00001 /* 00002 * SpanDSP - a series of DSP components for telephony 00003 * 00004 * t4.h - definitions for T.4 fax processing 00005 * 00006 * Written by Steve Underwood <steveu@coppice.org> 00007 * 00008 * Copyright (C) 2003 Steve Underwood 00009 * 00010 * All rights reserved. 00011 * 00012 * This program is free software; you can redistribute it and/or modify 00013 * it under the terms of the GNU General Public License version 2, as 00014 * published by the Free Software Foundation. 00015 * 00016 * This program is distributed in the hope that it will be useful, 00017 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00018 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00019 * GNU General Public License for more details. 00020 * 00021 * You should have received a copy of the GNU General Public License 00022 * along with this program; if not, write to the Free Software 00023 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 00024 * 00025 * $Id: t4.h,v 1.47 2007/12/14 13:27:30 steveu Exp $ 00026 */ 00027 00028 /*! \file */ 00029 00030 #if !defined(_SPANDSP_T4_H_) 00031 #define _SPANDSP_T4_H_ 00032 00033 /*! \page t4_page T.4 image compression and decompression 00034 00035 \section t4_page_sec_1 What does it do? 00036 The T.4 image compression and decompression routines implement the 1D and 2D 00037 encoding methods defined in ITU specification T.4. They also implement the pure 00038 2D encoding method defined in T.6. These are image compression algorithms used 00039 for FAX transmission. 00040 00041 \section t4_page_sec_1 How does it work? 00042 */ 00043 00044 typedef int (*t4_row_read_handler_t)(void *user_data, uint8_t buf[], size_t len); 00045 typedef int (*t4_row_write_handler_t)(void *user_data, const uint8_t buf[], size_t len); 00046 00047 /*! Supported compression modes. */ 00048 typedef enum 00049 { 00050 T4_COMPRESSION_ITU_T4_1D = 1, 00051 T4_COMPRESSION_ITU_T4_2D = 2, 00052 T4_COMPRESSION_ITU_T6 = 3 00053 } t4_image_compression_t; 00054 00055 /*! Supported X resolutions, in pixels per metre. */ 00056 typedef enum 00057 { 00058 T4_X_RESOLUTION_R4 = 4016, 00059 T4_X_RESOLUTION_R8 = 8031, 00060 T4_X_RESOLUTION_300 = 11811, 00061 T4_X_RESOLUTION_R16 = 16063, 00062 T4_X_RESOLUTION_600 = 23622, 00063 T4_X_RESOLUTION_800 = 31496, 00064 T4_X_RESOLUTION_1200 = 47244 00065 } t4_image_x_resolution_t; 00066 00067 /*! Supported Y resolutions, in pixels per metre. */ 00068 typedef enum 00069 { 00070 T4_Y_RESOLUTION_STANDARD = 3850, 00071 T4_Y_RESOLUTION_FINE = 7700, 00072 T4_Y_RESOLUTION_300 = 11811, 00073 T4_Y_RESOLUTION_SUPERFINE = 15400, /* 400 is 15748 */ 00074 T4_Y_RESOLUTION_600 = 23622, 00075 T4_Y_RESOLUTION_800 = 31496, 00076 T4_Y_RESOLUTION_1200 = 47244 00077 } t4_image_y_resolution_t; 00078 00079 /*! 00080 Exact widths in PELs for the difference resolutions, and page widths. 00081 Note: 00082 The A4 widths also apply to North American letter and legal. 00083 The R4 resolution widths are not supported in recent versions of T.30 00084 Only images of exactly these widths are acceptable for FAX transmisson. 00085 00086 R4 864 pels/215mm for ISO A4, North American Letter and Legal 00087 R4 1024 pels/255mm for ISO B4 00088 R4 1216 pels/303mm for ISO A3 00089 R8 1728 pels/215mm for ISO A4, North American Letter and Legal 00090 R8 2048 pels/255mm for ISO B4 00091 R8 2432 pels/303mm for ISO A3 00092 R16 3456 pels/215mm for ISO A4, North American Letter and Legal 00093 R16 4096 pels/255mm for ISO B4 00094 R16 4864 pels/303mm for ISO A3 00095 */ 00096 typedef enum 00097 { 00098 T4_WIDTH_R4_A4 = 864, 00099 T4_WIDTH_R4_B4 = 1024, 00100 T4_WIDTH_R4_A3 = 1216, 00101 T4_WIDTH_R8_A4 = 1728, 00102 T4_WIDTH_R8_B4 = 2048, 00103 T4_WIDTH_R8_A3 = 2432, 00104 T4_WIDTH_300_A4 = 2592, 00105 T4_WIDTH_300_B4 = 3072, 00106 T4_WIDTH_300_A3 = 3648, 00107 T4_WIDTH_R16_A4 = 3456, 00108 T4_WIDTH_R16_B4 = 4096, 00109 T4_WIDTH_R16_A3 = 4864, 00110 T4_WIDTH_600_A4 = 5184, 00111 T4_WIDTH_600_B4 = 6144, 00112 T4_WIDTH_600_A3 = 7296, 00113 T4_WIDTH_1200_A4 = 10368, 00114 T4_WIDTH_1200_B4 = 12288, 00115 T4_WIDTH_1200_A3 = 14592 00116 } t4_image_width_t; 00117 00118 /*! 00119 Length of the various supported paper sizes, in pixels at the various Y resolutions. 00120 Paper sizes are 00121 A4 (215mm x 297mm) 00122 B4 (255mm x 364mm) 00123 A3 (303mm x 418.56mm) 00124 North American Letter (215.9mm x 279.4mm) 00125 North American Legal (215.9mm x 355.6mm) 00126 Unlimited 00127 00128 T.4 does not accurately define the maximum number of scan lines in a page. A wide 00129 variety of maximum row counts are used in the real world. It is important not to 00130 set our sending limit too high, or a receiving machine might split pages. It is 00131 important not to set it too low, or we might clip pages. 00132 00133 Values seen for standard resolution A4 pages include 1037, 1045, 1109, 1126 and 1143. 00134 1109 seems the most-popular. At fine res 2150, 2196, 2200, 2237, 2252-2262, 2264, 00135 2286, and 2394 are used. 2255 seems the most popular. We try to use balanced choices 00136 here. 00137 */ 00138 typedef enum 00139 { 00140 /* A4 is 297mm long */ 00141 T4_LENGTH_STANDARD_A4 = 1143, 00142 T4_LENGTH_FINE_A4 = 2286, 00143 T4_LENGTH_300_A4 = 4665, 00144 T4_LENGTH_SUPERFINE_A4 = 4573, 00145 T4_LENGTH_600_A4 = 6998, 00146 T4_LENGTH_800_A4 = 9330, 00147 T4_LENGTH_1200_A4 = 13996, 00148 /* B4 is 364mm long */ 00149 T4_LENGTH_STANDARD_B4 = 1401, 00150 T4_LENGTH_FINE_B4 = 2802, 00151 T4_LENGTH_300_B4 = 0, 00152 T4_LENGTH_SUPERFINE_B4 = 5605, 00153 T4_LENGTH_600_B4 = 0, 00154 T4_LENGTH_800_B4 = 0, 00155 T4_LENGTH_1200_B4 = 0, 00156 /* North American letter is 279.4mm long */ 00157 T4_LENGTH_STANDARD_US_LETTER = 1075, 00158 T4_LENGTH_FINE_US_LETTER = 2151, 00159 T4_LENGTH_300_US_LETTER = 0, 00160 T4_LENGTH_SUPERFINE_US_LETTER = 4302, 00161 T4_LENGTH_600_US_LETTER = 0, 00162 T4_LENGTH_800_US_LETTER = 0, 00163 T4_LENGTH_1200_US_LETTER = 0, 00164 /* North American legal is 355.6mm long */ 00165 T4_LENGTH_STANDARD_US_LEGAL = 1369, 00166 T4_LENGTH_FINE_US_LEGAL = 2738, 00167 T4_LENGTH_300_US_LEGAL = 0, 00168 T4_LENGTH_SUPERFINE_US_LEGAL = 5476, 00169 T4_LENGTH_600_US_LEGAL = 0, 00170 T4_LENGTH_800_US_LEGAL = 0, 00171 T4_LENGTH_1200_US_LEGAL = 0 00172 } t4_image_length_t; 00173 00174 /*! 00175 T.4 FAX compression/decompression descriptor. This defines the working state 00176 for a single instance of a T.4 FAX compression or decompression channel. 00177 */ 00178 typedef struct 00179 { 00180 /* "Background" information about the FAX, which can be stored in a TIFF file. */ 00181 /*! \brief The vendor of the machine which produced the TIFF file. */ 00182 const char *vendor; 00183 /*! \brief The model of machine which produced the TIFF file. */ 00184 const char *model; 00185 /*! \brief The local ident string. */ 00186 const char *local_ident; 00187 /*! \brief The remote end's ident string. */ 00188 const char *far_ident; 00189 /*! \brief The FAX sub-address. */ 00190 const char *sub_address; 00191 /*! \brief The FAX DCS information, as an ASCII string. */ 00192 const char *dcs; 00193 /*! \brief The text which will be used in FAX page header. No text results 00194 in no header line. */ 00195 const char *header_info; 00196 00197 /*! \brief The type of compression used between the FAX machines. */ 00198 int line_encoding; 00199 /*! \brief The minimum number of encoded bits per row. This is a timing thing 00200 for hardware FAX machines. */ 00201 int min_bits_per_row; 00202 00203 /*! \brief The compression type for output to the TIFF file. */ 00204 int output_compression; 00205 /*! \brief The TIFF G3 FAX options. */ 00206 int output_t4_options; 00207 00208 /*! \brief Callback function to read a row of pixels from the image source. */ 00209 t4_row_read_handler_t row_read_handler; 00210 /*! \brief Opaque pointer passed to row_read_handler. */ 00211 void *row_read_user_data; 00212 /*! \brief Callback function to write a row of pixels to the image destination. */ 00213 t4_row_write_handler_t row_write_handler; 00214 /*! \brief Opaque pointer passed to row_write_handler. */ 00215 void *row_write_user_data; 00216 00217 /*! \brief The time at which handling of the current page began. */ 00218 time_t page_start_time; 00219 00220 /*! \brief The current number of bytes per row of uncompressed image data. */ 00221 int bytes_per_row; 00222 /*! \brief The size of the image in the image buffer, in bytes. */ 00223 int image_size; 00224 /*! \brief The current size of the image buffer. */ 00225 int image_buffer_size; 00226 /*! \brief A point to the image buffer. */ 00227 uint8_t *image_buffer; 00228 00229 /*! \brief The libtiff context for the current TIFF file */ 00230 TIFF *tiff_file; 00231 /*! \brief The current file name. */ 00232 const char *file; 00233 /*! \brief The first page to transfer. -1 to start at the beginning of the file. */ 00234 int start_page; 00235 /*! \brief The last page to transfer. -1 to continue to the end of the file. */ 00236 int stop_page; 00237 00238 /*! \brief The number of pages transferred to date. */ 00239 int pages_transferred; 00240 /*! \brief The number of pages in the current TIFF file. */ 00241 int pages_in_file; 00242 /*! \brief Column-to-column (X) resolution in pixels per metre. */ 00243 int x_resolution; 00244 /*! \brief Row-to-row (Y) resolution in pixels per metre. */ 00245 int y_resolution; 00246 /*! \brief Width of the current page, in pixels. */ 00247 int image_width; 00248 /*! \brief Length of the current page, in pixels. */ 00249 int image_length; 00250 /*! \brief Current pixel row number. */ 00251 int row; 00252 /*! \brief The current number of consecutive bad rows. */ 00253 int curr_bad_row_run; 00254 /*! \brief The longest run of consecutive bad rows seen in the current page. */ 00255 int longest_bad_row_run; 00256 /*! \brief The total number of bad rows in the current page. */ 00257 int bad_rows; 00258 00259 /*! \brief Incoming bit buffer for decompression. */ 00260 uint32_t rx_bitstream; 00261 /*! \brief The number of bits currently in rx_bitstream. */ 00262 int rx_bits; 00263 00264 /*! \brief This variable is set if we are treating the current row as a 2D encoded 00265 one. */ 00266 int row_is_2d; 00267 /*! \brief TRUE if the current run is black */ 00268 int its_black; 00269 /*! \brief The current length of the current row. */ 00270 int row_len; 00271 /*! \brief This variable is used to record the fact we have seen at least one EOL 00272 since we started decoding. We will not try to interpret the received 00273 data as an image until we have seen the first EOL. */ 00274 int first_eol_seen; 00275 /*! \brief This variable is used to count the consecutive EOLS we have seen. If it 00276 reaches six, this is the end of the image. */ 00277 int consecutive_eols; 00278 00279 /*! \brief Black and white run-lengths for the current row. */ 00280 uint32_t *cur_runs; 00281 /*! \brief Black and white run-lengths for the reference row. */ 00282 uint32_t *ref_runs; 00283 /*! \brief The number of runs currently in the reference row. */ 00284 int ref_steps; 00285 /*! \brief The current step into the reference row run-lengths buffer. */ 00286 int b_cursor; 00287 /*! \brief The current step into the current row run-lengths buffer. */ 00288 int a_cursor; 00289 00290 /*! \brief The reference or starting changing element on the coding line. At the 00291 start of the coding line, a0 is set on an imaginary white changing element 00292 situated just before the first element on the line. During the coding of 00293 the coding line, the position of a0 is defined by the previous coding mode. 00294 (See 4.2.1.3.2.). */ 00295 int a0; 00296 /*! \brief The first changing element on the reference line to the right of a0 and of 00297 opposite colour to a0. */ 00298 int b1; 00299 /*! \brief The length of the in-progress run of black or white. */ 00300 int run_length; 00301 /*! \brief 2D horizontal mode control. */ 00302 int black_white; 00303 00304 /*! \brief Encoded data bits buffer. */ 00305 uint32_t tx_bitstream; 00306 /*! \brief The number of bits currently in tx_bitstream. */ 00307 int tx_bits; 00308 00309 /*! \brief A pointer into the image buffer indicating where the last row begins */ 00310 int last_row_starts_at; 00311 /*! \brief A pointer into the image buffer indicating where the current row begins */ 00312 int row_starts_at; 00313 00314 /*! \brief Pointer to the buffer for the current pixel row. */ 00315 uint8_t *row_buf; 00316 00317 /*! \brief Pointer to the byte containing the next image bit to transmit. */ 00318 int bit_pos; 00319 /*! \brief Pointer to the bit within the byte containing the next image bit to transmit. */ 00320 int bit_ptr; 00321 00322 /*! \brief The current maximum contiguous rows that may be 2D encoded. */ 00323 int max_rows_to_next_1d_row; 00324 /*! \brief Number of rows left that can be 2D encoded, before a 1D encoded row 00325 must be used. */ 00326 int rows_to_next_1d_row; 00327 /*! \brief The current number of bits in the current encoded row. */ 00328 int row_bits; 00329 /*! \brief The minimum bits in any row of the current page. For monitoring only. */ 00330 int min_row_bits; 00331 /*! \brief The maximum bits in any row of the current page. For monitoring only. */ 00332 int max_row_bits; 00333 00334 /*! \brief Error and flow logging control */ 00335 logging_state_t logging; 00336 } t4_state_t; 00337 00338 /*! 00339 T.4 FAX compression/decompression statistics. 00340 */ 00341 typedef struct 00342 { 00343 /*! \brief The number of pages transferred so far. */ 00344 int pages_transferred; 00345 /*! \brief The number of pages in the file (<0 if unknown). */ 00346 int pages_in_file; 00347 /*! \brief The number of horizontal pixels in the most recent page. */ 00348 int width; 00349 /*! \brief The number of vertical pixels in the most recent page. */ 00350 int length; 00351 /*! \brief The number of bad pixel rows in the most recent page. */ 00352 int bad_rows; 00353 /*! \brief The largest number of bad pixel rows in a block in the most recent page. */ 00354 int longest_bad_row_run; 00355 /*! \brief The horizontal resolution of the page in pixels per metre */ 00356 int x_resolution; 00357 /*! \brief The vertical resolution of the page in pixels per metre */ 00358 int y_resolution; 00359 /*! \brief The type of compression used between the FAX machines */ 00360 int encoding; 00361 /*! \brief The size of the image, in bytes */ 00362 int image_size; 00363 } t4_stats_t; 00364 00365 #if defined(__cplusplus) 00366 extern "C" { 00367 #endif 00368 00369 /*! \brief Prepare for reception of a document. 00370 \param s The T.4 context. 00371 \param file The name of the file to be received. 00372 \param output_encoding The output encoding. 00373 \return A pointer to the context, or NULL if there was a problem. */ 00374 t4_state_t *t4_rx_init(t4_state_t *s, const char *file, int output_encoding); 00375 00376 /*! \brief Prepare to receive the next page of the current document. 00377 \param s The T.4 context. 00378 \return zero for success, -1 for failure. */ 00379 int t4_rx_start_page(t4_state_t *s); 00380 00381 /*! \brief Put a bit of the current document page. 00382 \param s The T.4 context. 00383 \param bit The data bit. 00384 \return TRUE when the bit ends the document page, otherwise FALSE. */ 00385 int t4_rx_put_bit(t4_state_t *s, int bit); 00386 00387 /*! \brief Put a byte of the current document page. 00388 \param s The T.4 context. 00389 \param byte The data byte. 00390 \return TRUE when the byte ends the document page, otherwise FALSE. */ 00391 int t4_rx_put_byte(t4_state_t *s, uint8_t byte); 00392 00393 /*! \brief Put a byte of the current document page. 00394 \param s The T.4 context. 00395 \param buf The buffer containing the chunk. 00396 \param len The length of the chunk. 00397 \return TRUE when the byte ends the document page, otherwise FALSE. */ 00398 int t4_rx_put_chunk(t4_state_t *s, const uint8_t buf[], int len); 00399 00400 /*! \brief Complete the reception of a page. 00401 \param s The T.4 receive context. 00402 \return 0 for success, otherwise -1. */ 00403 int t4_rx_end_page(t4_state_t *s); 00404 00405 /*! \brief End reception of a document. Tidy up, close the file and 00406 free the context. This should be used to end T.4 reception 00407 started with t4_rx_init. 00408 \param s The T.4 receive context. 00409 \return 0 for success, otherwise -1. */ 00410 int t4_rx_delete(t4_state_t *s); 00411 00412 /*! \brief End reception of a document. Tidy up and close the file. 00413 This should be used to end T.4 reception started with 00414 t4_rx_init. 00415 \param s The T.4 context. 00416 \return 0 for success, otherwise -1. */ 00417 int t4_rx_end(t4_state_t *s); 00418 00419 int t4_rx_set_row_write_handler(t4_state_t *s, t4_row_write_handler_t handler, void *user_data); 00420 00421 /*! \brief Set the encoding for the received data. 00422 \param s The T.4 context. 00423 \param encoding The encoding. */ 00424 void t4_rx_set_rx_encoding(t4_state_t *s, int encoding); 00425 00426 /*! \brief Set the expected width of the received image, in pixel columns. 00427 \param s The T.4 context. 00428 \param width The number of pixels across the image. */ 00429 void t4_rx_set_image_width(t4_state_t *s, int width); 00430 00431 /*! \brief Set the row-to-row (y) resolution to expect for a received image. 00432 \param s The T.4 context. 00433 \param resolution The resolution, in pixels per metre. */ 00434 void t4_rx_set_y_resolution(t4_state_t *s, int resolution); 00435 00436 /*! \brief Set the column-to-column (x) resolution to expect for a received image. 00437 \param s The T.4 context. 00438 \param resolution The resolution, in pixels per metre. */ 00439 void t4_rx_set_x_resolution(t4_state_t *s, int resolution); 00440 00441 /*! \brief Set the DCS information of the fax, for inclusion in the file. 00442 \param s The T.4 context. 00443 \param dcs The DCS information, formatted as an ASCII string. */ 00444 void t4_rx_set_dcs(t4_state_t *s, const char *dcs); 00445 00446 /*! \brief Set the sub-address of the fax, for inclusion in the file. 00447 \param s The T.4 context. 00448 \param sub_address The sub-address string. */ 00449 void t4_rx_set_sub_address(t4_state_t *s, const char *sub_address); 00450 00451 /*! \brief Set the identity of the remote machine, for inclusion in the file. 00452 \param s The T.4 context. 00453 \param ident The identity string. */ 00454 void t4_rx_set_far_ident(t4_state_t *s, const char *ident); 00455 00456 /*! \brief Set the vendor of the remote machine, for inclusion in the file. 00457 \param s The T.4 context. 00458 \param vendor The vendor string, or NULL. */ 00459 void t4_rx_set_vendor(t4_state_t *s, const char *vendor); 00460 00461 /*! \brief Set the model of the remote machine, for inclusion in the file. 00462 \param s The T.4 context. 00463 \param model The model string, or NULL. */ 00464 void t4_rx_set_model(t4_state_t *s, const char *model); 00465 00466 /*! \brief Prepare for transmission of a document. 00467 \param s The T.4 context. 00468 \param file The name of the file to be sent. 00469 \param start_page The first page to send. -1 for no restriction. 00470 \param stop_page The last page to send. -1 for no restriction. 00471 \return A pointer to the context, or NULL if there was a problem. */ 00472 t4_state_t *t4_tx_init(t4_state_t *s, const char *file, int start_page, int stop_page); 00473 00474 /*! \brief Prepare to send the next page of the current document. 00475 \param s The T.4 context. 00476 \return zero for success, -1 for failure. */ 00477 int t4_tx_start_page(t4_state_t *s); 00478 00479 /*! \brief Prepare the current page for a resend. 00480 \param s The T.4 context. 00481 \return zero for success, -1 for failure. */ 00482 int t4_tx_restart_page(t4_state_t *s); 00483 00484 /*! \brief Check for the existance of the next page. This information can 00485 be needed before it is determined that the current page is finished with. 00486 \param s The T.4 context. 00487 \return zero for next page found, -1 for failure. */ 00488 int t4_tx_more_pages(t4_state_t *s); 00489 00490 /*! \brief Complete the sending of a page. 00491 \param s The T.4 context. 00492 \return zero for success, -1 for failure. */ 00493 int t4_tx_end_page(t4_state_t *s); 00494 00495 /*! \brief Get the next bit of the current document page. The document will 00496 be padded for the current minimum scan line time. If the 00497 file does not contain an RTC (return to control) code at 00498 the end of the page, one will be added where appropriate. 00499 \param s The T.4 context. 00500 \return The next bit (i.e. 0 or 1). For the last bit of data, bit 1 is 00501 set (i.e. the returned value is 2 or 3). */ 00502 int t4_tx_get_bit(t4_state_t *s); 00503 00504 /*! \brief Get the next byte of the current document page. The document will 00505 be padded for the current minimum scan line time. If the 00506 file does not contain an RTC (return to control) code at 00507 the end of the page, one will be added where appropriate. 00508 \param s The T.4 context. 00509 \return The next byte. For the last byte of data, bit 8 is 00510 set. In this case, one or more bits of the byte may be padded with 00511 zeros, to complete the byte. */ 00512 int t4_tx_get_byte(t4_state_t *s); 00513 00514 /*! \brief Get the next chunk of the current document page. The document will 00515 be padded for the current minimum scan line time. If the 00516 file does not contain an RTC (return to control) code at 00517 the end of the page, one will be added where appropriate. 00518 \param s The T.4 context. 00519 \param buf The buffer into which the chunk is to written. 00520 \param max_len The maximum length of the chunk. 00521 \return The actual length of the chunk. If this is less than max_len it 00522 indicates that the end of the document has been reached. */ 00523 int t4_tx_get_chunk(t4_state_t *s, uint8_t buf[], int max_len); 00524 00525 /*! \brief Return the next bit of the current document page, without actually 00526 moving forward in the buffer. The document will be padded for the 00527 current minimum scan line time. If the file does not contain an 00528 RTC (return to control) code at the end of the page, one will be 00529 added. 00530 \param s The T.4 context. 00531 \return The next bit (i.e. 0 or 1). For the last bit of data, bit 1 is 00532 set (i.e. the returned value is 2 or 3). */ 00533 int t4_tx_check_bit(t4_state_t *s); 00534 00535 /*! \brief End the transmission of a document. Tidy up, close the file and 00536 free the context. This should be used to end T.4 transmission 00537 started with t4_tx_init. 00538 \param s The T.4 context. 00539 \return 0 for success, otherwise -1. */ 00540 int t4_tx_delete(t4_state_t *s); 00541 00542 /*! \brief End the transmission of a document. Tidy up and close the file. 00543 This should be used to end T.4 transmission started with t4_tx_init. 00544 \param s The T.4 context. 00545 \return 0 for success, otherwise -1. */ 00546 int t4_tx_end(t4_state_t *s); 00547 00548 /*! \brief Set the encoding for the encoded data. 00549 \param s The T.4 context. 00550 \param encoding The encoding. */ 00551 void t4_tx_set_tx_encoding(t4_state_t *s, int encoding); 00552 00553 /*! \brief Set the minimum number of encoded bits per row. This allows the 00554 makes the encoding process to be set to comply with the minimum row 00555 time specified by a remote receiving machine. 00556 \param s The T.4 context. 00557 \param bits The minimum number of bits per row. */ 00558 void t4_tx_set_min_row_bits(t4_state_t *s, int bits); 00559 00560 /*! \brief Set the identity of the local machine, for inclusion in page headers. 00561 \param s The T.4 context. 00562 \param ident The identity string. */ 00563 void t4_tx_set_local_ident(t4_state_t *s, const char *ident); 00564 00565 /*! Set the info field, included in the header line included in each page of an encoded 00566 FAX. This is a string of up to 50 characters. Other information (date, local ident, etc.) 00567 are automatically included in the header. If the header info is set to NULL or a zero 00568 length string, no header lines will be added to the encoded FAX. 00569 \brief Set the header info. 00570 \param s The T.4 context. 00571 \param info A string, of up to 50 bytes, which will form the info field. */ 00572 void t4_tx_set_header_info(t4_state_t *s, const char *info); 00573 00574 int t4_tx_set_row_read_handler(t4_state_t *s, t4_row_read_handler_t handler, void *user_data); 00575 00576 /*! \brief Get the row-to-row (y) resolution of the current page. 00577 \param s The T.4 context. 00578 \return The resolution, in pixels per metre. */ 00579 int t4_tx_get_y_resolution(t4_state_t *s); 00580 00581 /*! \brief Get the column-to-column (x) resolution of the current page. 00582 \param s The T.4 context. 00583 \return The resolution, in pixels per metre. */ 00584 int t4_tx_get_x_resolution(t4_state_t *s); 00585 00586 /*! \brief Get the width of the current page, in pixel columns. 00587 \param s The T.4 context. 00588 \return The number of columns. */ 00589 int t4_tx_get_image_width(t4_state_t *s); 00590 00591 /*! \brief Get the number of pages in the file. 00592 \param s The T.4 context. 00593 \return The number of pages, or -1 if there is an error. */ 00594 int t4_tx_get_pages_in_file(t4_state_t *s); 00595 00596 /*! Get the current image transfer statistics. 00597 \brief Get the current transfer statistics. 00598 \param s The T.4 context. 00599 \param t A pointer to a statistics structure. */ 00600 void t4_get_transfer_statistics(t4_state_t *s, t4_stats_t *t); 00601 00602 /*! Get the short text name of an encoding format. 00603 \brief Get the short text name of an encoding format. 00604 \param encoding The encoding type. 00605 \return A pointer to the string. */ 00606 const char *t4_encoding_to_str(int encoding); 00607 00608 #if defined(__cplusplus) 00609 } 00610 #endif 00611 00612 #endif 00613 /*- End of file ------------------------------------------------------------*/