mirror of
https://github.com/rtlsdrblog/rtl-sdr-blog.git
synced 2024-12-27 03:18:30 +01:00
rtl_fm: fix scanning
Signed-off-by: Steve Markgraf <steve@steve-m.de>
This commit is contained in:
Kyle Keen
Steve Markgraf
parent
8c3a99c8f7
commit
c4fcfbb46e
121
src/rtl_fm.c
121
src/rtl_fm.c
@ -34,6 +34,11 @@
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* pad output on hop
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* nearest gain approx
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* frequency ranges could be stored better
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* scaled AM demod amplification
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* auto-hop after time limit
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* peak detector to tune onto stronger signals
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* use slower sample rates (250k) for nbfm
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* offset tuning
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*/
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#include <errno.h>
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@ -66,12 +71,16 @@
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#define MAXIMUM_BUF_LENGTH (MAXIMUM_OVERSAMPLE * DEFAULT_BUF_LENGTH)
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#define AUTO_GAIN -100
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#define FREQUENCIES_LIMIT 1000
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static pthread_t demod_thread;
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static pthread_mutex_t data_ready; /* locked when no fresh data available */
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static pthread_mutex_t data_write; /* locked when r/w buffer */
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static int do_exit = 0;
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static pthread_cond_t data_ready; /* shared buffer filled */
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static pthread_rwlock_t data_rw; /* lock for shared buffer */
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static pthread_mutex_t data_mutex; /* because conds are dumb */
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static volatile int do_exit = 0;
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static rtlsdr_dev_t *dev = NULL;
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static int lcm_post[17] = {1,1,1,3,1,5,3,7,1,9,5,11,3,13,7,15,1};
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static int ACTUAL_BUF_LENGTH;
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static int *atan_lut = NULL;
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static int atan_lut_size = 131072; /* 512 KB */
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@ -95,7 +104,7 @@ struct fm_state
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int signal2_len;
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FILE *file;
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int edge;
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uint32_t freqs[1000];
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uint32_t freqs[FREQUENCIES_LIMIT];
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int freq_len;
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int freq_now;
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uint32_t sample_rate;
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@ -145,7 +154,7 @@ void usage(void)
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"\t[-C enables DC blocking of output (default: off)]\n"
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"\t[-A std/fast/lut choose atan math (default: std)]\n\n"
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"Produces signed 16 bit ints, use Sox or aplay to hear them.\n"
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"\trtl_fm ... - | play -t raw -r 24k -e signed-integer -b 16 -c 1 -V1 -\n"
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"\trtl_fm ... - | play -t raw -r 24k -es -b 16 -c 1 -V1 -\n"
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"\t | aplay -r 24k -f S16_LE -t raw -c 1\n"
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"\t -s 22.5k - | multimon -t raw /dev/stdin\n\n");
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exit(1);
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@ -158,7 +167,7 @@ sighandler(int signum)
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if (CTRL_C_EVENT == signum) {
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fprintf(stderr, "Signal caught, exiting!\n");
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do_exit = 1;
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rtlsdr_cancel_async(dev);
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//rtlsdr_cancel_async(dev);
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return TRUE;
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}
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return FALSE;
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@ -168,10 +177,14 @@ static void sighandler(int signum)
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{
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fprintf(stderr, "Signal caught, exiting!\n");
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do_exit = 1;
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rtlsdr_cancel_async(dev);
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//rtlsdr_cancel_async(dev);
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}
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#endif
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/* more cond dumbness */
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#define safe_cond_signal(n, m) pthread_mutex_lock(m); pthread_cond_signal(n); pthread_mutex_unlock(m)
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#define safe_cond_wait(n, m) pthread_mutex_lock(m); pthread_cond_wait(n, m); pthread_mutex_unlock(m)
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void rotate_90(unsigned char *buf, uint32_t len)
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/* 90 rotation is 1+0j, 0+1j, -1+0j, 0-1j
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or [0, 1, -3, 2, -4, -5, 7, -6] */
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@ -205,8 +218,8 @@ void low_pass(struct fm_state *fm, unsigned char *buf, uint32_t len)
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if (fm->prev_index < fm->downsample) {
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continue;
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}
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fm->signal[i2] = fm->now_r * fm->output_scale;
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fm->signal[i2+1] = fm->now_j * fm->output_scale;
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fm->signal[i2] = fm->now_r; // * fm->output_scale;
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fm->signal[i2+1] = fm->now_j; // * fm->output_scale;
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fm->prev_index = 0;
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fm->now_r = 0;
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fm->now_j = 0;
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@ -248,8 +261,8 @@ void low_pass_fir(struct fm_state *fm, unsigned char *buf, uint32_t len)
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if (fm->prev_index < fm->downsample) {
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continue;
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}
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fm->signal[i2] = fm->now_r * fm->output_scale;
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fm->signal[i2+1] = fm->now_j * fm->output_scale;
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fm->signal[i2] = fm->now_r; //* fm->output_scale;
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fm->signal[i2+1] = fm->now_j; //* fm->output_scale;
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fm->prev_index = 0;
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fm->now_r = 0;
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fm->now_j = 0;
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@ -432,7 +445,7 @@ void am_demod(struct fm_state *fm)
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//fm->signal2[i/2] = (int16_t)hypot(fm->signal[i], fm->signal[i+1]);
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pcm = fm->signal[i] * fm->signal[i];
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pcm += fm->signal[i+1] * fm->signal[i+1];
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fm->signal2[i/2] = (int16_t)sqrt(pcm); // * fm->output_scale;
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fm->signal2[i/2] = (int16_t)sqrt(pcm) * fm->output_scale;
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}
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fm->signal2_len = fm->signal_len/2;
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// lowpass? (3khz) highpass? (dc)
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@ -443,7 +456,7 @@ void usb_demod(struct fm_state *fm)
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int i, pcm;
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for (i = 0; i < (fm->signal_len); i += 2) {
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pcm = fm->signal[i] + fm->signal[i+1];
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fm->signal2[i/2] = (int16_t)pcm; // * fm->output_scale;
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fm->signal2[i/2] = (int16_t)pcm * fm->output_scale;
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}
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fm->signal2_len = fm->signal_len/2;
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}
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@ -453,7 +466,7 @@ void lsb_demod(struct fm_state *fm)
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int i, pcm;
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for (i = 0; i < (fm->signal_len); i += 2) {
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pcm = fm->signal[i] - fm->signal[i+1];
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fm->signal2[i/2] = (int16_t)pcm; // * fm->output_scale;
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fm->signal2[i/2] = (int16_t)pcm * fm->output_scale;
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}
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fm->signal2_len = fm->signal_len/2;
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}
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@ -545,7 +558,8 @@ static void optimal_settings(struct fm_state *fm, int freq, int hopping)
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fm->output_scale = (1<<15) / (128 * fm->downsample);
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if (fm->output_scale < 1) {
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fm->output_scale = 1;}
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fm->output_scale = 1;
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if (fm->mode_demod == &fm_demod) {
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fm->output_scale = 1;}
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/* Set the frequency */
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r = rtlsdr_set_center_freq(dev, (uint32_t)capture_freq);
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if (hopping) {
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@ -553,7 +567,7 @@ static void optimal_settings(struct fm_state *fm, int freq, int hopping)
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fprintf(stderr, "Oversampling input by: %ix.\n", fm->downsample);
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fprintf(stderr, "Oversampling output by: %ix.\n", fm->post_downsample);
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fprintf(stderr, "Buffer size: %0.2fms\n",
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1000 * 0.5 * lcm_post[fm->post_downsample] * (float)DEFAULT_BUF_LENGTH / (float)capture_rate);
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1000 * 0.5 * (float)ACTUAL_BUF_LENGTH / (float)capture_rate);
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if (r < 0) {
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fprintf(stderr, "WARNING: Failed to set center freq.\n");}
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else {
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@ -574,13 +588,14 @@ static void optimal_settings(struct fm_state *fm, int freq, int hopping)
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void full_demod(struct fm_state *fm)
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{
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int i, sr, freq_next, hop = 0;
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pthread_rwlock_wrlock(&data_rw);
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rotate_90(fm->buf, fm->buf_len);
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if (fm->fir_enable) {
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low_pass_fir(fm, fm->buf, fm->buf_len);
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} else {
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low_pass(fm, fm->buf, fm->buf_len);
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}
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pthread_mutex_unlock(&data_write);
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pthread_rwlock_unlock(&data_rw);
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fm->mode_demod(fm);
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if (fm->mode_demod == &raw_demod) {
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fwrite(fm->signal2, 2, fm->signal2_len, fm->file);
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@ -625,23 +640,41 @@ static void rtlsdr_callback(unsigned char *buf, uint32_t len, void *ctx)
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return;}
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if (!ctx) {
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return;}
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pthread_mutex_lock(&data_write);
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pthread_rwlock_wrlock(&data_rw);
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memcpy(fm2->buf, buf, len);
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fm2->buf_len = len;
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pthread_mutex_unlock(&data_ready);
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pthread_rwlock_unlock(&data_rw);
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safe_cond_signal(&data_ready, &data_mutex);
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/* single threaded uses 25% less CPU? */
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/* full_demod(fm2); */
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}
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static void sync_read(unsigned char *buf, uint32_t len, struct fm_state *fm)
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{
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int r, n_read;
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r = rtlsdr_read_sync(dev, buf, len, &n_read);
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if (r < 0) {
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fprintf(stderr, "WARNING: sync read failed.\n");
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return;
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}
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pthread_rwlock_wrlock(&data_rw);
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memcpy(fm->buf, buf, len);
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fm->buf_len = len;
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pthread_rwlock_unlock(&data_rw);
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safe_cond_signal(&data_ready, &data_mutex);
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//full_demod(fm);
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}
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static void *demod_thread_fn(void *arg)
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{
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struct fm_state *fm2 = arg;
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while (!do_exit) {
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pthread_mutex_lock(&data_ready);
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safe_cond_wait(&data_ready, &data_mutex);
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full_demod(fm2);
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if (fm2->exit_flag) {
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do_exit = 1;
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rtlsdr_cancel_async(dev);}
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//rtlsdr_cancel_async(dev);
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}
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}
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return 0;
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}
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@ -680,6 +713,8 @@ void frequency_range(struct fm_state *fm, char *arg)
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{
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fm->freqs[fm->freq_len] = (uint32_t)i;
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fm->freq_len++;
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if (fm->freq_len >= FREQUENCIES_LIMIT) {
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break;}
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}
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stop[-1] = ':';
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step[-1] = ':';
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@ -725,8 +760,9 @@ int main(int argc, char **argv)
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int ppm_error = 0;
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char vendor[256], product[256], serial[256];
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fm_init(&fm);
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pthread_mutex_init(&data_ready, NULL);
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pthread_mutex_init(&data_write, NULL);
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pthread_cond_init(&data_ready, NULL);
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pthread_rwlock_init(&data_rw, NULL);
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pthread_mutex_init(&data_mutex, NULL);
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while ((opt = getopt(argc, argv, "d:f:g:s:b:l:o:t:r:p:EFA:NWMULRDC")) != -1) {
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switch (opt) {
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@ -734,6 +770,8 @@ int main(int argc, char **argv)
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dev_index = atoi(optarg);
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break;
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case 'f':
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if (fm.freq_len >= FREQUENCIES_LIMIT) {
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break;}
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if (strchr(optarg, ':'))
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{frequency_range(&fm, optarg);}
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else
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@ -828,18 +866,28 @@ int main(int argc, char **argv)
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exit(1);
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}
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if (fm.freq_len >= FREQUENCIES_LIMIT) {
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fprintf(stderr, "Too many channels, maximum %i.\n", FREQUENCIES_LIMIT);
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exit(1);
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}
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if (fm.freq_len > 1 && fm.squelch_level == 0) {
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fprintf(stderr, "Please specify a squelch level. Required for scanning multiple frequencies.\n");
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exit(1);
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}
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if (fm.freq_len > 1) {
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fm.terminate_on_squelch = 0;
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}
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if (argc <= optind) {
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//usage();
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filename = "-";
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} else {
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filename = argv[optind];
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}
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buffer = malloc(lcm_post[fm.post_downsample] * DEFAULT_BUF_LENGTH * sizeof(uint8_t));
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ACTUAL_BUF_LENGTH = lcm_post[fm.post_downsample] * DEFAULT_BUF_LENGTH;
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buffer = malloc(ACTUAL_BUF_LENGTH * sizeof(uint8_t));
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device_count = rtlsdr_get_device_count();
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if (!device_count) {
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@ -875,6 +923,8 @@ int main(int argc, char **argv)
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#endif
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/* WBFM is special */
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// I really should loop over everything
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// but you are more wrong for scanning broadcast FM
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if (wb_mode) {
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fm.freqs[0] += 16000;
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}
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@ -921,17 +971,26 @@ int main(int argc, char **argv)
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fprintf(stderr, "WARNING: Failed to reset buffers.\n");}
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pthread_create(&demod_thread, NULL, demod_thread_fn, (void *)(&fm));
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rtlsdr_read_async(dev, rtlsdr_callback, (void *)(&fm),
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/*rtlsdr_read_async(dev, rtlsdr_callback, (void *)(&fm),
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DEFAULT_ASYNC_BUF_NUMBER,
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lcm_post[fm.post_downsample] * DEFAULT_BUF_LENGTH);
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ACTUAL_BUF_LENGTH);*/
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while (!do_exit) {
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sync_read(buffer, ACTUAL_BUF_LENGTH, &fm);
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}
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if (do_exit) {
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fprintf(stderr, "\nUser cancel, exiting...\n");}
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else {
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fprintf(stderr, "\nLibrary error %d, exiting...\n", r);}
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rtlsdr_cancel_async(dev);
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pthread_mutex_destroy(&data_ready);
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pthread_mutex_destroy(&data_write);
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//rtlsdr_cancel_async(dev);
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safe_cond_signal(&data_ready, &data_mutex);
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pthread_join(demod_thread, NULL);
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pthread_cond_destroy(&data_ready);
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pthread_rwlock_destroy(&data_rw);
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pthread_mutex_destroy(&data_mutex);
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if (fm.file != stdout) {
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fclose(fm.file);}
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@ -940,3 +999,5 @@ int main(int argc, char **argv)
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free (buffer);
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return r >= 0 ? r : -r;
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}
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// vim: tabstop=8:softtabstop=8:shiftwidth=8:noexpandtab
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