private/t4_t6_encode.h
/*
* SpanDSP - a series of DSP components for telephony
*
* private/t4_t6_encode.h - definitions for T.4/T.6 fax compression
*
* 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_T4_T6_ENCODE_H_)
#define _SPANDSP_PRIVATE_T4_T6_ENCODE_H_
/*!
T.4 1D, T4 2D and T6 compressor state.
*/
struct t4_t6_encode_state_s
{
/*! \brief The minimum number of encoded bits per row. This is a timing thing
for hardware FAX machines. */
int min_bits_per_row;
/*! \brief The current maximum contiguous rows that may be 2D encoded. */
int max_rows_to_next_1d_row;
/*! \brief Number of rows left that can be 2D encoded, before a 1D encoded row
must be used. */
int rows_to_next_1d_row;
/*! \brief The number of runs currently in the reference row. */
int ref_steps;
/*! \brief Pointer to the byte containing the next image bit to transmit. */
int bit_pos;
/*! \brief Pointer to the bit within the byte containing the next image bit to transmit. */
int bit_ptr;
/*! \brief Callback function to read a row of pixels from the image source. */
t4_row_read_handler_t row_read_handler;
/*! \brief Opaque pointer passed to row_read_handler. */
void *row_read_user_data;
};
#endif
/*- End of file ------------------------------------------------------------*/
t4_t6_encode_state_s
Definition private/t4_t6_encode.h:33
t4_t6_encode_state_s::min_bits_per_row
int min_bits_per_row
The minimum number of encoded bits per row. This is a timing thing for hardware FAX machines.
Definition private/t4_t6_encode.h:36
t4_t6_encode_state_s::rows_to_next_1d_row
int rows_to_next_1d_row
Number of rows left that can be 2D encoded, before a 1D encoded row must be used.
Definition private/t4_t6_encode.h:42
t4_t6_encode_state_s::row_read_user_data
void * row_read_user_data
Opaque pointer passed to row_read_handler.
Definition private/t4_t6_encode.h:55
t4_t6_encode_state_s::max_rows_to_next_1d_row
int max_rows_to_next_1d_row
The current maximum contiguous rows that may be 2D encoded.
Definition private/t4_t6_encode.h:38
t4_t6_encode_state_s::bit_pos
int bit_pos
Pointer to the byte containing the next image bit to transmit.
Definition private/t4_t6_encode.h:48
t4_t6_encode_state_s::ref_steps
int ref_steps
The number of runs currently in the reference row.
Definition private/t4_t6_encode.h:45
t4_t6_encode_state_s::row_read_handler
t4_row_read_handler_t row_read_handler
Callback function to read a row of pixels from the image source.
Definition private/t4_t6_encode.h:53
t4_t6_encode_state_s::bit_ptr
int bit_ptr
Pointer to the bit within the byte containing the next image bit to transmit.
Definition private/t4_t6_encode.h:50
t4_row_read_handler_t
int(* t4_row_read_handler_t)(void *user_data, uint8_t buf[], size_t len)
Definition t4_tx.h:36