kgoba-ft8_lib/ft8/pack.c

366 wiersze
8.6 KiB
C

#include "pack.h"
#include "text.h"
#include <stdbool.h>
#include <stdint.h>
#include <string.h>
#include <stdio.h>
#define NTOKENS ((uint32_t)2063592L)
#define MAX22 ((uint32_t)4194304L)
#define MAXGRID4 ((uint16_t)32400)
// TODO: This is wasteful, should figure out something more elegant
const char A0[] = " 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ+-./?";
const char A1[] = " 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
const char A2[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
const char A3[] = "0123456789";
const char A4[] = " ABCDEFGHIJKLMNOPQRSTUVWXYZ";
// Pack a special token, a 22-bit hash code, or a valid base call
// into a 28-bit integer.
int32_t pack28(const char* callsign)
{
// Check for special tokens first
if (starts_with(callsign, "DE "))
return 0;
if (starts_with(callsign, "QRZ "))
return 1;
if (starts_with(callsign, "CQ "))
return 2;
if (starts_with(callsign, "CQ_"))
{
int nnum = 0, nlet = 0;
// TODO:
}
// TODO: Check for <...> callsign
char c6[6] = { ' ', ' ', ' ', ' ', ' ', ' ' };
int length = 0; // strlen(callsign); // We will need it later
while (callsign[length] != ' ' && callsign[length] != 0)
{
length++;
}
// Copy callsign to 6 character buffer
if (starts_with(callsign, "3DA0") && 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
{
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, i1, i2, i3, i4, i5;
if ((i0 = char_index(A1, c6[0])) >= 0 && (i1 = char_index(A2, c6[1])) >= 0 && (i2 = char_index(A3, c6[2])) >= 0 && (i3 = char_index(A4, c6[3])) >= 0 && (i4 = char_index(A4, c6[4])) >= 0 && (i5 = char_index(A4, c6[5])) >= 0)
{
// This is a standard callsign
int32_t n28 = i0;
n28 = n28 * 36 + i1;
n28 = n28 * 10 + i2;
n28 = n28 * 27 + i3;
n28 = n28 * 27 + i4;
n28 = n28 * 27 + i5;
return NTOKENS + MAX22 + n28;
}
//char text[13];
//if (length > 13) return -1;
// TODO:
// Treat this as a nonstandard callsign: compute its 22-bit hash
return -1;
}
// Check if a string could be a valid standard callsign or a valid
// compound callsign.
// Return base call "bc" and a logical "cok" indicator.
bool chkcall(const char* call, char* bc)
{
int length = strlen(call); // n1=len_trim(w)
if (length > 11)
return false;
if (0 != strchr(call, '.'))
return false;
if (0 != strchr(call, '+'))
return false;
if (0 != strchr(call, '-'))
return false;
if (0 != strchr(call, '?'))
return false;
if (length > 6 && 0 != strchr(call, '/'))
return false;
// TODO: implement suffix parsing (or rework?)
return true;
}
uint16_t packgrid(const char* grid4)
{
if (grid4 == 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;
// 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;
}
// Pack Type 1 (Standard 77-bit message) and Type 2 (ditto, with a "/P" call)
int pack77_1(const char* msg, uint8_t* b77)
{
// Locate the first delimiter
const char* s1 = strchr(msg, ' ');
if (s1 == 0)
return -1;
const char* call1 = msg; // 1st call
const char* call2 = s1 + 1; // 2nd call
int32_t n28a = pack28(call1);
int32_t n28b = pack28(call2);
if (n28a < 0 || n28b < 0)
return -1;
uint16_t igrid4;
// Locate the second delimiter
const char* s2 = strchr(s1 + 1, ' ');
if (s2 != 0)
{
igrid4 = packgrid(s2 + 1);
}
else
{
// Two callsigns, no grid/report
igrid4 = packgrid(0);
}
uint8_t i3 = 1; // No suffix or /R
// TODO: check for suffixes
// Shift in ipa and ipb bits into n28a and n28b
n28a <<= 1; // ipa = 0
n28b <<= 1; // ipb = 0
// Pack into (28 + 1) + (28 + 1) + (1 + 15) + 3 bits
b77[0] = (n28a >> 21);
b77[1] = (n28a >> 13);
b77[2] = (n28a >> 5);
b77[3] = (uint8_t)(n28a << 3) | (uint8_t)(n28b >> 26);
b77[4] = (n28b >> 18);
b77[5] = (n28b >> 10);
b77[6] = (n28b >> 2);
b77[7] = (uint8_t)(n28b << 6) | (uint8_t)(igrid4 >> 10);
b77[8] = (igrid4 >> 2);
b77[9] = (uint8_t)(igrid4 << 6) | (uint8_t)(i3 << 3);
return 0;
}
void packtext77(const char* text, uint8_t* b77)
{
int length = strlen(text);
// Skip leading and trailing spaces
while (*text == ' ' && *text != 0)
{
++text;
--length;
}
while (length > 0 && text[length - 1] == ' ')
{
--length;
}
// Clear the first 72 bits representing a long number
for (int i = 0; i < 9; ++i)
{
b77[i] = 0;
}
// Now express the text as base-42 number stored
// in the first 72 bits of b77
for (int j = 0; j < 13; ++j)
{
// Multiply the long integer in b77 by 42
uint16_t x = 0;
for (int i = 8; i >= 0; --i)
{
x += b77[i] * (uint16_t)42;
b77[i] = (x & 0xFF);
x >>= 8;
}
// Get the index of the current char
if (j < length)
{
int q = char_index(A0, text[j]);
x = (q > 0) ? q : 0;
}
else
{
x = 0;
}
// Here we double each added number in order to have the result multiplied
// by two as well, so that it's a 71 bit number left-aligned in 72 bits (9 bytes)
x <<= 1;
// Now add the number to our long number
for (int i = 8; i >= 0; --i)
{
if (x == 0)
break;
x += b77[i];
b77[i] = (x & 0xFF);
x >>= 8;
}
}
// Set n3=0 (bits 71..73) and i3=0 (bits 74..76)
b77[8] &= 0xFE;
b77[9] &= 0x00;
}
int pack77(const char* msg, uint8_t* c77)
{
// Check Type 1 (Standard 77-bit message) or Type 2, with optional "/P"
if (0 == pack77_1(msg, c77))
{
return 0;
}
// TODO:
// Check 0.5 (telemetry)
// Check Type 4 (One nonstandard call and one hashed call)
// Default to free text
// i3=0 n3=0
packtext77(msg, c77);
return 0;
}
#ifdef UNIT_TEST
#include <iostream>
bool test1()
{
const char* inputs[] = {
"",
" ",
"ABC",
"A9",
"L9A",
"L7BC",
"L0ABC",
"LL3JG",
"LL3AJG",
"CQ ",
0
};
for (int i = 0; inputs[i]; ++i)
{
int32_t result = ft8_v2::pack28(inputs[i]);
printf("pack28(\"%s\") = %d\n", inputs[i], result);
}
return true;
}
bool test2()
{
const char* inputs[] = {
"CQ LL3JG",
"CQ LL3JG KO26",
"L0UAA LL3JG KO26",
"L0UAA LL3JG +02",
"L0UAA LL3JG RRR",
"L0UAA LL3JG 73",
0
};
for (int i = 0; inputs[i]; ++i)
{
uint8_t result[10];
int rc = ft8_v2::pack77_1(inputs[i], result);
printf("pack77_1(\"%s\") = %d\t[", inputs[i], rc);
for (int j = 0; j < 10; ++j)
{
printf("%02x ", result[j]);
}
printf("]\n");
}
return true;
}
int main()
{
test1();
test2();
return 0;
}
#endif