dahdi-linux/drivers/dahdi/biquad.h
Shaun Ruffell bf3fe05dfb wct4xxp: Moving the transmit short detection behind debug module param.
This needs some more testing before it's on by default.  If the card is
otherwise functioning, these messages may be confusing to the user.  If
the card is not functioning, the driver can be reloaded with debug to
check for this condition.

Signed-off-by: Shaun Ruffell <sruffell@digium.com>

git-svn-id: http://svn.asterisk.org/svn/dahdi/linux/trunk@9205 a0bf4364-ded3-4de4-8d8a-66a801d63aff
2010-08-27 21:59:27 +00:00

61 lines
1.6 KiB
C

/*
* SpanDSP - a series of DSP components for telephony
*
* biquad.h - General telephony bi-quad section routines (currently this just
* handles canonic/type 2 form)
*
* Written by Steve Underwood <steveu@coppice.org>
*
* Copyright (C) 2001 Steve Underwood
*
* All rights reserved.
*
*/
/*
* See http://www.asterisk.org for more information about
* the Asterisk project. Please do not directly contact
* any of the maintainers of this project for assistance;
* the project provides a web site, mailing lists and IRC
* channels for your use.
*
* This program is free software, distributed under the terms of
* the GNU General Public License Version 2 as published by the
* Free Software Foundation. See the LICENSE file included with
* this program for more details.
*/
static inline void biquad2_init (biquad2_state_t *bq,
int32_t gain,
int32_t a1,
int32_t a2,
int32_t b1,
int32_t b2)
{
bq->gain = gain;
bq->a1 = a1;
bq->a2 = a2;
bq->b1 = b1;
bq->b2 = b2;
bq->z1 = 0;
bq->z2 = 0;
}
/*- End of function --------------------------------------------------------*/
static inline int16_t biquad2 (biquad2_state_t *bq, int16_t sample)
{
int32_t y;
int32_t z0;
z0 = sample*bq->gain + bq->z1*bq->a1 + bq->z2*bq->a2;
y = z0 + bq->z1*bq->b1 + bq->z2*bq->b2;
bq->z2 = bq->z1;
bq->z1 = z0 >> 15;
y >>= 15;
return y;
}
/*- End of function --------------------------------------------------------*/
/*- End of file ------------------------------------------------------------*/