mirror
/
radiosonde_auto_rx
kopia lustrzana https://github.com/projecthorus/radiosonde_auto_rx
1
0
Forkuj 0
Kod Zgłoszenia Projekty Wydania Wiki Aktywność
radiosonde_auto_rx/scan/dft_detect.c

1523 wiersze
45 KiB
C
Czysty Wina Historia

/*
* compile:
* gcc dft_detect.c -lm -o dft_detect
* speedup:
* gcc -Ofast dft_detect.c -lm -o dft_detect
*
* author: zilog80
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <complex.h>
#ifndef M_PI
#define M_PI (3.1415926535897932384626433832795)
#endif
typedef unsigned char ui8_t;
typedef unsigned short ui16_t;
typedef unsigned int ui32_t;
typedef short i16_t;
typedef int i32_t;
static int option_verbose = 0, // ausfuehrliche Anzeige
option_inv = 0, // invertiert Signal
option_min = 0,
option_iq = 0,
option_dc = 0,
option_silent = 0,
option_cont = 0,
option_pcmraw = 0,
wavloaded = 0;
static int wav_channel = 0; // audio channel: left
//int dfm_sps = 2500;
static char dfm_header[] = "10011010100110010101101001010101"; // DFM-09
// "01100101011001101010010110101010"; // DFM-06
//int vai_sps = 4800;
static char rs41_header[] = "00001000011011010101001110001000"
"01000100011010010100100000011111";
static char rs92_header[] = //"10100110011001101001"
//"10100110011001101001"
"10100110011001101001"
"10100110011001101001"
"1010011001100110100110101010100110101001";
//int lms_sps = 4800; // lms6_403MHz
static char lms6_header[] = "0101011000001000""0001110010010111"
"0001101010100111""0011110100111110";
//int mk2a_sps = 9600; // lms6_1680MHz
static char mk2a_header[] = "0010100111""0010100111""0001001001""0010010101";
//int m10_sps = 9600;
static char m10_header[] = //"10011001100110010100110010011001";
"1001100110010100110010011001""1010"; // ofs=4/2 in frm_M10()
// frame byte[0..1]: byte[0]=framelen-1, byte[1]=type(8F=M2K2,9F=M10,AF=M10+,20=M20)
// M2K2 : 64 8F : 01100100 10001111
// M10 : 64 9F : 01100100 10011111 (framelen 0x64+1) (baud=9616)
// M10-aux: 76 9F : 01110110 10011111 (framelen 0x76+1)
// M10+ : 64 AF : 01100100 10101111 (w/ gtop-GPS)
// M20 : 45 20 : 01000101 00100000 (framelen 0x45+1) (baud=9600)
//int meisei_sps = 2400; // 0xFB6230 =
static char meisei_header[] = "110011001101001101001101010100101010110010101010"; // 11111011 01100010 00110000
//int mrz_sps = 2400;
static char mrz_header[] = "1001100110011001""1001101010101010"; // 0xAA 0xBF
//int imet54_sps = 4800;
static char imet54_header[] = "0000000001""0101010101""0001001001""0001001001"; // 0x00 0xAA 0x24 0x24
// imet_9600 / 1200 Hz;
static char imet_preamble[] = //"11110000111100001111000011110000"
//"11110000111100001111000011110000"
"11110000111100001111000011110000"
"11110000111100001111000011110000"; // 1200 Hz 0xAA 0xAA preamble
//int imet1ab_sps = 9600; // 1200 bits/sec // AFSK 1200/2400
static char imet1ab_header[] = "0000""11110000111100001111000011110000""1111" // idle
//"0000""10101100110010101100101010101100""1111"
"0000""10101100110010101100101010101100""1111"; // 0x96
// 11110000:1 , 001100110:0 // 11/4=2.1818..
static char imet1rs_header[] =
"0000""1111""0000""1111""0000""1111" // preamble
"0000""1111";
// imet1rs/imet4 1200Hz preamble , lead_out , 8N1 byte: lead-in 8bits lead-out , ...
// 1:1200Hz/0:2200Hz tones, bit-duration 1/1200 sec, phase ...
// bits: 1111111111111111111 10 10000000 10 ..;
// C34/C50: 2400 baud, 1:2900Hz/0:4800Hz
static char c34_preheader[] =
"01010101010101010101010101010101"; // 2900 Hz tone
// dft, dB-max(1000Hz..5000Hz) = 2900Hz ?
typedef struct {
int sps; // header: symbol rate, baud
int hLen;
int L;
char *header;
float BT;
float spb;
float thres;
int herrs;
float complex *Fm;
char *type;
int tn;
int lpFM;
int lpIQ;
float dc;
float df; // Df = df*sr_base;
} rsheader_t;
static float lpFM_bw[2] = { 4e3, 10e3 }; // FM-audio lowpass bandwidth
static float lpIQ_bw[3] = { 12e3, 22e3, 200e3 }; // IF iq lowpass bandwidth
static float set_lpIQ = 0.0;
#define tn_DFM 2
#define tn_RS41 3
#define tn_RS92 4
#define tn_M10 5
#define tn_M20 6
#define tn_LMS6 8
#define tn_MEISEI 9
#define tn_MRZ 12
#define tn_C34C50 15
#define tn_MK2LMS 18
#define tn_IMET5 24
#define tn_IMETa 25
#define tn_IMET4 26
#define tn_IMET1rs 28
#define tn_IMET1ab 29
#define Nrs 14
#define idxIMETafsk 11
#define idxRS 12
#define idxI4 13
static rsheader_t rs_hdr[Nrs] = {
{ 2500, 0, 0, dfm_header, 1.0, 0.0, 0.65, 2, NULL, "DFM9", tn_DFM, 0, 0, 0.0, 0.0}, // DFM6: -2 ?
{ 4800, 0, 0, rs41_header, 0.5, 0.0, 0.70, 2, NULL, "RS41", tn_RS41, 0, 0, 0.0, 0.0},
{ 4800, 0, 0, rs92_header, 0.5, 0.0, 0.70, 3, NULL, "RS92", tn_RS92, 0, 0, 0.0, 0.0}, // RS92NGP: 1680/400=4.2
{ 4800, 0, 0, lms6_header, 1.0, 0.0, 0.60, 8, NULL, "LMS6", tn_LMS6, 0, 0, 0.0, 0.0}, // lmsX: 7?
{ 4800, 0, 0, imet54_header, 0.5, 0.0, 0.80, 2, NULL, "IMET5", tn_IMET5, 0, 0, 0.0, 0.0}, // (rs_hdr[idxI5])
{ 9616, 0, 0, mk2a_header, 1.0, 0.0, 0.70, 2, NULL, "MK2LMS", tn_MK2LMS, 1, 2, 0.0, 0.0}, // Mk2a/LMS6-1680 , --IQ: decimate > 170kHz ...
{ 9608, 0, 0, m10_header, 1.0, 0.0, 0.76, 2, NULL, "M10", tn_M10, 1, 1, 0.0, 0.0}, // M10.tn=5 (baud=9616) , M20.tn=6 (baud=9600)
{ 2400, 0, 0, meisei_header, 1.0, 0.0, 0.70, 2, NULL, "MEISEI", tn_MEISEI, 0, 1, 0.0, 0.0},
{ 2400, 0, 0, mrz_header, 1.5, 0.0, 0.80, 2, NULL, "MRZ", tn_MRZ, 0, 0, 0.0, 0.0},
{ 5800, 0, 0, c34_preheader, 1.5, 0.0, 0.80, 2, NULL, "C34C50", tn_C34C50, 0, 1, 0.0, 0.0}, // C34/C50 2900 Hz tone
{ 9600, 0, 0, imet1ab_header, 1.0, 0.0, 0.80, 2, NULL, "IMET1AB", tn_IMET1ab, 1, 2, 0.0, 0.0}, // (rs_hdr[idxAB])
{ 9600, 0, 0, imet_preamble, 0.5, 0.0, 0.80, 4, NULL, "IMETafsk", tn_IMETa , 1, 0, 0.0, 0.0}, // IMET1AB, IMET1RS (IQ)IMET4
{ 9600, 0, 0, imet1rs_header, 0.5, 0.0, 0.80, 2, NULL, "IMET1RS", tn_IMET1rs, 0, 2, 0.0, 0.0}, // (rs_hdr[idxRS]) IMET4: lpIQ=0 ...
{ 9600, 0, 0, imet1rs_header, 0.5, 0.0, 0.80, 2, NULL, "IMET4", tn_IMET4, 1, 0, 0.0, 0.0}, // (rs_hdr[idxI4])
};
/*
// m10-false-positive:
// m10-preamble similar to rs41-preamble, parts of rs92/imet1ab, imet1ab; diffs:
// - iq: - modulation-index rs41 < rs92 < m10,
// - power level / frame < 1s, noise
// - fm: - frame duration <-> noise (variance/standard deviation)
// - pulse-shaping
// m10: 00110011 at 9600 sps
// rs41: 0 1 0 1 at 4800 sps
// - after header, m10-baudrate < rs41-baudrate
// - m10 top-carrier, fm-mean/average
// - m10-header ..110(1)0110011()011.. bit shuffle
// - m10 frame byte[1]=type(M2K2,M10,M10+)
*/
/*
// rs92
// imet1ab-false-positive
// ...
*/
#define FM_GAIN (0.8)
static int sr_base = 0;
static int sr_if = 0;
static int sample_rate = 0, bits_sample = 0, channels = 0;
static int wav_ch = 0; // 0: links bzw. mono; 1: rechts
static ui32_t sample_in, sample_out, delay;
static int M;
static float *buf_fm[3];
static float *bufs = NULL;
static char *rawbits = NULL;
/* ------------------------------------------------------------------------------------ */
// decimation
static ui32_t dsp__sr_base;
static ui32_t dsp__dectaps;
static ui32_t dsp__sample_dec;
static int dsp__decM = 1;
static float complex *dsp__decXbuffer;
static float complex *dsp__decMbuf;
static float complex *dsp__ex; // exp_lut
static ui32_t dsp__lut_len;
static float *ws_dec;
static double dsp__xlt_fq = 0.0;
static int LOG2N, N_DFT;
static float complex *ew;
static float complex *X, *Z, *cx;
static float *xn;
static float *db;
// FM: lowpass
static float *ws_lpFM[2];
static int dsp__lpFMtaps; // ui32_t
static float complex *Y;
static float complex *WS[2];
// IF: lowpass
static float *ws_lpIQ[2];
static int dsp__lpIQtaps; // ui32_t
static float complex *lpIQ_buf;
static void dft_raw(float complex *Z) {
int s, l, l2, i, j, k;
float complex w1, w2, T;
j = 1;
for (i = 1; i < N_DFT; i++) {
if (i < j) {
T = Z[j-1];
Z[j-1] = Z[i-1];
Z[i-1] = T;
}
k = N_DFT/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 = (float complex)1.0;
w2 = ew[s]; // cexp(-I*M_PI/(float)l2)
for (j = 1; j <= l2; j++) {
for (i = j; i <= N_DFT; 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;
}
}
}
static void dft(float *x, float complex *Z) {
int i;
for (i = 0; i < N_DFT; i++) Z[i] = (float complex)x[i];
dft_raw(Z);
}
static void Nidft(float complex *Z, float complex *z) {
int i;
for (i = 0; i < N_DFT; i++) z[i] = conj(Z[i]);
dft_raw(z);
// idft():
// for (i = 0; i < N_DFT; i++) z[i] = conj(z[i])/(float)N_DFT; // hier: z reell
}
static float freq2bin(int f) {
return f * N_DFT / (float)sample_rate;
}
static float bin2freq(int k) {
float fq = k / (float)N_DFT;
if ( fq >= 0.5) fq -= 1.0;
return fq*sample_rate;
}
/* ------------------------------------------------------------------------------------ */
static int getCorrDFT(int K, unsigned int pos, float *maxv, unsigned int *maxvpos, rsheader_t *rshd) {
int i;
int mp = -1;
float mx = 0.0;
float mx2 = 0.0;
float re_cx = 0.0;
double xnorm = 1.0;
unsigned int mpos = 0;
float dc = 0.0;
rshd->dc = 0.0;
if (K + rshd->L > N_DFT) return -1;
// if (sample_out < rshd->L) return -2; // nur falls K-4 < L
if (pos == 0) pos = sample_out;
bufs = buf_fm[rshd->lpIQ];
for (i = 0; i < K+rshd->L; i++) xn[i] = bufs[(pos+M -(K+rshd->L-1) + i) % M];
while (i < N_DFT) xn[i++] = 0.0;
dft(xn, X);
//dc = get_bufmu(pos-sample_out); //oder: dc = creal(X[0])/(K+rshd->L) = avg(xn) // zu lang (M10)
dc = 0.0;
if (option_dc) {
//X[0] = 0; // all samples in window
// L < K
for (i=K-rshd->L; i<K+rshd->L;i++) dc += xn[i]; // only last 2L samples (avoid M10 carrier offset)
dc /= 2.0*(float)rshd->L;
X[0] -= N_DFT*dc * 0.98;
}
rshd->dc = dc;
if (option_iq) {
// FM-lowpass(xn)
for (i = 0; i < N_DFT; i++) X[i] *= WS[rshd->lpFM][i];
}
if (option_dc || option_iq) { // mx = mx(xn[]), xn(lowpass, dc)
Nidft(X, cx);
for (i = 0; i < N_DFT; i++) xn[i] = creal(cx[i])/(float)N_DFT;
}
for (i = 0; i < N_DFT; i++) Z[i] = X[i] * rshd->Fm[i];
Nidft(Z, cx);
// relativ Peak - Normierung erst zum Schluss;
// dann jedoch nicht zwingend corr-Max wenn FM-Amplitude bzw. norm(x) nicht konstant
// (z.B. rs41 Signal-Pausen). Moeglicherweise wird dann wahres corr-Max in dem
// K-Fenster nicht erkannt, deshalb K nicht zu gross waehlen.
//
mx2 = 0.0; // t = L-1
for (i = rshd->L-1; i < K+rshd->L; i++) { // i=t .. i=t+K < t+1+K
re_cx = creal(cx[i]); // imag(cx)=0
//if (fabs(re_cx) > fabs(mx)) {
if (re_cx*re_cx > mx2) {
mx = re_cx;
mx2 = mx*mx;
mp = i;
}
}
if (mp == rshd->L-1 || mp == K+rshd->L-1) return -4; // Randwert
// mp == t mp == K+t
mpos = pos - (K + rshd->L-1) + mp; // t = L-1
xnorm = 0.0;
for (i = 0; i < rshd->L; i++) xnorm += xn[mp-i]*xn[mp-i];
xnorm = sqrt(xnorm);
mx /= xnorm*N_DFT;
if (option_iq) mpos -= dsp__lpFMtaps/2; // lowpass delay
*maxv = mx;
*maxvpos = mpos;
if (option_dc) {
rshd->df = rshd->dc / (2.0*FM_GAIN*dsp__decM); // freq offset estimate
}
return mp;
}
/* ------------------------------------------------------------------------------------ */
static 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;
}
static int read_wav_header(FILE *fp, int wav_channel) {
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) && strncmp(txt, "RF64", 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 (wav_channel >= 0 && wav_channel < channels) wav_ch = wav_channel;
else wav_ch = 0;
//fprintf(stderr, "channel-In : %d\n", wav_ch+1);
if (bits_sample != 8 && bits_sample != 16 && bits_sample != 32) return -1;
if (sample_rate == 900001) sample_rate -= 1;
return 0;
}
static int f32read_sample(FILE *fp, float *s) {
int i;
unsigned int word = 0;
short *b = (short*)&word;
float *f = (float*)&word;
for (i = 0; i < channels; i++) {
if (fread( &word, bits_sample/8, 1, fp) != 1) return EOF;
if (i == wav_ch) { // i = 0: links bzw. mono
//if (bits_sample == 8) sint = b-128; // 8bit: 00..FF, centerpoint 0x80=128
//if (bits_sample == 16) sint = (short)b;
if (bits_sample == 32) {
*s = *f;
}
else {
if (bits_sample == 8) { *b -= 128; }
*s = *b/128.0;
if (bits_sample == 16) { *s /= 256.0; }
}
}
}
return 0;
}
// IQ-dc
typedef struct {
double sumIQx;
double sumIQy;
float avgIQx;
float avgIQy;
ui32_t cnt;
ui32_t maxcnt;
} iq_dc_t;
static iq_dc_t IQdc;
static int f32read_csample(FILE *fp, float complex *z) {
float x, y;
if (bits_sample == 32) { //float32
float f[2];
if (fread( f, bits_sample/8, 2, fp) != 2) return EOF;
x = f[0];
y = f[1];
}
else if (bits_sample == 16) { //int16
short b[2];
if (fread( b, bits_sample/8, 2, fp) != 2) return EOF;
x = b[0]/32768.0;
y = b[1]/32768.0;
}
else { // bits_sample == 8 //uint8
ui8_t u[2];
if (fread( u, bits_sample/8, 2, fp) != 2) return EOF;
x = (u[0]-128)/128.0;
y = (u[1]-128)/128.0;
}
*z = (x - IQdc.avgIQx) + I*(y - IQdc.avgIQy);
IQdc.sumIQx += x;
IQdc.sumIQy += y;
IQdc.cnt += 1;
if (IQdc.cnt == IQdc.maxcnt) {
IQdc.avgIQx = IQdc.sumIQx/(float)IQdc.maxcnt;
IQdc.avgIQy = IQdc.sumIQy/(float)IQdc.maxcnt;
IQdc.sumIQx = 0; IQdc.sumIQy = 0; IQdc.cnt = 0;
}
return 0;
}
static int f32read_cblock(FILE *fp) {
int n;
int len;
float x, y;
len = dsp__decM;
if (bits_sample == 8) { //uint8
ui8_t u[2*dsp__decM];
len = fread( u, bits_sample/8, 2*dsp__decM, fp) / 2;
//for (n = 0; n < len; n++) dsp__decMbuf[n] = (u[2*n]-128)/128.0 + I*(u[2*n+1]-128)/128.0;
// u8: 0..255, 128 -> 0V
for (n = 0; n < len; n++) {
x = (u[2*n ]-128)/128.0;
y = (u[2*n+1]-128)/128.0;
dsp__decMbuf[n] = (x-IQdc.avgIQx) + I*(y-IQdc.avgIQy);
IQdc.sumIQx += x;
IQdc.sumIQy += y;
IQdc.cnt += 1;
if (IQdc.cnt == IQdc.maxcnt) {
IQdc.avgIQx = IQdc.sumIQx/(float)IQdc.maxcnt;
IQdc.avgIQy = IQdc.sumIQy/(float)IQdc.maxcnt;
IQdc.sumIQx = 0; IQdc.sumIQy = 0; IQdc.cnt = 0;
}
}
}
else if (bits_sample == 16) { //int16
short b[2*dsp__decM];
len = fread( b, bits_sample/8, 2*dsp__decM, fp) / 2;
for (n = 0; n < len; n++) {
x = b[2*n ]/32768.0;
y = b[2*n+1]/32768.0;
dsp__decMbuf[n] = (x-IQdc.avgIQx) + I*(y-IQdc.avgIQy);
IQdc.sumIQx += x;
IQdc.sumIQy += y;
IQdc.cnt += 1;
if (IQdc.cnt == IQdc.maxcnt) {
IQdc.avgIQx = IQdc.sumIQx/(float)IQdc.maxcnt;
IQdc.avgIQy = IQdc.sumIQy/(float)IQdc.maxcnt;
IQdc.sumIQx = 0; IQdc.sumIQy = 0; IQdc.cnt = 0;
}
}
}
else { // bits_sample == 32 //float32
float f[2*dsp__decM];
len = fread( f, bits_sample/8, 2*dsp__decM, fp) / 2;
for (n = 0; n < len; n++) {
x = f[2*n];
y = f[2*n+1];
dsp__decMbuf[n] = (x-IQdc.avgIQx) + I*(y-IQdc.avgIQy);
IQdc.sumIQx += x;
IQdc.sumIQy += y;
IQdc.cnt += 1;
if (IQdc.cnt == IQdc.maxcnt) {
IQdc.avgIQx = IQdc.sumIQx/(float)IQdc.maxcnt;
IQdc.avgIQy = IQdc.sumIQy/(float)IQdc.maxcnt;
IQdc.sumIQx = 0; IQdc.sumIQy = 0; IQdc.cnt = 0;
}
}
}
return len;
}
static double sinc(double x) {
double y;
if (x == 0) y = 1;
else y = sin(M_PI*x)/(M_PI*x);
return y;
}
static int lowpass_init(float f, int taps, float **pws) {
double *h, *w;
double norm = 0;
int n;
float *ws = NULL;
if (taps % 2 == 0) taps++; // odd/symmetric
if ( taps < 1 ) taps = 1;
h = (double*)calloc( taps+1, sizeof(double)); if (h == NULL) return -1;
w = (double*)calloc( taps+1, sizeof(double)); if (w == NULL) return -1;
ws = (float*)calloc( 2*taps+1, sizeof(float)); if (ws == NULL) return -1;
for (n = 0; n < taps; n++) {
w[n] = 7938/18608.0 - 9240/18608.0*cos(2*M_PI*n/(taps-1)) + 1430/18608.0*cos(4*M_PI*n/(taps-1)); // Blackmann
h[n] = 2*f*sinc(2*f*(n-(taps-1)/2));
ws[n] = w[n]*h[n];
norm += ws[n]; // 1-norm
}
for (n = 0; n < taps; n++) {
ws[n] /= norm; // 1-norm
}
for (n = 0; n < taps; n++) ws[taps+n] = ws[n]; // duplicate/unwrap
*pws = ws;
free(h); h = NULL;
free(w); w = NULL;
return taps;
}
// struct { int taps; double *ws}
static float complex lowpass0(float complex buffer[], ui32_t sample, ui32_t taps, float *ws) {
ui32_t n;
double complex w = 0;
for (n = 0; n < taps; n++) {
w += buffer[(sample+n+1)%taps]*ws[taps-1-n];
}
return (float complex)w;
}
static float complex lowpass(float complex buffer[], ui32_t sample, ui32_t taps, float *ws) {
ui32_t n;
ui32_t s = sample % taps;
double complex w = 0;
for (n = 0; n < taps; n++) {
w += buffer[n]*ws[taps+s-n]; // ws[taps+s-n] = ws[(taps+sample-n)%taps]
}
return (float complex)w;
// symmetry: ws[n] == ws[taps-1-n]
}
static int f32buf_sample(FILE *fp, int inv) {
float _s = 0.0;
float s[3];
static float complex z0_fm0;
static float complex z0_fm1;
static float complex z0;
float complex z_fm0=0, z_fm1=0;
float complex z, w;
double gain = FM_GAIN;
int i;
if (option_iq)
{
if (option_iq == 5) { // baseband decimation
ui32_t s_reset = dsp__dectaps*dsp__lut_len;
int j;
if ( f32read_cblock(fp) < dsp__decM ) return EOF;
for (j = 0; j < dsp__decM; j++) {
dsp__decXbuffer[dsp__sample_dec % dsp__dectaps] = dsp__decMbuf[j] * dsp__ex[dsp__sample_dec % dsp__lut_len];
dsp__sample_dec += 1;
if (dsp__sample_dec == s_reset) dsp__sample_dec = 0;
}
z = lowpass(dsp__decXbuffer, dsp__sample_dec, dsp__dectaps, ws_dec);
}
else if ( f32read_csample(fp, &z) == EOF ) return EOF;
// IF-lowpass
// a) detect signal bandwidth/center-fq (not reliable), or
// b) 3 FM-streams
//
lpIQ_buf[sample_in % dsp__lpIQtaps] = z;
z_fm0 = lowpass(lpIQ_buf, sample_in, dsp__lpIQtaps, ws_lpIQ[0]);
z_fm1 = lowpass(lpIQ_buf, sample_in, dsp__lpIQtaps, ws_lpIQ[1]);
// IQ: different modulation indices h=h(rs) -> FM-demod
w = z_fm0 * conj(z0_fm0);
s[0] = gain * carg(w)/M_PI;
z0_fm0 = z_fm0;
w = z_fm1 * conj(z0_fm1);
s[1] = gain * carg(w)/M_PI;
z0_fm1 = z_fm1;
w = z * conj(z0);
s[2] = gain * carg(w)/M_PI;
z0 = z;
}
else
{
if (f32read_sample(fp, &_s) == EOF) return EOF;
for (i = 0; i < 3; i++) s[i] = _s;
}
for (i = 0; i < 3; i++) {
if (inv) s[i]= -s[i];
buf_fm[i][sample_in % M] = s[i];
}
sample_out = sample_in - delay;
sample_in += 1;
return 0;
}
static int read_bufbit(int symlen, char *bits, unsigned int mvp, int reset, float dc, rsheader_t *rshd) {
// symlen==2: manchester2 0->10,1->01->1: 2.bit
static unsigned int rcount;
static float rbitgrenze;
double sum = 0.0;
bufs = buf_fm[rshd->lpIQ];
if (reset) {
rcount = 0;
rbitgrenze = 0;
}
// bei symlen=2 (Manchester) kein dc noetig,
// allerdings M10-header mit symlen=1
rbitgrenze += rshd->spb;
do {
sum += bufs[(rcount + mvp + M) % M] - dc;
rcount++;
} while (rcount < rbitgrenze); // n < spb
if (symlen == 2) {
rbitgrenze += rshd->spb;
do {
sum -= bufs[(rcount + mvp + M) % M] - dc;
rcount++;
} while (rcount < rbitgrenze); // n < spb
}
if (symlen != 2) {
if (sum >= 0) *bits = '1';
else *bits = '0';
}
else {
if (sum >= 0) strncpy(bits, "10", 2);
else strncpy(bits, "01", 2);
}
return 0;
}
static int headcmp(int symlen, unsigned int mvp, int inv, rsheader_t *rshd) {
int errs = 0;
int pos;
int step = 1;
int len = 0;
char sign = 0;
float dc = 0.0;
if (option_dc)
{
/*
len = rshd->L;
for (pos = 0; pos < len; pos++) {
dc += (double)bufs[(mvp - 1 - pos + M) % M];
}
dc /= (double)len;
*/
dc = rshd->dc;
}
if (symlen != 1) step = 2;
if (inv) sign=1;
len = rshd->hLen;
for (pos = 0; pos < len; pos += step) {
read_bufbit(symlen, rawbits+pos, mvp+1-(int)(rshd->hLen*rshd->spb), pos==0, dc, rshd);
}
rawbits[pos] = '\0';
while (len > 0) {
if ((rawbits[len-1]^sign) != rshd->header[len-1]) errs += 1;
len--;
}
return errs;
}
static ui8_t bits2byte(char *bitstr) {
int i, bit, d, byteval;
int bitpos;
bitpos = 0;
byteval = 0;
d = 1;
for (i = 0; i < 8; i++) {
//bit=*(bitstr+bitpos+i); /* little endian */
bit=*(bitstr+bitpos+7-i); /* big endian */
if (bit == '1') byteval += d;
else /*if ((bit == '0')*/ byteval += 0;
d <<= 1;
}
return byteval & 0xFF;
}
static int hw(ui8_t byte) {
int i;
int d = 0;
for (i = 0; i < 8; i++) {
d += (byte & 1);
byte >>= 1;
}
return d;
}
static ui32_t frm_M10(unsigned int mvp, int inv, rsheader_t *rshd) {
float dc = 0.0;
int pos2;
char bit0 = '0';
char mb[2];
char frmbit[16+1];
ui8_t b[2];
ui32_t bytes;
int ofs = (strlen(rshd->header) - 28)/2;
if (ofs < 0 || ofs > 8) ofs = 0;
if (option_dc) dc = rshd->dc;
bit0 = 0x30 + (inv > 0);
for (pos2 = 0; pos2 < 16; pos2 += 1) {
if (pos2 < ofs) {
mb[0] = rshd->header[28+2*pos2] ^ (inv>0);
}
else {
read_bufbit(2, mb, mvp, pos2==ofs, dc, rshd);
}
frmbit[pos2] = 0x31 ^ (bit0 ^ mb[0]);
bit0 = mb[0];
}
frmbit[pos2] = '\0';
b[0] = bits2byte(frmbit);
b[1] = bits2byte(frmbit+8);
bytes = (b[0]<<8) | b[1];
return bytes;
}
/* -------------------------------------------------------------------------- */
#define IF_SAMPLE_RATE 48000
#define IF_SAMPLE_RATE_MIN 32000
#define SQRT2 1.4142135624 // sqrt(2)
// sigma = sqrt(log(2)) / (2*PI*BT):
//#define SIGMA 0.2650103635 // BT=0.5: 0.2650103635 , BT=0.3: 0.4416839392
// Gaussian FM-pulse
static double Q(double x) {
return 0.5 - 0.5*erf(x/SQRT2);
}
static double pulse(double t, double sigma) {
return Q((t-0.5)/sigma) - Q((t+0.5)/sigma);
}
static double norm2_match(float *match, int n) {
int i;
double x, y = 0.0;
for (i = 0; i < n; i++) {
x = match[i];
y += x*x;
}
return y;
}
static int init_buffers() {
int i, j, pos;
double t;
double b0, b1, b2, b;
float normMatch;
int p2 = 1;
int K, L;
int n, k;
float *match = NULL;
float *m = NULL;
double BT = 0.5;
double sigma = sqrt(log(2)) / (2*M_PI*BT);
char *bits = NULL;
float spb = 0.0;
int hLen = 0;
int Lmax = 0;
sr_base = sample_rate;
sr_if = sample_rate;
if (option_iq == 5)
{
int IF_sr = IF_SAMPLE_RATE; // designated IF sample rate
int decM = 1; // decimate M:1
float f_lp; // dec_lowpass: lowpass_bw/2
float t_bw; // dec_lowpass: transition_bw
int taps; // dec_lowpass: taps
if (set_lpIQ > IF_sr) IF_sr = set_lpIQ;
sr_base = sample_rate;
if (option_min) IF_sr = IF_SAMPLE_RATE_MIN;
if (IF_sr > sr_base) IF_sr = sr_base;
if (IF_sr < sr_base) {
while (sr_base % IF_sr) IF_sr += 1;
decM = sr_base / IF_sr;
}
f_lp = (IF_sr+20e3)/(4.0*sr_base);
t_bw = (IF_sr-20e3)/*/2.0*/;
if (option_min) {
t_bw = (IF_sr-12e3);
}
if (t_bw < 0) t_bw = 10e3;
t_bw /= sr_base;
taps = 4.0/t_bw; if (taps%2==0) taps++;
taps = lowpass_init(f_lp, taps, &ws_dec);
if (taps < 0) return -1;
dsp__dectaps = taps;
dsp__sr_base = sr_base;
sample_rate = IF_sr; // sr_base/decM
dsp__decM = decM;
sr_if = IF_sr;
fprintf(stderr, "IF: %d\n", IF_sr);
fprintf(stderr, "dec: %d\n", decM);
}
if (option_iq == 5)
{
// look up table, exp-rotation
int W = 2*8; // 16 Hz window
int d = 1; // 1..W , groesster Teiler d <= W von sr_base
int freq = (int)( dsp__xlt_fq * (double)dsp__sr_base + 0.5);
int freq0 = freq; // init
double f0 = freq0 / (double)dsp__sr_base; // init
for (d = W; d > 0; d--) { // groesster Teiler d <= W von sr
if (dsp__sr_base % d == 0) break;
}
if (d == 0) d = 1; // d >= 1 ?
for (k = 0; k < W/2; k++) {
if ((freq+k) % d == 0) {
freq0 = freq + k;
break;
}
if ((freq-k) % d == 0) {
freq0 = freq - k;
break;
}
}
dsp__lut_len = dsp__sr_base / d;
f0 = freq0 / (double)dsp__sr_base;
dsp__ex = calloc(dsp__lut_len+1, sizeof(float complex));
if (dsp__ex == NULL) return -1;
for (n = 0; n < dsp__lut_len; n++) {
t = f0*(double)n;
dsp__ex[n] = cexp(t*2*M_PI*I);
}
dsp__decXbuffer = calloc( dsp__dectaps+1, sizeof(float complex));
if (dsp__decXbuffer == NULL) return -1;
dsp__decMbuf = calloc( dsp__decM+1, sizeof(float complex));
if (dsp__decMbuf == NULL) return -1;
}
if (option_iq)
{
float f_lp; // lowpass_bw
int taps; // lowpass taps: 4*sr/transition_bw
// FM lowpass -> xn[] in getCorrDFT()
taps = 4*sample_rate/2e3; if (taps%2==0) taps++; // 2kHz transition
//
f_lp = lpFM_bw[0]/(float)sample_rate; // RS41,DFM: 4kHz (FM-audio)
taps = lowpass_init(f_lp, taps, &ws_lpFM[0]); if (taps < 0) return -1;
//
f_lp = lpFM_bw[1]/(float)sample_rate; // M10: 10kHz (FM-audio)
taps = lowpass_init(f_lp, taps, &ws_lpFM[1]); if (taps < 0) return -1;
//
dsp__lpFMtaps = taps;
// IF lowpass
taps = 4*sample_rate/4e3; if (taps%2==0) taps++; // 4kHz transition
if (set_lpIQ > 100.0) { // set_lpIQ > 100Hz: overwrite lpIQ_bw[]
lpIQ_bw[0] = set_lpIQ;
lpIQ_bw[1] = set_lpIQ;
}
//
f_lp = lpIQ_bw[0]/(float)sample_rate/2.0; // RS41,DFM: 12kHz (IF/IQ)
taps = lowpass_init(f_lp, taps, &ws_lpIQ[0]); if (taps < 0) return -1;
//
f_lp = lpIQ_bw[1]/(float)sample_rate/2.0; // M10: 22kHz (IF/IQ)
taps = lowpass_init(f_lp, taps, &ws_lpIQ[1]); if (taps < 0) return -1;
//
dsp__lpIQtaps = taps;
lpIQ_buf = calloc( dsp__lpIQtaps+3, sizeof(float complex));
if (lpIQ_buf == NULL) return -1;
}
memset(&IQdc, 0, sizeof(IQdc));
IQdc.maxcnt = sample_rate/32;
if (dsp__decM > 1) IQdc.maxcnt *= dsp__decM;
for (j = 0; j < Nrs; j++) {
rs_hdr[j].spb = sample_rate/(float)rs_hdr[j].sps;
rs_hdr[j].hLen = strlen(rs_hdr[j].header);
rs_hdr[j].L = rs_hdr[j].hLen * rs_hdr[j].spb + 0.5;
if (rs_hdr[j].hLen > hLen) hLen = rs_hdr[j].hLen;
if (rs_hdr[j].L > Lmax) Lmax = rs_hdr[j].L;
}
// L = hLen * sample_rate/2500.0 + 0.5; // max(hLen*spb)
L = 2*Lmax;
M = 3*L;
//if (samples_per_bit < 6) M = 6*N;
sample_in = 0;
p2 = 1;
while (p2 < M) p2 <<= 1;
while (p2 < 0x2000) p2 <<= 1; // or 0x4000, if sample not too short
N_DFT = p2;
K = N_DFT - L;
LOG2N = log(N_DFT)/log(2)+0.1; // 32bit cpu ... intermediate floating-point precision
//while ((1 << LOG2N) < N_DFT) LOG2N++; // better N_DFT = (1 << LOG2N) ...
delay = L/16;
M = N_DFT + delay + 8; // L+K < M
rawbits = (char *)calloc( hLen+1, sizeof(char)); if (rawbits == NULL) return -100;
for (j = 0; j < 3; j++) {
buf_fm[j] = (float *)calloc( M+1, sizeof(float)); if (buf_fm[j] == NULL) return -100;
}
bufs = buf_fm[2];
xn = calloc(N_DFT+1, sizeof(float)); if (xn == NULL) return -1;
db = calloc(N_DFT+1, sizeof(float)); if (db == NULL) return -1;
ew = calloc(LOG2N+1, sizeof(float complex)); if (ew == NULL) return -1;
X = calloc(N_DFT+1, sizeof(float complex)); if (X == NULL) return -1;
Z = calloc(N_DFT+1, sizeof(float complex)); if (Z == NULL) return -1;
cx = calloc(N_DFT+1, sizeof(float complex)); if (cx == NULL) return -1;
for (n = 0; n < LOG2N; n++) {
k = 1 << n;
ew[n] = cexp(-I*M_PI/(float)k);
}
match = (float *)calloc( L+1, sizeof(float)); if (match == NULL) return -1;
m = (float *)calloc(N_DFT+1, sizeof(float)); if (m == NULL) return -1;
for (j = 0; j < idxRS; j++)
{
rs_hdr[j].Fm = (float complex *)calloc(N_DFT+1, sizeof(float complex)); if (rs_hdr[j].Fm == NULL) return -1;
bits = rs_hdr[j].header;
spb = rs_hdr[j].spb;
sigma = sqrt(log(2)) / (2*M_PI*rs_hdr[j].BT);
for (i = 0; i < rs_hdr[j].L; i++) {
pos = i/spb;
t = (i - pos*spb)/spb - 0.5;
b1 = ((bits[pos] & 0x1) - 0.5)*2.0;
b = b1*pulse(t, sigma);
if (pos > 0) {
b0 = ((bits[pos-1] & 0x1) - 0.5)*2.0;
b += b0*pulse(t+1, sigma);
}
if (pos < hLen-1) {
b2 = ((bits[pos+1] & 0x1) - 0.5)*2.0;
b += b2*pulse(t-1, sigma);
}
match[i] = b;
}
normMatch = sqrt(norm2_match(match, rs_hdr[j].L));
for (i = 0; i < rs_hdr[j].L; i++) {
match[i] /= normMatch;
}
for (i = 0; i < rs_hdr[j].L; i++) m[rs_hdr[j].L-1 - i] = match[i]; // t = L-1
while (i < N_DFT) m[i++] = 0.0;
dft(m, rs_hdr[j].Fm);
}
if (option_iq)
{
for (j = 0; j < 2; j++) {
WS[j] = (float complex *)calloc(N_DFT+1, sizeof(float complex)); if (WS[j] == NULL) return -1;
for (i = 0; i < dsp__lpFMtaps; i++) m[i] = ws_lpFM[j][i];
while (i < N_DFT) m[i++] = 0.0;
dft(m, WS[j]);
}
Y = (float complex *)calloc(N_DFT+1, sizeof(float complex)); if (Y == NULL) return -1;
}
free(match); match = NULL;
free(m); m = NULL;
return K;
}
static int free_buffers() {
int j;
for (j = 0; j < 3; j++) {
if (buf_fm[j]) { free(buf_fm[j]); buf_fm[j] = NULL; }
}
if (rawbits) { free(rawbits); rawbits = NULL; }
if (xn) { free(xn); xn = NULL; }
if (db) { free(xn); xn = NULL; }
if (ew) { free(ew); ew = NULL; }
if (X) { free(X); X = NULL; }
if (Z) { free(Z); Z = NULL; }
if (cx) { free(cx); cx = NULL; }
for (j = 0; j < idxRS; j++) {
if (rs_hdr[j].Fm) { free(rs_hdr[j].Fm); rs_hdr[j].Fm = NULL; }
}
// iq buffers
if (option_iq == 5)
{
if (dsp__decXbuffer) { free(dsp__decXbuffer); dsp__decXbuffer = NULL; }
if (dsp__decMbuf) { free(dsp__decMbuf); dsp__decMbuf = NULL; }
if (dsp__ex) { free(dsp__ex); dsp__ex = NULL; }
}
if (option_iq) {
for (j = 0; j < 2; j++) {
if (ws_lpFM[j]) { free(ws_lpFM[j]); ws_lpFM[j] = NULL; }
if (WS[j]) { free(WS[j]); WS[j] = NULL; }
}
if (Y) { free(Y); Y = NULL; }
for (j = 0; j < 1; j++) {
if (ws_lpIQ[j]) { free(ws_lpIQ[j]); ws_lpIQ[j] = NULL; }
}
if (lpIQ_buf) { free(lpIQ_buf); lpIQ_buf = NULL; }
}
return 0;
}
/* ------------------------------------------------------------------------------------ */
int main(int argc, char **argv) {
FILE *fp = NULL;
char *fpname = NULL;
int j;
int k, K;
float mv[Nrs];
unsigned int mv_pos[Nrs], mv0_pos[Nrs];
int mp[Nrs];
int header_found = 0;
int herrs;
float thres = 0.76;
float tl = -1.0;
int j_max;
float mv_max;
#ifdef CYGWIN
_setmode(fileno(stdin), _O_BINARY); // _setmode(_fileno(stdin), _O_BINARY);
#endif
setbuf(stdout, NULL);
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, " -c (continuous)\n");
fprintf(stderr, " --iq (IF iq-data)\n");
fprintf(stderr, " --IQ <fq> (baseband IQ at fq)\n");
fprintf(stderr, " --bw <kHz> (set IQ filter bw/kHz)\n");
return 0;
}
else if ( (strcmp(*argv, "-v") == 0) || (strcmp(*argv, "--verbose") == 0) ) {
option_verbose = 1;
}
else if ( (strcmp(*argv, "--iq") == 0) ) { option_iq = 1; }
else if (strcmp(*argv, "--IQ") == 0) { // fq baseband -> IF (rotate from and decimate)
double fq = 0.0; // --IQ <fq> , -0.5 < fq < 0.5
++argv;
if (*argv) fq = atof(*argv);
else return -1;
if (fq < -0.5) fq = -0.5;
if (fq > 0.5) fq = 0.5;
dsp__xlt_fq = -fq; // S(t) -> S(t)*exp(-f*2pi*I*t)
option_iq = 5;
}
else if (strcmp(*argv, "--bw") == 0) { // set IQ filter bandwidth / kHz
double bw_kHz = 0.0;
++argv;
if (*argv) bw_kHz = atof(*argv); else return -1;
if (bw_kHz < 1.0) bw_kHz = 0.0; // min. 1kHz
set_lpIQ = bw_kHz * 1e3;
}
else if ( (strcmp(*argv, "--dc") == 0) ) { option_dc = 1; }
else if (strcmp(*argv, "--min") == 0) {
option_min = 1;
}
else if ( (strcmp(*argv, "-L") == 0) ) {
// L-band 1680kHz (IQ: decimation not limited)
lpIQ_bw[0] = 32e3;
lpIQ_bw[1] = 200e3;
lpIQ_bw[2] = 400e3;
}
else if ( (strcmp(*argv, "-c") == 0) || (strcmp(*argv, "--cnt") == 0) ) {
option_cont = 1;
}
else if ( (strcmp(*argv, "-s") == 0) || (strcmp(*argv, "--silent") == 0) ) {
option_silent = 1;
}
else if ( (strcmp(*argv, "-t") == 0) || (strcmp(*argv, "--time") == 0) ) {
++argv;
if (*argv) tl = atof(*argv);
else return -50;
}
else if ( (strcmp(*argv, "--ch2") == 0) ) { wav_channel = 1; } // right channel (default: 0=left)
else if ( (strcmp(*argv, "--ths") == 0) ) {
++argv;
if (*argv) {
thres = atof(*argv);
for (j = 0; j < Nrs; j++) rs_hdr[j].thres = thres;
}
else return -50;
}
else if (strcmp(*argv, "-") == 0) {
++argv;
if (*argv) sample_rate = atoi(*argv); else return -1;
++argv;
if (*argv) bits_sample = atoi(*argv); else return -1;
channels = 2;
if (sample_rate < 1 || (bits_sample != 8 && bits_sample != 16 && bits_sample != 32)) {
fprintf(stderr, "- <sr> <bs>\n");
return -1;
}
option_pcmraw = 1;
}
else {
fp = fopen(*argv, "rb");
if (fp == NULL) {
fprintf(stderr, "error: open %s\n", *argv);
return -50;
}
wavloaded = 1;
}
++argv;
}
if (!wavloaded) fp = stdin;
if (option_pcmraw == 0) {
j = read_wav_header(fp, wav_channel);
if ( j < 0 ) {
fclose(fp);
fprintf(stderr, "error: wav header\n");
return -50;
}
}
if (option_iq && channels < 2) {
fprintf(stderr, "error: iq channels < 2\n");
return -50;
}
K = init_buffers();
if ( K < 0 ) {
fprintf(stderr, "error: init buffers\n");
return -50;
};
for (j = 0; j < Nrs; j++) {
mv[j] = 0.0;
mv_pos[j] = 0;
mp[j] = 0;
}
j_max = 0;
mv_max = 0.0;
k = 0;
while ( f32buf_sample(fp, option_inv) != EOF ) {
if (tl > 0 && sample_in > (tl+1)*sample_rate) break; // (int)sample_out < 0
k += 1;
if (k >= K-4) {
for (j = 0; j <= idxIMETafsk; j++) { // incl. IMET-preamble
#ifdef NOC34C50
if ( strncmp(rs_hdr[j].type, "C34C50", 6) == 0 ) continue;
#endif
mv0_pos[j] = mv_pos[j];
mp[j] = getCorrDFT(K, 0, mv+j, mv_pos+j, rs_hdr+j);
}
k = 0;
}
else {
//for (j = 0; j < Nrs; j++) mv[j] = 0.0;
continue;
}
header_found = 0;
for (j = 0; j <= idxIMETafsk; j++) // incl. IMET-preamble
{
if (mp[j] > 0 && (mv[j] > rs_hdr[j].thres || mv[j] < -rs_hdr[j].thres)) {
if (mv_pos[j] > mv0_pos[j]) {
herrs = headcmp(1, mv_pos[j], mv[j]<0, rs_hdr+j);
if (herrs < rs_hdr[j].herrs) // max bit-errors in header
{
if ( strncmp(rs_hdr[j].type, "M10", 3) == 0 || strncmp(rs_hdr[j].type, "M20", 3) == 0)
{
ui32_t bytes = frm_M10(mv_pos[j], mv[j]<0, rs_hdr+j);
int len = (bytes >> 8) & 0xFF;
int h = hw(bytes & 0x0F); // type byte xF or x0 ?
if (h < 2 || h == 2 && (bytes&0xF0) == 0x20) {
rs_hdr[j].type = "M20";
rs_hdr[j].tn = tn_M20; // M20: 45 20
}
else {
rs_hdr[j].type = "M10";
rs_hdr[j].tn = tn_M10; // M10: 64 9F , M10+: 64 AF , M10-dop: 64 49 (len > 0x60)
}
}
if ( strncmp(rs_hdr[j].type, "IMETafsk", 8) == 0 ) // ? j == idxIMETafsk
{
int n, m;
int D = N_DFT/2 - 3;
float df;
float pow2200, pow2400;
int bin2200, bin2400;
for (n = 0; n < N_DFT; n++) {
xn[n] = 0.0;
db[n] = 0.0;
}
n = 0;
while (n < sample_rate) { // 1 sec
if (f32buf_sample(fp, option_inv) == EOF) break;//goto ende;
xn[n % D] = buf_fm[rs_hdr[j].lpIQ][sample_out % M];
n++;
if (n % D == 0) {
dft(xn, X);
for (m = 0; m < N_DFT; m++) db[m] += cabs(X[m]);
}
}
df = bin2freq(1);
m = 50.0/df;
if (m < 1) m = 1;
if (freq2bin(2500) > N_DFT/2) goto ende;
bin2200 = freq2bin(2200);
pow2200 = 0.0;
for (n = 0; n < m; n++) pow2200 += db[ bin2200 - m/4 + n ];
bin2400 = freq2bin(2400);
pow2400 = 0.0;
for (n = 0; n < m; n++) pow2400 += db[ bin2400 - m/4 + n ];
mv[j] = fabs(mv[j]);
if (pow2200 > pow2400) { // IMET1RS: peak1: 1200Hz > peak2: 2200Hz > pow(800Hz)
int bin800 = freq2bin(800);
float pow800 = 0.0;
for (n = 0; n < m; n++) pow800 += db[ bin800 - m/4 + n ];
if (pow2200 > pow800) { // IMET -> IMET1RS/IMET4
int _j0 = j;
if (option_iq && set_lpIQ > 50e3) j = idxRS; else j = idxI4;
mv[j] = mv[_j0];
mv_pos[j] = mv_pos[_j0];
rs_hdr[j].dc = rs_hdr[_j0].dc;
rs_hdr[j].df = rs_hdr[_j0].df;
mv[_j0] = 0.0;
header_found = 1;
}
else mv[j] = 0.0;
}
else { // IMET -> IMET1AB ?
// IMET1AB post-processing might block MRZ detection
// skip after number of tries or detect imet1ab directly
//
mv[j] = 0.0;
}
}
else { // if not IMET
header_found = 1;
}
if (header_found) {
if (!option_silent && (mv[j] > rs_hdr[j].thres || mv[j] < -rs_hdr[j].thres)) {
if (option_verbose) fprintf(stdout, "sample: %d\n", mv_pos[j]);
fprintf(stdout, "%s: %.4f", rs_hdr[j].type, mv[j]);
if (option_dc && option_iq) {
fprintf(stdout, " , %+.1fHz", rs_hdr[j].df*sr_base);
if (option_verbose) {
fprintf(stdout, " [ fq-ofs: %+.6f", rs_hdr[j].df);
fprintf(stdout, " = %+.1fHz ]", rs_hdr[j].df*sr_base);
}
}
fprintf(stdout, "\n");
}
// if ((j < 3) && mv[j] < 0) header_found = -1;
if ( fabs(mv_max) < fabs(mv[j]) ) { // j-weights?
mv_max = mv[j];
j_max = j;
}
}
}
}
}
}
if (header_found && !option_cont) break;
header_found = 0;
for (j = 0; j < Nrs; j++) mv[j] = 0.0;
}
ende:
free_buffers();
fclose(fp);
// return only best result
// latest: j
if (mv_max) {
if (mv_max < 0 && j_max < 3) header_found = -1;
else header_found = 1;
}
else header_found = 0;
return (header_found * rs_hdr[j_max].tn);
}
Reference in New Issue View Git Blame Kopiuj bezpośredni odnośnik