1 /* 2 * SpanDSP - a series of DSP components for telephony 3 * 4 * private/t4_rx.h - definitions for T.4 FAX receive processing 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_RX_H_) 27 #define _SPANDSP_PRIVATE_T4_RX_H_ 28 29 typedef int (*t4_image_put_handler_t)(void *user_data, const uint8_t buf[], size_t len); 30 31 /*! 32 TIFF specific state information to go with T.4 compression or decompression handling. 33 */ 34 typedef struct 35 { 36 /*! \brief The current file name. */ 37 const char *file; 38 /*! \brief The libtiff context for the current TIFF file */ 39 TIFF *tiff_file; 40 41 /*! Image type - bilevel, gray, colour */ 42 int image_type; 43 /*! \brief The compression type for output to the TIFF file. */ 44 int compression; 45 /*! \brief The TIFF photometric setting for the current page. */ 46 uint16_t photo_metric; 47 /*! \brief The TIFF fill order setting for the current page. */ 48 uint16_t fill_order; 49 50 /*! \brief The number of pages in the current image file. */ 51 int pages_in_file; 52 53 /*! \brief The time at which handling of the current page began. */ 54 time_t page_start_time; 55 56 /*! \brief A point to the image buffer. */ 57 uint8_t *image_buffer; 58 /*! \brief The size of the image in the image buffer, in bytes. */ 59 int image_size; 60 /*! \brief The current size of the image buffer. */ 61 int image_buffer_size; 62 } t4_rx_tiff_state_t; 63 64 /*! 65 T.4 FAX decompression metadata descriptor. This contains information about the image 66 which may be relevant to the backend, but is not relevant to the image decoding process. 67 */ 68 typedef struct 69 { 70 /*! \brief The type of compression used on the wire. */ 71 int compression; 72 /*! \brief The width of the current page, in pixels. */ 73 uint32_t image_width; 74 /*! \brief The length of the current page, in pixels. */ 75 uint32_t image_length; 76 /*! \brief Column-to-column (X) resolution in pixels per metre. */ 77 int x_resolution; 78 /*! \brief Row-to-row (Y) resolution in pixels per metre. */ 79 int y_resolution; 80 81 /* "Background" information about the FAX, which can be stored in the image file. */ 82 /*! \brief The vendor of the machine which produced the file. */ 83 const char *vendor; 84 /*! \brief The model of machine which produced the file. */ 85 const char *model; 86 /*! \brief The remote end's ident string. */ 87 const char *far_ident; 88 /*! \brief The FAX sub-address. */ 89 const char *sub_address; 90 /*! \brief The FAX DCS information, as an ASCII hex string. */ 91 const char *dcs; 92 } t4_rx_metadata_t; 93 94 typedef struct 95 { 96 uint8_t *buf; 97 int buf_len; 98 int buf_ptr; 99 } no_decoder_state_t; 100 101 /*! 102 T.4 FAX decompression descriptor. This defines the working state 103 for a single instance of a T.4 FAX decompression channel. 104 */ 105 struct t4_rx_state_s 106 { 107 /*! \brief Callback function to write a row of pixels to the image destination. */ 108 t4_row_write_handler_t row_handler; 109 /*! \brief Opaque pointer passed to row_write_handler. */ 110 void *row_handler_user_data; 111 112 /*! \brief A bit mask of the currently supported image compression modes for writing 113 to the TIFF file. */ 114 int supported_tiff_compressions; 115 116 /*! \brief The number of pages transferred to date. */ 117 int current_page; 118 119 /*! \brief The size of the compressed image on the line side, in bits. */ 120 int line_image_size; 121 122 union 123 { 124 no_decoder_state_t no_decoder; 125 t4_t6_decode_state_t t4_t6; 126 t85_decode_state_t t85; 127 #if defined(SPANDSP_SUPPORT_T88) 128 t88_decode_state_t t88; 129 #endif 130 t42_decode_state_t t42; 131 t43_decode_state_t t43; 132 #if defined(SPANDSP_SUPPORT_T45) 133 t45_decode_state_t t45; 134 #endif 135 } decoder; 136 137 t4_image_put_handler_t image_put_handler; 138 139 int current_decoder; 140 141 /* Supporting information, like resolutions, which the backend may want. */ 142 t4_rx_metadata_t metadata; 143 144 /*! \brief All TIFF file specific state information for the T.4 context. */ 145 t4_rx_tiff_state_t tiff; 146 147 /*! \brief Error and flow logging control */ 148 logging_state_t logging; 149 }; 150 151 #endif 152 /*- End of file ------------------------------------------------------------*/ 153