Mercurial > hg > audiostuff
diff spandsp-0.0.6pre17/src/spandsp/super_tone_rx.h @ 4:26cd8f1ef0b1
import spandsp-0.0.6pre17
author | Peter Meerwald <pmeerw@cosy.sbg.ac.at> |
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date | Fri, 25 Jun 2010 15:50:58 +0200 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/spandsp-0.0.6pre17/src/spandsp/super_tone_rx.h Fri Jun 25 15:50:58 2010 +0200 @@ -0,0 +1,152 @@ +/* + * SpanDSP - a series of DSP components for telephony + * + * super_tone_rx.h - Flexible telephony supervisory tone detection. + * + * Written by Steve Underwood <steveu@coppice.org> + * + * Copyright (C) 2003 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: super_tone_rx.h,v 1.21 2009/02/10 13:06:47 steveu Exp $ + */ + +#if !defined(_SPANDSP_SUPER_TONE_RX_H_) +#define _SPANDSP_SUPER_TONE_RX_H_ + +/*! \page super_tone_rx_page Supervisory tone detection + +\section super_tone_rx_page_sec_1 What does it do? + +The supervisory tone detector may be configured to detect most of the world's +telephone supervisory tones - things like ringback, busy, number unobtainable, +and so on. + +\section super_tone_rx_page_sec_2 How does it work? + +The supervisory tone detector is passed a series of data structures describing +the tone patterns - the frequencies and cadencing - of the tones to be searched +for. It constructs one or more Goertzel filters to monitor the required tones. +If tones are close in frequency a single Goertzel set to the centre of the +frequency range will be used. This optimises the efficiency of the detector. The +Goertzel filters are applied without applying any special window functional +(i.e. they use a rectangular window), so they have a sinc like response. +However, for most tone patterns their rejection qualities are adequate. + +The detector aims to meet the need of the standard call progress tones, to +ITU-T E.180/Q.35 (busy, dial, ringback, reorder). Also, the extended tones, +to ITU-T E.180, Supplement 2 and EIA/TIA-464-A (recall dial tone, special +ringback tone, intercept tone, call waiting tone, busy verification tone, +executive override tone, confirmation tone). +*/ + +/*! Tone detection indication callback routine */ +typedef void (*tone_report_func_t)(void *user_data, int code, int level, int delay); + +typedef struct super_tone_rx_segment_s super_tone_rx_segment_t; + +typedef struct super_tone_rx_descriptor_s super_tone_rx_descriptor_t; + +typedef struct super_tone_rx_state_s super_tone_rx_state_t; + +#if defined(__cplusplus) +extern "C" +{ +#endif + +/*! Create a new supervisory tone detector descriptor. + \param desc The supervisory tone set desciptor. If NULL, the routine will allocate space for a + descriptor. + \return The supervisory tone set descriptor. +*/ +SPAN_DECLARE(super_tone_rx_descriptor_t *) super_tone_rx_make_descriptor(super_tone_rx_descriptor_t *desc); + +/*! Free a supervisory tone detector descriptor. + \param desc The supervisory tone set desciptor. + \return 0 for OK, -1 for fail. +*/ +SPAN_DECLARE(int) super_tone_rx_free_descriptor(super_tone_rx_descriptor_t *desc); + +/*! Add a new tone pattern to a supervisory tone detector set. + \param desc The supervisory tone set descriptor. + \return The new tone ID. */ +SPAN_DECLARE(int) super_tone_rx_add_tone(super_tone_rx_descriptor_t *desc); + +/*! Add a new tone pattern element to a tone pattern in a supervisory tone detector. + \param desc The supervisory tone set desciptor. + \param tone The tone ID within the descriptor. + \param f1 Frequency 1 (-1 for a silent period). + \param f2 Frequency 2 (-1 for a silent period, or only one frequency). + \param min The minimum duration, in ms. + \param max The maximum duration, in ms. + \return The new number of elements in the tone description. +*/ +SPAN_DECLARE(int) super_tone_rx_add_element(super_tone_rx_descriptor_t *desc, + int tone, + int f1, + int f2, + int min, + int max); + +/*! Initialise a supervisory tone detector. + \param s The supervisory tone detector context. + \param desc The tone descriptor. + \param callback The callback routine called to report the valid detection or termination of + one of the monitored tones. + \param user_data An opaque pointer passed when calling the callback routine. + \return The supervisory tone detector context. +*/ +SPAN_DECLARE(super_tone_rx_state_t *) super_tone_rx_init(super_tone_rx_state_t *s, + super_tone_rx_descriptor_t *desc, + tone_report_func_t callback, + void *user_data); + +/*! Release a supervisory tone detector. + \param s The supervisory tone context. + \return 0 for OK, -1 for fail. +*/ +SPAN_DECLARE(int) super_tone_rx_release(super_tone_rx_state_t *s); + +/*! Free a supervisory tone detector. + \param s The supervisory tone context. + \return 0 for OK, -1 for fail. +*/ +SPAN_DECLARE(int) super_tone_rx_free(super_tone_rx_state_t *s); + +/*! Define a callback routine to be called each time a tone pattern element is complete. This is + mostly used when analysing a tone. + \param s The supervisory tone context. + \param callback The callback routine. +*/ +SPAN_DECLARE(void) super_tone_rx_segment_callback(super_tone_rx_state_t *s, + void (*callback)(void *data, int f1, int f2, int duration)); + +/*! Apply supervisory tone detection processing to a block of audio samples. + \brief Apply supervisory tone detection processing to a block of audio samples. + \param super The supervisory tone context. + \param amp The audio sample buffer. + \param samples The number of samples in the buffer. + \return The number of samples processed. +*/ +SPAN_DECLARE(int) super_tone_rx(super_tone_rx_state_t *super, const int16_t amp[], int samples); + +#if defined(__cplusplus) +} +#endif + +#endif +/*- End of file ------------------------------------------------------------*/