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#include <stdio.h>
#include <stdint.h>
#include <math.h>
#include <string.h>
#include "../libsample/sample.h"
#include "../libsendevolumenregler/sendevolumenregler.h"
#define level2db(level) (20 * log10(level))
#define db2level(db) pow(10, (double)db / 20.0)
#define SAMPLERATE 48000
#define ABWAERTS_DBS (2.6 / 0.020) /* 2.6 dB in 20 ms */
#define AUFWAERTS_DBS 4.3
#define MINIMUM_DB -16.0
#define MAXIMUM_DB 2.6
static double test_frequency[3] = { 1000.0, 4000.0, 300.0 };
static sample_t samples_plus4db[SAMPLERATE];
static sample_t samples_minus20db[SAMPLERATE];
static sample_t samples_0db[SAMPLERATE];
/* generate 2 samples: one with -4 dB, the other with -16 dB */
static void generate_test_sample(double test_frequency)
{
int i;
double value;
for (i = 0; i < SAMPLERATE; i++) {
value = cos(2.0 * M_PI * test_frequency / (double)SAMPLERATE * i);
samples_plus4db[i] = value * db2level(4);
samples_minus20db[i] = value * db2level(-20);
samples_0db[i] = value;
}
}
static void check_level(sample_t *samples, const char *desc, double target_db, int when)
{
int i;
double last = 0.0, envelope = 0.0;
int up = 0;
double factor;
for (i = 0; i < when; i++) {
//puts(debug_amplitude(samples[i]));
if (last < samples[i]) {
up = 1;
} else if (last > samples[i]) {
if (up) {
envelope = last;
}
up = 0;
}
#if 0
if ((i % (SAMPLERATE/(SAMPLERATE/100))) == 0)
printf("%s: envelope = %.4f (val=%.4f) (when=%d ms)\n", desc, level2db(envelope), envelope, i * 1000 / SAMPLERATE);
#endif
last = samples[i];
}
factor = envelope / db2level(target_db);
printf("%s: envelope after %d ms is %.4f db (factor %.4f)\n", desc, i * 1000 / SAMPLERATE, level2db(envelope), factor);
if (factor > 1.1 || factor < 0.9) {
printf("**** ERROR: we expected a factor close to 1.0\n");
}
}
int main(void)
{
sendevolumenregler_t state;
sample_t samples[SAMPLERATE * 2];
int f;
for (f = 0; f < 3; f++) {
printf("Testing frequency %.0f Hz:\n", test_frequency[f]);
generate_test_sample(test_frequency[f]);
/* increment low level */
memcpy(samples, samples_minus20db, SAMPLERATE * sizeof(sample_t));
init_sendevolumenregler(&state, SAMPLERATE, ABWAERTS_DBS, AUFWAERTS_DBS, MAXIMUM_DB, MINIMUM_DB, 1.0);
sendevolumenregler(&state, samples, SAMPLERATE);
check_level(samples, "aufwaerts (-20 dB)", AUFWAERTS_DBS - 20.0, 1000 * SAMPLERATE / 1000);
/* decrement high level */
memcpy(samples, samples_plus4db, SAMPLERATE * sizeof(sample_t));
init_sendevolumenregler(&state, SAMPLERATE, ABWAERTS_DBS, AUFWAERTS_DBS, MAXIMUM_DB, MINIMUM_DB, 1.0);
sendevolumenregler(&state, samples, SAMPLERATE);
check_level(samples, "abwaerts (+4 dB)", MAXIMUM_DB / 2.0, 10 * SAMPLERATE / 1000);
check_level(samples, "abwaerts (+4 dB)", 0.0, 20 * SAMPLERATE / 1000);
/* 0 DB */
memcpy(samples, samples_0db, SAMPLERATE * sizeof(sample_t));
init_sendevolumenregler(&state, SAMPLERATE, ABWAERTS_DBS, AUFWAERTS_DBS, MAXIMUM_DB, MINIMUM_DB, 1.0);
check_level(samples, "unaffected level", 0.0, 1000 * SAMPLERATE / 1000);
puts("");
}
return 0;
}
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