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librtlsdr/src/rtl_fm.c

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/*
* 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>
* Copyright (C) 2015 by Hayati Ayguen <h_ayguen@web.de>
*
* 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
* scale squelch to other input parameters
* test all the demodulations
* pad output on hop
* frequency ranges could be stored better
* scaled AM demod amplification
* auto-hop after time limit
* peak detector to tune onto stronger signals
* fifo for active hop frequency
* clips
* noise squelch
* merge stereo patch
* merge soft agc 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>
#include <ctype.h>
#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
#ifdef NEED_PTHREADS_WORKARROUND
#define HAVE_STRUCT_TIMESPEC
#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 DEFAULT_BUFFER_DUMP 4096
#define FREQUENCIES_LIMIT 1024
static int BufferDump = DEFAULT_BUFFER_DUMP;
static int OutputToStdout = 1;
static int MinCaptureRate = 1000000;
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 int *atan_lut = NULL;
static int atan_lut_size = 131072; /* 512 KB */
static int atan_lut_coef = 8;
static int verbosity = 0;
static int printLevels = 0;
static int printLevelNo = 1;
static int levelMax = 0;
static int levelMaxMax = 0;
static double levelSum = 0.0;
enum trigExpr { crit_IN =0, crit_OUT, crit_LT, crit_GT };
char * aCritStr[] = { "in", "out", "<", ">" };
struct cmd_state
{
const char * filename;
FILE * file;
int lineNo;
char acLine[4096];
uint32_t freq;
int gain;
enum trigExpr trigCrit;
double refLevel;
double refLevelTol;
int numMeas;
int numBlockTrigger;
char * command;
char * args;
double levelSum;
int numSummed;
int omitFirstFreqLevels;
int waitTrigger[FREQUENCIES_LIMIT];
int statNumLevels[FREQUENCIES_LIMIT];
uint32_t statFreq[FREQUENCIES_LIMIT];
double statSumLevels[FREQUENCIES_LIMIT];
float statMinLevel[FREQUENCIES_LIMIT];
float statMaxLevel[FREQUENCIES_LIMIT];
};
struct dongle_state
{
int exit_flag;
pthread_t thread;
rtlsdr_dev_t *dev;
int dev_index;
uint32_t userFreq;
uint32_t freq;
uint32_t rate;
uint32_t bandwidth;
int gain;
int16_t buf16[MAXIMUM_BUF_LENGTH];
uint32_t buf_len;
int ppm_error;
int offset_tuning;
int direct_sampling;
int mute;
struct demod_state *demod_target;
};
struct demod_state
{
int exit_flag;
pthread_t thread;
int16_t lowpassed[MAXIMUM_BUF_LENGTH];
int lp_len;
int16_t lp_i_hist[10][6];
int16_t lp_q_hist[10][6];
int16_t result[MAXIMUM_BUF_LENGTH];
int16_t droop_i_hist[9];
int16_t droop_q_hist[9];
int result_len;
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_audio, dc_avg, adc_block_const;
int dc_block_raw, dc_avgI, dc_avgQ, rdc_block_const;
void (*mode_demod)(struct demod_state*);
pthread_rwlock_t rw;
pthread_cond_t ready;
pthread_mutex_t ready_m;
struct output_state *output_target;
struct cmd_state *cmd;
};
struct output_state
{
int exit_flag;
pthread_t thread;
FILE *file;
char *filename;
int16_t result[MAXIMUM_BUF_LENGTH];
int result_len;
int rate;
pthread_rwlock_t rw;
pthread_cond_t ready;
pthread_mutex_t ready_m;
};
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;
struct cmd_state *cmd;
};
// multiple of these, eventually
struct dongle_state dongle;
struct demod_state demod;
struct output_state output;
struct controller_state controller;
struct cmd_state cmd;
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[-C command_filename: command file with comma seperated values (.csv). sets modulation 'raw']\n"
"\t\tcommand file contains lines with: freq,gain,trig-crit,trig_level,trig_tolerance,#meas,#blocks,trigger_command,arguments\n"
"\t\t with trig_crit one of 'in', 'out', 'lt' or 'gt'\n"
"\t[-B num_samples at capture rate: remove that many samples at capture_rate after changing frequency (default: 4096)]\n"
"\t[-m minimum_capture_rate Hz (default: 1m, min=900k, max=3.2m)]\n"
"\t[-v increase verbosity (default: 0)]\n"
"\t[-M modulation (default: fm)]\n"
"\t fm or nbfm or nfm, wbfm or wfm, raw or iq, 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[-T enable bias-T on GPIO PIN 0 (works for rtl-sdr.com v3 dongles)]\n"
"\t[-D direct_sampling_mode (default: 0, 1 = I, 2 = Q, 3 = I below threshold, 4 = Q below threshold)]\n"
"\t[-D direct_sampling_threshold_frequency (default: 0 use tuner specific frequency threshold for 3 and 4)]\n"
"\t[-g tuner_gain (default: automatic)]\n"
"\t[-w tuner_bandwidth in Hz (default: automatic)]\n"
"\t[-l squelch_level (default: 0/off)]\n"
"\t[-L N prints levels every N calculations]\n"
"\t output are comma separated values (csv):\n"
"\t avg rms since last output, max rms since last output, overall max rms, squelch (paramed), rms, rms level, avg rms level\n"
"\t[-c de-emphasis_time_constant in us for wbfm. 'us' or 'eu' for 75/50 us (default: us)]\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 rdc: enable dc blocking filter on raw I/Q data at capture rate\n"
"\t adc: enable dc blocking filter on demodulated audio\n"
"\t dc: same as adc\n"
"\t rtlagc: enable rtl2832's digital agc (default: off)\n"
"\t agc: same as rtlagc\n"
"\t deemp: enable de-emphasis filter\n"
"\t direct: enable direct sampling (bypasses tuner, uses rtl2832 xtal)\n"
"\t offset: enable offset tuning (only e4000 tuner)\n"
"\t[-q dc_avg_factor for option rdc (default: 9)]\n"
"\t[-n disables demodulation output to stdout/file]\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 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 -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
/* uint8_t negation = 255 - x */
#define NEG_U8( x ) ( 255 - x )
/* MUL_PLUS_J: (a + j*b ) * j = -b + j * a */
/* MUL_MINUS_ONE: (a + j*b ) * -1 = -a + j * -b */
/* MUL_MINUS_J: (a + j*b ) * -j = b + j * -a */
#define MUL_PLUS_J_U8( X, J ) \
tmp = X[J]; \
X[J] = NEG_U8( X[J+1] ); \
X[J+1] = tmp
#define MUL_MINUS_ONE_U8( X, J ) \
X[J] = NEG_U8( X[J] ); \
X[J+1] = NEG_U8( X[J+1] )
#define MUL_MINUS_J_U8( X, J ) \
tmp = X[J]; \
X[J] = X[J+1]; \
X[J+1] = NEG_U8( tmp )
#define MUL_PLUS_J_INT( X, J ) \
tmp = X[J]; \
X[J] = - X[J+1]; \
X[J+1] = tmp
#define MUL_MINUS_ONE_INT( X, J ) \
X[J] = - X[J]; \
X[J+1] = - X[J+1]
#define MUL_MINUS_J_INT( X, J ) \
tmp = X[J]; \
X[J] = X[J+1]; \
X[J+1] = -tmp
void rotate16_90(int16_t *buf, uint32_t len)
{
/* 90 degree rotation is 1, +j, -1, -j */
uint32_t i;
int16_t tmp;
for (i=0; i<len; i+=8) {
MUL_PLUS_J_INT( buf, i+2 );
MUL_MINUS_ONE_INT( buf, i+4 );
MUL_MINUS_J_INT( buf, i+6 );
}
}
void rotate16_neg90(int16_t *buf, uint32_t len)
{
/* -90 degree rotation is 1, -j, -1, +j */
uint32_t i;
int16_t tmp;
for (i=0; i<len; i+=8) {
MUL_MINUS_J_INT( buf, i+2 );
MUL_MINUS_ONE_INT( buf, i+4 );
MUL_PLUS_J_INT( buf, i+6 );
}
}
void rotate_90(unsigned char *buf, uint32_t len)
{
/* 90 degree rotation is 1, +j, -1, -j */
uint32_t i;
unsigned char tmp;
for (i=0; i<len; i+=8) {
MUL_PLUS_J_U8( buf, i+2 );
MUL_MINUS_ONE_U8( buf, i+4 );
MUL_MINUS_J_U8( buf, i+6 );
}
}
void rotate_neg90(unsigned char *buf, uint32_t len)
{
/* -90 degree rotation is 1, -j, -1, +j */
uint32_t i;
unsigned char tmp;
for (i=0; i<len; i+=8) {
MUL_MINUS_J_U8( buf, 2 );
MUL_MINUS_ONE_U8( buf, 4 );
MUL_PLUS_J_U8( buf, 6 );
}
}
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;
}
static char * trim(char * s) {
char *p = s;
int l = strlen(p);
while(isspace(p[l - 1])) p[--l] = 0;
while(*p && isspace(*p)) ++p;
return p;
}
static void cmd_init(struct cmd_state *c)
{
int k;
c->filename = NULL;
c->file = NULL;
c->lineNo = 1;
c->freq = 0;
c->gain = 0;
c->trigCrit = crit_IN;
c->refLevel = 0.0;
c->refLevelTol = 0.0;
c->numMeas = 0;
c->numBlockTrigger = 0;
c->command = NULL;
c->args = NULL;
c->levelSum = 0.0;
c->numSummed = 0;
c->omitFirstFreqLevels = 1;
for (k = 0; k < FREQUENCIES_LIMIT; k++) {
c->waitTrigger[k] = 0;
c->statNumLevels[k] = 0;
c->statFreq[k] = 0;
c->statSumLevels[k] = 0.0;
c->statMinLevel[k] = 0.0F;
c->statMaxLevel[k] = 0.0F;
}
}
static int toNextCmdLine(struct cmd_state *c)
{
const char * delim = ",";
char * pLine = NULL;
char * pCmdFreq = NULL;
char * pCmdGain = NULL;
char * pCmdTrigCrit = NULL;
char * pCmdLevel = NULL;
char * pCmdTol = NULL;
char * pCmdNumMeas = NULL;
char * pCmdNumBlockTrigger = NULL;
int numValidLines = 1; /* assume valid lines */
while (1) {
if (c->file && feof(c->file)) {
if (!numValidLines) {
fprintf(stderr, "error: command file '%s' does not contain any valid lines!\n", c->filename);
return 0;
}
fclose(c->file);
c->file = NULL;
}
if (!c->file) {
c->file = fopen(c->filename, "r");
numValidLines = 0;
c->lineNo = 0;
}
if (!c->file)
return 0;
pLine = fgets(c->acLine, 4096, c->file);
if (!pLine) {
continue;
}
c->lineNo++;
pLine = trim(c->acLine);
if (pLine[0]=='#' || pLine[0]==0)
continue; /* detect comment lines and empty lines */
pCmdFreq = strtok(pLine, delim);
if (!pCmdFreq) { fprintf(stderr, "error parsing frequency in line %d of command file!\n", c->lineNo); continue; }
c->freq = (uint32_t)atofs(trim(pCmdFreq));
pCmdGain = strtok(NULL, delim);
if (!pCmdGain) { fprintf(stderr, "error parsing gain in line %d of command file!\n", c->lineNo); continue; }
pCmdGain = trim(pCmdGain);
if (!strcmp(pCmdGain,"auto") || !strcmp(pCmdGain,"a"))
c->gain = AUTO_GAIN;
else
c->gain = (int)(atof(pCmdGain) * 10);
pCmdTrigCrit = strtok(NULL, delim);
if (!pCmdTrigCrit) { fprintf(stderr, "error parsing expr in line %d of command file!\n", c->lineNo); continue; }
pCmdTrigCrit = trim(pCmdTrigCrit);
if (!strcmp(pCmdTrigCrit,"in")) c->trigCrit = crit_IN;
else if (!strcmp(pCmdTrigCrit,"==")) c->trigCrit = crit_IN;
else if (!strcmp(pCmdTrigCrit,"out")) c->trigCrit = crit_OUT;
else if (!strcmp(pCmdTrigCrit,"!=")) c->trigCrit = crit_OUT;
else if (!strcmp(pCmdTrigCrit,"<>")) c->trigCrit = crit_OUT;
else if (!strcmp(pCmdTrigCrit,"lt")) c->trigCrit = crit_LT;
else if (!strcmp(pCmdTrigCrit,"<")) c->trigCrit = crit_LT;
else if (!strcmp(pCmdTrigCrit,"gt")) c->trigCrit = crit_GT;
else if (!strcmp(pCmdTrigCrit,">")) c->trigCrit = crit_GT;
else { fprintf(stderr, "error parsing expr in line %d of command file!\n", c->lineNo); continue; }
pCmdLevel = strtok(NULL, delim);
if (!pCmdLevel) { fprintf(stderr, "error parsing level in line %d of command file!\n", c->lineNo); continue; }
c->refLevel = atof(trim(pCmdLevel));
pCmdTol = strtok(NULL, delim);
if (!pCmdTol) { fprintf(stderr, "error parsing tolerance in line %d of command file!\n", c->lineNo); continue; }
c->refLevelTol = atof(trim(pCmdTol));
pCmdNumMeas = strtok(NULL, delim);
if (!pCmdNumMeas) { fprintf(stderr, "error parsing #measurements in line %d of command file!\n", c->lineNo); continue; }
c->numMeas = atoi(trim(pCmdNumMeas));
if (c->numMeas <= 0) { fprintf(stderr, "warning: fixed #measurements from %d to 10 in line %d of command file!\n", c->numMeas, c->lineNo); c->numMeas=10; }
pCmdNumBlockTrigger = strtok(NULL, delim);
if (!pCmdNumBlockTrigger) { fprintf(stderr, "error parsing #blockTrigger in line %d of command file!\n", c->lineNo); continue; }
c->numBlockTrigger = atoi(trim(pCmdNumBlockTrigger));
c->command = strtok(NULL, delim);
/* no check: allow empty string. just trim it */
if (c->command)
c->command = trim(c->command);
c->args = strtok(NULL, delim);
/* no check: allow empty string. just trim it */
if (c->args)
c->args = trim(c->args);
if (verbosity >= 2)
fprintf(stderr, "read from cmd file: freq %.3f kHz, gain %0.1f dB, level %s {%.1f +/- %.1f}, cmd '%s %s'\n",
c->freq /1000.0, c->gain /10.0,
aCritStr[c->trigCrit], c->refLevel, c->refLevelTol,
(c->command ? c->command : "%"), (c->args ? c->args : "") );
numValidLines++;
return 1;
}
return 0;
}
static int testTrigCrit(struct cmd_state *c, double level)
{
switch(c->trigCrit)
{
case crit_IN: return ( c->refLevel-c->refLevelTol <= level && level <= c->refLevel+c->refLevelTol );
case crit_OUT: return ( c->refLevel-c->refLevelTol > level || level > c->refLevel+c->refLevelTol );
case crit_LT: return ( level < c->refLevel-c->refLevelTol );
case crit_GT: return ( level > c->refLevel+c->refLevelTol );
}
return 0;
}
static void checkTriggerCommand(struct cmd_state *c)
{
char acRepFreq[32], acRepGain[32], acRepMLevel[32], acRepRefLevel[32], acRepRefTolerance[32];
char * execSearchStrings[7] = { "!freq!", "!gain!", "!mlevel!", "!crit!", "!reflevel!", "!reftol!", NULL };
char * execReplaceStrings[7] = { acRepFreq, acRepGain, acRepMLevel, NULL, acRepRefLevel, acRepRefTolerance, NULL };
double triggerLevel;
int k, triggerCommand = 0;
if (c->numSummed != c->numMeas)
return;
if (c->omitFirstFreqLevels) {
/* workaround: measured levels of first controlled frequency looks wrong! */
c->omitFirstFreqLevels--;
return;
}
/* decrease all counters */
for ( k = 0; k < FREQUENCIES_LIMIT; k++ ) {
if ( c->waitTrigger[k] > 0 ) {
c->waitTrigger[k] -= c->numMeas;
if ( c->waitTrigger[k] < 0 )
c->waitTrigger[k] = 0;
}
}
triggerLevel = 20.0 * log10( 1E-10 + c->levelSum / c->numSummed );
triggerCommand = testTrigCrit(c, triggerLevel);
/* update statistics */
if ( c->lineNo < FREQUENCIES_LIMIT ) {
if ( c->statNumLevels[c->lineNo] == 0 ) {
++c->statNumLevels[c->lineNo];
c->statFreq[c->lineNo] = c->freq;
c->statSumLevels[c->lineNo] = triggerLevel;
c->statMinLevel[c->lineNo] = (float)triggerLevel;
c->statMaxLevel[c->lineNo] = (float)triggerLevel;
} else if ( c->statFreq[c->lineNo] == c->freq ) {
++c->statNumLevels[c->lineNo];
c->statSumLevels[c->lineNo] += triggerLevel;
if ( c->statMinLevel[c->lineNo] > (float)triggerLevel )
c->statMinLevel[c->lineNo] = (float)triggerLevel;
if ( c->statMaxLevel[c->lineNo] < (float)triggerLevel )
c->statMaxLevel[c->lineNo] = (float)triggerLevel;
}
}
if ( c->lineNo < FREQUENCIES_LIMIT && c->waitTrigger[c->lineNo] <= 0 ) {
c->waitTrigger[c->lineNo] = triggerCommand ? c->numBlockTrigger : 0;
if (verbosity)
fprintf(stderr, "frequency %.3f kHz: level %.1f dB => %s\n",
(double)c->freq /1000.0, triggerLevel, (triggerCommand ? "activates trigger" : "does not trigger") );
if (triggerCommand && c->command && c->command[0]) {
fprintf(stderr, "command to trigger is '%s %s'\n", c->command, c->args);
/* prepare search/replace of special parameters for command arguments */
snprintf(acRepFreq, 32, "%u", c->freq);
snprintf(acRepGain, 32, "%d", c->gain);
snprintf(acRepMLevel, 32, "%d", (int)(0.5 + triggerLevel*10.0) );
execReplaceStrings[3] = aCritStr[c->trigCrit];
snprintf(acRepRefLevel, 32, "%d", (int)(0.5 + c->refLevel*10.0) );
snprintf(acRepRefTolerance, 32, "%d", (int)(0.5 + c->refLevelTol*10.0) );
executeInBackground( c->command, c->args, execSearchStrings, execReplaceStrings );
}
} else {
fprintf(stderr, "frequency %.3f kHz: level %.1f dB => %s, blocks for %d\n",
(double)c->freq /1000.0, triggerLevel, (triggerCommand ? "would trigger" : "does not trigger"),
(c->lineNo < FREQUENCIES_LIMIT ? c->waitTrigger[c->lineNo] : -1 ) );
}
c->numSummed++;
}
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?
{
int i=0, i2=0;
int fast = (int)s->rate_out;
int slow = s->rate_out2;
while (i < s->result_len) {
s->now_lpr += s->result[i];
i++;
s->prev_lpr_index += slow;
if (s->prev_lpr_index < fast) {
continue;
}
s->result[i2] = (int16_t)(s->now_lpr / (fast/slow));
s->prev_lpr_index -= fast;
s->now_lpr = 0;
i2 += 1;
}
s->result_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 / 3.14159 * (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)) / 3.14159 * (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;
}
void fm_demod(struct demod_state *fm)
{
int i, pcm;
int16_t *lp = fm->lowpassed;
pcm = polar_discriminant(lp[0], lp[1],
fm->pre_r, fm->pre_j);
fm->result[0] = (int16_t)pcm;
for (i = 2; i < (fm->lp_len-1); i += 2) {
switch (fm->custom_atan) {
case 0:
pcm = polar_discriminant(lp[i], lp[i+1],
lp[i-2], lp[i-1]);
break;
case 1:
pcm = polar_disc_fast(lp[i], lp[i+1],
lp[i-2], lp[i-1]);
break;
case 2:
pcm = polar_disc_lut(lp[i], lp[i+1],
lp[i-2], lp[i-1]);
break;
}
fm->result[i/2] = (int16_t)pcm;
}
fm->pre_r = lp[fm->lp_len - 2];
fm->pre_j = lp[fm->lp_len - 1];
fm->result_len = fm->lp_len/2;
}
void am_demod(struct demod_state *fm)
// todo, fix this extreme laziness
{
int i, pcm;
int16_t *lp = fm->lowpassed;
int16_t *r = fm->result;
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];
r[i/2] = (int16_t)sqrt(pcm) * fm->output_scale;
}
fm->result_len = fm->lp_len/2;
// lowpass? (3khz) highpass? (dc)
}
void usb_demod(struct demod_state *fm)
{
int i, pcm;
int16_t *lp = fm->lowpassed;
int16_t *r = fm->result;
for (i = 0; i < fm->lp_len; i += 2) {
pcm = lp[i] + lp[i+1];
r[i/2] = (int16_t)pcm * fm->output_scale;
}
fm->result_len = fm->lp_len/2;
}
void lsb_demod(struct demod_state *fm)
{
int i, pcm;
int16_t *lp = fm->lowpassed;
int16_t *r = fm->result;
for (i = 0; i < fm->lp_len; i += 2) {
pcm = lp[i] - lp[i+1];
r[i/2] = (int16_t)pcm * fm->output_scale;
}
fm->result_len = fm->lp_len/2;
}
void raw_demod(struct demod_state *fm)
{
int i;
for (i = 0; i < fm->lp_len; i++) {
fm->result[i] = (int16_t)fm->lowpassed[i];
}
fm->result_len = fm->lp_len;
}
void deemph_filter(struct demod_state *fm)
{
static int avg; // cheating...
int i, d;
// de-emph IIR
// avg = avg * (1 - alpha) + sample * alpha;
for (i = 0; i < fm->result_len; i++) {
d = fm->result[i] - avg;
if (d > 0) {
avg += (d + fm->deemph_a/2) / fm->deemph_a;
} else {
avg += (d - fm->deemph_a/2) / fm->deemph_a;
}
fm->result[i] = (int16_t)avg;
}
}
void dc_block_audio_filter(struct demod_state *fm)
{
int i, avg;
int64_t sum = 0;
for (i=0; i < fm->result_len; i++) {
sum += fm->result[i];
}
avg = sum / fm->result_len;
avg = (avg + fm->dc_avg * fm->adc_block_const) / ( fm->adc_block_const + 1 );
for (i=0; i < fm->result_len; i++) {
fm->result[i] -= avg;
}
fm->dc_avg = avg;
}
void dc_block_raw_filter(struct demod_state *fm, int16_t *buf, int len)
{
/* derived from dc_block_audio_filter,
running over the raw I/Q components
*/
int i, avgI, avgQ;
int64_t sumI = 0;
int64_t sumQ = 0;
for (i = 0; i < len; i += 2) {
sumI += buf[i];
sumQ += buf[i+1];
}
avgI = sumI / ( len / 2 );
avgQ = sumQ / ( len / 2 );
avgI = (avgI + fm->dc_avgI * fm->rdc_block_const) / ( fm->rdc_block_const + 1 );
avgQ = (avgQ + fm->dc_avgQ * fm->rdc_block_const) / ( fm->rdc_block_const + 1 );
for (i = 0; i < len; i += 2) {
buf[i] -= avgI;
buf[i+1] -= avgQ;
}
fm->dc_avgI = avgI;
fm->dc_avgQ = avgQ;
}
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, int omitDCfix)
/* largely lifted from rtl_power */
{
double dc, err;
int i, num;
int32_t t, s;
uint32_t p; /* use sign bit to prevent overflow */
p = 0;
t = 0L;
while (len > step * 32768) /* 8 bit squared = 16 bit. limit to 2^16 for 32 bit squared sum */
++step; /* increase step to prevent overflow */
for (i=0; i<len; i+=step) {
s = (long)samples[i];
t += s;
p += s * s;
}
if (omitDCfix) {
/* DC is already corrected. No need to do it again */
num = len / step;
return (int)sqrt( (double)(p) / num );
}
/* 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);
}
void arbitrary_upsample(int16_t *buf1, int16_t *buf2, int len1, int len2)
/* linear interpolation, len1 < len2 */
{
int i = 1;
int j = 0;
int tick = 0;
double frac; // use integers...
while (j < len2) {
frac = (double)tick / (double)len2;
buf2[j] = (int16_t)(buf1[i-1]*(1-frac) + buf1[i]*frac);
j++;
tick += len1;
if (tick > len2) {
tick -= len2;
i++;
}
if (i >= len1) {
i = len1 - 1;
tick = len2;
}
}
}
void arbitrary_downsample(int16_t *buf1, int16_t *buf2, int len1, int len2)
/* fractional boxcar lowpass, len1 > len2 */
{
int i = 1;
int j = 0;
int tick = 0;
double remainder = 0;
double frac; // use integers...
buf2[0] = 0;
while (j < len2) {
frac = 1.0;
if ((tick + len2) > len1) {
frac = (double)(len1 - tick) / (double)len2;}
buf2[j] += (int16_t)((double)buf1[i] * frac + remainder);
remainder = (double)buf1[i] * (1.0-frac);
tick += len2;
i++;
if (tick > len1) {
j++;
buf2[j] = 0;
tick -= len1;
}
if (i >= len1) {
i = len1 - 1;
tick = len1;
}
}
for (j=0; j<len2; j++) {
buf2[j] = buf2[j] * len2 / len1;}
}
void arbitrary_resample(int16_t *buf1, int16_t *buf2, int len1, int len2)
/* up to you to calculate lengths and make sure it does not go OOB
* okay for buffers to overlap, if you are downsampling */
{
if (len1 < len2) {
arbitrary_upsample(buf1, buf2, len1, len2);
} else {
arbitrary_downsample(buf1, buf2, len1, len2);
}
}
void full_demod(struct demod_state *d)
{
struct cmd_state *c = d->cmd;
double freqK, avgRms, rmsLevel, avgRmsLevel;
int i, ds_p;
int sr = 0;
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, d->dc_block_raw);
if (sr >= 0) {
if (sr < d->squelch_level) {
d->squelch_hits++;
for (i=0; i<d->lp_len; i++) {
d->lowpassed[i] = 0;
}
} else {
d->squelch_hits = 0;}
}
}
if (printLevels) {
if (!sr)
sr = rms(d->lowpassed, d->lp_len, 1, d->dc_block_raw);
--printLevelNo;
if (printLevels && sr >= 0) {
levelSum += sr;
if (levelMax < sr) levelMax = sr;
if (levelMaxMax < sr) levelMaxMax = sr;
if (!printLevelNo) {
printLevelNo = printLevels;
freqK = dongle.userFreq /1000.0;
avgRms = levelSum / printLevels;
rmsLevel = 20.0 * log10( 1E-10 + sr );
avgRmsLevel = 20.0 * log10( 1E-10 + avgRms );
fprintf(stderr, "%.3f kHz, %.1f avg rms, %d max rms, %d max max rms, %d squelch rms, %d rms, %.1f dB rms level, %.2f dB avg rms level\n",
freqK, avgRms, levelMax, levelMaxMax, d->squelch_level, sr, rmsLevel, avgRmsLevel );
levelMax = 0;
levelSum = 0;
}
}
}
if (c->filename) {
if (!sr)
sr = rms(d->lowpassed, d->lp_len, 1, d->dc_block_raw);
if (!c->numSummed)
c->levelSum = 0;
if (c->numSummed < c->numMeas && sr >= 0) {
c->levelSum += sr;
c->numSummed++;
}
}
d->mode_demod(d); /* lowpassed -> result */
if (d->mode_demod == &raw_demod) {
return;
}
/* todo, fm noise squelch */
// use nicer filter here too?
if (d->post_downsample > 1) {
d->result_len = low_pass_simple(d->result, d->result_len, d->post_downsample);}
if (d->deemph) {
deemph_filter(d);}
if (d->dc_block_audio) {
dc_block_audio_filter(d);}
if (d->rate_out2 > 0) {
low_pass_real(d);
//arbitrary_resample(d->result, d->result, d->result_len, d->result_len * d->rate_out2 / d->rate_out);
}
}
static void rtlsdr_callback(unsigned char *buf, uint32_t len, void *ctx)
{
struct dongle_state *s = ctx;
struct demod_state *d = s->demod_target;
struct cmd_state *c = d->cmd;
int i, muteLen = s->mute;
if (do_exit) {
return;}
if (!ctx) {
return;}
if (s->mute) {
if(muteLen > (int)len)
muteLen = len;
s->mute -= muteLen; /* we may need to mute multiple blocks */
if(!c->filename) {
for (i=0; i<muteLen; i++)
buf[i] = 127;
}
}
/* 1st: convert to 16 bit - to allow easier calculation of DC */
for (i=0; i<(int)len; i++) {
s->buf16[i] = ( (int16_t)buf[i] - 127 );
}
/* 2nd: do DC filtering BEFORE up-mixing */
if (d->dc_block_raw) {
dc_block_raw_filter(d, s->buf16, (int)len);
}
if (muteLen && c->filename)
return; /* "mute" after the dc_block_raw_filter(), giving it time to remove the new DC */
/* 3rd: down-mixing */
if (!s->offset_tuning) {
rotate16_neg90(s->buf16, (int)len);
}
pthread_rwlock_wrlock(&d->rw);
memcpy(d->lowpassed, s->buf16, 2*len);
d->lp_len = len;
pthread_rwlock_unlock(&d->rw);
safe_cond_signal(&d->ready, &d->ready_m);
}
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 output_state *o = d->output_target;
struct cmd_state *c = d->cmd;
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;
}
if (d->squelch_level && d->squelch_hits > d->conseq_squelch) {
d->squelch_hits = d->conseq_squelch + 1; /* hair trigger */
safe_cond_signal(&controller.hop, &controller.hop_m);
continue;
}
if (do_exit)
break;
if (c->filename && c->numSummed >= c->numMeas) {
checkTriggerCommand(c);
safe_cond_signal(&controller.hop, &controller.hop_m);
continue;
}
if (OutputToStdout) {
pthread_rwlock_wrlock(&o->rw);
memcpy(o->result, d->result, 2*d->result_len);
o->result_len = d->result_len;
pthread_rwlock_unlock(&o->rw);
safe_cond_signal(&o->ready, &o->ready_m);
}
}
return 0;
}
static void *output_thread_fn(void *arg)
{
struct output_state *s = arg;
while (!do_exit) {
// use timedwait and pad out under runs
safe_cond_wait(&s->ready, &s->ready_m);
pthread_rwlock_rdlock(&s->rw);
fwrite(s->result, 2, s->result_len, s->file);
pthread_rwlock_unlock(&s->rw);
}
return 0;
}
static void optimal_settings(uint32_t freq, uint32_t rate)
{
// giant ball of hacks
// seems unable to do a single pass, 2:1
uint32_t capture_freq, capture_rate;
struct dongle_state *d = &dongle;
struct demod_state *dm = &demod;
struct controller_state *cs = &controller;
dm->downsample = (MinCaptureRate / dm->rate_in) + 1;
if (dm->downsample_passes) {
dm->downsample_passes = (int)log2(dm->downsample) + 1;
dm->downsample = 1 << dm->downsample_passes;
}
if (verbosity >= 2) {
fprintf(stderr, "downsample_passes = %d (= # of fifth_order() iterations), downsample = %d\n", dm->downsample_passes, dm->downsample );
}
capture_freq = freq;
capture_rate = dm->downsample * dm->rate_in;
if (verbosity >= 2)
fprintf(stderr, "capture_rate = dm->downsample * dm->rate_in = %d * %d = %d\n", dm->downsample, dm->rate_in, capture_rate );
if (!d->offset_tuning) {
capture_freq = freq - capture_rate/4;
if (verbosity >= 2)
fprintf(stderr, "optimal_settings(freq = %u): capture_freq = freq - capture_rate/4 = %u\n", freq, capture_freq );
}
capture_freq += cs->edge * dm->rate_in / 2;
if (verbosity >= 2)
fprintf(stderr, "optimal_settings(freq = %u): capture_freq += cs->edge * dm->rate_in / 2 = %d * %d / 2 = %u\n", freq, cs->edge, dm->rate_in, capture_freq );
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->userFreq = freq;
d->freq = capture_freq;
d->rate = capture_rate;
if (verbosity >= 2)
fprintf(stderr, "optimal_settings(freq = %u) delivers freq %.0f, rate %.0f\n", freq, (double)d->freq, (double)d->rate );
}
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, r, execWaitHop = 1;
struct controller_state *s = arg;
struct cmd_state *c = s->cmd;
if (s->wb_mode) {
if (verbosity)
fprintf(stderr, "wbfm: adding 16000 Hz to every input frequency\n");
for (i=0; i < s->freq_len; i++) {
s->freqs[i] += 16000;}
}
/* set up primary channel */
if (c->filename) {
dongle.mute = dongle.rate; /* over a second - until parametrized the dongle */
toNextCmdLine(c);
/*fprintf(stderr, "\nswitched to next command line. new freq %u\n", c->freq);*/
s->freqs[0] = c->freq;
execWaitHop = 0;
}
optimal_settings(s->freqs[0], demod.rate_in);
if (dongle.direct_sampling) {
verbose_direct_sampling(dongle.dev, 1);}
if (dongle.offset_tuning) {
verbose_offset_tuning(dongle.dev);}
/* Set the frequency */
if (verbosity) {
fprintf(stderr, "verbose_set_frequency(%.3f kHz)\n", (double)dongle.userFreq /1000.0);
if (!dongle.offset_tuning)
fprintf(stderr, " frequency is away from parametrized one, to avoid negative impact from dc\n");
}
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 */
if (verbosity)
fprintf(stderr, "verbose_set_sample_rate(%.0f Hz)\n", (double)dongle.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) {
if (execWaitHop)
safe_cond_wait(&s->hop, &s->hop_m);
execWaitHop = 1; /* execute following safe_cond_wait()'s */
/* fprintf(stderr, "\nreceived hop condition\n"); */
if (s->freq_len <= 1 && !c->filename) {
continue;}
if (!c->filename) {
/* 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 = DEFAULT_BUFFER_DUMP;
} else {
dongle.mute = 2 * 3200000; /* over a second - until parametrized the dongle */
c->numSummed = 0;
toNextCmdLine(c);
optimal_settings(c->freq, demod.rate_in);
/* 1- set center frequency */
rtlsdr_set_center_freq(dongle.dev, dongle.freq);
/* 2- Set the tuner gain */
if (c->gain == AUTO_GAIN) {
r = rtlsdr_set_tuner_gain_mode(dongle.dev, 0);
if (r != 0)
fprintf(stderr, "WARNING: Failed to set automatic tuner gain.\n");
} else {
c->gain = nearest_gain(dongle.dev, c->gain);
r = rtlsdr_set_tuner_gain_mode(dongle.dev, 1);
if (r < 0)
fprintf(stderr, "WARNING: Failed to enable manual gain.\n");
r = rtlsdr_set_tuner_gain(dongle.dev, c->gain);
if (r != 0)
fprintf(stderr, "WARNING: Failed to set tuner gain.\n");
}
/* 3- Set tuner bandwidth */
r = rtlsdr_set_tuner_bandwidth(dongle.dev, dongle.bandwidth);
if (r < 0)
fprintf(stderr, "WARNING: Failed to set bandwidth.\n");
/* 4- Set ADC samplerate *
r = rtlsdr_set_sample_rate(dongle.dev, dongle.rate);
if (r < 0)
fprintf(stderr, "WARNING: Failed to set sample rate.\n");
*/
c->levelSum = 0;
c->numSummed = 0;
/* reset DC filters */
demod.dc_avg = 0;
demod.dc_avgI = 0;
demod.dc_avgQ = 0;
dongle.mute = BufferDump;
}
}
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->demod_target = &demod;
s->bandwidth = 0;
s->buf_len = 32 * 512; /* see rtl_tcp */
}
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->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_audio = 0;
s->dc_avg = 0;
s->adc_block_const = 9;
s->dc_block_raw = 0;
s->dc_avgI = 0;
s->dc_avgQ = 0;
s->rdc_block_const = 9;
pthread_rwlock_init(&s->rw, NULL);
pthread_cond_init(&s->ready, NULL);
pthread_mutex_init(&s->ready_m, NULL);
s->output_target = &output;
s->cmd = &cmd;
}
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)
{
s->rate = DEFAULT_SAMPLE_RATE;
pthread_rwlock_init(&s->rw, NULL);
pthread_cond_init(&s->ready, NULL);
pthread_mutex_init(&s->ready_m, NULL);
}
void output_cleanup(struct output_state *s)
{
pthread_rwlock_destroy(&s->rw);
pthread_cond_destroy(&s->ready);
pthread_mutex_destroy(&s->ready_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);
s->cmd = &cmd;
}
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 (controller.freq_len > 1 && demod.squelch_level == 0) {
fprintf(stderr, "Please specify a squelch level. Required for scanning multiple frequencies.\n");
exit(1);
}
}
int main(int argc, char **argv)
{
#ifndef _WIN32
struct sigaction sigact;
#endif
int r, opt;
int dev_given = 0;
int custom_ppm = 0;
int enable_biastee = 0;
enum rtlsdr_ds_mode ds_mode = RTLSDR_DS_IQ;
uint32_t ds_temp, ds_threshold = 0;
int timeConstant = 75; /* default: U.S. 75 uS */
int rtlagc = 0;
dongle_init(&dongle);
demod_init(&demod);
output_init(&output);
controller_init(&controller);
cmd_init(&cmd);
while ((opt = getopt(argc, argv, "d:f:C:B:m:g:s:b:l:L:o:t:r:p:E:q:F:A:M:c:h:w:D:Tnv")) != -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 'C':
cmd.filename = optarg;
demod.mode_demod = &raw_demod;
break;
case 'm':
MinCaptureRate = (int)atofs(optarg);
break;
case 'B':
BufferDump = atoi(optarg);
break;
case 'n':
OutputToStdout = 0;
break;
case 'g':
dongle.gain = (int)(atof(optarg) * 10);
break;
case 'l':
demod.squelch_level = (int)atof(optarg);
break;
case 'L':
printLevels = (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("dc", optarg) == 0 || strcmp("adc", optarg) == 0) {
demod.dc_block_audio = 1;}
if (strcmp("rdc", optarg) == 0) {
demod.dc_block_raw = 1;}
if (strcmp("deemp", optarg) == 0) {
demod.deemph = 1;}
if (strcmp("direct", optarg) == 0) {
dongle.direct_sampling = 1;}
if (strcmp("offset", optarg) == 0) {
dongle.offset_tuning = 1;}
if (strcmp("rtlagc", optarg) == 0 || strcmp("agc", optarg) == 0) {
rtlagc = 1;}
break;
case 'q':
demod.rdc_block_const = atoi(optarg);
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;}
break;
case 'M':
if (strcmp("nbfm", optarg) == 0 || strcmp("nfm", optarg) == 0 || strcmp("fm", optarg) == 0) {
demod.mode_demod = &fm_demod;}
if (strcmp("raw", optarg) == 0 || strcmp("iq", 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 || strcmp("wfm", optarg) == 0) {
controller.wb_mode = 1;
demod.mode_demod = &fm_demod;
demod.rate_in = 170000;
demod.rate_out = 170000;
demod.rate_out2 = 32000;
demod.custom_atan = 1;
//demod.post_downsample = 4;
demod.deemph = 1;
demod.squelch_level = 0;}
break;
case 'c':
if (strcmp("us", optarg) == 0)
timeConstant = 75;
else if (strcmp("eu", optarg) == 0)
timeConstant = 50;
else
timeConstant = (int)atof(optarg);
break;
case 'T':
enable_biastee = 1;
break;
case 'D':
ds_temp = (uint32_t)( atofs(optarg) + 0.5 );
if (ds_temp <= RTLSDR_DS_Q_BELOW)
ds_mode = (enum rtlsdr_ds_mode)ds_temp;
else
ds_threshold = ds_temp;
break;
case 'v':
++verbosity;
break;
case 'w':
dongle.bandwidth = (uint32_t)atofs(optarg);
break;
case 'h':
case '?':
default:
usage();
break;
}
}
if (verbosity)
fprintf(stderr, "verbosity set to %d\n", verbosity);
/* 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);
#else
SetConsoleCtrlHandler( (PHANDLER_ROUTINE) sighandler, TRUE );
#endif
if (demod.deemph) {
double tc = (double)timeConstant * 1e-6;
demod.deemph_a = (int)round(1.0/((1.0-exp(-1.0/(demod.rate_out * tc)))));
if (verbosity)
fprintf(stderr, "using wbfm deemphasis filter with time constant %d us\n", timeConstant );
}
/* 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);
}
rtlsdr_set_agc_mode(dongle.dev, rtlagc);
rtlsdr_set_bias_tee(dongle.dev, enable_biastee);
if (enable_biastee)
fprintf(stderr, "activated bias-T on GPIO PIN 0\n");
verbose_ppm_set(dongle.dev, dongle.ppm_error);
/* Set direct sampling with threshold */
rtlsdr_set_ds_mode(dongle.dev, ds_mode, ds_threshold);
verbose_set_bandwidth(dongle.dev, dongle.bandwidth);
if (verbosity && dongle.bandwidth)
{
int r;
uint32_t in_bw, out_bw, last_bw = 0;
fprintf(stderr, "Supported bandwidth values in kHz:\n");
for ( in_bw = 1; in_bw < 3200; ++in_bw )
{
r = rtlsdr_set_and_get_tuner_bandwidth(dongle.dev, in_bw*1000, &out_bw, 0 /* =apply_bw */);
if ( r == 0 && out_bw != 0 && ( out_bw != last_bw || in_bw == 1 ) )
fprintf(stderr, "%s%.1f", (in_bw==1 ? "" : ", "), out_bw/1000.0 );
last_bw = out_bw;
}
fprintf(stderr,"\n");
}
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);
}
}
//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(1000000); /* it looks, that startup of dongle level takes some time at startup! */
pthread_create(&output.thread, NULL, output_thread_fn, (void *)(&output));
pthread_create(&demod.thread, NULL, demod_thread_fn, (void *)(&demod));
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);
safe_cond_signal(&output.ready, &output.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 (cmd.filename) {
int k;
/* output scan statistics */
for (k = 0; k < FREQUENCIES_LIMIT; k++) {
if (cmd.statNumLevels[k] > 0)
fprintf(stderr, "%u, %.1f, %.2f, %.1f\n", cmd.statFreq[k], cmd.statMinLevel[k], cmd.statSumLevels[k] / cmd.statNumLevels[k], cmd.statMaxLevel[k] );
}
}
if (output.file != stdout) {
fclose(output.file);}
rtlsdr_close(dongle.dev);
return r >= 0 ? r : -r;
}
// vim: tabstop=8:softtabstop=8:shiftwidth=8:noexpandtab
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