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>
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 ------------------------------------------------------------*/

Repositories maintained by Peter Meerwald, pmeerw@pmeerw.net.