diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/fl2k_iq.c | 47 |
1 files changed, 24 insertions, 23 deletions
diff --git a/src/fl2k_iq.c b/src/fl2k_iq.c index 26fcbfe..6d253e0 100644 --- a/src/fl2k_iq.c +++ b/src/fl2k_iq.c @@ -78,8 +78,8 @@ int base_freq = 1440000; int rf_to_baseband_sample_ratio; int input_freq = 48000; -complex double *ampbuf; -complex double *slopebuf; +complex float *ampbuf; +complex float *slopebuf; int writepos, readpos; void usage(void) @@ -145,27 +145,27 @@ struct trigonometric_table_S { static struct trigonometric_table_S trig_table = { .initialized = 0 }; typedef struct { - double sample_freq; - double freq; + float sample_freq; + float freq; unsigned long int phase; unsigned long int phase_step; - complex double amplitude; - complex double ampslope; + complex float amplitude; + complex float ampslope; } dds_t; -static inline void dds_set_freq(dds_t *dds, double freq) +static inline void dds_set_freq(dds_t *dds, float freq) { dds->freq = freq; dds->phase_step = (freq / dds->sample_freq) * 2 * M_PI * ANG_INCR; } -static inline void dds_set_amp(dds_t *dds, complex double amplitude, complex double ampslope) +static inline void dds_set_amp(dds_t *dds, complex float amplitude, complex float ampslope) { dds->amplitude = amplitude; dds->ampslope = ampslope; } -dds_t dds_init(double sample_freq, double freq, double phase, double amp) +dds_t dds_init(float sample_freq, float freq, float phase, float amp) { dds_t dds; int i; @@ -176,7 +176,7 @@ dds_t dds_init(double sample_freq, double freq, double phase, double amp) dds_set_amp(&dds, amp, 0); /* Initialize sine table, prescaled for 16 bit signed integer */ if (!trig_table.initialized) { - double incr = 1.0 / (double)TRIG_TABLE_LEN; + float incr = 1.0 / (float)TRIG_TABLE_LEN; for (i = 0; i < TRIG_TABLE_LEN; i++){ trig_table.sine[i] = sin(incr * i * DDS_2PI) * 32767; trig_table.cosine[i] = cos(incr * i * DDS_2PI) * 32767; @@ -222,8 +222,8 @@ static inline void dds_real_buf(dds_t *dds, int8_t *buf, int count) * in the amp buffer */ static void *iq_worker(void *arg) { - register double freq; - register double tmp; + register float freq; + register float tmp; dds_t base_signal; int8_t *tmp_ptr; uint32_t len = 0; @@ -286,9 +286,10 @@ static inline int writelen(int maxlen) return r; } -static inline complex double modulate_sample_iq(const int lastwritepos, const complex double lastamp, const complex double sample) +static inline float complex modulate_sample_iq(const int lastwritepos, const float complex lastamp, const float complex sample) { - complex double amp, slope; + float complex amp; + float complex slope; /* Calculate modulator amplitudes at this point to lessen * the calculations needed in the signal generator */ @@ -301,7 +302,7 @@ static inline complex double modulate_sample_iq(const int lastwritepos, const co the dds parameters. In fact this gives us a very efficient and pretty good interpolation filter. */ slope = amp - lastamp; - slope = slope * 1.0/ (double) rf_to_baseband_sample_ratio; + slope = slope * 1.0/ (float) rf_to_baseband_sample_ratio; slopebuf[writepos] = slope; ampbuf[writepos] = lastamp; @@ -313,11 +314,11 @@ void iq_modulator() { unsigned int i; size_t len; - double freq; - complex double lastamp = 0; + float freq; + float complex lastamp = 0; int16_t baseband_buf[BASEBAND_BUF_SIZE][2]; uint32_t lastwritepos = writepos; - complex double sample; + float complex sample; while (!do_exit) { len = writelen(BASEBAND_BUF_SIZE); @@ -331,7 +332,7 @@ void iq_modulator() } for (i = 0; i < len; i++) { - sample = (double) baseband_buf[i][0] / 32768.0 + I * (double) baseband_buf[i][1] / 32768.0; + sample = (float) baseband_buf[i][0] / 32768.0 + I * (float) baseband_buf[i][1] / 32768.0; /* Modulate and buffer the sample */ lastamp = modulate_sample_iq(lastwritepos, lastamp, sample); @@ -446,13 +447,13 @@ int main(int argc, char **argv) txbuf = buf2; /* Decoded audio */ - slopebuf = malloc(BUFFER_SAMPLES * sizeof(double complex)); - ampbuf = malloc(BUFFER_SAMPLES * sizeof(double complex)); + slopebuf = malloc(BUFFER_SAMPLES * sizeof(float complex)); + ampbuf = malloc(BUFFER_SAMPLES * sizeof(float complex)); readpos = 0; writepos = 1; - fprintf(stderr, "Samplerate:\t%3.2f MHz\n", (double)samp_rate/1000000); - fprintf(stderr, "Center frequency:\t%5.0f kHz\n", (double)base_freq/1000); + 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); pthread_mutex_init(&cb_mutex, NULL); pthread_mutex_init(&iq_mutex, NULL); |