session-ios/Libraries/spandsp/spandsp/spandsp/private/dtmf.h

112 lines
3.9 KiB
C

/*
* SpanDSP - a series of DSP components for telephony
*
* private/dtmf.h - DTMF tone generation and detection
*
* Written by Steve Underwood <steveu@coppice.org>
*
* Copyright (C) 2001, 2005 Steve Underwood
*
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License version 2.1,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* $Id: dtmf.h,v 1.1 2008/10/13 13:14:01 steveu Exp $
*/
#if !defined(_SPANDSP_PRIVATE_DTMF_H_)
#define _SPANDSP_PRIVATE_DTMF_H_
/*!
DTMF generator state descriptor. This defines the state of a single
working instance of a DTMF generator.
*/
struct dtmf_tx_state_s
{
tone_gen_state_t tones;
float low_level;
float high_level;
int on_time;
int off_time;
union
{
queue_state_t queue;
uint8_t buf[QUEUE_STATE_T_SIZE(MAX_DTMF_DIGITS)];
} queue;
};
/*!
DTMF digit detector descriptor.
*/
struct dtmf_rx_state_s
{
/*! Optional callback funcion to deliver received digits. */
digits_rx_callback_t digits_callback;
/*! An opaque pointer passed to the callback function. */
void *digits_callback_data;
/*! Optional callback funcion to deliver real time digit state changes. */
tone_report_func_t realtime_callback;
/*! An opaque pointer passed to the real time callback function. */
void *realtime_callback_data;
/*! TRUE if dialtone should be filtered before processing */
int filter_dialtone;
#if defined(SPANDSP_USE_FIXED_POINT)
/*! 350Hz filter state for the optional dialtone filter. */
float z350[2];
/*! 440Hz filter state for the optional dialtone filter. */
float z440[2];
/*! Maximum acceptable "normal" (lower bigger than higher) twist ratio. */
float normal_twist;
/*! Maximum acceptable "reverse" (higher bigger than lower) twist ratio. */
float reverse_twist;
/*! Minimum acceptable tone level for detection. */
int32_t threshold;
/*! The accumlating total energy on the same period over which the Goertzels work. */
int32_t energy;
#else
/*! 350Hz filter state for the optional dialtone filter. */
float z350[2];
/*! 440Hz filter state for the optional dialtone filter. */
float z440[2];
/*! Maximum acceptable "normal" (lower bigger than higher) twist ratio. */
float normal_twist;
/*! Maximum acceptable "reverse" (higher bigger than lower) twist ratio. */
float reverse_twist;
/*! Minimum acceptable tone level for detection. */
float threshold;
/*! The accumlating total energy on the same period over which the Goertzels work. */
float energy;
#endif
/*! Tone detector working states for the row tones. */
goertzel_state_t row_out[4];
/*! Tone detector working states for the column tones. */
goertzel_state_t col_out[4];
/*! The result of the last tone analysis. */
uint8_t last_hit;
/*! The confirmed digit we are currently receiving */
uint8_t in_digit;
/*! The current sample number within a processing block. */
int current_sample;
/*! The number of digits which have been lost due to buffer overflows. */
int lost_digits;
/*! The number of digits currently in the digit buffer. */
int current_digits;
/*! The received digits buffer. This is a NULL terminated string. */
char digits[MAX_DTMF_DIGITS + 1];
};
#endif
/*- End of file ------------------------------------------------------------*/