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-rw-r--r--binding/rtl_fm.c1267
1 files changed, 0 insertions, 1267 deletions
diff --git a/binding/rtl_fm.c b/binding/rtl_fm.c
deleted file mode 100644
index 1c6a6b2..0000000
--- a/binding/rtl_fm.c
+++ /dev/null
@@ -1,1267 +0,0 @@
-/*
- * 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) 2016, 2017 Konsulko Group
- *
- * 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/>.
- */
-
-/*
- * Note that this version replaces the standalone main() with separate
- * init/start/stop API calls to allow building into another application.
- * Other than removing the separate controller thread and adding an output
- * function callback, other changes have been kept to a minimum to
- * potentially allow using other rtl_fm features by modifying rtl_fm_init.
- *
- * December 2016, Scott Murray <scott.murray@konsulko.com>
- */
-
-/*
- * 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 <unistd.h>
-#include <math.h>
-#include <pthread.h>
-
-#include "rtl-sdr.h"
-#include "rtl_fm.h"
-#include "convenience/convenience.h"
-
-#define DEFAULT_SAMPLE_RATE 24000
-#define DEFAULT_BUF_LENGTH RTL_FM_DEFAULT_BUF_LENGTH
-#define MAXIMUM_OVERSAMPLE RTL_FM_MAXIMUM_OVERSAMPLE
-#define MAXIMUM_BUF_LENGTH RTL_FM_MAXIMUM_BUF_LENGTH
-#define AUTO_GAIN -100
-#define BUFFER_DUMP 4096
-
-#define FREQUENCIES_LIMIT 1000
-
-#define DEFAULT_SQUELCH_LEVEL 140
-#define DEFAULT_CONSEQ_SQUELCH 10
-
-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;
-
-struct dongle_state
-{
- int exit_flag;
- pthread_t thread;
- rtlsdr_dev_t *dev;
- int dev_index;
- uint32_t freq;
- uint32_t rate;
- int gain;
- uint16_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, dc_avg;
- 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 output_state
-{
- int exit_flag;
- pthread_t thread;
- rtl_fm_output_fn_t output_fn;
- void *output_fn_data;
- 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;
-
- void (*freq_callback)(uint32_t, void*);
- void *freq_callback_data;
-
- int scanning;
- int scan_direction;
- void (*scan_callback)(uint32_t, void*);
- void *scan_callback_data;
- uint32_t scan_step;
- uint32_t scan_min;
- uint32_t scan_max;
- int scan_squelch_level;
- int scan_squelch_count;
-};
-
-// multiple of these, eventually
-struct dongle_state dongle;
-struct demod_state demod;
-struct output_state output;
-struct controller_state controller;
-
-#if 0
-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},
-};
-
-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;
- }
-}
-
-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?
-{
- 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_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 * 9) / 10;
- for (i=0; i < fm->result_len; i++) {
- fm->result[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);
-}
-
-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)
-{
- 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);
- 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;
- }
- }
- 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) {
- dc_block_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)
-{
- int i;
- struct dongle_state *s = ctx;
- struct demod_state *d = s->demod_target;
-
- if (do_exit) {
- return;}
- if (!ctx) {
- return;}
- if (s->mute) {
- for (i=0; i<s->mute; i++) {
- buf[i] = 127;}
- s->mute = 0;
- }
- if (!s->offset_tuning) {
- rotate_90(buf, len);}
- for (i=0; i<(int)len; i++) {
- s->buf16[i] = (int16_t)buf[i] - 127;}
- 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;
- fprintf(stderr, "dongle_thread_fn running\n");
- rtlsdr_read_async(s->dev, rtlsdr_callback, s, 0, s->buf_len);
- fprintf(stderr, "dongle_thread_fn exited!\n");
- return 0;
-}
-
-static void rtl_fm_scan_callback(void)
-{
- struct controller_state *s = &controller;
- uint32_t frequency = rtl_fm_get_freq();
-
- if(!s->scanning)
- return;
-
- if(!s->scan_direction) {
- frequency += s->scan_step;
- if(frequency > s->scan_max)
- frequency = s->scan_min;
- } else {
- frequency -= s->scan_step;
- if(frequency < s->scan_min)
- frequency = s->scan_max;
- }
-
- rtl_fm_set_freq(frequency);
-}
-
-static void rtl_fm_scan_end_callback(void)
-{
- struct controller_state *s = &controller;
-
- if(!s->scanning)
- return;
-
- rtl_fm_scan_stop();
-
- if(s->scan_callback)
- s->scan_callback(rtl_fm_get_freq(), s->scan_callback_data);
-}
-
-static void *demod_thread_fn(void *arg)
-{
- struct demod_state *d = arg;
- struct output_state *o = d->output_target;
- fprintf(stderr, "demod_thread_fn running\n");
- 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) {
- if(d->squelch_hits > d->conseq_squelch) {
- d->squelch_hits = d->conseq_squelch + 1; /* hair trigger */
- //safe_cond_signal(&controller.hop, &controller.hop_m);
- rtl_fm_scan_callback();
- continue;
- } else if(!d->squelch_hits) {
- rtl_fm_scan_end_callback();
- }
- }
- 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);
- }
- fprintf(stderr, "demod_thread_fn exited!\n");
- return 0;
-}
-
-static void *output_thread_fn(void *arg)
-{
- struct output_state *s = arg;
- fprintf(stderr, "output_thread_fn running\n");
- while (!do_exit) {
- // use timedwait and pad out under runs
- safe_cond_wait(&s->ready, &s->ready_m);
- pthread_rwlock_rdlock(&s->rw);
- if(s->output_fn) {
- s->output_fn(s->result, s->result_len, s->output_fn_data);
- }
- pthread_rwlock_unlock(&s->rw);
- }
- fprintf(stderr, "output_thread_fn exited!\n");
- 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 = (1000000 / 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->offset_tuning) {
- 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;
-}
-
-
-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;
-}
-
-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 = DEFAULT_CONSEQ_SQUELCH;
- s->terminate_on_squelch = 0;
- s->squelch_hits = DEFAULT_CONSEQ_SQUELCH + 1;
- 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 = 0;
- 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;
-}
-
-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;
- s->output_fn = NULL;
- s->output_fn_data = NULL;
- 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);
-}
-
-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 rtl_fm_init(uint32_t freq,
- uint32_t sample_rate,
- uint32_t resample_rate,
- rtl_fm_output_fn_t output_fn,
- void *output_fn_data)
-{
- int r = 0;
-
- dongle_init(&dongle);
- demod_init(&demod);
- output_init(&output);
- controller_init(&controller);
-
- /*
- * Simulate the effects of command line arguments:
- *
- * -W wbfm -s <sample rate> -r <resample rate>
- */
-
- /* Set initial frequency */
- controller.freqs[0] = freq;
- controller.freq_len++;
-
- /* Set mode to wbfm */
- 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;
- controller.scan_squelch_count = DEFAULT_CONSEQ_SQUELCH;
- controller.scan_squelch_level = DEFAULT_SQUELCH_LEVEL;
- demod.squelch_level = 0;
-
- /* Adjust frequency for wb mode */
- controller.freqs[0] += 16000;
-
- /* Set sample rate */
- demod.rate_in = sample_rate;
- demod.rate_out = sample_rate;
-
- /* Set resample rate */
- output.rate = (int) resample_rate;
- demod.rate_out2 = (int) resample_rate;
-
- /* Set output function pointer */
- if(output_fn) {
- output.output_fn = output_fn;
- output.output_fn_data = output_fn_data;
- }
-
- /* 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;
- }
-
- ACTUAL_BUF_LENGTH = lcm_post[demod.post_downsample] * DEFAULT_BUF_LENGTH;
-
- dongle.dev_index = verbose_device_search("0");
- if (dongle.dev_index < 0) {
- return -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);
- return r;
- }
-
- 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);
- }
-
- verbose_ppm_set(dongle.dev, dongle.ppm_error);
-
- //r = rtlsdr_set_testmode(dongle.dev, 1);
-
- return r;
-}
-
-void rtl_fm_start(void)
-{
- struct controller_state *s = &controller;
-
- /*
- * A bunch of the following is pulled from the controller_thread_fn,
- * which has been removed.
- */
-
- /* Reset endpoint before we start reading from it (mandatory) */
- verbose_reset_buffer(dongle.dev);
-
- /* set up primary channel */
- 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 */
- 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);
- usleep(100000);
-
- rtl_fm_scan_stop();
-
- do_exit = 0;
- 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));
-}
-
-void rtl_fm_set_freq(uint32_t freq)
-{
- struct controller_state *s = &controller;
-
- if(s->freqs[0] == freq)
- return;
-
- s->freqs[0] = freq;
- s->freq_len = 1;
-
- if (s->wb_mode) {
- s->freqs[0] += 16000;
- }
-
- optimal_settings(s->freqs[0], demod.rate_in);
- if (dongle.offset_tuning) {
- verbose_offset_tuning(dongle.dev);
- }
- rtlsdr_set_center_freq(dongle.dev, dongle.freq);
-
- // It does not look like refreshing the sample rate is desirable
- // (e.g. the scanning code in the removed controller thread function
- // did not do it), and behavior seemed a bit less robust with it
- // present. However, I am leaving this here as a reminder to revisit
- // via some more testing.
- //rtlsdr_set_sample_rate(dongle.dev, dongle.rate);
-
- // This triggers a mute during the frequency change
- dongle.mute = BUFFER_DUMP;
-
- if(s->freq_callback)
- s->freq_callback(freq, s->freq_callback_data);
-}
-
-void rtl_fm_set_freq_callback(void (*callback)(uint32_t, void *),
- void *data)
-{
- struct controller_state *s = &controller;
-
- s->freq_callback = callback;
- s->freq_callback_data = data;
-}
-
-uint32_t rtl_fm_get_freq(void)
-{
- struct controller_state *s = &controller;
- uint32_t frequency = s->freqs[0];
-
- if (s->wb_mode)
- frequency -= 16000;
-
- return frequency;
-}
-
-void rtl_fm_stop(void)
-{
- rtl_fm_scan_stop();
-
- rtlsdr_cancel_async(dongle.dev);
- do_exit = 1;
- 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);
-}
-
-void rtl_fm_scan_start(int direction,
- void (*callback)(uint32_t, void *),
- void *data,
- uint32_t step,
- uint32_t min,
- uint32_t max)
-{
- struct controller_state *s = &controller;
- struct demod_state *dm = &demod;
- uint32_t frequency = rtl_fm_get_freq();
-
- if(s->scanning && s->scan_direction == direction)
- return;
-
- s->scanning = 1;
- s->scan_direction = direction;
- s->scan_callback = callback;
- s->scan_callback_data = data;
- s->scan_step = step;
- s->scan_min = min;
- s->scan_max = max;
-
- /* Start scan by stepping in the desired direction */
- if(!direction) {
- frequency += s->scan_step;
- if(frequency > s->scan_max)
- frequency = s->scan_min;
- } else {
- frequency -= s->scan_step;
- if(frequency < s->scan_min)
- frequency = s->scan_max;
- }
-
- rtl_fm_set_freq(frequency);
-
- dm->conseq_squelch = s->scan_squelch_count;
- dm->squelch_hits = s->scan_squelch_count + 1;
- dm->squelch_level = s->scan_squelch_level;
-}
-
-void rtl_fm_scan_stop(void)
-{
- struct controller_state *s = &controller;
- struct demod_state *dm = &demod;
-
- s->scanning = 0;
-
- dm->squelch_hits = s->scan_squelch_count + 1;
- dm->squelch_level = 0;
-}
-
-void rtl_fm_scan_set_squelch_level(int level)
-{
- struct controller_state *s = &controller;
-
- s->scan_squelch_level = level;
-}
-
-void rtl_fm_scan_set_squelch_limit(int count)
-{
- struct controller_state *s = &controller;
-
- s->scan_squelch_count = count;
-}
-
-void rtl_fm_cleanup(void)
-{
- //dongle_cleanup(&dongle);
- demod_cleanup(&demod);
- output_cleanup(&output);
- controller_cleanup(&controller);
-
- rtlsdr_close(dongle.dev);
-}
-
-// vim: tabstop=8:softtabstop=8:shiftwidth=8:noexpandtab