178 lines
6.9 KiB
C
178 lines
6.9 KiB
C
/*
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* SpanDSP - a series of DSP components for telephony
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*
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* t31.h - A T.31 compatible class 1 FAX modem interface.
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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 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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#if !defined(_SPANDSP_T31_H_)
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#define _SPANDSP_T31_H_
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/*! \page t31_page T.31 Class 1 FAX modem protocol handling
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\section t31_page_sec_1 What does it do?
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The T.31 class 1 FAX modem modules implements a class 1 interface to the FAX
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modems in spandsp.
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\section t31_page_sec_2 How does it work?
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*/
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/*!
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T.31 descriptor. This defines the working state for a single instance of
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a T.31 FAX modem.
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*/
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typedef struct t31_state_s t31_state_t;
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typedef int (*t31_modem_control_handler_t)(t31_state_t *s, void *user_data, int op, const char *num);
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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(void) t31_call_event(t31_state_t *s, int event);
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/*! Return the amount of free space in the AT COMMAND BUFFER.
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\brief Return the amount of free space in the AT COMMAND BUFFER.
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\param s The T.31 modem context.
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\return The number of bytes of free space. */
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SPAN_DECLARE(int) t31_at_rx_free_space(t31_state_t *s);
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SPAN_DECLARE(int) t31_at_rx(t31_state_t *s, const char *t, int len);
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/*! Process a block of received T.31 modem audio samples.
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\brief Process a block of received T.31 modem audio samples.
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\param s The T.31 modem 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 samples unprocessed. */
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SPAN_DECLARE(int) t31_rx(t31_state_t *s, int16_t amp[], int len);
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/*! Fake processing of a missing block of received T.31 modem 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 T.31 modem audio samples.
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\param s The T.31 modem context.
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\param len The number of samples to fake.
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\return The number of samples unprocessed. */
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SPAN_DECLARE(int) t31_rx_fillin(t31_state_t *s, int len);
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/*! Generate a block of T.31 modem audio samples.
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\brief Generate a block of T.31 modem audio samples.
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\param s The T.31 modem 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) t31_tx(t31_state_t *s, int16_t amp[], int max_len);
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SPAN_DECLARE(int) t31_t38_send_timeout(t31_state_t *s, int samples);
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/*! Select whether silent audio will be sent when transmit is idle.
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\brief Select whether silent audio will be sent when transmit is idle.
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\param s The T.31 modem context.
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\param transmit_on_idle True if silent audio should be output when the transmitter is
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idle. False to transmit zero length audio when the transmitter is idle. The default
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behaviour is false.
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*/
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SPAN_DECLARE(void) t31_set_transmit_on_idle(t31_state_t *s, bool transmit_on_idle);
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/*! Select whether TEP mode will be used (or time allowed for it (when transmitting).
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\brief Select whether TEP mode will be used.
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\param s The T.31 modem context.
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\param use_tep True if TEP is to be used.
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*/
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SPAN_DECLARE(void) t31_set_tep_mode(t31_state_t *s, bool use_tep);
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/*! Select whether T.38 data will be paced as it is transmitted.
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\brief Select whether T.38 data will be paced.
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\param s The T.31 modem context.
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\param without_pacing True if data is to be sent as fast as possible. False if it is
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to be paced.
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*/
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SPAN_DECLARE(void) t31_set_t38_config(t31_state_t *s, bool without_pacing);
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/*! Set audio or T.38 mode.
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\brief Set audio or T.38 mode.
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\param s The T.31 modem context.
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\param t38_mode True for T.38 mode operation. False for audio mode operation.
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*/
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SPAN_DECLARE(void) t31_set_mode(t31_state_t *s, bool t38_mode);
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/*! Get a pointer to the logging context associated with a T.31 context.
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\brief Get a pointer to the logging context associated with a T.31 context.
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\param s The T.31 context.
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\return A pointer to the logging context, or NULL.
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*/
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SPAN_DECLARE(logging_state_t *) t31_get_logging_state(t31_state_t *s);
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/*! Get a pointer to the AT interpreter context associated with a T.31 context.
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\brief Get a pointer to the AT interpreter context associated with a T.31 context.
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\param s The T.31 context.
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\return A pointer to the AT interpreter context, or NULL.
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*/
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SPAN_DECLARE(at_state_t *) t31_get_at_state(t31_state_t *s);
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/*! Get a pointer to the T.38 core context associated with a T.31 context.
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\brief Get a pointer to the T.38 core context associated with a T.31 context.
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\param s The T.31 context.
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\return A pointer to the T.38 core context, or NULL.
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*/
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SPAN_DECLARE(t38_core_state_t *) t31_get_t38_core_state(t31_state_t *s);
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/*! Initialise a T.31 context. This must be called before the first
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use of the context, to initialise its contents.
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\brief Initialise a T.31 context.
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\param s The T.31 context.
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\param at_tx_handler A callback routine to handle AT interpreter channel output.
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\param at_tx_user_data An opaque pointer passed in called to at_tx_handler.
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\param modem_control_handler A callback routine to handle control of the modem (off-hook, etc).
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\param modem_control_user_data An opaque pointer passed in called to modem_control_handler.
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\param tx_t38_packet_handler ???
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\param tx_t38_packet_user_data ???
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\return A pointer to the T.31 context. */
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SPAN_DECLARE(t31_state_t *) t31_init(t31_state_t *s,
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at_tx_handler_t at_tx_handler,
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void *at_tx_user_data,
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t31_modem_control_handler_t modem_control_handler,
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void *modem_control_user_data,
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t38_tx_packet_handler_t tx_t38_packet_handler,
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void *tx_t38_packet_user_data);
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/*! Release a T.31 context.
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\brief Release a T.31 context.
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\param s The T.31 context.
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\return 0 for OK */
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SPAN_DECLARE(int) t31_release(t31_state_t *s);
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/*! Free a T.31 context.
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\brief Release a T.31 context.
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\param s The T.31 context.
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\return 0 for OK */
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SPAN_DECLARE(int) t31_free(t31_state_t *s);
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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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