195 lines
6.5 KiB
C
195 lines
6.5 KiB
C
/*
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* SpanDSP - a series of DSP components for telephony
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*
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* v18.h - V.18 text telephony for the deaf.
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*
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* Written by Steve Underwood <steveu@coppice.org>
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*
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* Copyright (C) 2004-2009 Steve Underwood
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*
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* All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License version 2.1,
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* as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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/*! \file */
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/*! \page v18_page The V.18 text telephony protocols
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\section v18_page_sec_1 What does it do?
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\section v18_page_sec_2 How does it work?
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*/
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#if !defined(_SPANDSP_V18_H_)
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#define _SPANDSP_V18_H_
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typedef struct v18_state_s v18_state_t;
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enum
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{
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V18_MODE_NONE = 0x0001,
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/* V.18 Annex A - Weitbrecht TDD at 45.45bps (US TTY), half-duplex, 5 bit baudot (USA). */
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V18_MODE_5BIT_4545 = 0x0002,
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/* V.18 Annex A - Weitbrecht TDD at 50bps (International TTY), half-duplex, 5 bit baudot (UK, Australia and others). */
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V18_MODE_5BIT_50 = 0x0004,
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/* V.18 Annex B - DTMF encoding of ASCII (Denmark, Holland and others). */
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V18_MODE_DTMF = 0x0008,
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/* V.18 Annex C - EDT (European Deaf Telephone) 110bps, V.21, half-duplex, ASCII (Germany, Austria, Switzerland and others). */
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V18_MODE_EDT = 0x0010,
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/* V.18 Annex D - 300bps, Bell 103, duplex, ASCII (USA). */
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V18_MODE_BELL103 = 0x0020,
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/* V.18 Annex E - 1200bps Videotex terminals, ASCII (France). */
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V18_MODE_V23VIDEOTEX = 0x0040,
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/* V.18 Annex F - V.21 text telephone, V.21, duplex, ASCII (Sweden, Norway and Finland). */
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V18_MODE_V21TEXTPHONE = 0x0080,
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/* V.18 Annex G - V.18 text telephone mode. */
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V18_MODE_V18TEXTPHONE = 0x0100,
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/* V.18 Annex A - Used during probing. */
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V18_MODE_5BIT_476 = 0x0200,
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/* Use repetitive shift characters where character set shifts are used */
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V18_MODE_REPETITIVE_SHIFTS_OPTION = 0x1000
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};
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/* Automoding sequences for different countries */
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enum
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{
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V18_AUTOMODING_GLOBAL = 0,
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V18_AUTOMODING_NONE,
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/* 5-bit, V.21, V.23, EDT, DTMF, Bell 103 */
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V18_AUTOMODING_AUSTRALIA,
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V18_AUTOMODING_IRELAND,
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/* EDT, V.21, V.23, 5-bit, DTMF, Bell 103 */
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V18_AUTOMODING_GERMANY,
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V18_AUTOMODING_SWITZERLAND,
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V18_AUTOMODING_ITALY,
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V18_AUTOMODING_SPAIN,
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V18_AUTOMODING_AUSTRIA,
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/* DTMF, V.21, V.23, 5-bit, EDT, Bell 103 */
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V18_AUTOMODING_NETHERLANDS,
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/* V.21, DTMF, 5-bit, EDT, V.23, Bell 103 */
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V18_AUTOMODING_ICELAND,
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V18_AUTOMODING_NORWAY,
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V18_AUTOMODING_SWEDEN,
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V18_AUTOMODING_FINALND,
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V18_AUTOMODING_DENMARK,
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/* V.21, 5-bit, V.23, EDT, DTMF, Bell 103 */
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V18_AUTOMODING_UK,
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/* 5-bit, Bell 103, V.21, V.23, EDT, DTMF */
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V18_AUTOMODING_USA,
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/* V.23, EDT, DTMF, 5-bit, V.21, Bell 103 */
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V18_AUTOMODING_FRANCE,
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V18_AUTOMODING_BELGIUM,
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V18_AUTOMODING_END
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};
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#if defined(__cplusplus)
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extern "C"
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{
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#endif
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SPAN_DECLARE(logging_state_t *) v18_get_logging_state(v18_state_t *s);
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/*! Initialise a V.18 context.
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\brief Initialise a V.18 context.
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\param s The V.18 context.
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\param calling_party True if caller mode, else answerer mode.
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\param mode Mode of operation.
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\param nation National variant for automoding.
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\param put_msg A callback routine called to deliver the received text
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to the application.
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\param user_data An opaque pointer for the callback routine.
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\return A pointer to the V.18 context, or NULL if there was a problem. */
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SPAN_DECLARE(v18_state_t *) v18_init(v18_state_t *s,
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bool calling_party,
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int mode,
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int nation,
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put_msg_func_t put_msg,
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void *user_data);
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/*! Release a V.18 context.
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\brief Release a V.18 context.
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\param s The V.18 context.
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\return 0 for OK. */
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SPAN_DECLARE(int) v18_release(v18_state_t *s);
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/*! Free a V.18 context.
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\brief Release a V.18 context.
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\param s The V.18 context.
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\return 0 for OK. */
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SPAN_DECLARE(int) v18_free(v18_state_t *s);
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/*! Generate a block of V.18 audio samples.
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\brief Generate a block of V.18 audio samples.
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\param s The V.18 context.
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\param amp The audio sample buffer.
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\param max_len The number of samples to be generated.
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\return The number of samples actually generated.
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*/
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SPAN_DECLARE(int) v18_tx(v18_state_t *s, int16_t amp[], int max_len);
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/*! Process a block of received V.18 audio samples.
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\brief Process a block of received V.18 audio samples.
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\param s The V.18 context.
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\param amp The audio sample buffer.
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\param len The number of samples in the buffer.
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\return The number of unprocessed samples.
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*/
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SPAN_DECLARE(int) v18_rx(v18_state_t *s, const int16_t amp[], int len);
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/*! Fake processing of a missing block of received V.18 audio samples.
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(e.g due to packet loss).
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\brief Fake processing of a missing block of received V.18 audio samples.
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\param s The V.18 context.
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\param len The number of samples to fake.
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\return The number of unprocessed samples.
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*/
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SPAN_DECLARE(int) v18_rx_fillin(v18_state_t *s, int len);
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/*! \brief Put a string to a V.18 context's input buffer.
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\param s The V.18 context.
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\param msg The string to be added.
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\param len The length of the string. If negative, the string is
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assumed to be a NULL terminated string.
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\return The number of characters actually added. This may be less than the
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length of the digit string, if the buffer fills up. If the string is
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invalid, this function will return -1. */
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SPAN_DECLARE(int) v18_put(v18_state_t *s, const char msg[], int len);
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/*! \brief Get the current mode of a V.18 connection.
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\param s The V.18 context.
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\return The mode. */
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SPAN_DECLARE(int) v18_get_current_mode(v18_state_t *s);
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/*! \brief Return a short name for an V.18 mode
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\param mode The code for the V.18 mode.
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\return A pointer to the name.
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*/
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SPAN_DECLARE(const char *) v18_mode_to_str(int mode);
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#if defined(__cplusplus)
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}
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#endif
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#endif
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/*- End of file ------------------------------------------------------------*/
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