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modulate rds like a normal person

This commit is contained in:
Kuba 2025-02-25 16:58:51 +00:00
parent d75cfd4dd1
commit 195600cfbd
1 changed files with 3 additions and 7 deletions
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10
src/pifmrds/rds.c
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@ -25,6 +25,8 @@
#include <stdlib.h> #include <stdlib.h>
#include "waveforms.h" #include "waveforms.h"
float carrier_57[] = {0.0, 1.0, 1.2246467991473532e-16, -1.0}; // sine wave at 57 kHz, 228 kHz sample rate, 4 samples because 57 kHz is 4 times the sample rate
#define RT_LENGTH 64 #define RT_LENGTH 64
#define PS_LENGTH 8 #define PS_LENGTH 8
#define GROUP_LENGTH 4 #define GROUP_LENGTH 4
@ -237,14 +239,8 @@ void get_rds_samples(float *buffer, int count, int stereo, int ct_clock_enabled,
out_sample_index++; out_sample_index++;
if(out_sample_index >= SAMPLE_BUFFER_SIZE) out_sample_index = 0; if(out_sample_index >= SAMPLE_BUFFER_SIZE) out_sample_index = 0;
// modulate at 57 kHz // modulate at 57 kHz
switch(phase) { sample = sample * carrier_57[phase];
case 0:
case 2: sample = 0; break;
case 1: break;
case 3: sample = -sample; break;
}
phase++; phase++;
if(phase >= 4) phase = 0; if(phase >= 4) phase = 0;