telephony.h

00001 /*
00002  * SpanDSP - a series of DSP components for telephony
00003  *
00004  * telephony.h - some very basic telephony definitions
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: telephony.h,v 1.18 2009/03/23 14:17:42 steveu Exp $
00026  */
00027 
00028 #if !defined(_SPANDSP_TELEPHONY_H_)
00029 #define _SPANDSP_TELEPHONY_H_
00030 
00031 #if defined(_M_IX86)  ||  defined(_M_X64)
00032 #if defined(LIBSPANDSP_EXPORTS)
00033 #define SPAN_DECLARE(type)              __declspec(dllexport) type __stdcall
00034 #define SPAN_DECLARE_NONSTD(type)       __declspec(dllexport) type __cdecl
00035 #define SPAN_DECLARE_DATA               __declspec(dllexport)
00036 #else
00037 #define SPAN_DECLARE(type)              __declspec(dllimport) type __stdcall
00038 #define SPAN_DECLARE_NONSTD(type)       __declspec(dllimport) type __cdecl
00039 #define SPAN_DECLARE_DATA               __declspec(dllimport)
00040 #endif
00041 #elif defined(SPANDSP_USE_EXPORT_CAPABILITY)  &&  (defined(__GNUC__)  ||  defined(__SUNCC__))
00042 #define SPAN_DECLARE(type)              __attribute__((visibility("default"))) type
00043 #define SPAN_DECLARE_NONSTD(type)       __attribute__((visibility("default"))) type
00044 #define SPAN_DECLARE_DATA               __attribute__((visibility("default")))
00045 #else
00046 #define SPAN_DECLARE(type)              /**/ type
00047 #define SPAN_DECLARE_NONSTD(type)       /**/ type
00048 #define SPAN_DECLARE_DATA               /**/
00049 #endif
00050 
00051 #define SAMPLE_RATE                 8000
00052 
00053 /* This is based on A-law, but u-law is only 0.03dB different */
00054 #define DBM0_MAX_POWER              (3.14f + 3.02f)
00055 #define DBM0_MAX_SINE_POWER         (3.14f)
00056 /* This is based on the ITU definition of dbOv in G.100.1 */
00057 #define DBOV_MAX_POWER              (0.0f)
00058 #define DBOV_MAX_SINE_POWER         (-3.02f)
00059 
00060 /*! \brief A handler for pure receive. The buffer cannot be altered. */
00061 typedef int (span_rx_handler_t)(void *s, const int16_t amp[], int len);
00062 
00063 /*! \brief A handler for receive, where the buffer can be altered. */
00064 typedef int (span_mod_handler_t)(void *s, int16_t amp[], int len);
00065 
00066 /*! \brief A handler for missing receive data fill-in. */
00067 typedef int (span_rx_fillin_handler_t)(void *s, int len);
00068 
00069 /*! \brief A handler for transmit, where the buffer will be filled. */
00070 typedef int (span_tx_handler_t)(void *s, int16_t amp[], int max_len);
00071 
00072 #define ms_to_samples(t)            (((t)*SAMPLE_RATE)/1000)
00073 #define us_to_samples(t)            (((t)*SAMPLE_RATE)/1000000)
00074 
00075 #if !defined(FALSE)
00076 #define FALSE 0
00077 #endif
00078 #if !defined(TRUE)
00079 #define TRUE (!FALSE)
00080 #endif
00081 
00082 #if defined(__cplusplus)
00083 /* C++ doesn't seem to have sane rounding functions/macros yet */
00084 #if !defined(WIN32)
00085 #define lrint(x) ((long int) (x))
00086 #define lrintf(x) ((long int) (x))
00087 #endif
00088 #endif
00089 
00090 #endif
00091 /*- End of file ------------------------------------------------------------*/

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