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/*
* Copyright (c) 2000 Hellmuth Michaelis. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*---------------------------------------------------------------------------
*
* i4b_l1lib.c - general useful L1 procedures
* ------------------------------------------
*
* $Id: i4b_l1lib.c,v 1.3 2000/05/29 15:41:41 hm Exp $
*
* $FreeBSD$
*
* last edit-date: [Mon May 29 15:24:21 2000]
*
*---------------------------------------------------------------------------*/
#include <sys/param.h>
#include <sys/systm.h>
#include <machine/i4b_debug.h>
#include <machine/i4b_ioctl.h>
#include <machine/i4b_trace.h>
#include <i4b/layer1/i4b_l1.h>
#define TEL_IDLE_MIN (BCH_MAX_DATALEN/2)
/*---------------------------------------------------------------------------*
* telephony silence detection
*---------------------------------------------------------------------------*/
int
i4b_l1_bchan_tel_silence(unsigned char *data, int len)
{
register int i = 0;
register int j = 0;
/* count idle bytes */
for(;i < len; i++)
{
if((*data >= 0xaa) && (*data <= 0xac))
j++;
data++;
}
#ifdef NOTDEF
printf("i4b_l1_bchan_tel_silence: got %d silence bytes in frame\n", j);
#endif
if(j < (TEL_IDLE_MIN))
return(0);
else
return(1);
}
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