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/*
* Copyright (C) 2002 Philip Blundell <philb@gnu.org>
* Copyright (C) 2002 Moray Allan <moray@sermisy.org>
*
* 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.
*/
#include <unistd.h>
#include <gsm/gsm.h>
#include <glib.h>
#include <string.h>
gboolean stop;
#define NSAMP 160
/*
* The GSM codec requires complete frames. When reading from the network,
* short reads can occur: this function coalesces them together. When reading
* from a local device this will be equivalent to plain read().
*/
size_t
cooked_read (int infd, void *buf, size_t bufsiz)
{
int n;
size_t bytes = 0;
do {
n = read (infd, buf + bytes, bufsiz - bytes);
if (n < 0)
return n;
bytes += n;
} while (bytes < bufsiz && n);
return bytes;
}
int
sound_encode (int infd, int outfd)
{
gushort indata[NSAMP];
gushort indata1[2*NSAMP];
gsm_frame outdata;
size_t r;
gsm g = gsm_create ();
stop = FALSE;
do {
guint i;
r = cooked_read (infd, indata1, sizeof (indata1));
if (r < 0)
{
gsm_destroy (g);
return -1;
}
if (r < sizeof (indata1))
memset (indata1 + r, 0, sizeof(indata1) - r);
for (i = 0; i < NSAMP; i++)
indata[i] = indata1[2*i];
gsm_encode (g, indata, outdata);
if (write (outfd, outdata, sizeof (outdata)) < sizeof (outdata))
{
gsm_destroy (g);
return -1;
}
} while (r == sizeof (indata1) && !stop);
gsm_destroy (g);
return 0;
}
int
sound_decode (int infd, int outfd)
{
gushort outdata[NSAMP];
gushort outdata1[NSAMP * 2];
gsm_frame indata;
size_t r;
gsm g = gsm_create ();
stop = FALSE;
do {
guint i;
r = read (infd, indata, sizeof (indata));
if (r <= 0)
{
gsm_destroy (g);
return r ? -1 : 0;
}
if (r < sizeof (indata))
memset (indata + r, 0, sizeof(indata) - r);
gsm_decode (g, indata, outdata);
for (i = 0; i < NSAMP; i++)
{
outdata1[2*i] = outdata[i];
outdata1[2*i+1] = outdata[i];
}
if (write (outfd, outdata1, sizeof (outdata1)) < sizeof (outdata1))
{
gsm_destroy (g);
return -1;
}
} while (!stop);
gsm_destroy (g);
close (infd);
close (outfd);
return 0;
}
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