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view spandsp-0.0.3/spandsp-0.0.3/src/spandsp/super_tone_tx.h @ 5:f762bf195c4b
import spandsp-0.0.3
author | Peter Meerwald <pmeerw@cosy.sbg.ac.at> |
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date | Fri, 25 Jun 2010 16:00:21 +0200 |
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/* * SpanDSP - a series of DSP components for telephony * * super_tone_tx.h - Flexible telephony supervisory tone generation. * * Written by Steve Underwood <steveu@coppice.org> * * Copyright (C) 2001 Steve Underwood * * All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2, 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 General Public License for more details. * * You should have received a copy of the GNU 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_tx.h,v 1.8 2006/10/24 13:45:28 steveu Exp $ */ #if !defined(_SUPER_TONE_TX_H_) #define _SUPER_TONE_TX_H_ /*! \page super_tone_tx_page Supervisory tone generation \section super_tone_tx_page_sec_1 What does it do? The supervisory tone generator may be configured to generate most of the world's telephone supervisory tones - things like ringback, busy, number unobtainable, and so on. It uses tree structure tone descriptions, which can deal with quite complex cadence patterns. \section super_tone_tx_page_sec_2 How does it work? */ typedef struct super_tone_tx_step_s super_tone_tx_step_t; typedef struct { int32_t phase_rate[2]; float gain[2]; uint32_t phase[2]; int current_position; int level; super_tone_tx_step_t *levels[4]; int cycles[4]; } super_tone_tx_state_t; struct super_tone_tx_step_s { int32_t phase_rate[2]; float gain[2]; int tone; int length; int cycles; super_tone_tx_step_t *next; super_tone_tx_step_t *nest; }; super_tone_tx_step_t *super_tone_tx_make_step(super_tone_tx_step_t *s, float f1, float l1, float f2, float l2, int length, int cycles); void super_tone_tx_free(super_tone_tx_step_t *s); /*! Initialise a supervisory tone generator. \brief Initialise a supervisory tone generator. \param s The supervisory tone generator context. \param tree The supervisory tone tree to be generated. \return The supervisory tone generator context. */ super_tone_tx_state_t *super_tone_tx_init(super_tone_tx_state_t *s, super_tone_tx_step_t *tree); /*! Generate a block of audio samples for a supervisory tone pattern. \brief Generate a block of audio samples for a supervisory tone pattern. \param tone The supervisory tone context. \param amp The audio sample buffer. \param max_samples The maximum number of samples to be generated. \return The number of samples generated. */ int super_tone_tx(super_tone_tx_state_t *s, int16_t amp[], int max_samples); #endif /*- End of file ------------------------------------------------------------*/