private/t38_non_ecm_buffer.h

00001 /*
00002  * SpanDSP - a series of DSP components for telephony
00003  *
00004  * private/t38_non_ecm_buffer.h - A rate adapting buffer for T.38 non-ECM image
00005  *                                and TCF data
00006  *
00007  * Written by Steve Underwood <steveu@coppice.org>
00008  *
00009  * Copyright (C) 2005, 2006, 2007, 2008 Steve Underwood
00010  *
00011  * All rights reserved.
00012  *
00013  * This program is free software; you can redistribute it and/or modify
00014  * it under the terms of the GNU Lesser General Public License version 2.1,
00015  * as published by the Free Software Foundation.
00016  *
00017  * This program is distributed in the hope that it will be useful,
00018  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00019  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00020  * GNU Lesser General Public License for more details.
00021  *
00022  * You should have received a copy of the GNU Lesser General Public
00023  * License along with this program; if not, write to the Free Software
00024  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
00025  *
00026  * $Id: t38_non_ecm_buffer.h,v 1.2 2008/10/13 14:19:18 steveu Exp $
00027  */
00028 
00029 #if !defined(_SPANDSP_PRIVATE_T38_NON_ECM_BUFFER_H_)
00030 #define _SPANDSP_PRIVATE_T38_NON_ECM_BUFFER_H_
00031 
00032 /*! \brief A flow controlled non-ECM image data buffer, for buffering T.38 to analogue
00033            modem data.
00034 */
00035 struct t38_non_ecm_buffer_state_s
00036 {
00037     /*! \brief Minimum number of bits per row, used when fill bits are being deleted on the
00038                link, and restored at the emitting gateway. */
00039     int min_row_bits;
00040 
00041     /*! \brief non-ECM modem transmit data buffer. */
00042     uint8_t data[T38_NON_ECM_TX_BUF_LEN];
00043     /*! \brief The current write point in the buffer. */
00044     int in_ptr;
00045     /*! \brief The current read point in the buffer. */
00046     int out_ptr;
00047     /*! \brief The location of the most recent EOL marker in the buffer. */
00048     int latest_eol_ptr;
00049     /*! \brief The number of bits to date in the current row, used when min_row_bits is
00050                to be applied. */
00051     int row_bits;
00052 
00053     /*! \brief The bit stream entering the buffer, used to detect EOLs */
00054     unsigned int bit_stream;
00055     /*! \brief The non-ECM flow control fill octet (0xFF before the first data, and 0x00
00056                once data has started). */
00057     uint8_t flow_control_fill_octet;
00058     /*! \brief TRUE if we are in the initial all ones part of non-ECM transmission. */
00059     int at_initial_all_ones;
00060     /*! \brief TRUE is the end of non-ECM data indication has been received. */
00061     int data_finished;
00062     /*! \brief The current octet being transmitted from the buffer. */
00063     unsigned int octet;
00064     /*! \brief The current bit number in the current non-ECM octet. */
00065     int bit_no;
00066     /*! \brief TRUE if in image data mode, as opposed to TCF mode. */
00067     int image_data_mode;
00068 
00069     /*! \brief The number of octets input to the buffer. */
00070     int in_octets;
00071     /*! \brief The number of rows input to the buffer. */
00072     int in_rows;
00073     /*! \brief The number of non-ECM fill octets generated for minimum row bits
00074                purposes. */
00075     int min_row_bits_fill_octets;
00076     /*! \brief The number of octets output from the buffer. */
00077     int out_octets;
00078     /*! \brief The number of rows output from the buffer. */
00079     int out_rows;
00080     /*! \brief The number of non-ECM fill octets generated for flow control
00081                purposes. */
00082     int flow_control_fill_octets;
00083 };
00084 
00085 #endif
00086 /*- End of file ------------------------------------------------------------*/

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