diff options
| -rw-r--r-- | src/fl2k_iq.c | 30 |
1 files changed, 19 insertions, 11 deletions
diff --git a/src/fl2k_iq.c b/src/fl2k_iq.c index 6d253e0..2dce59b 100644 --- a/src/fl2k_iq.c +++ b/src/fl2k_iq.c @@ -81,17 +81,19 @@ int input_freq = 48000; complex float *ampbuf; complex float *slopebuf; int writepos, readpos; +int swap_iq = 0; void usage(void) { fprintf(stderr, - "fl2k_iq, an IQ modulator for FL2K VGA dongles\n\n" - "Usage:" - "\t[-d device index (default: 0)]\n" - "\t[-c center frequency (default: 1440 kHz)]\n" - "\t[-i input baseband sample rate (default: 48000 Hz)]\n" - "\t[-s samplerate in Hz (default: 96 MS/s)]\n" - "\tfilename (use '-' to read from stdin)\n\n" + "fl2k_iq, an IQ modulator for FL2K VGA dongles\n\n" + "Usage:" + "\t[-d device index (default: 0)]\n" + "\t[-c center frequency (default: 1440 kHz)]\n" + "\t[-i input baseband sample rate (default: 48000 Hz)]\n" + "\t[-s samplerate in Hz (default: 96 MS/s)]\n" + "\t[-w swap I & Q (invert spectrum)\n" + "\tfilename (use '-' to read from stdin)\n\n" ); exit(1); } @@ -321,6 +323,7 @@ void iq_modulator() float complex sample; while (!do_exit) { + int swap = swap_iq; len = writelen(BASEBAND_BUF_SIZE); if (len > 1) { len = fread(baseband_buf, 4, len, file); @@ -332,7 +335,7 @@ void iq_modulator() } for (i = 0; i < len; i++) { - sample = (float) baseband_buf[i][0] / 32768.0 + I * (float) baseband_buf[i][1] / 32768.0; + sample = (float) baseband_buf[i][0+swap] / 32768.0 + I * (float) baseband_buf[i][1-swap] / 32768.0; /* Modulate and buffer the sample */ lastamp = modulate_sample_iq(lastwritepos, lastamp, sample); @@ -384,7 +387,7 @@ int main(int argc, char **argv) }; while (1) { - opt = getopt_long(argc, argv, "d:c:i:s:", long_options, &option_index); + opt = getopt_long(argc, argv, "wd:c:i:s:", long_options, &option_index); /* end of options reached */ if (opt == -1) @@ -406,6 +409,9 @@ int main(int argc, char **argv) case 's': samp_rate = (uint32_t)atof(optarg); break; + case 'w': + swap_iq = 1; + break; default: usage(); break; @@ -452,8 +458,10 @@ int main(int argc, char **argv) readpos = 0; writepos = 1; - fprintf(stderr, "Samplerate:\t%3.2f MHz\n", (float)samp_rate/1000000); - fprintf(stderr, "Center frequency:\t%5.0f kHz\n", (float)base_freq/1000); + fprintf(stderr, "Samplerate: %3.2f MHz\n", (float)samp_rate/1000000); + fprintf(stderr, "Center frequency: %5.0f kHz\n", (float)base_freq/1000); + if(swap_iq) + fprintf(stderr, "Spectral inversion active.\n"); pthread_mutex_init(&cb_mutex, NULL); pthread_mutex_init(&iq_mutex, NULL); |