110 lines
2.9 KiB
C++
Executable File
110 lines
2.9 KiB
C++
Executable File
/*
|
|
* Audio Library for Linux and Windows
|
|
* ===================================
|
|
* Author: DJ0ABR
|
|
*
|
|
* Author: Kurt Moraw, Ham radio: DJ0ABR, github: dj0abr
|
|
* License: GPL-3
|
|
*
|
|
* compilation:
|
|
* Windows ... Visual Studio
|
|
* Linux ... make
|
|
*
|
|
* Documentation see: libkmaudio.h
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* 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 General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
|
*
|
|
* libkmaudio_resampler.cpp ... converts audio streams
|
|
* between 44100 and 48000 samples/s in both directions
|
|
* uses the libliquid library
|
|
*/
|
|
#include "libkmaudio.h"
|
|
|
|
#define MAXRLEN 3000
|
|
|
|
resamp_crcf q[MAXDEVICES];
|
|
float fresamp[MAXDEVICES][MAXRLEN];
|
|
|
|
unsigned int h_len = 13; // filter semi-length (filter delay)
|
|
float r = 0.9f; // resampling rate (output/input)
|
|
float bw = 0.45f; // resampling filter bandwidth
|
|
float slsl = 60.0f; // resampling filter sidelobe suppression level
|
|
unsigned int npfb = 32; // number of filters in bank (timing resolution)
|
|
|
|
void resampler_create(int devidx)
|
|
{
|
|
static int f = 1;
|
|
if(f)
|
|
{
|
|
f = 0;
|
|
for (int i = 0; i < MAXDEVICES; i++)
|
|
q[i] = NULL;
|
|
}
|
|
|
|
printf("create resampler %d real %d req %d\n", devidx, devlist[devidx].real_samprate, devlist[devidx].requested_samprate);
|
|
|
|
if (q[devidx] != NULL) resamp_crcf_destroy(q[devidx]);
|
|
|
|
int src_rate = 0;
|
|
int dst_rate = 0;
|
|
if (devlist[devidx].in_out == 0)
|
|
{
|
|
// capture device:
|
|
src_rate = devlist[devidx].real_samprate;
|
|
dst_rate = devlist[devidx].requested_samprate;
|
|
}
|
|
else
|
|
{
|
|
// playback device:
|
|
src_rate = devlist[devidx].requested_samprate;
|
|
dst_rate = devlist[devidx].real_samprate;
|
|
}
|
|
|
|
r = (float)dst_rate / (float)src_rate;
|
|
|
|
printf("%f %f %f\n", r, (float)dst_rate, (float)src_rate);
|
|
|
|
q[devidx] = resamp_crcf_create(r, h_len, bw, slsl, npfb);
|
|
}
|
|
|
|
|
|
|
|
float* resample(int id, float*psamp, int len, int *pnewlen)
|
|
{
|
|
int didx = 0;
|
|
|
|
for (int i = 0; i < len; i++)
|
|
{
|
|
unsigned int num_written = 0;
|
|
liquid_float_complex in;
|
|
liquid_float_complex out[2];
|
|
in.real = psamp[i];
|
|
in.imag = 0;
|
|
|
|
resamp_crcf_execute(q[id], in, out, &num_written);
|
|
for (unsigned int r = 0; r < num_written; r++)
|
|
{
|
|
if (didx < MAXRLEN)
|
|
fresamp[id][didx++] = out[r].real;
|
|
else
|
|
printf("MAXRLEN too small\n");
|
|
}
|
|
}
|
|
|
|
*pnewlen = didx;
|
|
|
|
return fresamp[id];
|
|
}
|