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rtl_fm: fix auto/manual gain

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Signed-off-by: Steve Markgraf <steve@steve-m.de>
This commit is contained in:
Kyle Keen
2012-09-04 09:50:36 -04:00
committed by Steve Markgraf
parent c792c4aeac
commit f4a8a570c4
1 changed files with 18 additions and 9 deletions
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27
src/rtl_fm.c
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@@ -59,7 +59,8 @@
#define DEFAULT_BUF_LENGTH (1 * 16384)
#define MINIMAL_BUF_LENGTH 512
#define MAXIMAL_BUF_LENGTH (256 * 16384)
#define CONSEQ_SQUELCH 4
#define CONSEQ_SQUELCH 4
#define AUTO_GAIN -100
static pthread_t demod_thread;
static sem_t data_ready;
@@ -103,7 +104,7 @@ void usage(void)
"\t (use multiple -f for scanning)\n"
"\t[-s samplerate (default: 24000 Hz)]\n"
"\t[-d device_index (default: 0)]\n"
"\t[-g tuner_gain (default: -1dB)]\n"
"\t[-g tuner_gain (default: automatic)]\n"
"\t[-l squelch_level (default: 150)]\n"
"\t[-E freq sets lower edge (default: center)]\n"
"\tfilename (a '-' dumps samples to stdout)\n\n"
@@ -311,8 +312,8 @@ int mad(int *samples, int len, int step)
/* mean average deviation */
{
int i=0, sum=0, ave=0;
if (len == 0)
{return 0;}
if (len == 0)
{return 0;}
for (i=0; i<len; i+=step) {
sum += samples[i];
}
@@ -369,7 +370,7 @@ static void optimal_settings(struct fm_state *fm, int freq, int hopping)
fprintf(stderr, "WARNING: Failed to set center freq.\n");}
else {
fprintf(stderr, "Tuned to %u Hz.\n", capture_freq);}
/* Set the sample rate */
fprintf(stderr, "Sampling at %u Hz.\n", capture_rate);
r = rtlsdr_set_sample_rate(dev, (uint32_t)capture_rate);
@@ -439,7 +440,7 @@ int main(int argc, char **argv)
char *filename = NULL;
int n_read;
int r, opt;
int i, gain = -10; // tenths of a dB
int i, gain = AUTO_GAIN; // tenths of a dB
uint8_t *buffer;
uint32_t dev_index = 0;
int device_count;
@@ -538,11 +539,19 @@ int main(int argc, char **argv)
build_fir(&fm);
/* Set the tuner gain */
r = rtlsdr_set_tuner_gain(dev, gain);
if (r < 0)
if (gain == AUTO_GAIN) {
r = rtlsdr_set_tuner_gain_mode(dev, 0);
} else {
r = rtlsdr_set_tuner_gain_mode(dev, 1);
r = rtlsdr_set_tuner_gain(dev, gain);
}
if (r != 0) {
fprintf(stderr, "WARNING: Failed to set tuner gain.\n");
else
} else if (gain == AUTO_GAIN) {
fprintf(stderr, "Tuner gain set to automatic.\n");
} else {
fprintf(stderr, "Tuner gain set to %0.2f dB.\n", gain/10.0);
}
if(strcmp(filename, "-") == 0) { /* Write samples to stdout */
fm.file = stdout;