;
return n; // Standard callsign
}
}
return -1;
}
static int32_t pack28(const char* callsign, const ftx_callsign_hash_interface_t* hash_if, uint8_t* ip)
{
LOG(LOG_DEBUG, "pack28() callsign [%s]\n", callsign);
*ip = 0;
// Check for special tokens first
if (equals(callsign, "DE"))
return 0;
if (equals(callsign, "QRZ"))
return 1;
if (equals(callsign, "CQ"))
return 2;
int length = strlen(callsign);
LOG(LOG_DEBUG, "Callsign length = %d\n", length);
if (starts_with(callsign, "CQ_") && length < 8)
{
int nnum = 0, nlet = 0;
// TODO: decode CQ_nnn or CQ_abcd
LOG(LOG_WARN, "CQ_nnn/CQ_abcd detected, not implemented\n");
return -1;
}
// Detect /R and /P suffix for basecall check
int length_base = length;
if (ends_with(callsign, "/P") || ends_with(callsign, "/R"))
{
LOG(LOG_DEBUG, "Suffix /P or /R detected\n");
*ip = 1;
length_base = length - 2;
}
int32_t n28 = pack_basecall(callsign, length_base);
if (n28 >= 0)
{
// Callsign can be encoded as a standard basecall with optional /P or /R suffix
if (!save_callsign(hash_if, callsign, NULL, NULL, NULL))
return -1; // Error (some problem with callsign contents)
return NTOKENS + MAX22 + (uint32_t)n28; // Standard callsign
}
if ((length >= 3) && (length <= 11))
{
// Treat this as a nonstandard callsign: compute its 22-bit hash
LOG(LOG_DEBUG, "Encoding as non-standard callsign\n");
uint32_t n22;
if (!save_callsign(hash_if, callsign, &n22, NULL, NULL))
return -1; // Error (some problem with callsign contents)
*ip = 0;
return NTOKENS + n22; // 22-bit hashed callsign
}
return -1; // Error
}
static int unpack28(uint32_t n28, uint8_t ip, uint8_t i3, const ftx_callsign_hash_interface_t* hash_if, char* result)
{
LOG(LOG_DEBUG, "unpack28() n28=%d i3=%d\n", n28, i3);
// Check for special tokens DE, QRZ, CQ, CQ_nnn, CQ_aaaa
if (n28 < NTOKENS)
{
if (n28 <= 2u)
{
if (n28 == 0)
strcpy(result, "DE");
else if (n28 == 1)
strcpy(result, "QRZ");
else /* if (n28 == 2) */
strcpy(result, "CQ");
return 0; // Success
}
if (n28 <= 1002u)
{
// CQ nnn with 3 digits
strcpy(result, "CQ ");
int_to_dd(result + 3, n28 - 3, 3, false);
return 0; // Success
}
if (n28 <= 532443ul)
{
// CQ ABCD with 4 alphanumeric symbols
uint32_t n = n28 - 1003u;
char aaaa[5];
aaaa[4] = '\0';
for (int i = 3; /* no condition */; --i)
{
aaaa[i] = charn(n % 27u, FT8_CHAR_TABLE_LETTERS_SPACE);
if (i == 0)
break;
n /= 27u;
}
strcpy(result, "CQ ");
strcat(result, trim_front(aaaa));
return 0; // Success
}
// unspecified
return -1;
}
n28 = n28 - NTOKENS;
if (n28 < MAX22)
{
// This is a 22-bit hash of a result
lookup_callsign(hash_if, FTX_CALLSIGN_HASH_22_BITS, n28, result);
return 0; // Success
}
// Standard callsign
uint32_t n = n28 - MAX22;
char callsign[7];
callsign[6] = '\0';
callsign[5] = charn(n % 27, FT8_CHAR_TABLE_LETTERS_SPACE);
n /= 27;
callsign[4] = charn(n % 27, FT8_CHAR_TABLE_LETTERS_SPACE);
n /= 27;
callsign[3] = charn(n % 27, FT8_CHAR_TABLE_LETTERS_SPACE);
n /= 27;
callsign[2] = charn(n % 10, FT8_CHAR_TABLE_NUMERIC);
n /= 10;
callsign[1] = charn(n % 36, FT8_CHAR_TABLE_ALPHANUM);
n /= 36;
callsign[0] = charn(n % 37, FT8_CHAR_TABLE_ALPHANUM_SPACE);
// Copy callsign to 6 character buffer
if (starts_with(callsign, "3D0") && !is_space(callsign[3]))
{
// Work-around for Swaziland prefix: 3D0XYZ -> 3DA0XYZ
memcpy(result, "3DA0", 4);
trim_copy(result + 4, callsign + 3);
}
else if ((callsign[0] == 'Q') && is_letter(callsign[1]))
{
// Work-around for Guinea prefixes: QA0XYZ -> 3XA0XYZ
memcpy(result, "3X", 2);
trim_copy(result + 2, callsign + 1);
}
else
{
// Skip trailing and leading whitespace in case of a short callsign
trim_copy(result, callsign);
}
int length = strlen(result);
if (length < 3)
return -1; // Callsign too short
// Check if we should append /R or /P suffix
if (ip != 0)
{
if (i3 == 1)
strcat(result, "/R");
else if (i3 == 2)
strcat(result, "/P");
else
return -2;
}
// Save the result to hash table
save_callsign(hash_if, result, NULL, NULL, NULL);
return 0; // Success
}
static bool pack58(const ftx_callsign_hash_interface_t* hash_if, const char* callsign, uint64_t* n58)
{
// Decode one of the calls from 58 bit encoded string
const char* src = callsign;
if (*src == '<')
src++;
int length = 0;
uint64_t result = 0;
char c11[12];
while (*src != '\0' && *src != '<' && (length < 11))
{
c11[length] = *src;
int j = nchar(*src, FT8_CHAR_TABLE_ALPHANUM_SPACE_SLASH);
if (j < 0)
return false;
result = (result * 38) + j;
src++;
length++;
}
c11[length] = '\0';
if (!save_callsign(hash_if, c11, NULL, NULL, NULL))
return false;
*n58 = result;
LOG(LOG_DEBUG, "pack58('%s')=%016llx\n", callsign, *n58);
return true;
}
static bool unpack58(uint64_t n58, const ftx_callsign_hash_interface_t* hash_if, char* callsign)
{
// Decode one of the calls from 58 bit encoded string
char c11[12];
c11[11] = '\0';
uint64_t n58_backup = n58;
for (int i = 10; /* no condition */; --i)
{
c11[i] = charn(n58 % 38, FT8_CHAR_TABLE_ALPHANUM_SPACE_SLASH);
if (i == 0)
break;
n58 /= 38;
}
// The decoded string will be right-aligned, so trim all whitespace (also from back just in case)
trim_copy(callsign, c11);
LOG(LOG_DEBUG, "unpack58(%016llx)=%s\n", n58_backup, callsign);
// Save the decoded call in a hash table for later
if (strlen(callsign) >= 3)
return save_callsign(hash_if, callsign, NULL, NULL, NULL);
return false;
}
static uint16_t packgrid(const char* grid4)
{
if (grid4 == 0 || grid4[0] == '\0')
{
// Two callsigns only, no report/grid
return MAXGRID4 + 1;
}
// Take care of special cases
if (equals(grid4, "RRR"))
return MAXGRID4 + 2;
if (equals(grid4, "RR73"))
return MAXGRID4 + 3;
if (equals(grid4, "73"))
return MAXGRID4 + 4;
// TODO: Check for "R " prefix before a 4 letter grid
// Check for standard 4 letter grid
if (in_range(grid4[0], 'A', 'R') && in_range(grid4[1], 'A', 'R') && is_digit(grid4[2]) && is_digit(grid4[3]))
{
uint16_t igrid4 = (grid4[0] - 'A');
igrid4 = igrid4 * 18 + (grid4[1] - 'A');
igrid4 = igrid4 * 10 + (grid4[2] - '0');
igrid4 = igrid4 * 10 + (grid4[3] - '0');
return igrid4;
}
// Parse report: +dd / -dd / R+dd / R-dd
// TODO: check the range of dd
if (grid4[0] == 'R')
{
int dd = dd_to_int(grid4 + 1, 3);
uint16_t irpt = 35 + dd;
return (MAXGRID4 + irpt) | 0x8000; // ir = 1
}
else
{
int dd = dd_to_int(grid4, 3);
uint16_t irpt = 35 + dd;
return (MAXGRID4 + irpt); // ir = 0
}
return MAXGRID4 + 1;
}
static int unpackgrid(uint16_t igrid4, uint8_t ir, char* extra)
{
char* dst = extra;
if (igrid4 <= MAXGRID4)
{
// Extract 4 symbol grid locator
if (ir > 0)
{
// In case of ir=1 add an "R " before grid
dst = stpcpy(dst, "R ");
}
uint16_t n = igrid4;
dst[4] = '\0';
dst[3] = '0' + (n % 10); // 0..9
n /= 10;
dst[2] = '0' + (n % 10); // 0..9
n /= 10;
dst[1] = 'A' + (n % 18); // A..R
n /= 18;
dst[0] = 'A' + (n % 18); // A..R
// if (ir > 0 && strncmp(call_to, "CQ", 2) == 0) return -1;
}
else
{
// Extract report
int irpt = igrid4 - MAXGRID4;
// Check special cases first (irpt > 0 always)
if (irpt == 1)
dst[0] = '\0';
else if (irpt == 2)
strcpy(dst, "RRR");
else if (irpt == 3)
strcpy(dst, "RR73");
else if (irpt == 4)
strcpy(dst, "73");
else
{
// Extract signal report as a two digit number with a + or - sign
if (ir > 0)
{
*dst++ = 'R'; // Add "R" before report
}
int_to_dd(dst, irpt - 35, 2, true);
}
// if (irpt >= 2 && strncmp(call_to, "CQ", 2) == 0) return -1;
}
return 0;
}