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don't use malloc in the rds modulator

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This commit is contained in:
KubaPro010
2025-03-12 15:39:09 +01:00
parent c65a69a328
commit eeace56821
7 changed files with 31 additions and 58 deletions
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65
src/modulator.c
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@@ -3,20 +3,14 @@
#include "waveforms.h"
#include "modulator.h"
static struct rds_t *rds;
static float **waveform;
static struct rds_t rds;
static float waveform[2][FILTER_SIZE];
void init_rds_objects() {
rds = malloc(sizeof(struct rds_t));
rds->bit_buffer = malloc(BITS_PER_GROUP);
rds->sample_buffer =
malloc(SAMPLE_BUFFER_SIZE * sizeof(float));
waveform = malloc(2 * sizeof(float));
memset(&rds, 0, sizeof(rds));
for (uint8_t i = 0; i < 2; i++) {
// This is the bpsk, so waveform[0] is 0 degrees out of phase but waveform[1] is 180 degrees, bpsk
waveform[i] = malloc(FILTER_SIZE * sizeof(float));
// This is the bpsk, so waveform[0] is 0 degrees out of phase but waveform[1] is 180 degrees, bpsk
for (uint16_t j = 0; j < FILTER_SIZE; j++) {
waveform[i][j] = i ?
+waveform_biphase[j] : -waveform_biphase[j];
@@ -24,18 +18,6 @@ void init_rds_objects() {
}
}
void exit_rds_objects() {
free(rds->sample_buffer);
free(rds->bit_buffer);
free(rds);
for (uint8_t i = 0; i < 2; i++) {
free(waveform[i]);
}
free(waveform);
}
/* Get an RDS sample. This generates the envelope of the waveform using
* pre-generated elementary waveform samples.
*/
@@ -43,40 +25,39 @@ float get_rds_sample() {
uint16_t idx;
float *cur_waveform;
float sample;
if (rds->sample_count == SAMPLES_PER_BIT) {
if (rds.sample_count == SAMPLES_PER_BIT) {
// New Sample
if (rds->bit_pos == BITS_PER_GROUP) {
if (rds.bit_pos == BITS_PER_GROUP) {
// New bit stream
get_rds_bits(rds->bit_buffer);
rds->bit_pos = 0;
get_rds_bits(rds.bit_buffer);
rds.bit_pos = 0;
}
// Differentially encode, so 1111 becomes 1000 and 0001 becomes 0001
rds->cur_bit = rds->bit_buffer[rds->bit_pos++];
rds->prev_output = rds->cur_output;
rds->cur_output = rds->prev_output ^ rds->cur_bit;
rds.cur_bit = rds.bit_buffer[rds.bit_pos++];
rds.prev_output = rds.cur_output;
rds.cur_output = rds.prev_output ^ rds.cur_bit;
idx = rds->in_sample_index;
cur_waveform = waveform[rds->cur_output]; // get the waveform, this is the biphase in a 0/180 degree phase shift
idx = rds.in_sample_index;
cur_waveform = waveform[rds.cur_output]; // get the waveform, this is the biphase in a 0/180 degree phase shift
for (uint16_t i = 0; i < FILTER_SIZE; i++) {
rds->sample_buffer[idx++] += *cur_waveform++;
rds.sample_buffer[idx++] += *cur_waveform++;
if (idx == SAMPLE_BUFFER_SIZE) idx = 0;
}
rds->in_sample_index += SAMPLES_PER_BIT;
if (rds->in_sample_index == SAMPLE_BUFFER_SIZE)
rds->in_sample_index = 0;
rds.in_sample_index += SAMPLES_PER_BIT;
if (rds.in_sample_index == SAMPLE_BUFFER_SIZE)
rds.in_sample_index = 0;
rds->sample_count = 0;
rds.sample_count = 0;
}
rds->sample_count++;
rds.sample_count++;
sample = rds->sample_buffer[rds->out_sample_index];
sample = rds.sample_buffer[rds.out_sample_index];
rds->sample_buffer[rds->out_sample_index++] = 0;
if (rds->out_sample_index == SAMPLE_BUFFER_SIZE)
rds->out_sample_index = 0;
rds.sample_buffer[rds.out_sample_index++] = 0;
if (rds.out_sample_index == SAMPLE_BUFFER_SIZE)
rds.out_sample_index = 0;
return sample;
}