116 lines
3.8 KiB
C
116 lines
3.8 KiB
C
/*
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* SpanDSP - a series of DSP components for telephony
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*
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* v42.h
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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) 2003, 2011 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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/*! \page v42_page V.42 modem error correction
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\section v42_page_sec_1 What does it do?
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The V.42 specification defines an error correcting protocol for PSTN modems, based on
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HDLC and LAP. This makes it similar to an X.25 link. A special variant of LAP, known
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as LAP-M, is defined in the V.42 specification. A means for modems to determine if the
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far modem supports V.42 is also defined.
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\section v42_page_sec_2 How does it work?
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*/
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#if !defined(_SPANDSP_V42_H_)
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#define _SPANDSP_V42_H_
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typedef struct v42_state_s v42_state_t;
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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(const char *) lapm_status_to_str(int status);
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SPAN_DECLARE(void) lapm_receive(void *user_data, const uint8_t *frame, int len, int ok);
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SPAN_DECLARE(void) v42_start(v42_state_t *s);
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SPAN_DECLARE(void) v42_stop(v42_state_t *s);
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/*! Set the busy status of the local end of a V.42 context.
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\param s The V.42 context.
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\param busy The new local end busy status.
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\return The previous local end busy status.
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*/
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SPAN_DECLARE(int) v42_set_local_busy_status(v42_state_t *s, int busy);
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/*! Get the busy status of the far end of a V.42 context.
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\param s The V.42 context.
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\return The far end busy status.
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*/
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SPAN_DECLARE(int) v42_get_far_busy_status(v42_state_t *s);
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SPAN_DECLARE(void) v42_rx_bit(void *user_data, int bit);
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SPAN_DECLARE(int) v42_tx_bit(void *user_data);
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SPAN_DECLARE(void) v42_set_status_callback(v42_state_t *s, modem_status_func_t callback, void *user_data);
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/*! Get the logging context associated with a V.42 context.
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\brief Get the logging context associated with a V.42 context.
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\param s The V.42 context.
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\return A pointer to the logging context */
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SPAN_DECLARE(logging_state_t *) v42_get_logging_state(v42_state_t *s);
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/*! Initialise a V.42 context.
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\param s The V.42 context.
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\param calling_party True if caller mode, else answerer mode.
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\param detect True to perform the V.42 detection, else go straight into LAP.M
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\param iframe_get A callback function to handle received frames of data.
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\param iframe_put A callback function to get frames of data for transmission.
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\param user_data An opaque pointer passed to the frame handler routines.
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\return ???
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*/
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SPAN_DECLARE(v42_state_t *) v42_init(v42_state_t *s,
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bool calling_party,
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bool detect,
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get_msg_func_t iframe_get,
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put_msg_func_t iframe_put,
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void *user_data);
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/*! Restart a V.42 context.
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\param s The V.42 context.
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*/
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SPAN_DECLARE(void) v42_restart(v42_state_t *s);
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/*! Release a V.42 context.
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\param s The V.42 context.
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\return 0 if OK */
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SPAN_DECLARE(int) v42_release(v42_state_t *s);
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/*! Free a V.42 context.
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\param s The V.42 context.
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\return 0 if OK */
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SPAN_DECLARE(int) v42_free(v42_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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