mirror of
https://github.com/signalwire/freeswitch.git
synced 2025-08-13 17:38:59 +00:00
inital checkin of spandsp from http://www.soft-switch.org/downloads/snapshots/spandsp/spandsp-20080829.tar.gz
git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@9425 d0543943-73ff-0310-b7d9-9358b9ac24b2
This commit is contained in:
Michael Jerris
291
libs/spandsp/src/dds_int.c
Normal file
291
libs/spandsp/src/dds_int.c
Normal file
@@ -0,0 +1,291 @@
|
||||
/*
|
||||
* SpanDSP - a series of DSP components for telephony
|
||||
*
|
||||
* dds.c
|
||||
*
|
||||
* Written by Steve Underwood <steveu@coppice.org>
|
||||
*
|
||||
* Copyright (C) 2003 Steve Underwood
|
||||
*
|
||||
* All rights reserved.
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify
|
||||
* it under the terms of the GNU Lesser General Public License version 2.1,
|
||||
* as published by the Free Software Foundation.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU Lesser General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU Lesser General Public
|
||||
* License along with this program; if not, write to the Free Software
|
||||
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
||||
*
|
||||
* $Id: dds_int.c,v 1.9 2008/07/02 14:48:25 steveu Exp $
|
||||
*/
|
||||
|
||||
/*! \file */
|
||||
|
||||
#if defined(HAVE_CONFIG_H)
|
||||
#include <config.h>
|
||||
#endif
|
||||
|
||||
#include <inttypes.h>
|
||||
#include "floating_fudge.h"
|
||||
#if defined(HAVE_TGMATH_H)
|
||||
#include <tgmath.h>
|
||||
#endif
|
||||
#if defined(HAVE_MATH_H)
|
||||
#include <math.h>
|
||||
#endif
|
||||
|
||||
#include "spandsp/telephony.h"
|
||||
#include "spandsp/complex.h"
|
||||
#include "spandsp/dds.h"
|
||||
|
||||
#if !defined(M_PI)
|
||||
# define M_PI 3.14159265358979323846 /* pi */
|
||||
#endif
|
||||
|
||||
/* In a A-law or u-law channel, a 128 step sine table is adequate to keep the spectral
|
||||
mess due to the DDS at a similar level to the spectral mess due to the A-law or u-law
|
||||
compression. */
|
||||
#define SLENK 7
|
||||
#define DDS_STEPS (1 << SLENK)
|
||||
#define DDS_SHIFT (32 - 2 - SLENK)
|
||||
|
||||
/* This is a simple set of direct digital synthesis (DDS) functions to generate sine
|
||||
waves. This version uses a 128 entry sin/cos table to cover one quadrant. */
|
||||
|
||||
static const int16_t sine_table[DDS_STEPS] =
|
||||
{
|
||||
201,
|
||||
603,
|
||||
1005,
|
||||
1407,
|
||||
1809,
|
||||
2210,
|
||||
2611,
|
||||
3012,
|
||||
3412,
|
||||
3812,
|
||||
4211,
|
||||
4609,
|
||||
5007,
|
||||
5404,
|
||||
5800,
|
||||
6195,
|
||||
6590,
|
||||
6983,
|
||||
7376,
|
||||
7767,
|
||||
8157,
|
||||
8546,
|
||||
8933,
|
||||
9319,
|
||||
9704,
|
||||
10088,
|
||||
10469,
|
||||
10850,
|
||||
11228,
|
||||
11605,
|
||||
11980,
|
||||
12354,
|
||||
12725,
|
||||
13095,
|
||||
13463,
|
||||
13828,
|
||||
14192,
|
||||
14553,
|
||||
14912,
|
||||
15269,
|
||||
15624,
|
||||
15976,
|
||||
16326,
|
||||
16673,
|
||||
17018,
|
||||
17361,
|
||||
17700,
|
||||
18037,
|
||||
18372,
|
||||
18703,
|
||||
19032,
|
||||
19358,
|
||||
19681,
|
||||
20001,
|
||||
20318,
|
||||
20632,
|
||||
20943,
|
||||
21251,
|
||||
21555,
|
||||
21856,
|
||||
22154,
|
||||
22449,
|
||||
22740,
|
||||
23028,
|
||||
23312,
|
||||
23593,
|
||||
23870,
|
||||
24144,
|
||||
24414,
|
||||
24680,
|
||||
24943,
|
||||
25202,
|
||||
25457,
|
||||
25708,
|
||||
25956,
|
||||
26199,
|
||||
26439,
|
||||
26674,
|
||||
26906,
|
||||
27133,
|
||||
27357,
|
||||
27576,
|
||||
27791,
|
||||
28002,
|
||||
28209,
|
||||
28411,
|
||||
28610,
|
||||
28803,
|
||||
28993,
|
||||
29178,
|
||||
29359,
|
||||
29535,
|
||||
29707,
|
||||
29875,
|
||||
30038,
|
||||
30196,
|
||||
30350,
|
||||
30499,
|
||||
30644,
|
||||
30784,
|
||||
30920,
|
||||
31050,
|
||||
31177,
|
||||
31298,
|
||||
31415,
|
||||
31527,
|
||||
31634,
|
||||
31737,
|
||||
31834,
|
||||
31927,
|
||||
32015,
|
||||
32099,
|
||||
32177,
|
||||
32251,
|
||||
32319,
|
||||
32383,
|
||||
32442,
|
||||
32496,
|
||||
32546,
|
||||
32590,
|
||||
32629,
|
||||
32664,
|
||||
32693,
|
||||
32718,
|
||||
32738,
|
||||
32753,
|
||||
32762,
|
||||
32767,
|
||||
};
|
||||
|
||||
int32_t dds_phase_rate(float frequency)
|
||||
{
|
||||
return (int32_t) (frequency*65536.0f*65536.0f/SAMPLE_RATE);
|
||||
}
|
||||
/*- End of function --------------------------------------------------------*/
|
||||
|
||||
float dds_frequency(int32_t phase_rate)
|
||||
{
|
||||
return (float) phase_rate*(float) SAMPLE_RATE/(65536.0f*65536.0f);
|
||||
}
|
||||
/*- End of function --------------------------------------------------------*/
|
||||
|
||||
int dds_scaling_dbm0(float level)
|
||||
{
|
||||
return (int) (powf(10.0f, (level - DBM0_MAX_SINE_POWER)/20.0f)*32767.0f);
|
||||
}
|
||||
/*- End of function --------------------------------------------------------*/
|
||||
|
||||
int dds_scaling_dbov(float level)
|
||||
{
|
||||
return (int) (powf(10.0f, (level - DBOV_MAX_SINE_POWER)/20.0f)*32767.0f);
|
||||
}
|
||||
/*- End of function --------------------------------------------------------*/
|
||||
|
||||
int16_t dds_lookup(uint32_t phase)
|
||||
{
|
||||
uint32_t step;
|
||||
int16_t amp;
|
||||
|
||||
phase >>= DDS_SHIFT;
|
||||
step = phase & (DDS_STEPS - 1);
|
||||
if ((phase & DDS_STEPS))
|
||||
step = (DDS_STEPS - 1) - step;
|
||||
amp = sine_table[step];
|
||||
if ((phase & (2*DDS_STEPS)))
|
||||
amp = -amp;
|
||||
return amp;
|
||||
}
|
||||
/*- End of function --------------------------------------------------------*/
|
||||
|
||||
int16_t dds_offset(uint32_t phase_acc, int32_t phase_offset)
|
||||
{
|
||||
return dds_lookup(phase_acc + phase_offset);
|
||||
}
|
||||
/*- End of function --------------------------------------------------------*/
|
||||
|
||||
void dds_advance(uint32_t *phase_acc, int32_t phase_rate)
|
||||
{
|
||||
*phase_acc += phase_rate;
|
||||
}
|
||||
/*- End of function --------------------------------------------------------*/
|
||||
|
||||
int16_t dds(uint32_t *phase_acc, int32_t phase_rate)
|
||||
{
|
||||
int16_t amp;
|
||||
|
||||
amp = dds_lookup(*phase_acc);
|
||||
*phase_acc += phase_rate;
|
||||
return amp;
|
||||
}
|
||||
/*- End of function --------------------------------------------------------*/
|
||||
|
||||
int16_t dds_mod(uint32_t *phase_acc, int32_t phase_rate, int scale, int32_t phase)
|
||||
{
|
||||
int16_t amp;
|
||||
|
||||
amp = (int16_t) ((dds_lookup(*phase_acc + phase)*scale) >> 15);
|
||||
*phase_acc += phase_rate;
|
||||
return amp;
|
||||
}
|
||||
/*- End of function --------------------------------------------------------*/
|
||||
|
||||
complexi_t dds_lookup_complexi(uint32_t phase)
|
||||
{
|
||||
return complex_seti(dds_lookup(phase + (1 << 30)), dds_lookup(phase));
|
||||
}
|
||||
/*- End of function --------------------------------------------------------*/
|
||||
|
||||
complexi_t dds_complexi(uint32_t *phase_acc, int32_t phase_rate)
|
||||
{
|
||||
complexi_t amp;
|
||||
|
||||
amp = complex_seti(dds_lookup(*phase_acc + (1 << 30)), dds_lookup(*phase_acc));
|
||||
*phase_acc += phase_rate;
|
||||
return amp;
|
||||
}
|
||||
/*- End of function --------------------------------------------------------*/
|
||||
|
||||
complexi_t dds_complexi_mod(uint32_t *phase_acc, int32_t phase_rate, int scale, int32_t phase)
|
||||
{
|
||||
complexi_t amp;
|
||||
|
||||
amp = complex_seti((dds_lookup(*phase_acc + phase + (1 << 30))*scale) >> 15,
|
||||
(dds_lookup(*phase_acc + phase)*scale) >> 15);
|
||||
*phase_acc += phase_rate;
|
||||
return amp;
|
||||
}
|
||||
/*- End of function --------------------------------------------------------*/
|
||||
/*- End of file ------------------------------------------------------------*/
|
||||
Reference in New Issue
Block a user