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