keenerd-rtl-sdr/src/rtl_fm.c

1744 wiersze
43 KiB
C

/*
* rtl-sdr, turns your Realtek RTL2832 based DVB dongle into a SDR receiver
* Copyright (C) 2012 by Steve Markgraf <steve@steve-m.de>
* Copyright (C) 2012 by Hoernchen <la@tfc-server.de>
* Copyright (C) 2012 by Kyle Keen <keenerd@gmail.com>
* Copyright (C) 2013 by Elias Oenal <EliasOenal@gmail.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/*
* written because people could not do real time
* FM demod on Atom hardware with GNU radio
* based on rtl_sdr.c and rtl_tcp.c
*
* lots of locks, but that is okay
* (no many-to-many locks)
*
* todo:
* sanity checks
* frequency ranges could be stored better
* auto-hop after time limit
* peak detector to tune onto stronger signals
* fifo for active hop frequency
* clips
* noise squelch
* merge stereo patch
* merge udp patch
* testmode to detect overruns
* watchdog to reset bad dongle
* fix oversampling
*/
#include <errno.h>
#include <signal.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#ifdef __APPLE__
#include <sys/time.h>
#else
#include <time.h>
#endif
#ifndef _WIN32
#include <unistd.h>
#else
#include <windows.h>
#include <fcntl.h>
#include <io.h>
#include "getopt/getopt.h"
#define usleep(x) Sleep(x/1000)
#if defined(_MSC_VER) && _MSC_VER < 1800
#define round(x) (x > 0.0 ? floor(x + 0.5): ceil(x - 0.5))
#endif
#define _USE_MATH_DEFINES
#endif
#include <math.h>
#include <pthread.h>
#include <libusb.h>
#include "rtl-sdr.h"
#include "convenience/convenience.h"
#define DEFAULT_SAMPLE_RATE 24000
#define DEFAULT_BUF_LENGTH (1 * 16384)
#define MAXIMUM_OVERSAMPLE 16
#define MAXIMUM_BUF_LENGTH (MAXIMUM_OVERSAMPLE * DEFAULT_BUF_LENGTH)
#define AUTO_GAIN -100
#define BUFFER_DUMP 4096
#define MAXIMUM_RATE 2400000
#define FREQUENCIES_LIMIT 1000
#define PI_INT (1<<14)
#define ONE_INT (1<<14)
static volatile int do_exit = 0;
static int lcm_post[17] = {1,1,1,3,1,5,3,7,1,9,5,11,3,13,7,15,1};
static int ACTUAL_BUF_LENGTH;
static uint32_t MINIMUM_RATE = 1000000;
static int *atan_lut = NULL;
static int atan_lut_size = 131072; /* 512 KB */
static int atan_lut_coef = 8;
// rewrite as dynamic and thread-safe for multi demod/dongle
#define SHARED_SIZE 6
int16_t shared_samples[SHARED_SIZE][MAXIMUM_BUF_LENGTH];
int ss_busy[SHARED_SIZE] = {0};
enum agc_mode_t
{
agc_off = 0,
agc_normal,
agc_aggressive
};
struct dongle_state
{
int exit_flag;
pthread_t thread;
rtlsdr_dev_t *dev;
int dev_index;
uint32_t freq;
uint32_t rate;
int gain;
int16_t *buf16;
uint32_t buf_len;
int ppm_error;
int offset_tuning;
int direct_sampling;
int mute;
int pre_rotate;
struct demod_state *targets[2];
};
struct agc_state
{
int32_t gain_num;
int32_t gain_den;
int32_t gain_max;
int peak_target;
int attack_step;
int decay_step;
int error;
};
struct translate_state
{
double angle; /* radians */
int16_t *sincos; /* pairs */
int len;
int i;
};
struct demod_state
{
int exit_flag;
pthread_t thread;
int16_t *lowpassed;
int lp_len;
int16_t lp_i_hist[10][6];
int16_t lp_q_hist[10][6];
int16_t droop_i_hist[9];
int16_t droop_q_hist[9];
int rate_in;
int rate_out;
int rate_out2;
int now_r, now_j;
int pre_r, pre_j;
int prev_index;
int downsample; /* min 1, max 256 */
int post_downsample;
int output_scale;
int squelch_level, conseq_squelch, squelch_hits, terminate_on_squelch;
int downsample_passes;
int comp_fir_size;
int custom_atan;
int deemph, deemph_a;
int now_lpr;
int prev_lpr_index;
int dc_block, dc_avg;
int rotate_enable;
struct translate_state rotate;
enum agc_mode_t agc_mode;
struct agc_state *agc;
void (*mode_demod)(struct demod_state*);
pthread_rwlock_t rw;
pthread_cond_t ready;
pthread_mutex_t ready_m;
struct buffer_bucket *output_target;
};
struct buffer_bucket
{
int16_t *buf;
int len;
pthread_rwlock_t rw;
pthread_cond_t ready;
pthread_mutex_t ready_m;
pthread_mutex_t trycond_m;
int trycond;
};
struct output_state
{
int exit_flag;
pthread_t thread;
FILE *file;
char *filename;
struct buffer_bucket results[2];
int rate;
int wav_format;
int padded;
int lrmix;
};
struct controller_state
{
int exit_flag;
pthread_t thread;
uint32_t freqs[FREQUENCIES_LIMIT];
int freq_len;
int freq_now;
int edge;
int wb_mode;
pthread_cond_t hop;
pthread_mutex_t hop_m;
};
// multiple of these, eventually
struct dongle_state dongle;
struct demod_state demod;
struct demod_state demod2;
struct output_state output;
struct controller_state controller;
void usage(void)
{
fprintf(stderr,
"rtl_fm, a simple narrow band FM demodulator for RTL2832 based DVB-T receivers\n\n"
"Use:\trtl_fm -f freq [-options] [filename]\n"
"\t-f frequency_to_tune_to [Hz]\n"
"\t use multiple -f for scanning (requires squelch)\n"
"\t ranges supported, -f 118M:137M:25k\n"
"\t[-M modulation (default: fm)]\n"
"\t fm, wbfm, raw, am, usb, lsb\n"
"\t wbfm == -M fm -s 170k -o 4 -A fast -r 32k -l 0 -E deemp\n"
"\t raw mode outputs 2x16 bit IQ pairs\n"
"\t[-s sample_rate (default: 24k)]\n"
"\t[-d device_index (default: 0)]\n"
"\t[-g tuner_gain (default: automatic)]\n"
"\t[-l squelch_level (default: 0/off)]\n"
//"\t for fm squelch is inverted\n"
//"\t[-o oversampling (default: 1, 4 recommended)]\n"
"\t[-p ppm_error (default: 0)]\n"
"\t[-E enable_option (default: none)]\n"
"\t use multiple -E to enable multiple options\n"
"\t edge: enable lower edge tuning\n"
"\t no-dc: disable dc blocking filter\n"
"\t deemp: enable de-emphasis filter\n"
"\t swagc: enable software agc (only for AM modes)\n"
"\t swagc-aggressive: enable aggressive software agc (only for AM modes)\n"
"\t direct: enable direct sampling\n"
"\t no-mod: enable no-mod direct sampling\n"
"\t offset: enable offset tuning\n"
"\t wav: generate WAV header\n"
"\t pad: pad output gaps with zeros\n"
"\t lrmix: one channel goes to left audio, one to right (broken)\n"
"\t remember to enable stereo (-c 2) in sox\n"
"\tfilename ('-' means stdout)\n"
"\t omitting the filename also uses stdout\n\n"
"Experimental options:\n"
"\t[-r resample_rate (default: none / same as -s)]\n"
"\t[-t squelch_delay (default: 10)]\n"
"\t +values will mute/scan, -values will exit\n"
"\t[-F fir_size (default: off)]\n"
"\t enables low-leakage downsample filter\n"
"\t size can be 0 or 9. 0 has bad roll off\n"
"\t[-A std/fast/lut/ale choose atan math (default: std)]\n"
//"\t[-C clip_path (default: off)\n"
//"\t (create time stamped raw clips, requires squelch)\n"
//"\t (path must have '\%s' and will expand to date_time_freq)\n"
//"\t[-H hop_fifo (default: off)\n"
//"\t (fifo will contain the active frequency)\n"
"\n"
"Produces signed 16 bit ints, use Sox or aplay to hear them.\n"
"\trtl_fm ... | play -t raw -r 24k -es -b 16 -c 1 -V1 -\n"
"\t | aplay -r 24k -f S16_LE -t raw -c 1\n"
"\t -M wbfm | play -r 32k ... \n"
"\t -E wav | play -t wav - \n"
"\t -s 22050 | multimon -t raw /dev/stdin\n\n");
exit(1);
}
#ifdef _WIN32
BOOL WINAPI
sighandler(int signum)
{
if (CTRL_C_EVENT == signum) {
fprintf(stderr, "Signal caught, exiting!\n");
do_exit = 1;
rtlsdr_cancel_async(dongle.dev);
return TRUE;
}
return FALSE;
}
#else
static void sighandler(int signum)
{
fprintf(stderr, "Signal caught, exiting!\n");
do_exit = 1;
rtlsdr_cancel_async(dongle.dev);
}
#endif
/* more cond dumbness */
#define safe_cond_signal(n, m) pthread_mutex_lock(m); pthread_cond_signal(n); pthread_mutex_unlock(m)
#define safe_cond_wait(n, m) pthread_mutex_lock(m); pthread_cond_wait(n, m); pthread_mutex_unlock(m)
/* {length, coef, coef, coef} and scaled by 2^15
for now, only length 9, optimal way to get +85% bandwidth */
#define CIC_TABLE_MAX 10
int cic_9_tables[][10] = {
{0,},
{9, -156, -97, 2798, -15489, 61019, -15489, 2798, -97, -156},
{9, -128, -568, 5593, -24125, 74126, -24125, 5593, -568, -128},
{9, -129, -639, 6187, -26281, 77511, -26281, 6187, -639, -129},
{9, -122, -612, 6082, -26353, 77818, -26353, 6082, -612, -122},
{9, -120, -602, 6015, -26269, 77757, -26269, 6015, -602, -120},
{9, -120, -582, 5951, -26128, 77542, -26128, 5951, -582, -120},
{9, -119, -580, 5931, -26094, 77505, -26094, 5931, -580, -119},
{9, -119, -578, 5921, -26077, 77484, -26077, 5921, -578, -119},
{9, -119, -577, 5917, -26067, 77473, -26067, 5917, -577, -119},
{9, -199, -362, 5303, -25505, 77489, -25505, 5303, -362, -199},
};
#if defined(_MSC_VER) && _MSC_VER < 1800
double log2(double n)
{
return log(n) / log(2.0);
}
#endif
void rotate_90(unsigned char *buf, uint32_t len)
/* 90 rotation is 1+0j, 0+1j, -1+0j, 0-1j
or [0, 1, -3, 2, -4, -5, 7, -6] */
{
uint32_t i;
unsigned char tmp;
for (i=0; i<len; i+=8) {
/* uint8_t negation = 255 - x */
tmp = 255 - buf[i+3];
buf[i+3] = buf[i+2];
buf[i+2] = tmp;
buf[i+4] = 255 - buf[i+4];
buf[i+5] = 255 - buf[i+5];
tmp = 255 - buf[i+6];
buf[i+6] = buf[i+7];
buf[i+7] = tmp;
}
}
int translate_init(struct translate_state *ts)
/* two pass: first to find optimal length, second to alloc/fill */
{
int max_length = 100000;
int i, s, c, best_i;
double a, a2, err, best_360;
if (fabs(ts->angle) < 2*M_PI/max_length) {
fprintf(stderr, "angle too small or array too short\n");
return 1;
}
ts->i = 0;
ts->sincos = NULL;
if (ts->len) {
max_length = ts->len;
ts->sincos = malloc(max_length * sizeof(int16_t));
}
a = 0.0;
err = 0.0;
best_i = 0;
best_360 = 4.0;
for (i=0; i < max_length; i+=2) {
s = (int)round(sin(a + err) * (1<<14));
c = (int)round(cos(a + err) * (1<<14));
a2 = atan2(s, c);
err = fmod(a, 2*M_PI) - a2;
a += ts->angle;
while (a > M_PI) {
a -= 2*M_PI;}
while (a < -M_PI) {
a += 2*M_PI;}
if (i != 0 && fabs(a) < best_360) {
best_i = i;
best_360 = fabs(a);
}
if (i != 0 && fabs(a) < 0.0000001) {
break;}
if (ts->sincos) {
ts->sincos[i] = s;
ts->sincos[i+1] = c;
//fprintf(stderr, "%i %i %i\n", i, s, c);
}
}
if (ts->sincos) {
return 0;
}
ts->len = best_i + 2;
return translate_init(ts);
}
void translate(struct demod_state *d)
{
int i, len, sc_i, sc_len;
int32_t tmp, ar, aj, br, bj;
int16_t *buf = d->lowpassed;
int16_t *sincos = d->rotate.sincos;
len = d->lp_len;
sc_i = d->rotate.i;
sc_len = d->rotate.len;
for (i=0; i<len; i+=2, sc_i+=2) {
sc_i = sc_i % sc_len;
ar = (int32_t)buf[i];
aj = (int32_t)buf[i+1];
br = (int32_t)sincos[sc_i];
bj = (int32_t)sincos[sc_i+1];
tmp = ar*br - aj*bj;
buf[i] = (int16_t)(tmp >> 14);
tmp = aj*br + ar*bj;
buf[i+1] = (int16_t)(tmp >> 14);
}
d->rotate.i = sc_i;
}
void low_pass(struct demod_state *d)
/* simple square window FIR */
{
int i=0, i2=0;
while (i < d->lp_len) {
d->now_r += d->lowpassed[i];
d->now_j += d->lowpassed[i+1];
i += 2;
d->prev_index++;
if (d->prev_index < d->downsample) {
continue;
}
d->lowpassed[i2] = d->now_r; // * d->output_scale;
d->lowpassed[i2+1] = d->now_j; // * d->output_scale;
d->prev_index = 0;
d->now_r = 0;
d->now_j = 0;
i2 += 2;
}
d->lp_len = i2;
}
int low_pass_simple(int16_t *signal2, int len, int step)
// no wrap around, length must be multiple of step
{
int i, i2, sum;
for(i=0; i < len; i+=step) {
sum = 0;
for(i2=0; i2<step; i2++) {
sum += (int)signal2[i + i2];
}
//signal2[i/step] = (int16_t)(sum / step);
signal2[i/step] = (int16_t)(sum);
}
signal2[i/step + 1] = signal2[i/step];
return len / step;
}
void low_pass_real(struct demod_state *s)
/* simple square window FIR */
// add support for upsampling?
{
int16_t *lp = s->lowpassed;
int i=0, i2=0;
int fast = (int)s->rate_out;
int slow = s->rate_out2;
while (i < s->lp_len) {
s->now_lpr += lp[i];
i++;
s->prev_lpr_index += slow;
if (s->prev_lpr_index < fast) {
continue;
}
lp[i2] = (int16_t)(s->now_lpr / (fast/slow));
s->prev_lpr_index -= fast;
s->now_lpr = 0;
i2 += 1;
}
s->lp_len = i2;
}
void fifth_order(int16_t *data, int length, int16_t *hist)
/* for half of interleaved data */
{
int i;
int16_t a, b, c, d, e, f;
a = hist[1];
b = hist[2];
c = hist[3];
d = hist[4];
e = hist[5];
f = data[0];
/* a downsample should improve resolution, so don't fully shift */
data[0] = (a + (b+e)*5 + (c+d)*10 + f) >> 4;
for (i=4; i<length; i+=4) {
a = c;
b = d;
c = e;
d = f;
e = data[i-2];
f = data[i];
data[i/2] = (a + (b+e)*5 + (c+d)*10 + f) >> 4;
}
/* archive */
hist[0] = a;
hist[1] = b;
hist[2] = c;
hist[3] = d;
hist[4] = e;
hist[5] = f;
}
void generic_fir(int16_t *data, int length, int *fir, int16_t *hist)
/* Okay, not at all generic. Assumes length 9, fix that eventually. */
{
int d, temp, sum;
for (d=0; d<length; d+=2) {
temp = data[d];
sum = 0;
sum += (hist[0] + hist[8]) * fir[1];
sum += (hist[1] + hist[7]) * fir[2];
sum += (hist[2] + hist[6]) * fir[3];
sum += (hist[3] + hist[5]) * fir[4];
sum += hist[4] * fir[5];
data[d] = sum >> 15 ;
hist[0] = hist[1];
hist[1] = hist[2];
hist[2] = hist[3];
hist[3] = hist[4];
hist[4] = hist[5];
hist[5] = hist[6];
hist[6] = hist[7];
hist[7] = hist[8];
hist[8] = temp;
}
}
/* define our own complex math ops
because ARMv5 has no hardware float */
void multiply(int ar, int aj, int br, int bj, int *cr, int *cj)
{
*cr = ar*br - aj*bj;
*cj = aj*br + ar*bj;
}
int polar_discriminant(int ar, int aj, int br, int bj)
{
int cr, cj;
double angle;
multiply(ar, aj, br, -bj, &cr, &cj);
angle = atan2((double)cj, (double)cr);
return (int)(angle / M_PI * (1<<14));
}
int fast_atan2(int y, int x)
/* pre scaled for int16 */
{
int yabs, angle;
int pi4=(1<<12), pi34=3*(1<<12); // note pi = 1<<14
if (x==0 && y==0) {
return 0;
}
yabs = y;
if (yabs < 0) {
yabs = -yabs;
}
if (x >= 0) {
angle = pi4 - pi4 * (x-yabs) / (x+yabs);
} else {
angle = pi34 - pi4 * (x+yabs) / (yabs-x);
}
if (y < 0) {
return -angle;
}
return angle;
}
int polar_disc_fast(int ar, int aj, int br, int bj)
{
int cr, cj;
multiply(ar, aj, br, -bj, &cr, &cj);
return fast_atan2(cj, cr);
}
int atan_lut_init(void)
{
int i = 0;
atan_lut = malloc(atan_lut_size * sizeof(int));
for (i = 0; i < atan_lut_size; i++) {
atan_lut[i] = (int) (atan((double) i / (1<<atan_lut_coef)) / M_PI * (1<<14));
}
return 0;
}
int polar_disc_lut(int ar, int aj, int br, int bj)
{
int cr, cj, x, x_abs;
multiply(ar, aj, br, -bj, &cr, &cj);
/* special cases */
if (cr == 0 || cj == 0) {
if (cr == 0 && cj == 0)
{return 0;}
if (cr == 0 && cj > 0)
{return 1 << 13;}
if (cr == 0 && cj < 0)
{return -(1 << 13);}
if (cj == 0 && cr > 0)
{return 0;}
if (cj == 0 && cr < 0)
{return 1 << 14;}
}
/* real range -32768 - 32768 use 64x range -> absolute maximum: 2097152 */
x = (cj << atan_lut_coef) / cr;
x_abs = abs(x);
if (x_abs >= atan_lut_size) {
/* we can use linear range, but it is not necessary */
return (cj > 0) ? 1<<13 : -1<<13;
}
if (x > 0) {
return (cj > 0) ? atan_lut[x] : atan_lut[x] - (1<<14);
} else {
return (cj > 0) ? (1<<14) - atan_lut[-x] : -atan_lut[-x];
}
return 0;
}
int esbensen(int ar, int aj, int br, int bj)
/*
input signal: s(t) = a*exp(-i*w*t+p)
a = amplitude, w = angular freq, p = phase difference
solve w
s' = -i(w)*a*exp(-i*w*t+p)
s'*conj(s) = -i*w*a*a
s'*conj(s) / |s|^2 = -i*w
*/
{
int cj, dr, dj;
int scaled_pi = 2608; /* 1<<14 / (2*pi) */
dr = (br - ar) * 2;
dj = (bj - aj) * 2;
cj = bj*dr - br*dj; /* imag(ds*conj(s)) */
return (scaled_pi * cj / (ar*ar+aj*aj+1));
}
void fm_demod(struct demod_state *fm)
{
int i, pcm = 0;
int16_t *lp = fm->lowpassed;
int16_t pr = fm->pre_r;
int16_t pj = fm->pre_j;
for (i = 0; i < (fm->lp_len-1); i += 2) {
switch (fm->custom_atan) {
case 0:
pcm = polar_discriminant(lp[i], lp[i+1], pr, pj);
break;
case 1:
pcm = polar_disc_fast(lp[i], lp[i+1], pr, pj);
break;
case 2:
pcm = polar_disc_lut(lp[i], lp[i+1], pr, pj);
break;
case 3:
pcm = esbensen(lp[i], lp[i+1], pr, pj);
break;
}
pr = lp[i];
pj = lp[i+1];
fm->lowpassed[i/2] = (int16_t)pcm;
}
fm->pre_r = pr;
fm->pre_j = pj;
fm->lp_len = fm->lp_len / 2;
}
void am_demod(struct demod_state *fm)
// todo, fix this extreme laziness
{
int32_t i, pcm;
int16_t *lp = fm->lowpassed;
for (i = 0; i < fm->lp_len; i += 2) {
// hypot uses floats but won't overflow
//r[i/2] = (int16_t)hypot(lp[i], lp[i+1]);
pcm = lp[i] * lp[i];
pcm += lp[i+1] * lp[i+1];
lp[i/2] = (int16_t)sqrt(pcm) * fm->output_scale;
}
fm->lp_len = fm->lp_len / 2;
// lowpass? (3khz)
}
void usb_demod(struct demod_state *fm)
{
int i, pcm;
int16_t *lp = fm->lowpassed;
for (i = 0; i < fm->lp_len; i += 2) {
pcm = lp[i] + lp[i+1];
lp[i/2] = (int16_t)pcm * fm->output_scale;
}
fm->lp_len = fm->lp_len / 2;
}
void lsb_demod(struct demod_state *fm)
{
int i, pcm;
int16_t *lp = fm->lowpassed;
for (i = 0; i < fm->lp_len; i += 2) {
pcm = lp[i] - lp[i+1];
lp[i/2] = (int16_t)pcm * fm->output_scale;
}
fm->lp_len = fm->lp_len / 2;
}
void raw_demod(struct demod_state *fm)
{
return;
}
void deemph_filter(struct demod_state *fm)
{
static int avg; // cheating, not threadsafe
int i, d;
int16_t *lp = fm->lowpassed;
// de-emph IIR
// avg = avg * (1 - alpha) + sample * alpha;
for (i = 0; i < fm->lp_len; i++) {
d = lp[i] - avg;
if (d > 0) {
avg += (d + fm->deemph_a/2) / fm->deemph_a;
} else {
avg += (d - fm->deemph_a/2) / fm->deemph_a;
}
lp[i] = (int16_t)avg;
}
}
void dc_block_filter(struct demod_state *fm)
{
int i, avg;
int64_t sum = 0;
int16_t *lp = fm->lowpassed;
for (i=0; i < fm->lp_len; i++) {
sum += lp[i];
}
avg = (int)(sum / fm->lp_len);
avg = (avg + fm->dc_avg * 9) / 10;
for (i=0; i < fm->lp_len; i++) {
lp[i] -= avg;
}
fm->dc_avg = avg;
}
int mad(int16_t *samples, int len, int step)
/* mean average deviation */
{
int i=0, sum=0, ave=0;
if (len == 0)
{return 0;}
for (i=0; i<len; i+=step) {
sum += samples[i];
}
ave = sum / (len * step);
sum = 0;
for (i=0; i<len; i+=step) {
sum += abs(samples[i] - ave);
}
return sum / (len / step);
}
int rms(int16_t *samples, int len, int step)
/* largely lifted from rtl_power */
{
int i;
long p, t, s;
double dc, err;
p = t = 0L;
for (i=0; i<len; i+=step) {
s = (long)samples[i];
t += s;
p += s * s;
}
/* correct for dc offset in squares */
dc = (double)(t*step) / (double)len;
err = t * 2 * dc - dc * dc * len;
return (int)sqrt((p-err) / len);
}
int squelch_to_rms(int db, struct dongle_state *dongle, struct demod_state *demod)
/* 0 dB = 1 rms at 50dB gain and 1024 downsample */
{
double linear, gain, downsample;
if (db == 0) {
return 0;}
linear = pow(10.0, (double)db/20.0);
gain = 50.0;
if (dongle->gain != AUTO_GAIN) {
gain = (double)(dongle->gain) / 10.0;
}
gain = 50.0 - gain;
gain = pow(10.0, gain/20.0);
downsample = 1024.0 / (double)demod->downsample;
linear = linear / gain;
linear = linear / downsample;
return (int)linear + 1;
}
void software_agc(struct demod_state *d)
{
int i = 0;
int peaked = 0;
int32_t output = 0;
int abs_output = 0;
struct agc_state *agc = d->agc;
int16_t *lp = d->lowpassed;
int attack_step = agc->attack_step;
int aggressive = agc_aggressive == d->agc_mode;
float peak_factor = 1.0;
for (i=0; i < d->lp_len; i++) {
output = (int32_t)lp[i] * agc->gain_num + agc->error;
agc->error = output % agc->gain_den;
output /= agc->gain_den;
abs_output = abs(output);
peaked = abs_output > agc->peak_target;
if (peaked && aggressive && attack_step <= 1) {
peak_factor = fmin(5.0, (float) abs_output / agc->peak_target);
attack_step = (int) (pow(agc->attack_step - peak_factor, peak_factor) * (176 + 3 * peak_factor));
}
if (peaked) {
agc->gain_num -= attack_step;
if (aggressive) {
attack_step = (int) (attack_step / 1.2);
}
} else {
agc->gain_num += agc->decay_step;
}
if (agc->gain_num < agc->gain_den) {
agc->gain_num = agc->gain_den;}
if (agc->gain_num > agc->gain_max) {
agc->gain_num = agc->gain_max;}
if (output >= (1<<15)) {
output = (1<<15) - 1;}
if (output < -(1<<15)) {
output = -(1<<15) + 1;}
lp[i] = (int16_t)output;
}
}
void full_demod(struct demod_state *d)
{
int i, ds_p;
int do_squelch = 0;
int sr = 0;
if(d->rotate_enable) {
translate(d);
}
ds_p = d->downsample_passes;
if (ds_p) {
for (i=0; i < ds_p; i++) {
fifth_order(d->lowpassed, (d->lp_len >> i), d->lp_i_hist[i]);
fifth_order(d->lowpassed+1, (d->lp_len >> i) - 1, d->lp_q_hist[i]);
}
d->lp_len = d->lp_len >> ds_p;
/* droop compensation */
if (d->comp_fir_size == 9 && ds_p <= CIC_TABLE_MAX) {
generic_fir(d->lowpassed, d->lp_len,
cic_9_tables[ds_p], d->droop_i_hist);
generic_fir(d->lowpassed+1, d->lp_len-1,
cic_9_tables[ds_p], d->droop_q_hist);
}
} else {
low_pass(d);
}
/* power squelch */
if (d->squelch_level) {
sr = rms(d->lowpassed, d->lp_len, 1);
if (sr < d->squelch_level) {
do_squelch = 1;}
}
if (do_squelch) {
d->squelch_hits++;
for (i=0; i<d->lp_len; i++) {
d->lowpassed[i] = 0;
}
} else {
d->squelch_hits = 0;
}
if (d->squelch_level && d->squelch_hits > d->conseq_squelch) {
d->agc->gain_num = d->agc->gain_den;
}
d->mode_demod(d); /* lowpassed -> lowpassed */
if (d->mode_demod == &raw_demod) {
return;}
if (d->dc_block) {
dc_block_filter(d);}
if (d->agc_mode != agc_off) {
software_agc(d);}
/* todo, fm noise squelch */
// use nicer filter here too?
if (d->post_downsample > 1) {
d->lp_len = low_pass_simple(d->lowpassed, d->lp_len, d->post_downsample);}
if (d->deemph) {
deemph_filter(d);}
if (d->rate_out2 > 0) {
low_pass_real(d);
//arbitrary_resample(d->lowpassed, d->lowpassed, d->lp_len, d->lp_len * d->rate_out2 / d->rate_out);
}
}
int16_t* mark_shared_buffer(void)
{
int i = 0;
for (i=0; i<SHARED_SIZE; i++) {
if (ss_busy[i] == 0) {
ss_busy[i] = 1;
return shared_samples[i];
}
}
/* worst case, nuke a buffer */
ss_busy[0];
return shared_samples[0];
}
int unmark_shared_buffer(int16_t *buf)
{
int i;
for (i=0; i<SHARED_SIZE; i++) {
if (shared_samples[i] == buf) {
ss_busy[i] = 0;
return 0;
}
}
return 1;
}
static void rtlsdr_callback(unsigned char *buf, uint32_t len, void *ctx)
{
int i;
struct dongle_state *s = ctx;
struct demod_state *d;
struct demod_state *d2;
if (do_exit) {
return;}
if (!s) {
return;}
d = s->targets[0];
d2 = s->targets[1];
if (s->mute) {
for (i=0; i<s->mute; i++) {
buf[i] = 127;}
s->mute = 0;
}
if (s->pre_rotate) {
rotate_90(buf, len);}
for (i=0; i<(int)len; i++) {
s->buf16[i] = (int16_t)buf[i] - 127;}
if (d2 != NULL) {
pthread_rwlock_wrlock(&d2->rw);
d2->lowpassed = mark_shared_buffer();
memcpy(d2->lowpassed, s->buf16, 2*len);
d2->lp_len = len;
pthread_rwlock_unlock(&d2->rw);
safe_cond_signal(&d2->ready, &d2->ready_m);
}
pthread_rwlock_wrlock(&d->rw);
d->lowpassed = s->buf16;
d->lp_len = len;
pthread_rwlock_unlock(&d->rw);
safe_cond_signal(&d->ready, &d->ready_m);
s->buf16 = mark_shared_buffer();
}
static void *dongle_thread_fn(void *arg)
{
struct dongle_state *s = arg;
rtlsdr_read_async(s->dev, rtlsdr_callback, s, 0, s->buf_len);
return 0;
}
static void *demod_thread_fn(void *arg)
{
struct demod_state *d = arg;
struct buffer_bucket *o = d->output_target;
while (!do_exit) {
safe_cond_wait(&d->ready, &d->ready_m);
pthread_rwlock_wrlock(&d->rw);
full_demod(d);
pthread_rwlock_unlock(&d->rw);
if (d->exit_flag) {
do_exit = 1;
}
pthread_rwlock_wrlock(&o->rw);
o->buf = d->lowpassed;
o->len = d->lp_len;
pthread_rwlock_unlock(&o->rw);
if (controller.freq_len > 1 && d->squelch_level && \
d->squelch_hits > d->conseq_squelch) {
unmark_shared_buffer(d->lowpassed);
d->squelch_hits = d->conseq_squelch + 1; /* hair trigger */
safe_cond_signal(&controller.hop, &controller.hop_m);
continue;
}
safe_cond_signal(&o->ready, &o->ready_m);
pthread_mutex_lock(&o->trycond_m);
o->trycond = 0;
pthread_mutex_unlock(&o->trycond_m);
}
return 0;
}
#ifndef _WIN32
static int get_nanotime(struct timespec *ts)
{
int rv = ENOSYS;
#ifdef __unix__
rv = clock_gettime(CLOCK_MONOTONIC, ts);
#elif __APPLE__
struct timeval tv;
rv = gettimeofday(&tv, NULL);
ts->tv_sec = tv.tv_sec;
ts->tv_nsec = tv.tv_usec * 1000L;
#endif
return rv;
}
#endif
static void *output_thread_fn(void *arg)
{
int j, r = 0;
struct output_state *s = arg;
struct buffer_bucket *b0 = &s->results[0];
struct buffer_bucket *b1 = &s->results[1];
int64_t i, duration, samples = 0LL, samples_now;
#ifdef _WIN32
LARGE_INTEGER perfFrequency;
LARGE_INTEGER start_time;
LARGE_INTEGER now_time;
QueryPerformanceFrequency(&perfFrequency);
QueryPerformanceCounter(&start_time);
#else
struct timespec start_time;
struct timespec now_time;
get_nanotime(&start_time);
#endif
while (!do_exit) {
if (s->lrmix) {
safe_cond_wait(&b0->ready, &b0->ready_m);
pthread_rwlock_rdlock(&b0->rw);
safe_cond_wait(&b1->ready, &b1->ready_m);
pthread_rwlock_rdlock(&b1->rw);
for(j=0; j < b0->len; j++) {
fwrite(b0->buf+j, 2, 1, s->file);
fwrite(b1->buf+j, 2, 1, s->file);
}
unmark_shared_buffer(b1->buf);
pthread_rwlock_unlock(&b1->rw);
unmark_shared_buffer(b0->buf);
pthread_rwlock_unlock(&b0->rw);
continue;
}
if (!s->padded) {
safe_cond_wait(&b0->ready, &b0->ready_m);
pthread_rwlock_rdlock(&b0->rw);
fwrite(b0->buf, 2, b0->len, s->file);
unmark_shared_buffer(b0->buf);
pthread_rwlock_unlock(&b0->rw);
continue;
}
/* padding requires output at constant rate */
/* pthread_cond_timedwait is terrible, roll our own trycond */
usleep(2000);
pthread_mutex_lock(&b0->trycond_m);
r = b0->trycond;
b0->trycond = 1;
pthread_mutex_unlock(&b0->trycond_m);
if (r == 0) {
pthread_rwlock_rdlock(&b0->rw);
fwrite(b0->buf, 2, b0->len, s->file);
unmark_shared_buffer(b0->buf);
samples += (int64_t)b0->len;
pthread_rwlock_unlock(&b0->rw);
continue;
}
#ifdef _WIN32
QueryPerformanceCounter(&now_time);
duration = now_time.QuadPart - start_time.QuadPart;
samples_now = (duration * s->rate) / perfFrequency.QuadPart;
#else
get_nanotime(&now_time);
duration = now_time.tv_sec - start_time.tv_sec;
duration *= 1000000000L;
duration += (now_time.tv_nsec - start_time.tv_nsec);
samples_now = (duration * s->rate) / 1000000000UL;
#endif
if (samples_now < samples) {
continue;}
for (i=samples; i<samples_now; i++) {
fputc(0, s->file);
fputc(0, s->file);
}
samples = samples_now;
}
return 0;
}
static void optimal_settings(int freq, int rate)
{
// giant ball of hacks
// seems unable to do a single pass, 2:1
int capture_freq, capture_rate;
struct dongle_state *d = &dongle;
struct demod_state *dm = &demod;
struct controller_state *cs = &controller;
dm->downsample = (MINIMUM_RATE / dm->rate_in) + 1;
if (dm->downsample_passes) {
dm->downsample_passes = (int)log2(dm->downsample) + 1;
dm->downsample = 1 << dm->downsample_passes;
}
capture_freq = freq;
capture_rate = dm->downsample * dm->rate_in;
if (d->pre_rotate) {
capture_freq = freq + capture_rate/4;}
capture_freq += cs->edge * dm->rate_in / 2;
dm->output_scale = (1<<15) / (128 * dm->downsample);
if (dm->output_scale < 1) {
dm->output_scale = 1;}
if (dm->mode_demod == &fm_demod) {
dm->output_scale = 1;}
d->freq = (uint32_t)capture_freq;
d->rate = (uint32_t)capture_rate;
//d->pre_rotate = 0;
//demod.rotate_enable = 1;
//demod.rotate.angle = -0.25 * 2 * M_PI;
//translate_init(&demod.rotate);
}
void clone_demod(struct demod_state *d2, struct demod_state *d1)
/* copy from d1 to d2 */
{
d2->rate_in = d1->rate_in;
d2->rate_out = d1->rate_out;
d2->rate_out2 = d1->rate_out2;
d2->downsample = d1->downsample;
d2->downsample_passes = d1->downsample_passes;
d2->post_downsample = d1->post_downsample;
d2->output_scale = d1->output_scale;
d2->squelch_level = d1->squelch_level;
d2->conseq_squelch = d1->conseq_squelch;
d2->squelch_hits = d1->squelch_hits;
d2->terminate_on_squelch = d1->terminate_on_squelch;
d2->comp_fir_size = d1->comp_fir_size;
d2->custom_atan = d1->custom_atan;
d2->deemph = d1->deemph;
d2->deemph_a = d1->deemph_a;
d2->dc_block = d1->dc_block;
d2->rotate_enable = d1->rotate_enable;
d2->agc_mode = d1->agc_mode;
d2->mode_demod = d1->mode_demod;
}
void optimal_lrmix(void)
{
double angle1, angle2;
uint32_t freq, freq1, freq2, bw, dongle_bw, mr;
if (controller.freq_len != 2) {
fprintf(stderr, "error: lrmix requires two frequencies\n");
do_exit = 1;
exit(1);
}
if (output.padded) {
fprintf(stderr, "warning: lrmix does not support padding\n");
}
freq1 = controller.freqs[0];
freq2 = controller.freqs[1];
bw = demod.rate_out;
freq = freq1 / 2 + freq2 / 2 + bw;
mr = (uint32_t)abs((int64_t)freq1 - (int64_t)freq2) + bw;
if (mr > MINIMUM_RATE) {
MINIMUM_RATE = mr;}
dongle.pre_rotate = 0;
optimal_settings(freq, bw);
output.padded = 0;
clone_demod(&demod2, &demod);
//demod2 = demod;
demod2.output_target = &output.results[1];
dongle.targets[1] = &demod2;
dongle_bw = dongle.rate;
if (dongle_bw > MAXIMUM_RATE) {
fprintf(stderr, "error: unable to find optimal settings\n");
do_exit = 1;
exit(1);
}
angle1 = ((double)freq1 - (double)freq) / (double)dongle_bw;
demod.rotate.angle = angle1 * 2 * M_PI;
angle2 = ((double)freq2 - (double)freq) / (double)dongle_bw;
demod2.rotate.angle = angle2 * 2 * M_PI;
translate_init(&demod.rotate);
translate_init(&demod2.rotate);
//fprintf(stderr, "a1 %f, a2 %f\n", angle1, angle2);
}
static void *controller_thread_fn(void *arg)
{
// thoughts for multiple dongles
// might be no good using a controller thread if retune/rate blocks
int i;
struct controller_state *s = arg;
if (s->wb_mode) {
for (i=0; i < s->freq_len; i++) {
s->freqs[i] += 16000;}
}
/* set up primary channel */
optimal_settings(s->freqs[0], demod.rate_in);
demod.squelch_level = squelch_to_rms(demod.squelch_level, &dongle, &demod);
if (dongle.direct_sampling) {
verbose_direct_sampling(dongle.dev, dongle.direct_sampling);}
if (dongle.offset_tuning) {
verbose_offset_tuning(dongle.dev);}
/* set up lrmix */
if (output.lrmix) {
optimal_lrmix();
}
/* Set the frequency */
verbose_set_frequency(dongle.dev, dongle.freq);
fprintf(stderr, "Oversampling input by: %ix.\n", demod.downsample);
fprintf(stderr, "Oversampling output by: %ix.\n", demod.post_downsample);
fprintf(stderr, "Buffer size: %0.2fms\n",
1000 * 0.5 * (float)ACTUAL_BUF_LENGTH / (float)dongle.rate);
/* Set the sample rate */
verbose_set_sample_rate(dongle.dev, dongle.rate);
fprintf(stderr, "Output at %u Hz.\n", demod.rate_in/demod.post_downsample);
while (!do_exit) {
safe_cond_wait(&s->hop, &s->hop_m);
if (s->freq_len <= 1) {
continue;}
if (output.lrmix) {
continue;}
/* hacky hopping */
s->freq_now = (s->freq_now + 1) % s->freq_len;
optimal_settings(s->freqs[s->freq_now], demod.rate_in);
rtlsdr_set_center_freq(dongle.dev, dongle.freq);
dongle.mute = BUFFER_DUMP;
}
return 0;
}
void frequency_range(struct controller_state *s, char *arg)
{
char *start, *stop, *step;
int i;
start = arg;
stop = strchr(start, ':') + 1;
stop[-1] = '\0';
step = strchr(stop, ':') + 1;
step[-1] = '\0';
for(i=(int)atofs(start); i<=(int)atofs(stop); i+=(int)atofs(step))
{
s->freqs[s->freq_len] = (uint32_t)i;
s->freq_len++;
if (s->freq_len >= FREQUENCIES_LIMIT) {
break;}
}
stop[-1] = ':';
step[-1] = ':';
}
void dongle_init(struct dongle_state *s)
{
s->rate = DEFAULT_SAMPLE_RATE;
s->gain = AUTO_GAIN; // tenths of a dB
s->mute = 0;
s->direct_sampling = 0;
s->offset_tuning = 0;
s->pre_rotate = 1;
s->targets[0] = &demod;
s->targets[1] = NULL;
s->buf16 = mark_shared_buffer();
}
void demod_init(struct demod_state *s)
{
s->rate_in = DEFAULT_SAMPLE_RATE;
s->rate_out = DEFAULT_SAMPLE_RATE;
s->squelch_level = 0;
s->conseq_squelch = 10;
s->terminate_on_squelch = 0;
s->squelch_hits = 11;
s->downsample_passes = 0;
s->comp_fir_size = 0;
s->prev_index = 0;
s->post_downsample = 1; // once this works, default = 4
s->custom_atan = 0;
s->deemph = 0;
s->agc_mode = agc_off;
s->rotate_enable = 0;
s->rotate.len = 0;
s->rotate.sincos = NULL;
s->rate_out2 = -1; // flag for disabled
s->mode_demod = &fm_demod;
s->pre_j = s->pre_r = s->now_r = s->now_j = 0;
s->prev_lpr_index = 0;
s->deemph_a = 0;
s->now_lpr = 0;
s->dc_block = 1;
s->dc_avg = 0;
pthread_rwlock_init(&s->rw, NULL);
pthread_cond_init(&s->ready, NULL);
pthread_mutex_init(&s->ready_m, NULL);
s->output_target = &output.results[0];
s->lowpassed = NULL;
}
void demod_cleanup(struct demod_state *s)
{
pthread_rwlock_destroy(&s->rw);
pthread_cond_destroy(&s->ready);
pthread_mutex_destroy(&s->ready_m);
}
void output_init(struct output_state *s)
{
int i;
//s->rate = DEFAULT_SAMPLE_RATE;
for (i=0; i<2; i++) {
pthread_rwlock_init(&s->results[i].rw, NULL);
pthread_cond_init(&s->results[i].ready, NULL);
pthread_mutex_init(&s->results[i].ready_m, NULL);
pthread_mutex_init(&s->results[i].trycond_m, NULL);
s->results[i].trycond = 1;
s->results[i].buf = NULL;
}
}
void output_cleanup(struct output_state *s)
{
int i;
for (i=0; i<2; i++) {
pthread_rwlock_destroy(&s->results[i].rw);
pthread_cond_destroy(&s->results[i].ready);
pthread_mutex_destroy(&s->results[i].ready_m);
pthread_mutex_destroy(&s->results[i].trycond_m);
}
}
void controller_init(struct controller_state *s)
{
s->freqs[0] = 100000000;
s->freq_len = 0;
s->edge = 0;
s->wb_mode = 0;
pthread_cond_init(&s->hop, NULL);
pthread_mutex_init(&s->hop_m, NULL);
}
void controller_cleanup(struct controller_state *s)
{
pthread_cond_destroy(&s->hop);
pthread_mutex_destroy(&s->hop_m);
}
void sanity_checks(void)
{
if (controller.freq_len == 0) {
fprintf(stderr, "Please specify a frequency.\n");
exit(1);
}
if (controller.freq_len >= FREQUENCIES_LIMIT) {
fprintf(stderr, "Too many channels, maximum %i.\n", FREQUENCIES_LIMIT);
exit(1);
}
if (!output.lrmix && controller.freq_len > 1 && demod.squelch_level == 0) {
fprintf(stderr, "Please specify a squelch level. Required for scanning multiple frequencies.\n");
exit(1);
}
if (demod.mode_demod == &raw_demod && output.lrmix) {
fprintf(stderr, "'raw' is not a supported demodulator for lrmix\n");
exit(1);
}
}
int agc_init(struct demod_state *s)
{
struct agc_state *agc;
agc = malloc(sizeof(struct agc_state));
s->agc = agc;
agc->gain_den = 1<<15;
agc->peak_target = 1<<14;
agc->gain_max = 256 * agc->gain_den;
agc->gain_num = agc->gain_den;
agc->decay_step = 1;
agc->attack_step = 2;
if (s->agc_mode == agc_aggressive) {
agc->decay_step = agc->decay_step * 4;
agc->attack_step = agc->attack_step * 5;
}
return 0;
}
int generate_header(struct demod_state *d, struct output_state *o)
{
int i, s_rate, b_rate;
char *channels = "\1\0";
char *align = "\2\0";
uint8_t samp_rate[4] = {0, 0, 0, 0};
uint8_t byte_rate[4] = {0, 0, 0, 0};
s_rate = o->rate;
b_rate = o->rate * 2;
if (d->mode_demod == &raw_demod || o->lrmix) {
channels = "\2\0";
align = "\4\0";
b_rate *= 2;
}
for (i=0; i<4; i++) {
samp_rate[i] = (uint8_t)((s_rate >> (8*i)) & 0xFF);
byte_rate[i] = (uint8_t)((b_rate >> (8*i)) & 0xFF);
}
fwrite("RIFF", 1, 4, o->file);
fwrite("\xFF\xFF\xFF\xFF", 1, 4, o->file); /* size */
fwrite("WAVE", 1, 4, o->file);
fwrite("fmt ", 1, 4, o->file);
fwrite("\x10\0\0\0", 1, 4, o->file); /* size */
fwrite("\1\0", 1, 2, o->file); /* pcm */
fwrite(channels, 1, 2, o->file);
fwrite(samp_rate, 1, 4, o->file);
fwrite(byte_rate, 1, 4, o->file);
fwrite(align, 1, 2, o->file);
fwrite("\x10\0", 1, 2, o->file); /* bits per channel */
fwrite("data", 1, 4, o->file);
fwrite("\xFF\xFF\xFF\xFF", 1, 4, o->file); /* size */
return 0;
}
int main(int argc, char **argv)
{
#ifndef _WIN32
struct sigaction sigact;
#endif
int r, opt;
int dev_given = 0;
int custom_ppm = 0;
dongle_init(&dongle);
demod_init(&demod);
demod_init(&demod2);
output_init(&output);
controller_init(&controller);
while ((opt = getopt(argc, argv, "d:f:g:s:b:l:o:t:r:p:E:F:A:M:h")) != -1) {
switch (opt) {
case 'd':
dongle.dev_index = verbose_device_search(optarg);
dev_given = 1;
break;
case 'f':
if (controller.freq_len >= FREQUENCIES_LIMIT) {
break;}
if (strchr(optarg, ':'))
{frequency_range(&controller, optarg);}
else
{
controller.freqs[controller.freq_len] = (uint32_t)atofs(optarg);
controller.freq_len++;
}
break;
case 'g':
dongle.gain = (int)(atof(optarg) * 10);
break;
case 'l':
demod.squelch_level = (int)atof(optarg);
break;
case 's':
demod.rate_in = (uint32_t)atofs(optarg);
demod.rate_out = (uint32_t)atofs(optarg);
break;
case 'r':
output.rate = (int)atofs(optarg);
demod.rate_out2 = (int)atofs(optarg);
break;
case 'o':
fprintf(stderr, "Warning: -o is very buggy\n");
demod.post_downsample = (int)atof(optarg);
if (demod.post_downsample < 1 || demod.post_downsample > MAXIMUM_OVERSAMPLE) {
fprintf(stderr, "Oversample must be between 1 and %i\n", MAXIMUM_OVERSAMPLE);}
break;
case 't':
demod.conseq_squelch = (int)atof(optarg);
if (demod.conseq_squelch < 0) {
demod.conseq_squelch = -demod.conseq_squelch;
demod.terminate_on_squelch = 1;
}
break;
case 'p':
dongle.ppm_error = atoi(optarg);
custom_ppm = 1;
break;
case 'E':
if (strcmp("edge", optarg) == 0) {
controller.edge = 1;}
if (strcmp("no-dc", optarg) == 0) {
demod.dc_block = 0;}
if (strcmp("deemp", optarg) == 0) {
demod.deemph = 1;}
if (strcmp("swagc", optarg) == 0) {
demod.agc_mode = agc_normal;}
if (strcmp("swagc-aggressive", optarg) == 0) {
demod.agc_mode = agc_aggressive;}
if (strcmp("direct", optarg) == 0) {
dongle.direct_sampling = 1;}
if (strcmp("no-mod", optarg) == 0) {
dongle.direct_sampling = 3;}
if (strcmp("offset", optarg) == 0) {
dongle.offset_tuning = 1;
dongle.pre_rotate = 0;}
if (strcmp("wav", optarg) == 0) {
output.wav_format = 1;}
if (strcmp("pad", optarg) == 0) {
output.padded = 1;}
if (strcmp("lrmix", optarg) == 0) {
output.lrmix = 1;}
break;
case 'F':
demod.downsample_passes = 1; /* truthy placeholder */
demod.comp_fir_size = atoi(optarg);
break;
case 'A':
if (strcmp("std", optarg) == 0) {
demod.custom_atan = 0;}
if (strcmp("fast", optarg) == 0) {
demod.custom_atan = 1;}
if (strcmp("lut", optarg) == 0) {
atan_lut_init();
demod.custom_atan = 2;}
if (strcmp("ale", optarg) == 0) {
demod.custom_atan = 3;}
break;
case 'M':
if (strcmp("fm", optarg) == 0) {
demod.mode_demod = &fm_demod;}
if (strcmp("raw", optarg) == 0) {
demod.mode_demod = &raw_demod;}
if (strcmp("am", optarg) == 0) {
demod.mode_demod = &am_demod;}
if (strcmp("usb", optarg) == 0) {
demod.mode_demod = &usb_demod;}
if (strcmp("lsb", optarg) == 0) {
demod.mode_demod = &lsb_demod;}
if (strcmp("wbfm", optarg) == 0) {
controller.wb_mode = 1;
demod.mode_demod = &fm_demod;
demod.rate_in = 170000;
demod.rate_out = 170000;
demod.rate_out2 = 32000;
output.rate = 32000;
demod.custom_atan = 1;
//demod.post_downsample = 4;
demod.deemph = 1;
demod.squelch_level = 0;}
break;
case 'h':
default:
usage();
break;
}
}
agc_init(&demod);
/* quadruple sample_rate to limit to Δθ to ±π/2 */
demod.rate_in *= demod.post_downsample;
if (!output.rate) {
output.rate = demod.rate_out;}
sanity_checks();
if (controller.freq_len > 1) {
demod.terminate_on_squelch = 0;}
if (argc <= optind) {
output.filename = "-";
} else {
output.filename = argv[optind];
}
ACTUAL_BUF_LENGTH = lcm_post[demod.post_downsample] * DEFAULT_BUF_LENGTH;
if (!dev_given) {
dongle.dev_index = verbose_device_search("0");
}
if (dongle.dev_index < 0) {
exit(1);
}
r = rtlsdr_open(&dongle.dev, (uint32_t)dongle.dev_index);
if (r < 0) {
fprintf(stderr, "Failed to open rtlsdr device #%d.\n", dongle.dev_index);
exit(1);
}
#ifndef _WIN32
sigact.sa_handler = sighandler;
sigemptyset(&sigact.sa_mask);
sigact.sa_flags = 0;
sigaction(SIGINT, &sigact, NULL);
sigaction(SIGTERM, &sigact, NULL);
sigaction(SIGQUIT, &sigact, NULL);
sigaction(SIGPIPE, &sigact, NULL);
signal(SIGPIPE, SIG_IGN);
#else
SetConsoleCtrlHandler( (PHANDLER_ROUTINE) sighandler, TRUE );
output.padded = 0;
#endif
if (demod.deemph) {
demod.deemph_a = (int)round(1.0/((1.0-exp(-1.0/(demod.rate_out * 75e-6)))));
}
/* Set the tuner gain */
if (dongle.gain == AUTO_GAIN) {
verbose_auto_gain(dongle.dev);
} else {
dongle.gain = nearest_gain(dongle.dev, dongle.gain);
verbose_gain_set(dongle.dev, dongle.gain);
}
if (!custom_ppm) {
verbose_ppm_eeprom(dongle.dev, &(dongle.ppm_error));
}
verbose_ppm_set(dongle.dev, dongle.ppm_error);
if (strcmp(output.filename, "-") == 0) { /* Write samples to stdout */
output.file = stdout;
#ifdef _WIN32
_setmode(_fileno(output.file), _O_BINARY);
#endif
} else {
output.file = fopen(output.filename, "wb");
if (!output.file) {
fprintf(stderr, "Failed to open %s\n", output.filename);
exit(1);
}
}
if (output.wav_format) {
generate_header(&demod, &output);
}
//r = rtlsdr_set_testmode(dongle.dev, 1);
/* Reset endpoint before we start reading from it (mandatory) */
verbose_reset_buffer(dongle.dev);
pthread_create(&controller.thread, NULL, controller_thread_fn, (void *)(&controller));
usleep(100000);
pthread_create(&output.thread, NULL, output_thread_fn, (void *)(&output));
pthread_create(&demod.thread, NULL, demod_thread_fn, (void *)(&demod));
if (output.lrmix) {
pthread_create(&demod2.thread, NULL, demod_thread_fn, (void *)(&demod2));
}
pthread_create(&dongle.thread, NULL, dongle_thread_fn, (void *)(&dongle));
while (!do_exit) {
usleep(100000);
}
if (do_exit) {
fprintf(stderr, "\nUser cancel, exiting...\n");}
else {
fprintf(stderr, "\nLibrary error %d, exiting...\n", r);}
rtlsdr_cancel_async(dongle.dev);
pthread_join(dongle.thread, NULL);
safe_cond_signal(&demod.ready, &demod.ready_m);
pthread_join(demod.thread, NULL);
if (output.lrmix) {
safe_cond_signal(&demod2.ready, &demod2.ready_m);
pthread_join(demod2.thread, NULL);
}
safe_cond_signal(&output.results[0].ready, &output.results[0].ready_m);
safe_cond_signal(&output.results[1].ready, &output.results[1].ready_m);
pthread_join(output.thread, NULL);
safe_cond_signal(&controller.hop, &controller.hop_m);
pthread_join(controller.thread, NULL);
//dongle_cleanup(&dongle);
demod_cleanup(&demod);
output_cleanup(&output);
controller_cleanup(&controller);
if (output.file != stdout) {
fclose(output.file);}
rtlsdr_close(dongle.dev);
return r >= 0 ? r : -r;
}
// vim: tabstop=8:softtabstop=8:shiftwidth=8:noexpandtab