radiosonde_auto_rx/c34/c34dft.c

555 wiersze
14 KiB
C

/*
C34
(empfohlen: sample rate 48kHz)
*/
#include <stdio.h>
#include <string.h>
#include <complex.h>
#include <math.h>
typedef unsigned char ui8_t;
int option_verbose = 0,
option_raw = 0,
option_dft = 0,
wavloaded = 0;
typedef struct {
int frnr;
int jahr; int monat; int tag;
int std; int min; int sek;
double lat; double lon; double h;
unsigned chk;
} gpx_t;
gpx_t gpx;
/* ------------------------------------------------------------------------------------ */
#define BAUD_RATE 2400
int sample_rate = 0, bits_sample = 0, channels = 0;
//float samples_per_bit = 0;
int findstr(char *buff, char *str, int pos) {
int i;
for (i = 0; i < 4; i++) {
if (buff[(pos+i)%4] != str[i]) break;
}
return i;
}
int read_wav_header(FILE *fp) {
char txt[4+1] = "\0\0\0\0";
unsigned char dat[4];
int byte, p=0;
if (fread(txt, 1, 4, fp) < 4) return -1;
if (strncmp(txt, "RIFF", 4)) return -1;
if (fread(txt, 1, 4, fp) < 4) return -1;
// pos_WAVE = 8L
if (fread(txt, 1, 4, fp) < 4) return -1;
if (strncmp(txt, "WAVE", 4)) return -1;
// pos_fmt = 12L
for ( ; ; ) {
if ( (byte=fgetc(fp)) == EOF ) return -1;
txt[p % 4] = byte;
p++; if (p==4) p=0;
if (findstr(txt, "fmt ", p) == 4) break;
}
if (fread(dat, 1, 4, fp) < 4) return -1;
if (fread(dat, 1, 2, fp) < 2) return -1;
if (fread(dat, 1, 2, fp) < 2) return -1;
channels = dat[0] + (dat[1] << 8);
if (fread(dat, 1, 4, fp) < 4) return -1;
memcpy(&sample_rate, dat, 4); //sample_rate = dat[0]|(dat[1]<<8)|(dat[2]<<16)|(dat[3]<<24);
if (fread(dat, 1, 4, fp) < 4) return -1;
if (fread(dat, 1, 2, fp) < 2) return -1;
//byte = dat[0] + (dat[1] << 8);
if (fread(dat, 1, 2, fp) < 2) return -1;
bits_sample = dat[0] + (dat[1] << 8);
// pos_dat = 36L + info
for ( ; ; ) {
if ( (byte=fgetc(fp)) == EOF ) return -1;
txt[p % 4] = byte;
p++; if (p==4) p=0;
if (findstr(txt, "data", p) == 4) break;
}
if (fread(dat, 1, 4, fp) < 4) return -1;
fprintf(stderr, "sample_rate: %d\n", sample_rate);
fprintf(stderr, "bits : %d\n", bits_sample);
fprintf(stderr, "channels : %d\n", channels);
if ((bits_sample != 8) && (bits_sample != 16)) return -1;
//samples_per_bit = sample_rate/(float)BAUD_RATE;
//fprintf(stderr, "samples/bit: %.2f\n", samples_per_bit);
return 0;
}
#define EOF_INT 0x1000000
int read_signed_sample(FILE *fp) { // int = i32_t
int byte, i, ret; // EOF -> 0x1000000
for (i = 0; i < channels; i++) {
// i = 0: links bzw. mono
byte = fgetc(fp);
if (byte == EOF) return EOF_INT;
if (i == 0) ret = byte;
if (bits_sample == 16) {
byte = fgetc(fp);
if (byte == EOF) return EOF_INT;
if (i == 0) ret += byte << 8;
}
}
if (bits_sample == 8) return ret-128;
if (bits_sample == 16) return (short)ret;
return ret;
}
/* ------------------------------------------------------------------------------------ */
#define LOG2N 6 // 2^7 = 128 = N
#define N 64 // 128 Vielfaches von 22 oder 10 unten
#define WLEN 40 // (2*(48000/BAUDRATE))
#define BITS (4+8) // 1110 bbbbbbbb (oder: 0 bbbbbbbb 1 11) (8N1, 11-idle)
#define LEN_BITFRAME 84 // 7*(4+8)
#define HEADLEN 28
char header[] = "1110000000001110111111111110";
char buf[HEADLEN+1] = "x";
int bufpos = -1;
char headerstr[] = "1110 00000000 1110 11111111";
int bitpos;
ui8_t bits[LEN_BITFRAME+1] = { 1, 1, 1, 0};
ui8_t bytes[LEN_BITFRAME/BITS];
double x[N];
double complex Z[N], w[N], expw[N][N], ew[N*N];
int ptr;
double Hann[N], buffer[N+1], xn[N];
void init_dft() {
int i, k, n;
for (i = 0; i < N; i++) Hann[i] = 0;
for (i = 0; i < WLEN; i++) Hann[i] = 0.5 * (1 - cos( 2 * M_PI * i / (double)(WLEN-1) ) );
//Hann[i+(N-1-WLEN)/2] = 0.5 * (1 - cos( 2 * M_PI * i / (double)(WLEN-1) ) );
for (k = 0; k < N; k++) {
w[k] = -I*2*M_PI * k / (double)N;
for (n = 0; n < N; n++) {
expw[k][n] = cexp( w[k] * n );
ew[k*n] = expw[k][n];
}
}
}
double dft_k(int k) {
int n;
double complex Zk;
Zk = 0;
for (n = 0; n < N; n++) {
Zk += xn[n] * ew[k*n];
}
return cabs(Zk);
}
void dft() {
int k, n;
for (k = 0; k < N/2; k++) { // xn reell, brauche nur N/2 unten
Z[k] = 0;
for (n = 0; n < N; n++) {
Z[k] += xn[n] * ew[k*n];
}
}
}
void dft2() {
int s, l, l2, i, j, k;
double complex w1, w2, T;
for (i = 0; i < N; i++) {
Z[i] = (double complex)xn[i];
}
j = 1;
for (i = 1; i < N; i++) {
if (i < j) {
T = Z[j-1];
Z[j-1] = Z[i-1];
Z[i-1] = T;
}
k = N/2;
while (k < j) {
j = j - k;
k = k/2;
}
j = j + k;
}
for (s = 0; s < LOG2N; s++) {
l2 = 1 << s;
l = l2 << 1;
w1 = (double complex)1.0;
w2 = cexp(-I*M_PI/(double)l2);
for (j = 1; j <= l2; j++) {
for (i = j; i <= N; i += l) {
k = i + l2;
T = Z[k-1] * w1;
Z[k-1] = Z[i-1] - T;
Z[i-1] = Z[i-1] + T;
}
w1 = w1 * w2;
}
}
}
int max_bin() {
int k, kmax;
double max;
max = 0; kmax = 0;
for (k = 0; k < N/2-1; k++) {
if (cabs(Z[k]) > max) {
max = cabs(Z[k]);
kmax = k;
}
}
return kmax;
}
double freq2bin(int f) {
return f * N / (double)sample_rate;
}
int bin2freq(int k) {
return sample_rate * k / N;
}
/* ------------------------------------------------------------------------------------ */
void inc_bufpos() {
bufpos = (bufpos+1) % HEADLEN;
}
int compare() {
int i=0, j = bufpos;
while (i < HEADLEN) {
if (j < 0) j = HEADLEN-1;
if (buf[j] != header[HEADLEN-1-i]) break;
j--;
i++;
}
return i;
}
int bits2bytes(ui8_t bits[], ui8_t bytes[]) {
int i, j, byteval=0, d=1;
for (j = 0; j < 7; j++) {
byteval=0; d=1;
for (i = 4; i < BITS; i++) { // little endian
/* for (i = 7; i >= 0; i--) { // big endian */
if (bits[BITS*j+i] == 1) byteval += d;
else /*(bits[BITS*j+i] == 0)*/ byteval += 0;
d <<= 1;
}
bytes[j] = byteval;
}
return 0;
}
void printGPX() {
int i;
printf(" %4d-%02d-%02d", gpx.jahr, gpx.monat, gpx.tag);
printf(" %2d:%02d:%02d", gpx.std, gpx.min, gpx.sek);
printf(" ");
printf(" lat: %.5f°", gpx.lat);
printf(" lon: %.5f°", gpx.lon);
printf(" h: %.1fm", gpx.h);
if (option_verbose) {
printf(" # ");
for (i = 0; i < 5; i++) printf("%d", (gpx.chk>>i)&1);
}
printf("\n");
}
// Chechsum Fletcher16
unsigned check2(ui8_t *bytes, int len) {
int sum1, sum2;
int i;
sum1 = 0;
sum2 = 0;
for (i = 0; i < len; i++) {
sum1 += bytes[i];
sum2 += (len-i)*bytes[i];
}
sum1 = sum1 & 0xFF;
sum2 = (-1-sum2) & 0xFF; // = (~sum2) & 0xFF;
return sum2 | (sum1<<8);
}
/* // equivalent
unsigned check16(ui8_t *bytes, int len) {
unsigned sum1, sum2;
int i;
sum1 = sum2 = 0;
for (i = 0; i < len; i++) {
sum1 = (sum1 + bytes[i]) % 0x100;
sum2 = (sum2 + sum1) % 0x100;
}
sum2 = (~sum2) & 0xFF; // 1's complement
return sum2 | (sum1<<8);
}
*/
double NMEAll(int ll) { // NMEA GGA,GLL: ll/1e4=(D)DDMM.mmmm
int deg = ll / 1000000;
double min = (ll - deg*1000000)/1e4;
return deg+min/60.0;
}
int evalBytes() {
int i, val = 0;
ui8_t id = bytes[0];
unsigned check;
check = ((bytes[5]<<8)|bytes[6]) != check2(bytes, 5);
for (i = 0; i < 4; i++) val |= bytes[4-i] << (8*i);
if (id == 0x14 ) { // date
int tag = val / 10000;
int mon = (val-tag*10000) / 100;
int jrz = val % 100;
gpx.tag = tag;
gpx.monat = mon;
gpx.jahr = 2000+jrz;
gpx.chk = (gpx.chk & ~(0x1<<0)) | (check<<0);
}
else if (id == 0x15 ) { // time
int std = val / 10000;
int min = (val-std*10000) / 100;
int sek = val % 100;
gpx.std = std;
gpx.min = min;
gpx.sek = sek;
gpx.chk = (gpx.chk & ~(0x1<<1)) | (check<<1);
}
else if (id == 0x16 ) { // lat: wie NMEA mit Faktor 1e4
gpx.lat = NMEAll(val);
gpx.chk = (gpx.chk & ~(0x1<<2)) | (check<<2);
}
else if (id == 0x17 ) { // lon: wie NMEA mit Faktor 1e4
gpx.lon = NMEAll(val);
gpx.chk = (gpx.chk & ~(0x1<<3)) | (check<<3);
}
else if (id == 0x18 ) { // alt: decimeter
gpx.h = val/10.0;
gpx.chk = (gpx.chk & ~(0x1<<4)) | (check<<4);
}
if (id == 0x18 && !option_raw) printGPX();
return check;
}
void printRaw() {
int j;
//if ( ((bytes[5]<<8)|bytes[6]) == check2(bytes, 5))
{
printf("%s", headerstr);
for (j = 0; j < LEN_BITFRAME; j++) {
if (j%BITS == 0) printf(" ");
if (j%BITS == 4) printf(" ");
printf("%d", bits[j]);
}
printf(" : ");
printf("%02X%02X ", 0x00, 0xFF);
printf("%02X ", bytes[0]);
printf("%02X%02X%02X%02X ", bytes[1], bytes[2], bytes[3], bytes[4]);
printf("%02X%02X", bytes[5], bytes[6]);
if (option_verbose) {
printf(" # %04X", check2(bytes, 5));
}
printf("\n");
}
}
int main(int argc, char *argv[]) {
FILE *fp;
char *fpname;
int sample;
unsigned int sample_count;
int i, j, kmax, k0, k1;
int bit = 8, bit0 = 8;
int pos = 0, pos0 = 0;
int header_found = 0;
int bitlen; // sample_rate/BAUD_RATE
int len;
double k_f0, k_f1, k_df;
double cb0, cb1;
fpname = argv[0];
++argv;
while ((*argv) && (!wavloaded)) {
if ( (strcmp(*argv, "-h") == 0) || (strcmp(*argv, "--help") == 0) ) {
fprintf(stderr, "%s [options] audio.wav\n", fpname);
fprintf(stderr, " options:\n");
fprintf(stderr, " -v, --verbose\n");
fprintf(stderr, " -r, --raw\n");
return 0;
}
else if ( (strcmp(*argv, "-v") == 0) || (strcmp(*argv, "--verbose") == 0) ) {
option_verbose = 1;
}
else if ( (strcmp(*argv, "-r") == 0) || (strcmp(*argv, "--raw") == 0) ) {
option_raw = 1;
}
else if ( (strcmp(*argv, "-d1") == 0) || (strcmp(*argv, "--dft1") == 0) ) {
option_dft = 1;
}
else if ( (strcmp(*argv, "-d2") == 0) || (strcmp(*argv, "--dft2") == 0) ) {
option_dft = 2;
}
else {
fp = fopen(*argv, "rb");
if (fp == NULL) {
fprintf(stderr, "%s konnte nicht geoeffnet werden\n", *argv);
return -1;
}
wavloaded = 1;
}
++argv;
}
if (!wavloaded) fp = stdin;
i = read_wav_header(fp);
if (i) {
fclose(fp);
return -1;
}
bitlen = sample_rate/BAUD_RATE;
k_f0 = freq2bin(4700); // bit0: 4800Hz
k_f1 = freq2bin(2900); // bit1: 3000Hz
k_df = fabs(k_f0-k_f1)/2.5;
k0 = (int)(k_f0+.5);
k1 = (int)(k_f1+.5);
init_dft();
ptr = -1; sample_count = -1;
while ((sample=read_signed_sample(fp)) < EOF_INT) {
ptr++;
sample_count++;
if (ptr == N) ptr = 0;
buffer[ptr] = sample / (double)(1<<bits_sample);
if (sample_count < N) continue;
for (j = 0; j < N; j++) {
xn[j] = Hann[j]*buffer[(ptr + j + 1)%N];
}
if (option_dft) {
if (option_dft == 2) dft2();
else dft();
kmax = max_bin();
if (kmax > k_f0-k_df && kmax < k_f0+k_df) bit = 0; // kmax = freq2bin(4800): 4800Hz
else if (kmax > k_f1-k_df && kmax < k_f1+k_df) bit = 1; // kmax = freq2bin(3000): 3000Hz
}
else {
cb0 = dft_k(k0);
cb1 = dft_k(k1);
if ( cb0 > cb1 ) bit = 0; // freq2bin(4800) : 4800Hz
else bit = 1; // freq2bin(3000) : 3000Hz
}
if (bit != bit0) {
pos0 = pos;
pos = sample_count; //sample_count-(N-1)/2
len = (pos-pos0+bitlen/2)/bitlen; //(pos-pos0)/bitlen + 0.5;
for (i = 0; i < len; i++) {
inc_bufpos();
buf[bufpos] = 0x30 + bit0;
if (!header_found) {
if (compare() >= HEADLEN) {
header_found = 1;
bitpos = 4;
}
}
else {
bits[bitpos] = bit0;
bitpos++;
if (bitpos >= LEN_BITFRAME) {
bits2bytes(bits, bytes);
if (option_raw) {
printRaw();
}
else {
evalBytes();
}
bitpos = 0;
header_found = 0;
}
}
}
bit0 = bit;
}
}
printf("\n");
fclose(fp);
return 0;
}