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private/t30.h

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00001 /*
00002  * SpanDSP - a series of DSP components for telephony
00003  *
00004  * private/t30.h - definitions for T.30 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 Lesser General Public License version 2.1,
00014  * as 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 Lesser General Public License for more details.
00020  *
00021  * You should have received a copy of the GNU Lesser General Public
00022  * License along with this program; if not, write to the Free Software
00023  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
00024  *
00025  * $Id: t30.h,v 1.3 2009/01/29 18:30:14 steveu Exp $
00026  */
00027 
00028 /*! \file */
00029 
00030 #if !defined(_SPANDSP_PRIVATE_T30_H_)
00031 #define _SPANDSP_PRIVATE_T30_H_
00032 
00033 /*!
00034     T.30 FAX channel descriptor. This defines the state of a single working
00035     instance of a T.30 FAX channel.
00036 */
00037 struct t30_state_s
00038 {
00039     /* This must be kept the first thing in the structure, so it can be pointed
00040        to reliably as the structures change over time. */
00041     /*! \brief T.4 context for reading or writing image data. */
00042     t4_state_t t4;
00043     
00044     int operation_in_progress;
00045 
00046     /*! \brief TRUE if behaving as the calling party */
00047     int calling_party;
00048     
00049     /*! \brief The received DCS, formatted as an ASCII string, for inclusion
00050                in the TIFF file. */
00051     char rx_dcs_string[T30_MAX_DIS_DTC_DCS_LEN*3 + 1];
00052     /*! \brief The text which will be used in FAX page header. No text results
00053                in no header line. */
00054     char header_info[T30_MAX_PAGE_HEADER_INFO + 1];
00055     /*! \brief The information fields received. */
00056     t30_exchanged_info_t rx_info;
00057     /*! \brief The information fields to be transmitted. */
00058     t30_exchanged_info_t tx_info;
00059     /*! \brief The country of origin of the remote machine, if known, else NULL. */
00060     const char *country;
00061     /*! \brief The vendor of the remote machine, if known, else NULL. */
00062     const char *vendor;
00063     /*! \brief The model of the remote machine, if known, else NULL. */
00064     const char *model;
00065 
00066     /*! \brief A pointer to a callback routine to be called when phase B events
00067         occur. */
00068     t30_phase_b_handler_t *phase_b_handler;
00069     /*! \brief An opaque pointer supplied in event B callbacks. */
00070     void *phase_b_user_data;
00071     /*! \brief A pointer to a callback routine to be called when phase D events
00072         occur. */
00073     t30_phase_d_handler_t *phase_d_handler;
00074     /*! \brief An opaque pointer supplied in event D callbacks. */
00075     void *phase_d_user_data;
00076     /*! \brief A pointer to a callback routine to be called when phase E events
00077         occur. */
00078     t30_phase_e_handler_t *phase_e_handler;
00079     /*! \brief An opaque pointer supplied in event E callbacks. */
00080     void *phase_e_user_data;
00081     /*! \brief A pointer to a callback routine to be called when frames are
00082         exchanged. */
00083     t30_real_time_frame_handler_t *real_time_frame_handler;
00084     /*! \brief An opaque pointer supplied in real time frame callbacks. */
00085     void *real_time_frame_user_data;
00086 
00087     /*! \brief A pointer to a callback routine to be called when document events
00088         (e.g. end of transmitted document) occur. */
00089     t30_document_handler_t *document_handler;
00090     /*! \brief An opaque pointer supplied in document callbacks. */
00091     void *document_user_data;
00092 
00093     /*! \brief The handler for changes to the receive mode */
00094     t30_set_handler_t *set_rx_type_handler;
00095     /*! \brief An opaque pointer passed to the handler for changes to the receive mode */
00096     void *set_rx_type_user_data;
00097     /*! \brief The handler for changes to the transmit mode */
00098     t30_set_handler_t *set_tx_type_handler;
00099     /*! \brief An opaque pointer passed to the handler for changes to the transmit mode */
00100     void *set_tx_type_user_data;
00101 
00102     /*! \brief The transmitted HDLC frame handler. */
00103     t30_send_hdlc_handler_t *send_hdlc_handler;
00104     /*! \brief An opaque pointer passed to the transmitted HDLC frame handler. */
00105     void *send_hdlc_user_data;
00106 
00107     /*! \brief The DIS code for the minimum scan row time we require. This is usually 0ms,
00108         but if we are trying to simulate another type of FAX machine, we may need a non-zero
00109         value here. */
00110     uint8_t local_min_scan_time_code;
00111 
00112     /*! \brief The current T.30 phase. */
00113     int phase;
00114     /*! \brief The T.30 phase to change to when the current phase ends. */
00115     int next_phase;
00116     /*! \brief The current state of the T.30 state machine. */
00117     int state;
00118     /*! \brief The step in sending a sequence of HDLC frames. */
00119     int step;
00120 
00121     /*! \brief The preparation buffer for the DCS message to be transmitted. */
00122     uint8_t dcs_frame[T30_MAX_DIS_DTC_DCS_LEN];
00123     /*! \brief The length of the DCS message to be transmitted. */
00124     int dcs_len;
00125     /*! \brief The preparation buffer for DIS or DTC message to be transmitted. */
00126     uint8_t local_dis_dtc_frame[T30_MAX_DIS_DTC_DCS_LEN];
00127     /*! \brief The length of the DIS or DTC message to be transmitted. */
00128     int local_dis_dtc_len;
00129     /*! \brief The last DIS or DTC message received form the far end. */
00130     uint8_t far_dis_dtc_frame[T30_MAX_DIS_DTC_DCS_LEN];
00131     /*! \brief The length of the last DIS or DTC message received form the far end. */
00132     int far_dis_dtc_len;
00133     /*! \brief TRUE if a valid DIS has been received from the far end. */
00134     int dis_received;
00135 
00136     /*! \brief A flag to indicate a message is in progress. */
00137     int in_message;
00138 
00139     /*! \brief TRUE if the short training sequence should be used. */
00140     int short_train;
00141 
00142     /*! \brief A count of the number of bits in the trainability test. This counts down to zero when
00143         sending TCF, and counts up when receiving it. */
00144     int tcf_test_bits;
00145     /*! \brief The current count of consecutive received zero bits, during the trainability test. */
00146     int tcf_current_zeros;
00147     /*! \brief The maximum consecutive received zero bits seen to date, during the trainability test. */
00148     int tcf_most_zeros;
00149 
00150     /*! \brief The current fallback step for the fast message transfer modem. */
00151     int current_fallback;
00152     /*! \brief The subset of supported modems allowed at the current time, allowing for negotiation. */
00153     int current_permitted_modems;
00154     /*! \brief TRUE if a carrier is present. Otherwise FALSE. */
00155     int rx_signal_present;
00156     /*! \brief TRUE if a modem has trained correctly. */
00157     int rx_trained;
00158     /*! \brief TRUE if a valid HDLC frame has been received in the current reception period. */
00159     int rx_frame_received;
00160 
00161     /*! \brief Current reception mode. */
00162     int current_rx_type;
00163     /*! \brief Current transmission mode. */
00164     int current_tx_type;
00165 
00166     /*! \brief T0 is the answer timeout when calling another FAX machine.
00167         Placing calls is handled outside the FAX processing, but this timeout keeps
00168         running until V.21 modulation is sent or received.
00169         T1 is the remote terminal identification timeout (in audio samples). */
00170     int timer_t0_t1;
00171     /*! \brief T2, T2A and T2B are the HDLC command timeouts.
00172                T4, T4A and T4B are the HDLC response timeouts (in audio samples). */
00173     int timer_t2_t4;
00174     /*! \brief A value specifying which of the possible timers is currently running in timer_t2_t4 */
00175     int timer_t2_t4_is;
00176     /*! \brief Procedural interrupt timeout (in audio samples). */
00177     int timer_t3;
00178     /*! \brief This is only used in error correcting mode. */
00179     int timer_t5;
00180     /*! \brief This is only used in full duplex (e.g. ISDN) modes. */
00181     int timer_t6;
00182     /*! \brief This is only used in full duplex (e.g. ISDN) modes. */
00183     int timer_t7;
00184     /*! \brief This is only used in full duplex (e.g. ISDN) modes. */
00185     int timer_t8;
00186 
00187     /*! \brief TRUE once the far end FAX entity has been detected. */
00188     int far_end_detected;
00189 
00190     /*! \brief TRUE if a local T.30 interrupt is pending. */
00191     int local_interrupt_pending;
00192     /*! \brief The image coding being used on the line. */
00193     int line_encoding;
00194     /*! \brief The image coding being used for output files. */
00195     int output_encoding;
00196     /*! \brief The current DCS message minimum scan time code. */
00197     uint8_t min_scan_time_code;
00198     /*! \brief The X direction resolution of the current image, in pixels per metre. */
00199     int x_resolution;
00200     /*! \brief The Y direction resolution of the current image, in pixels per metre. */
00201     int y_resolution;
00202     /*! \brief The width of the current image, in pixels. */
00203     t4_image_width_t image_width;
00204     /*! \brief Current number of retries of the action in progress. */
00205     int retries;
00206     /*! \brief TRUE if error correcting mode is used. */
00207     int error_correcting_mode;
00208     /*! \brief The number of HDLC frame retries, if error correcting mode is used. */
00209     int error_correcting_mode_retries;
00210     /*! \brief The current count of consecutive T30_PPR messages. */
00211     int ppr_count;
00212     /*! \brief The current count of consecutive T30_RNR messages. */
00213     int receiver_not_ready_count;
00214     /*! \brief The number of octets to be used per ECM frame. */
00215     int octets_per_ecm_frame;
00216     /*! \brief The ECM partial page buffer. */
00217     uint8_t ecm_data[256][260];
00218     /*! \brief The lengths of the frames in the ECM partial page buffer. */
00219     int16_t ecm_len[256];
00220     /*! \brief A bit map of the OK ECM frames, constructed as a PPR frame. */
00221     uint8_t ecm_frame_map[3 + 32];
00222     
00223     /*! \brief The current page number for receiving, in ECM mode. This is reset at the start of a call. */
00224     int ecm_rx_page;
00225     /*! \brief The current page number for sending, in ECM mode. This is reset at the start of a call. */
00226     int ecm_tx_page;
00227     /*! \brief The current block number, in ECM mode */
00228     int ecm_block;
00229     /*! \brief The number of frames in the current block number, in ECM mode */
00230     int ecm_frames;
00231     /*! \brief The number of frames sent in the current burst of image transmission, in ECM mode */
00232     int ecm_frames_this_tx_burst;
00233     /*! \brief The current ECM frame, during ECM transmission. */
00234     int ecm_current_tx_frame;
00235     /*! \brief TRUE if we are at the end of an ECM page to se sent - i.e. there are no more
00236         partial pages still to come. */
00237     int ecm_at_page_end;
00238     int next_tx_step;
00239     /* The FCF for the next receive step */
00240     uint8_t next_rx_step;
00241     /*! \brief Image file name for image reception. */
00242     char rx_file[256];
00243     /*! \brief The last page we are prepared accept for a received image file. -1 means no restriction. */
00244     int rx_stop_page;
00245     /*! \brief Image file name to be sent. */
00246     char tx_file[256];
00247     /*! \brief The first page to be sent from the image file. -1 means no restriction. */
00248     int tx_start_page;
00249     /*! \brief The last page to be sent from the image file. -1 means no restriction. */
00250     int tx_stop_page;
00251     int current_status;
00252     /*! \brief Internet Aware FAX mode bit mask. */
00253     int iaf;
00254     /*! \brief A bit mask of the currently supported modem types. */
00255     int supported_modems;
00256     /*! \brief A bit mask of the currently supported image compression modes. */
00257     int supported_compressions;
00258     /*! \brief A bit mask of the currently supported image resolutions. */
00259     int supported_resolutions;
00260     /*! \brief A bit mask of the currently supported image sizes. */
00261     int supported_image_sizes;
00262     /*! \brief A bit mask of the currently supported T.30 special features. */
00263     int supported_t30_features;
00264     /*! \brief TRUE is ECM mode handling is enabled. */
00265     int ecm_allowed;
00266     
00267     /*! \brief the FCF2 field of the last PPS message we received. */
00268     uint8_t last_pps_fcf2;
00269     /*! \brief The number of the first ECM frame which we do not currently received correctly. For
00270         a partial page received correctly, this will be one greater than the number of frames it
00271         contains. */
00272     int ecm_first_bad_frame;
00273     /*! \brief A count of successfully received ECM frames, to assess progress as a basis for
00274         deciding whether to continue error correction when PPRs keep repeating. */
00275     int ecm_progress;
00276 
00277     /*! \brief Error and flow logging control */
00278     logging_state_t logging;
00279 };
00280 
00281 #endif
00282 /*- End of file ------------------------------------------------------------*/

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