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C-Netz: Add hack to increase voice deviation for some newer phone

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This commit is contained in:
Andreas Eversberg
2016-08-03 12:02:15 +02:00
parent 3a7388ba7f
commit e484814c0a
2 changed files with 26 additions and 2 deletions
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17
src/cnetz/dsp.c
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@@ -33,6 +33,8 @@
#include "telegramm.h"
#include "dsp.h"
extern int voice_deviation;
/* test function to mirror received audio from ratio back to radio */
//#define TEST_SCRAMBLE
/* test the audio quality after cascading two scramblers (TEST_SCRAMBLE must be defined) */
@@ -721,6 +723,18 @@ again:
/* pre-emphasis is only used when scrambler is off, see FTZ 171 TR 60 Clause 4 */
if (cnetz->pre_emphasis && !cnetz->scrambler)
pre_emphasis(&cnetz->estate, speech_buffer, speech_length);
/* change level */
if (voice_deviation != 1) {
int sample, j;
for (j = 0; j < speech_length; j++) {
sample = speech_buffer[j] * voice_deviation;
if (sample > 32767)
sample = 32767;
if (sample < -32768)
sample = -32768;
speech_buffer[j] = sample;
}
}
speech_pos = 0;
}
/* copy speech as long as we have something left in buffer */
@@ -791,7 +805,8 @@ void unshrink_speech(cnetz_t *cnetz, int16_t *speech_buffer, int count)
y_last = cnetz->offset_y_last;
factor = cnetz->offset_factor;
for (i = 0; i < count; i++) {
x = (double)speech_buffer[i];
/* change level */
x = (double)speech_buffer[i] / voice_deviation;
/* high-pass to remove low level frequencies, caused by level jump between audio chunks */
y = factor * (y_last + x - x_last);
x_last = x;