spandsp  0.0.6
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 
00026 #if !defined(_SPANDSP_PRIVATE_BELL_R2_MF_H_)
00027 #define _SPANDSP_PRIVATE_BELL_R2_MF_H_
00028 
00029 /*!
00030     Bell MF generator state descriptor. This defines the state of a single
00031     working instance of a Bell MF generator.
00032 */
00033 struct bell_mf_tx_state_s
00034 {
00035     /*! The tone generator. */
00036     tone_gen_state_t tones;
00037     int current_sample;
00038     union
00039     {
00040         queue_state_t queue;
00041         uint8_t buf[QUEUE_STATE_T_SIZE(MAX_BELL_MF_DIGITS)];
00042     } queue;
00043 };
00044 
00045 /*!
00046     Bell MF digit detector descriptor.
00047 */
00048 struct bell_mf_rx_state_s
00049 {
00050     /*! Optional callback funcion to deliver received digits. */
00051     digits_rx_callback_t digits_callback;
00052     /*! An opaque pointer passed to the callback function. */
00053     void *digits_callback_data;
00054     /*! Tone detector working states */
00055     goertzel_state_t out[6];
00056     /*! Short term history of results from the tone detection, using in persistence checking */
00057     uint8_t hits[5];
00058     /*! The current sample number within a processing block. */
00059     int current_sample;
00060 
00061     /*! The number of digits which have been lost due to buffer overflows. */
00062     int lost_digits;
00063     /*! The number of digits currently in the digit buffer. */
00064     int current_digits;
00065     /*! The received digits buffer. This is a NULL terminated string. */
00066     char digits[MAX_BELL_MF_DIGITS + 1];
00067 };
00068 
00069 /*!
00070     MFC/R2 tone detector descriptor.
00071 */
00072 struct r2_mf_tx_state_s
00073 {
00074     /*! The tone generator. */
00075     tone_gen_state_t tone;
00076     /*! TRUE if generating forward tones, otherwise generating reverse tones. */
00077     int fwd;
00078     /*! The current digit being generated. */
00079     int digit;
00080 };
00081 
00082 /*!
00083     MFC/R2 tone detector descriptor.
00084 */
00085 struct r2_mf_rx_state_s
00086 {
00087     /*! Optional callback funcion to deliver received digits. */
00088     tone_report_func_t callback;
00089     /*! An opaque pointer passed to the callback function. */
00090     void *callback_data;
00091     /*! TRUE is we are detecting forward tones. FALSE if we are detecting backward tones */
00092     int fwd;
00093     /*! Tone detector working states */
00094     goertzel_state_t out[6];
00095     /*! The current sample number within a processing block. */
00096     int current_sample;
00097     /*! The currently detected digit. */
00098     int current_digit;
00099 };
00100 
00101 #endif
00102 /*- End of file ------------------------------------------------------------*/