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Correcting all levels and move all remaining integer samples to sample_t

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The leves are based on the standards of each mobile network. They
are adjusted to the specified frequency deviation now.
This commit is contained in:
Andreas Eversberg
2017-01-29 07:25:12 +01:00
parent bd7ccc5fa0
commit 7e45f556ce
38 changed files with 484 additions and 397 deletions
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38
src/cnetz/dsp.c
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@@ -43,9 +43,12 @@ extern int voice_deviation;
#define PI M_PI
#define BANDWIDTH 5500.0 /* maximum bandwidth */
#define FSK_DEVIATION 10000
#define COMPANDOR_0DB 30000
#define MAX_DEVIATION 4000.0
#define MAX_MODULATION 5280.0
#define DBM0_DEVIATION 4000.0 /* deviation of dBm0 at 1 kHz */
#define COMPANDOR_0DB 1.0 /* A level of 0dBm (1.0) shall be unaccected */
#define FSK_DEVIATION (2500.0 / DBM0_DEVIATION) /* no emphasis */
#define MAX_DISPLAY 1.4 /* something above dBm0, no emphasis */
#define BITRATE 5280.0 /* bits per second */
#define BLOCK_BITS 198 /* duration of one time slot including pause at beginning and end */
#define CUT_OFF_OFFSET 300.0 /* cut off frequency for offset filter (level correction between subsequent audio chunks) */
@@ -76,7 +79,7 @@ static void dsp_init_ramp(cnetz_t *cnetz)
c = -sqrt(-c);
else
c = sqrt(c);
ramp_down[i] = (int)(c * (double)cnetz->fsk_deviation);
ramp_down[i] = c * (double)cnetz->fsk_deviation;
ramp_up[i] = -ramp_down[i];
}
}
@@ -90,9 +93,8 @@ int dsp_init_sender(cnetz_t *cnetz, int measure_speed, double clock_speed[2], do
PDEBUG_CHAN(DDSP, DEBUG_DEBUG, "Init FSK for 'Sender'.\n");
/* set deviation and modulation parameters */
cnetz->sender.bandwidth = BANDWIDTH;
cnetz->sender.sample_deviation = 2500.0 / (double)FSK_DEVIATION;
/* set modulation parameters */
sender_set_fm(&cnetz->sender, MAX_DEVIATION, MAX_MODULATION, DBM0_DEVIATION, MAX_DISPLAY);
if (measure_speed) {
cnetz->measure_speed = measure_speed;
@@ -119,7 +121,7 @@ int dsp_init_sender(cnetz_t *cnetz, int measure_speed, double clock_speed[2], do
}
/* create devation and ramp */
cnetz->fsk_deviation = FSK_DEVIATION; /* be sure not to overflow -32767 .. 32767 */
cnetz->fsk_deviation = FSK_DEVIATION;
dsp_init_ramp(cnetz);
cnetz->fsk_noise = noise;
@@ -465,7 +467,7 @@ static int fsk_distributed_encode(cnetz_t *cnetz, const char *bits)
} while (phase < 256.0);
phase -= 256.0;
}
*marker = -32768; /* indicator for inserting speech */
*marker = 999; /* marker for inserting speech */
}
/* add 46 * (1+4+1 + 60) bits */
for (i = 0; i < 46; i++) {
@@ -556,7 +558,7 @@ static int fsk_distributed_encode(cnetz_t *cnetz, const char *bits)
} while (phase < 256.0);
phase -= 256.0;
}
*marker = -32768; /* indicator for inserting speech */
*marker = 999; /* marker for inserting speech */
}
/* depending on the number of samples, return the number */
@@ -706,7 +708,7 @@ again:
if (length - count < copy)
copy = length - count;
for (i = 0; i < copy; i++) {
if (*spl == -32768) {
if (*spl == 999) {
/* marker found to insert new chunk of audio */
jitter_load(&cnetz->sender.dejitter, speech_buffer, 100);
/* 1. compress dynamics */
@@ -722,15 +724,9 @@ again:
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;
}
int j;
for (j = 0; j < speech_length; j++)
speech_buffer[j] *= (double)voice_deviation;
}
speech_pos = 0;
}
@@ -801,7 +797,7 @@ void unshrink_speech(cnetz_t *cnetz, sample_t *speech_buffer, int count)
factor = cnetz->offset_factor;
for (i = 0; i < count; i++) {
/* change level */
x = speech_buffer[i] / voice_deviation;
x = speech_buffer[i] / (double)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;