IQ: translate/lowpass/demod

dump
Zilog80 2016-01-22 23:17:48 +01:00
rodzic 4beae92bfb
commit dbeb70a480
2 zmienionych plików z 378 dodań i 0 usunięć

BIN
iq/dfmIQ.wav 100644

Plik binarny nie jest wyświetlany.

378
iq/wavIQ.c 100644
Wyświetl plik

@ -0,0 +1,378 @@
/*
gcc wavIQ.c -lm -o wavIQ
./wavIQ -s dfmIQ.wav > IQswap.wav
./wavIQ -t -10600 IQswap.wav > IQtransl1.wav
./wavIQ -l 6000 IQtransl1.wav > IQlowpass1.wav
./wavIQ -d1 IQlowpass1.wav > IQdemod1.wav
sox IQdemod1.wav -r 48000 IQdemod48k1.wav
./wavIQ -t 11100 IQswap.wav > IQtransl2.wav
./wavIQ -l 6000 IQtransl2.wav > IQlowpass2.wav
./wavIQ -d1 IQlowpass2.wav > IQdemod2.wav
sox IQdemod2.wav -r 48000 IQdemod48k2.wav
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <complex.h>
#define SWAPIQ 0x10
#define TRANSLATE 0x20
#define LOWPASS 0x30
#define DEMOD 0x40
#define PI (3.1415926535897932384626433832795)
int sample_rate, bits_sample;
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_IQwavheader(FILE *fp, int *sample_rate, int *bits_sample, unsigned char ch, FILE *fout) {
unsigned int channels = 0, size = 0;
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; fwrite(txt, 1, 4, fout);
if (strncmp(txt, "RIFF", 4)) return -1;
if (fread(dat, 1, 4, fp) < 4) return -1;
size = dat[0] | (dat[1] << 8) | (dat[2] << 16) | (dat[3] << 24); //fprintf(stderr, "filesize: 0x%08x = %d\n", size+8, size+8);
if (ch == 1) size = (size+8-44)/2 + 44-8;
for (byte = 0; byte < 4; byte++) { dat[byte] = size & 0xFF; size >>= 8; }
fwrite(dat, 1, 4, fout);
// pos_WAVE = 8L
if (fread(txt, 1, 4, fp) < 4) return -1; fwrite(txt, 1, 4, fout);
if (strncmp(txt, "WAVE", 4)) return -1;
// pos_fmt = 12L
for ( ; ; ) {
if ( (byte=fgetc(fp)) == EOF ) return -1; fprintf(fout, "%c", byte & 0xFF);
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; fwrite(dat, 1, 4, fout);
if (fread(dat, 1, 2, fp) < 2) return -1; fwrite(dat, 1, 2, fout);
if (fread(dat, 1, 2, fp) < 2) return -1;
channels = dat[0] + (dat[1] << 8);
dat[0] = ch; fwrite(dat, 1, 2, fout);
if (fread(dat, 1, 4, fp) < 4) return -1; fwrite(dat, 1, 4, fout);
*sample_rate = dat[0] | (dat[1] << 8) | (dat[2] << 16) | (dat[3] << 24); //memcpy(&sr, dat, 4);
if (fread(dat, 1, 4, fp) < 4) return -1; fwrite(dat, 1, 4, fout);
if (fread(dat, 1, 2, fp) < 2) return -1; fwrite(dat, 1, 2, fout);
if (fread(dat, 1, 2, fp) < 2) return -1; fwrite(dat, 1, 2, fout);
*bits_sample = dat[0] + (dat[1] << 8);
if ((*bits_sample != 8) && (*bits_sample != 16)) return -2;
// pos_dat = 36L + info
for ( ; ; ) {
if ( (byte=fgetc(fp)) == EOF ) return -1; fprintf(fout, "%c", byte & 0xFF);
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;
size = dat[0] | (dat[1] << 8) | (dat[2] << 16) | (dat[3] << 24); //fprintf(stderr, "datasize: 0x%08x = %d\n", size, size);
if (ch == 1) size = size/2;
for (byte = 0; byte < 4; byte++) { dat[byte] = size & 0xFF; size >>= 8; }
fwrite(dat, 1, 4, fout);
if (channels != 2) return -3; // I&Q
/*
fprintf(stderr, "sample_rate: %d\n", *sample_rate);
fprintf(stderr, "bits : %d\n", *bits_sample);
fprintf(stderr, "channels : %d\n", channels);
*/
return 0;
}
int read_csample(FILE *fp, double complex *z) {
short x = 0, y = 0;
if (fread( &x, bits_sample/8, 1, fp) != 1) return EOF;
if (fread( &y, bits_sample/8, 1, fp) != 1) return EOF;
*z = x + I*y;
if (bits_sample == 8) {
*z -= 128 + I*128;
}
return 0;
}
int write_csample(FILE *fp, double complex w) {
int u, v;
if (bits_sample == 8) {
w += 128 + I*128;
}
u = creal(w);
v = cimag(w);
// 16 bit (short) -> (int)
fwrite( &u, bits_sample/8, 1, fp); // + 0000 .. 7FFF -> 0000 0000 .. 0000 7FFF
fwrite( &v, bits_sample/8, 1, fp); // - 8000 .. FFFF -> FFFF 8000 .. FFFF FFFF
return 0;
}
int write_sample(FILE *fp, double x) {
int b;
if (bits_sample == 8) {
x = x + 128.0;
}
else x *= 256.0;
b = (int)x;
// 16 bit (short) -> (int)
fwrite( &b, bits_sample/8, 1, fp); // + 0000 .. 7FFF -> 0000 0000 .. 0000 7FFF
// - 8000 .. FFFF -> FFFF 8000 .. FFFF FFFF
return 0;
}
//
// lowpass
double sinc(double x) {
double y;
if (x == 0) y = 1;
else y = sin(PI*x)/(PI*x);
return y;
}
double *ws = NULL;
int lowpass_init(int fs, int lpf) { // lpf = lowpass freq bandwidth = 2*lp_freq
double f = (double)lpf/fs;
int M = 2*((2*fs)/1200);
double *h, *w;
double norm = 0;
int n;
ws = (double*)calloc( M+1, sizeof(double));
h = (double*)calloc( M+1, sizeof(double));
w = (double*)calloc( M+1, sizeof(double));
for (n = 0; n < M+1; n++) {
w[n] = 0.54 - 0.46*cos(2*PI*n/M) + 0.08*cos(4*PI*n/M);
h[n] = 2*f*sinc(2*f*(n-M/2));
ws[n] = w[n]*h[n];
norm += ws[n];
}
for (n = 0; n < M+1; n++) {
ws[n] /= norm;
}
free(h); h = NULL;
free(w); w = NULL;
return M;
}
double complex lowpass(double complex buffer[], int sample, int M) {
int n;
double complex w = 0;
if (sample > M) {
for (n = 0; n < M+1; n++) {
w += buffer[(sample+n+1)%(M+1)]*ws[M-n];
}
}
return w;
}
// lowpass
//
int main(int argc, char *argv[]) {
FILE *fp = NULL, *fout = NULL;
char *fpname = NULL;
unsigned char ch = 0;
int option = 0, phi = 0, wavloaded = 0;
int sample = 0, M = 0;
double t, f = 0, fm, gain;
double complex z = 0, z0 = 0, w = 0,
*buffer = NULL;
fpname = argv[0];
++argv;
while ((*argv) && (!wavloaded)) {
if ( (strcmp(*argv, "-h") == 0) || (strcmp(*argv, "--help") == 0) ) {
fprintf(stderr, "%s <option> IQ.wav\n", fpname);
fprintf(stderr, " options:\n");
fprintf(stderr, " -s (swap IQ)\n");
fprintf(stderr, " -t <freq> (translate)\n");
fprintf(stderr, " -l <freq> (lowpass)\n");
fprintf(stderr, " -d1,2 (demod fm)\n");
return 0;
}
else if (strcmp(*argv, "-s") == 0) option = SWAPIQ;
else if (strcmp(*argv, "-t") == 0) {
++argv;
if (*argv) {
if (strcmp(*argv, "-") == 0) f = 4800;
else f = (double)atoi(*argv);
option = TRANSLATE;
}
else return -1;
}
else if (strcmp(*argv, "-l") == 0) {
++argv;
if (*argv) {
if (strcmp(*argv, "-") == 0) f = 0;
else f = (double)atoi(*argv);
option = LOWPASS;
}
else return -1;
}
else if (strcmp(*argv, "-d1") == 0) { option = DEMOD; phi = 1; }
else if (strcmp(*argv, "-d2") == 0) { option = DEMOD; phi = 2; }
else {
if (!option) return 0;
fp = fopen(*argv, "rb");
if (fp == NULL) {
fprintf(stderr, "%s konnte nicht geoeffnet werden\n", *argv);
return -1;
}
wavloaded = 1;
}
++argv;
}
/*
if ( !option ) {
if (wavloaded) fclose(fp);
return 0;
}
*/
if (!wavloaded) fp = stdin;
if ( (option & 0xF0) == (DEMOD & 0xF0) ) ch = 1;
else ch = 2;
fout = stdout; //fopen("tmp_out.wav", "wb");
if (read_IQwavheader(fp, &sample_rate, &bits_sample, ch, fout) != 0) {
fprintf(stderr, "error: wav header\n");
return -1;
}
sample = 0;
switch ( option ) {
case SWAPIQ:
while ( read_csample(fp, &z) != EOF ) {
w = cimag(z) + I*creal(z); // = cexp(I*PI/2) * conj(z) = I * conj(z);
write_csample(fout, w);
sample++;
}
break;
case TRANSLATE:
while ( read_csample(fp, &z) != EOF ) {
t = (double)sample / sample_rate;
w = cexp(t*2*PI*f*I) * z;
write_csample(fout, w);
sample++;
}
break;
case LOWPASS:
M = lowpass_init(sample_rate, f);
buffer = (double complex*)calloc( M+1, sizeof(double complex));
w = 0;
while ( read_csample(fp, &z) != EOF ) {
buffer[sample % (M+1)] = z;
if (sample > M) {
w = lowpass(buffer, sample, M);
}
write_csample(fout, w);
sample++;
}
free(ws); ws = NULL;
free(buffer); buffer = NULL;
break;
case DEMOD:
z0 = 0;
gain = 128.0;
while ( read_csample(fp, &z) != EOF ) {
w = z * conj(z0);
switch ( phi ) { // d_phi-Algo
case 1: fm = carg(w); break; // = atan2( cimag(w) , creal(w) );
case 2: fm = cimag(w) / (cabs(z0)*cabs(z0)); break;
} //fm3 = cimag(w); // FM: |z|=const
write_sample(fout, fm*gain/PI);
z0 = z;
sample++;
}
break;
}
fclose(fp);
fclose(fout);
return 0;
}
/*
$ ./dfm06 -v IQdemod48k1.wav
[174] 2015-03-17 13:09:50.0 lat: 49.8792503 lon: 7.5075282 h: 12690.37 dir: 10.7 hV: 6.32 vV: 4.24 (ID:219892)
[176] 2015-03-17 13:09:52.0 lat: 49.8793662 lon: 7.5075404 h: 12700.00 dir: 355.6 hV: 6.54 vV: 4.26
[177] 2015-03-17 13:09:53.0 lat: 49.8794272 lon: 7.5075275 h: 12704.36 dir: 351.9 hV: 7.02 vV: 4.43
[178] 2015-03-17 13:09:53.0 lat: 49.8794272 lon: 7.5075275 h: 12704.36 dir: 351.9 hV: 7.02 vV: 4.43 (ID:219892)
[179] 2015-03-17 13:09:55.0 lat: 49.8795518 lon: 7.5074921 h: 12712.85 dir: 348.7 hV: 7.69 vV: 4.32
[180] 2015-03-17 13:09:56.0 lat: 49.8796194 lon: 7.5074641 h: 12716.99 dir: 343.1 hV: 8.10 vV: 4.06
[181] 2015-03-17 13:09:57.0 lat: 49.8796903 lon: 7.5074358 h: 12721.57 dir: 348.4 hV: 8.32 vV: 4.21 (ID:219892)
[182] 2015-03-17 13:09:58.0 lat: 49.8797624 lon: 7.5074170 h: 12726.25 dir: 352.8 hV: 8.05 vV: 3.97
[183] 2015-03-17 13:09:59.0 lat: 49.8798346 lon: 7.5074085 h: 12730.47 dir: 357.8 hV: 8.26 vV: 4.05
[184] 2015-03-17 13:10:00.0 lat: 49.8799102 lon: 7.5074023 h: 12734.09 dir: 356.9 hV: 8.32 vV: 3.75 (ID:219892)
[185] 2015-03-17 13:10:01.0 lat: 49.8799832 lon: 7.5073979 h: 12738.27 dir: 358.5 hV: 8.00 vV: 3.86
[187] 2015-03-17 13:10:03.0 lat: 49.8801186 lon: 7.5073991 h: 12747.34 dir: 3.3 hV: 7.46 vV: 3.92
[189] 2015-03-17 13:10:05.0 lat: 49.8802583 lon: 7.5073884 h: 12756.31 dir: 356.1 hV: 7.96 vV: 4.06 (ID:219892)
[190] 2015-03-17 13:10:06.0 lat: 49.8803284 lon: 7.5073828 h: 12761.98 dir: 359.1 hV: 7.65 vV: 4.39
[191] 2015-03-17 13:10:07.0 lat: 49.8803981 lon: 7.5073832 h: 12766.71 dir: 1.8 hV: 7.89 vV: 4.33 (ID:219892)
$ ./dfm06 -v IQdemod48k2.wav
[ 98] 2015-03-17 13:09:50.0 lat: 50.0256187 lon: 7.7031148 h: 7769.69 dir: 29.8 hV: 24.51 vV: -3.19
[100] 2015-03-17 13:09:52.0 lat: 50.0260194 lon: 7.7033832 h: 7763.78 dir: 17.4 hV: 23.08 vV: -2.86 (ID:314377)
[102] 2015-03-17 13:09:54.0 lat: 50.0263766 lon: 7.7035243 h: 7758.33 dir: 14.3 hV: 17.77 vV: -2.91 (ID:314377)
[103] 2015-03-17 13:09:55.0 lat: 50.0265190 lon: 7.7035243 h: 7758.33 dir: 14.3 hV: 17.77 vV: -2.91
[104] 2015-03-17 13:09:56.0 lat: 50.0266437 lon: 7.7036882 h: 7751.58 dir: 32.0 hV: 15.49 vV: -3.21
[105] 2015-03-17 13:09:57.0 lat: 50.0267637 lon: 7.7038221 h: 7748.31 dir: 38.6 hV: 17.80 vV: -3.20
[106] 2015-03-17 13:09:58.0 lat: 50.0268982 lon: 7.7039888 h: 7744.80 dir: 38.2 hV: 20.83 vV: -3.03 (ID:314377)
[107] 2015-03-17 13:09:59.0 lat: 50.0270588 lon: 7.7041688 h: 7741.81 dir: 34.0 hV: 23.10 vV: -3.05
[108] 2015-03-17 13:10:00.0 lat: 50.0272429 lon: 7.7043378 h: 7738.74 dir: 27.3 hV: 24.46 vV: -3.11
[109] 2015-03-17 13:10:01.0 lat: 50.0274422 lon: 7.7044741 h: 7735.21 dir: 20.1 hV: 24.08 vV: -3.33 (ID:314377)
[110] 2015-03-17 13:10:02.0 lat: 50.0276412 lon: 7.7045709 h: 7731.91 dir: 14.7 hV: 22.36 vV: -3.25
[111] 2015-03-17 13:10:03.0 lat: 50.0278256 lon: 7.7046368 h: 7728.77 dir: 11.8 hV: 19.88 vV: -3.16
[112] 2015-03-17 13:10:05.0 lat: 50.0281218 lon: 7.7047649 h: 7723.05 dir: 23.9 hV: 15.49 vV: -2.95 (ID:314377)
[114] 2015-03-17 13:10:07.0 lat: 50.0283693 lon: 7.7050185 h: 7716.84 dir: 38.6 hV: 18.67 vV: -3.14
*/