session-ios/Libraries/spandsp/spandsp/spandsp/private/t4_tx.h

143 lines
4.9 KiB
C

/*
* SpanDSP - a series of DSP components for telephony
*
* private/t4_tx.h - definitions for T.4 FAX transmit processing
*
* 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.
*
* $Id: t4_tx.h,v 1.7.2.4 2009/12/21 17:18:40 steveu Exp $
*/
#if !defined(_SPANDSP_PRIVATE_T4_TX_H_)
#define _SPANDSP_PRIVATE_T4_TX_H_
typedef struct t4_t6_encode_state_s t4_t6_encode_state_t;
/*!
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 The text which will be used in FAX page header. No text results
in no header line. */
const char *header_info;
/*! \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;
};
/*!
T.4 FAX compression/decompression descriptor. This defines the working state
for a single instance of a T.4 FAX compression or decompression channel.
*/
struct t4_state_s
{
/*! \brief The same structure is used for T.4 transmit and receive. This variable
records which mode is in progress. */
int rx;
/*! \brief The type of compression used between the FAX machines. */
int line_encoding;
/*! \brief The time at which handling of the current page began. */
time_t page_start_time;
/*! \brief The size of the compressed image on the line side, in bits. */
int line_image_size;
/*! \brief The current number of bytes per row of uncompressed image data. */
int bytes_per_row;
/*! \brief The size of the image in the image buffer, in bytes. */
int image_size;
/*! \brief The current size of the image buffer. */
int image_buffer_size;
/*! \brief A point to the image buffer. */
uint8_t *image_buffer;
/*! \brief The number of pages transferred to date. */
int current_page;
/*! \brief Column-to-column (X) resolution in pixels per metre. */
int x_resolution;
/*! \brief Row-to-row (Y) resolution in pixels per metre. */
int y_resolution;
/*! \brief Width of the current page, in pixels. */
int image_width;
/*! \brief Length of the current page, in pixels. */
int image_length;
/*! \brief Current pixel row number. */
int row;
/*! \brief This variable is set if we are treating the current row as a 2D encoded
one. */
int row_is_2d;
/*! \brief The current length of the current row. */
int row_len;
/*! \brief Black and white run-lengths for the current row. */
uint32_t *cur_runs;
/*! \brief Black and white run-lengths for the reference row. */
uint32_t *ref_runs;
/*! \brief Pointer to the buffer for the current pixel row. */
uint8_t *row_buf;
/*! \brief Encoded data bits buffer. */
uint32_t tx_bitstream;
/*! \brief The number of bits currently in tx_bitstream. */
int tx_bits;
/*! \brief The current number of bits in the current encoded row. */
int row_bits;
/*! \brief The minimum bits in any row of the current page. For monitoring only. */
int min_row_bits;
/*! \brief The maximum bits in any row of the current page. For monitoring only. */
int max_row_bits;
/*! \brief Error and flow logging control */
logging_state_t logging;
/*! \brief All TIFF file specific state information for the T.4 context. */
t4_tiff_state_t tiff;
t4_t6_decode_state_t t4_t6_rx;
t4_t6_encode_state_t t4_t6_tx;
};
#endif
/*- End of file ------------------------------------------------------------*/