freeswitch/libs/spandsp/src/spandsp/private/v29tx.h

99 lines
3.7 KiB
C

/*
* SpanDSP - a series of DSP components for telephony
*
* private/v29tx.h - ITU V.29 modem transmit part
*
* 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.
*/
#if !defined(_SPANDSP_PRIVATE_V29TX_H_)
#define _SPANDSP_PRIVATE_V29TX_H_
/*! The number of taps in the pulse shaping/bandpass filter */
#define V29_TX_FILTER_STEPS 9
/*!
V.29 modem transmit side descriptor. This defines the working state for a
single instance of a V.29 modem transmitter.
*/
struct v29_tx_state_s
{
/*! \brief The bit rate of the modem. Valid values are 4800, 7200 and 9600. */
int bit_rate;
/*! \brief The callback function used to get the next bit to be transmitted. */
get_bit_func_t get_bit;
/*! \brief A user specified opaque pointer passed to the get_bit function. */
void *get_bit_user_data;
/*! \brief The callback function used to report modem status changes. */
modem_status_func_t status_handler;
/*! \brief A user specified opaque pointer passed to the status function. */
void *status_user_data;
/*! \brief Gain required to achieve the specified output power, not allowing
for the size of the current constellation. */
float base_gain;
/*! \brief Gain required to achieve the specified output power, allowing
for the size of the current constellation. */
#if defined(SPANDSP_USE_FIXED_POINT)
int32_t gain;
#else
float gain;
#endif
/*! \brief The route raised cosine (RRC) pulse shaping filter buffer. */
#if defined(SPANDSP_USE_FIXED_POINT)
complexi16_t rrc_filter[2*V29_TX_FILTER_STEPS];
#else
complexf_t rrc_filter[2*V29_TX_FILTER_STEPS];
#endif
/*! \brief Current offset into the RRC pulse shaping filter buffer. */
int rrc_filter_step;
/*! \brief The register for the data scrambler. */
uint32_t scramble_reg;
/*! \brief The register for the training scrambler. */
uint8_t training_scramble_reg;
/*! \brief TRUE if transmitting the training sequence, or shutting down transmission.
FALSE if transmitting user data. */
int in_training;
/*! \brief A counter used to track progress through sending the training sequence. */
int training_step;
/*! \brief An offset value into the table of training parameters, used to match the
training pattern to the bit rate. */
int training_offset;
/*! \brief The current phase of the carrier (i.e. the DDS parameter). */
uint32_t carrier_phase;
/*! \brief The update rate for the phase of the carrier (i.e. the DDS increment). */
int32_t carrier_phase_rate;
/*! \brief The current fractional phase of the baud timing. */
int baud_phase;
/*! \brief The code number for the current position in the constellation. */
int constellation_state;
/*! \brief The get_bit function in use at any instant. */
get_bit_func_t current_get_bit;
/*! \brief Error and flow logging control */
logging_state_t logging;
};
#endif
/*- End of file ------------------------------------------------------------*/