Mercurial > hg > audiostuff
view 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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/* * 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 ------------------------------------------------------------*/