williamp/osmocom-analog
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Move samples of int16_t format to sample_t, that is of type double

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This prepares the correction of all levels
This commit is contained in:
Andreas Eversberg
2017-01-27 16:57:34 +01:00
parent 538a959128
commit 7ea3bc188d
74 changed files with 471 additions and 447 deletions
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22
src/cnetz/scrambler.c
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@@ -19,6 +19,7 @@
#include <stdint.h>
#include <math.h>
#include "../common/sample.h"
#include "scrambler.h"
#define PI M_PI
@@ -42,7 +43,8 @@ void scrambler_init(void)
int i;
for (i = 0; i < 256; i++) {
carrier[i] = sin((double)i / 256.0 * 2 * PI);
/* our amplitude must be doubled, since we have one spectrum above and one below carrier */
carrier[i] = sin((double)i / 256.0 * 2 * PI) * 2.0;
}
}
@@ -56,10 +58,8 @@ void scrambler_setup(scrambler_t *scrambler, int samplerate)
* Then we got spectrum above carrier and mirrored spectrum below carrier.
* Afterwards we cut off carrier frequency and frequencies above carrier.
*/
void scrambler(scrambler_t *scrambler, int16_t *samples, int length)
void scrambler(scrambler_t *scrambler, sample_t *samples, int length)
{
double spl[length];
int32_t sample;
double phaseshift, phase;
int i;
@@ -68,7 +68,7 @@ void scrambler(scrambler_t *scrambler, int16_t *samples, int length)
for (i = 0; i < length; i++) {
/* modulate samples to carrier */
spl[i] = (double)samples[i] / 32768.0 * carrier[((uint8_t)phase) & 0xff];
samples[i] *= carrier[((uint8_t)phase) & 0xff];
phase += phaseshift;
if (phase >= 256.0)
phase -= 256.0;
@@ -77,17 +77,7 @@ void scrambler(scrambler_t *scrambler, int16_t *samples, int length)
scrambler->carrier_phase256 = phase;
/* cut off carrier frequency and modulation above carrier frequency */
filter_process(&scrambler->lp, spl, length);
for (i = 0; i < length; i++) {
/* store result */
sample = spl[i] * 2.0 * 32768.0;
if (sample > 32767)
sample = 32767;
else if (sample < -32768)
sample = -32768;
*samples++ = sample;
}
filter_process(&scrambler->lp, samples, length);
}