Mercurial > hg > audiostuff
diff spandsp-0.0.6pre17/src/spandsp/private/t38_gateway.h @ 4:26cd8f1ef0b1
import spandsp-0.0.6pre17
author | Peter Meerwald <pmeerw@cosy.sbg.ac.at> |
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date | Fri, 25 Jun 2010 15:50:58 +0200 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/spandsp-0.0.6pre17/src/spandsp/private/t38_gateway.h Fri Jun 25 15:50:58 2010 +0200 @@ -0,0 +1,207 @@ +/* + * SpanDSP - a series of DSP components for telephony + * + * private/t38_gateway.h - A T.38, less the packet exchange part + * + * Written by Steve Underwood <steveu@coppice.org> + * + * Copyright (C) 2005, 2006, 2007 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: t38_gateway.h,v 1.5 2009/11/07 08:58:58 steveu Exp $ + */ + +/*! \file */ + +#if !defined(_SPANDSP_PRIVATE_T38_GATEWAY_H_) +#define _SPANDSP_PRIVATE_T38_GATEWAY_H_ + +/*! + T.38 gateway T.38 side channel descriptor. +*/ +typedef struct +{ + /*! Core T.38 IFP support */ + t38_core_state_t t38; + + /*! \brief TRUE if the NSF, NSC, and NSS are to be suppressed by altering + their contents to something the far end will not recognise. */ + int suppress_nsx_len[2]; + /*! \brief TRUE if we need to corrupt the HDLC frame in progress, so the receiver cannot + interpret it. The two values are for the two directions. */ + int corrupt_current_frame[2]; + + /*! \brief the current class of field being received - i.e. none, non-ECM or HDLC */ + int current_rx_field_class; + /*! \brief The T.38 indicator currently in use */ + int in_progress_rx_indicator; + + /*! \brief The current T.38 data type being sent. */ + int current_tx_data_type; +} t38_gateway_t38_state_t; + +/*! + T.38 gateway audio side channel descriptor. +*/ +typedef struct +{ + /*! \brief The FAX modem set for the audio side fo the gateway. */ + fax_modems_state_t modems; + /*! \brief The current receive signal handler. Actual receiving hop between this + and a dummy receive routine. */ + span_rx_handler_t *base_rx_handler; +} t38_gateway_audio_state_t; + +/*! + T.38 gateway T.38 side state. +*/ +typedef struct +{ + /*! \brief non-ECM and HDLC modem receive data buffer. */ + uint8_t data[T38_RX_BUF_LEN]; + /*! \brief Current pointer into the data buffer. */ + int data_ptr; + /*! \brief The current octet being received as non-ECM data. */ + unsigned int bit_stream; + /*! \brief The number of bits taken from the modem for the current scan row. This + is used during non-ECM transmission will fill bit removal to see that + T.38 packet transmissions do not stretch too far apart. */ + int bits_absorbed; + /*! \brief The current bit number in the current non-ECM octet. */ + int bit_no; + /*! \brief Progressively calculated CRC for HDLC messages received from a modem. */ + uint16_t crc; + /*! \brief TRUE if non-ECM fill bits are to be stripped when sending image data. */ + int fill_bit_removal; + /*! \brief The number of octets to send in each image packet (non-ECM or ECM) at the current + rate and the current specified packet interval. */ + int octets_per_data_packet; + + /*! \brief Bits into the non-ECM buffer */ + int in_bits; + /*! \brief Octets fed out from the non-ECM buffer */ + int out_octets; +} t38_gateway_to_t38_state_t; + +/*! + T.38 gateway HDLC buffer. +*/ +typedef struct +{ + /*! \brief HDLC message buffers. */ + uint8_t buf[T38_MAX_HDLC_LEN]; + /*! \brief HDLC message lengths. */ + int len; + /*! \brief HDLC message status flags. */ + int flags; + /*! \brief HDLC buffer contents. */ + int contents; +} t38_gateway_hdlc_buf_t; + +/*! + T.38 gateway HDLC state. +*/ +typedef struct +{ + /*! \brief HDLC message buffers. */ + t38_gateway_hdlc_buf_t buf[T38_TX_HDLC_BUFS]; +#if 0 + /*! \brief HDLC message buffers. */ + uint8_t buf[T38_TX_HDLC_BUFS][T38_MAX_HDLC_LEN]; + /*! \brief HDLC message lengths. */ + int len[T38_TX_HDLC_BUFS]; + /*! \brief HDLC message status flags. */ + int flags[T38_TX_HDLC_BUFS]; + /*! \brief HDLC buffer contents. */ + int contents[T38_TX_HDLC_BUFS]; +#endif + /*! \brief HDLC buffer number for input. */ + int in; + /*! \brief HDLC buffer number for output. */ + int out; +} t38_gateway_hdlc_state_t; + +/*! + T.38 gateway core descriptor. +*/ +typedef struct +{ + /*! \brief A bit mask of the currently supported modem types. */ + int supported_modems; + /*! \brief TRUE if ECM FAX mode is allowed through the gateway. */ + int ecm_allowed; + + /*! \brief TRUE if in image data modem is to use short training. This usually + follows image_data_mode, but in ECM mode T.30 defines recovery + conditions in which long training is used for image data. */ + int short_train; + /*! \brief TRUE if in image data mode, as opposed to TCF mode. */ + int image_data_mode; + /*! \brief The minimum permitted bits per FAX scan line row. */ + int min_row_bits; + + /*! \brief TRUE if we should count the next MCF as a page end, else FALSE */ + int count_page_on_mcf; + /*! \brief The number of pages for which a confirm (MCF) message was returned. */ + int pages_confirmed; + + /*! \brief TRUE if we are in error correcting (ECM) mode */ + int ecm_mode; + /*! \brief The current bit rate for the fast modem. */ + int fast_bit_rate; + /*! \brief The current fast receive modem type. */ + int fast_rx_modem; + /*! \brief The type of fast receive modem currently active, which may be T38_NONE */ + int fast_rx_active; + + /*! \brief The current timed operation. */ + int timed_mode; + /*! \brief The number of samples until the next timeout event */ + int samples_to_timeout; + + /*! Buffer for HDLC and non-ECM data going to the T.38 channel */ + t38_gateway_to_t38_state_t to_t38; + /*! Buffer for data going to an HDLC modem. */ + t38_gateway_hdlc_state_t hdlc_to_modem; + /*! Buffer for data going to a non-ECM mode modem. */ + t38_non_ecm_buffer_state_t non_ecm_to_modem; + + /*! \brief A pointer to a callback routine to be called when frames are + exchanged. */ + t38_gateway_real_time_frame_handler_t *real_time_frame_handler; + /*! \brief An opaque pointer supplied in real time frame callbacks. */ + void *real_time_frame_user_data; +} t38_gateway_core_state_t; + +/*! + T.38 gateway state. +*/ +struct t38_gateway_state_s +{ + /*! T.38 side state */ + t38_gateway_t38_state_t t38x; + /*! Audio side state */ + t38_gateway_audio_state_t audio; + /*! T.38 core state */ + t38_gateway_core_state_t core; + + /*! \brief Error and flow logging control */ + logging_state_t logging; +}; + +#endif +/*- End of file ------------------------------------------------------------*/