private/bell_r2_mf.h

00001 /*
00002  * SpanDSP - a series of DSP components for telephony
00003  *
00004  * bell_r2_mf.h - Bell MF and MFC/R2 tone generation and detection.
00005  *
00006  * Written by Steve Underwood <steveu@coppice.org>
00007  *
00008  * Copyright (C) 2001 Steve Underwood
00009  *
00010  * All rights reserved.
00011  *
00012  * This program is free software; you can redistribute it and/or modify
00013  * it under the terms of the GNU Lesser General Public License version 2.1,
00014  * as published by the Free Software Foundation.
00015  *
00016  * This program is distributed in the hope that it will be useful,
00017  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00018  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00019  * GNU Lesser General Public License for more details.
00020  *
00021  * You should have received a copy of the GNU Lesser General Public
00022  * License along with this program; if not, write to the Free Software
00023  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
00024  *
00025  * $Id: bell_r2_mf.h,v 1.2 2008/10/13 14:19:18 steveu Exp $
00026  */
00027 
00028 #if !defined(_SPANDSP_PRIVATE_BELL_R2_MF_H_)
00029 #define _SPANDSP_PRIVATE_BELL_R2_MF_H_
00030 
00031 /*!
00032     Bell MF generator state descriptor. This defines the state of a single
00033     working instance of a Bell MF generator.
00034 */
00035 struct bell_mf_tx_state_s
00036 {
00037     /*! The tone generator. */
00038     tone_gen_state_t tones;
00039     int current_sample;
00040     union
00041     {
00042         queue_state_t queue;
00043         uint8_t buf[QUEUE_STATE_T_SIZE(MAX_BELL_MF_DIGITS)];
00044     } queue;
00045 };
00046 
00047 /*!
00048     Bell MF digit detector descriptor.
00049 */
00050 struct bell_mf_rx_state_s
00051 {
00052     /*! Optional callback funcion to deliver received digits. */
00053     digits_rx_callback_t digits_callback;
00054     /*! An opaque pointer passed to the callback function. */
00055     void *digits_callback_data;
00056     /*! Tone detector working states */
00057     goertzel_state_t out[6];
00058     /*! Short term history of results from the tone detection, using in persistence checking */
00059     uint8_t hits[5];
00060     /*! The current sample number within a processing block. */
00061     int current_sample;
00062 
00063     /*! The number of digits which have been lost due to buffer overflows. */
00064     int lost_digits;
00065     /*! The number of digits currently in the digit buffer. */
00066     int current_digits;
00067     /*! The received digits buffer. This is a NULL terminated string. */
00068     char digits[MAX_BELL_MF_DIGITS + 1];
00069 };
00070 
00071 /*!
00072     MFC/R2 tone detector descriptor.
00073 */
00074 struct r2_mf_tx_state_s
00075 {
00076     /*! The tone generator. */
00077     tone_gen_state_t tone;
00078     /*! TRUE if generating forward tones, otherwise generating reverse tones. */
00079     int fwd;
00080     /*! The current digit being generated. */
00081     int digit;
00082 };
00083 
00084 /*!
00085     MFC/R2 tone detector descriptor.
00086 */
00087 struct r2_mf_rx_state_s
00088 {
00089     /*! Optional callback funcion to deliver received digits. */
00090     tone_report_func_t callback;
00091     /*! An opaque pointer passed to the callback function. */
00092     void *callback_data;
00093     /*! TRUE is we are detecting forward tones. FALSE if we are detecting backward tones */
00094     int fwd;
00095     /*! Tone detector working states */
00096     goertzel_state_t out[6];
00097     /*! The current sample number within a processing block. */
00098     int current_sample;
00099     /*! The currently detected digit. */
00100     int current_digit;
00101 };
00102 
00103 #endif
00104 /*- End of file ------------------------------------------------------------*/

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