spandsp 3.0.0
private/t4_t6_encode.h
1/*
2 * SpanDSP - a series of DSP components for telephony
3 *
4 * private/t4_t6_encode.h - definitions for T.4/T.6 fax compression
5 *
6 * Written by Steve Underwood <steveu@coppice.org>
7 *
8 * Copyright (C) 2003 Steve Underwood
9 *
10 * All rights reserved.
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU Lesser General Public License version 2.1,
14 * as published by the Free Software Foundation.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU Lesser General Public License for more details.
20 *
21 * You should have received a copy of the GNU Lesser General Public
22 * License along with this program; if not, write to the Free Software
23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 */
25
26#if !defined(_SPANDSP_PRIVATE_T4_T6_ENCODE_H_)
27#define _SPANDSP_PRIVATE_T4_T6_ENCODE_H_
28
29/*!
30 T.4 1D, T4 2D and T6 compressor state.
31*/
33{
34 /*! \brief Callback function to read a row of pixels from the image source. */
36 /*! \brief Opaque pointer passed to row_read_handler. */
38
39 /*! \brief The type of compression used. */
41 /*! \brief Width of the current page, in pixels. */
43 /*! \brief The minimum number of encoded bits per row. This is a timing thing
44 for hardware FAX machines. */
46 /*! \brief The current maximum contiguous rows that may be 2D encoded. */
48
49 /*! \brief Length of the current page, in pixels. */
51 /*! \brief The current number of bytes per row of uncompressed image data. */
53
54 /*! \brief Number of rows left that can be 2D encoded, before a 1D encoded row
55 must be used. */
57 /*! \brief The current number of bits in the current encoded row. */
59
60 /*! \brief This variable is set if we are treating the current row as a 2D encoded
61 one. */
63
64 /*! \brief Encoded data bits buffer. */
65 uint32_t tx_bitstream;
66 /*! \brief The number of bits currently in tx_bitstream. */
68 /*! \brief The working chunk of the output bit stream */
69 uint8_t *bitstream;
70 /*! \brief Input pointer to the output bit stream buffer. */
72 /*! \brief Output pointer to the output bit stream buffer. */
74 /*! \brief Pointer to the bit within the byte containing the next image bit to transmit. */
76
77 /*! \brief Black and white run-lengths for the current row. */
78 uint32_t *cur_runs;
79 /*! \brief Black and white run-lengths for the reference row. */
80 uint32_t *ref_runs;
81 /*! \brief The number of runs currently in the reference row. */
83
84 /*! \brief The minimum bits in any row of the current page. For monitoring only. */
86 /*! \brief The maximum bits in any row of the current page. For monitoring only. */
88
89 /*! \brief The size of the compressed image, in bits. */
91
92 /*! \brief Error and flow logging control */
94};
95
96#endif
97/*- End of file ------------------------------------------------------------*/
Definition private/logging.h:34
Definition private/t4_t6_encode.h:33
int image_width
Width of the current page, in pixels.
Definition private/t4_t6_encode.h:42
int bytes_per_row
The current number of bytes per row of uncompressed image data.
Definition private/t4_t6_encode.h:52
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:45
uint32_t tx_bitstream
Encoded data bits buffer.
Definition private/t4_t6_encode.h:65
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:56
int min_row_bits
The minimum bits in any row of the current page. For monitoring only.
Definition private/t4_t6_encode.h:85
uint32_t * cur_runs
Black and white run-lengths for the current row.
Definition private/t4_t6_encode.h:78
void * row_read_user_data
Opaque pointer passed to row_read_handler.
Definition private/t4_t6_encode.h:37
int max_rows_to_next_1d_row
The current maximum contiguous rows that may be 2D encoded.
Definition private/t4_t6_encode.h:47
int tx_bits
The number of bits currently in tx_bitstream.
Definition private/t4_t6_encode.h:67
int compressed_image_size
The size of the compressed image, in bits.
Definition private/t4_t6_encode.h:90
uint32_t * ref_runs
Black and white run-lengths for the reference row.
Definition private/t4_t6_encode.h:80
int bit_pos
Pointer to the bit within the byte containing the next image bit to transmit.
Definition private/t4_t6_encode.h:75
int bitstream_optr
Output pointer to the output bit stream buffer.
Definition private/t4_t6_encode.h:73
int ref_steps
The number of runs currently in the reference row.
Definition private/t4_t6_encode.h:82
uint8_t * bitstream
The working chunk of the output bit stream.
Definition private/t4_t6_encode.h:69
int row_bits
The current number of bits in the current encoded row.
Definition private/t4_t6_encode.h:58
int bitstream_iptr
Input pointer to the output bit stream buffer.
Definition private/t4_t6_encode.h:71
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:35
logging_state_t logging
Error and flow logging control.
Definition private/t4_t6_encode.h:93
bool row_is_2d
This variable is set if we are treating the current row as a 2D encoded one.
Definition private/t4_t6_encode.h:62
int max_row_bits
The maximum bits in any row of the current page. For monitoring only.
Definition private/t4_t6_encode.h:87
int image_length
Length of the current page, in pixels.
Definition private/t4_t6_encode.h:50
int encoding
The type of compression used.
Definition private/t4_t6_encode.h:40
int(* t4_row_read_handler_t)(void *user_data, uint8_t buf[], size_t len)
Definition t4_tx.h:34