122 lines
2.6 KiB
C
122 lines
2.6 KiB
C
/*
|
|
* zyxel.c
|
|
*
|
|
* Converts the ZyXEL 1496 2, 3 and 4 bit voice format to the pvf format
|
|
* and the other way around. The conversion algorithm is based on the
|
|
* ZyXEL vcnvt program.
|
|
*
|
|
* The ZyXEL 2864 and the ISDN4Linux driver can also store voice data in
|
|
* this format.
|
|
*
|
|
* $Id: zyxel.c,v 1.4 1998/09/09 21:07:06 gert Exp $
|
|
*
|
|
*/
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#include "pvf.h"
|
|
|
|
static int Mx[3][8] =
|
|
{
|
|
{0x3800, 0x5600, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000},
|
|
{0x399a, 0x3a9f, 0x4d14, 0x6607, 0x0000, 0x0000, 0x0000, 0x0000},
|
|
{0x3556, 0x3556, 0x399A, 0x3A9F, 0x4200, 0x4D14, 0x6607, 0x6607}
|
|
};
|
|
|
|
int zyxeltopvf (FILE *fd_in, FILE *fd_out, int nbits, pvf_header *header_out)
|
|
{
|
|
state_t s;
|
|
int a = 0;
|
|
int d = 5;
|
|
int sign;
|
|
int e;
|
|
|
|
if (nbits == 30)
|
|
nbits = 3;
|
|
|
|
if ((nbits != 2) && (nbits != 3) && (nbits != 4))
|
|
return(FAIL);
|
|
|
|
s = init_state;
|
|
|
|
while ((e = read_bits(fd_in, &s, nbits)) != EOF)
|
|
{
|
|
|
|
if ((nbits == 4) && (e == 0))
|
|
d = 4;
|
|
|
|
sign = (e >> (nbits - 1)) ? (-1) : (1);
|
|
e = e & bitmask[nbits - 1];
|
|
a = (a * 4093 + 2048) >> 12;
|
|
a += sign * ((e << 1) + 1) * d >> 1;
|
|
|
|
if (d & 1)
|
|
a++;
|
|
|
|
header_out->write_pvf_data(fd_out, a << 10);
|
|
d = (d * Mx[nbits - 2][e] + 0x2000) >> 14;
|
|
|
|
if (d < 5)
|
|
d = 5;
|
|
|
|
};
|
|
|
|
return(OK);
|
|
}
|
|
|
|
int pvftozyxel (FILE *fd_in, FILE *fd_out, int nbits, pvf_header *header_in)
|
|
{
|
|
int a = 0;
|
|
int d = 5;
|
|
state_t s;
|
|
int e;
|
|
int nmax;
|
|
int sign;
|
|
int delta;
|
|
int data_new;
|
|
|
|
s = init_state;
|
|
|
|
while (!feof(fd_in))
|
|
{
|
|
data_new = header_in->read_pvf_data(fd_in);
|
|
e = 0;
|
|
nmax = 1 << (nbits - 1);
|
|
delta = (data_new >> 10) - a;
|
|
|
|
if (delta < 0)
|
|
{
|
|
e = nmax;
|
|
delta = -delta;
|
|
};
|
|
|
|
while((--nmax) && (delta > d))
|
|
{
|
|
delta -= d;
|
|
e++;
|
|
};
|
|
|
|
if ((nbits == 4) && ((e & 0x0f) == 0))
|
|
e = 0x08;
|
|
|
|
write_bits(fd_out, &s, nbits, e);
|
|
a = (a * 4093 + 2048) >> 12;
|
|
sign = (e >> (nbits - 1)) ? (-1) : (1);
|
|
e = e & bitmask[nbits - 1];
|
|
a += sign * ((e << 1) + 1) * d >> 1;
|
|
|
|
if (d & 1)
|
|
a++;
|
|
|
|
d = (d * Mx[nbits - 2][e] + 0x2000) >> 14;
|
|
|
|
if (d < 5)
|
|
d = 5;
|
|
|
|
};
|
|
|
|
if (s.nleft > 0)
|
|
write_bits(fd_out, &s, 8 - s.nleft, 0x00);
|
|
|
|
return(OK);
|
|
}
|