--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/spandsp-0.0.3/spandsp-0.0.3/src/spandsp/telephony.h	Fri Jun 25 16:00:21 2010 +0200
@@ -0,0 +1,67 @@
+/*
+ * SpanDSP - a series of DSP components for telephony
+ *
+ * telephony.h - some very basic telephony definitions
+ *
+ * Written by Steve Underwood <steveu@coppice.org>
+ *
+ * Copyright (C) 2003 Steve Underwood
+ *
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2, 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * $Id: telephony.h,v 1.9 2006/11/28 16:59:57 steveu Exp $
+ */
+
+#if !defined(_TELEPHONY_H_)
+#define _TELEPHONY_H_
+
+#define SAMPLE_RATE             8000
+
+/* This is based on A-law, but u-law is only 0.03dB different */
+#define DBM0_MAX_POWER          (3.14f + 3.02f)
+#define DBM0_MAX_SINE_POWER     (3.14f)
+/* This is based on the ITU definition of dbOv in G.100.1 */
+#define DBOV_MAX_POWER          (0.0f)
+#define DBOV_MAX_SINE_POWER     (-3.02f)
+
+/*! \brief A handler for pure receive. The buffer cannot be altered. */
+typedef int (span_rx_handler_t)(void *s, const int16_t amp[], int len);
+
+/*! \brief A handler for receive, where the buffer can be altered. */
+typedef int (span_mod_handler_t)(void *s, int16_t amp[], int len);
+
+/*! \brief A handler for transmit, where the buffer will be filled. */
+typedef int (span_tx_handler_t)(void *s, int16_t amp[], int max_len);
+
+#define ms_to_samples(t)    (((t)*SAMPLE_RATE)/1000)
+
+#if !defined(FALSE)
+#define FALSE 0
+#endif
+#if !defined(TRUE)
+#define TRUE (!FALSE)
+#endif
+
+#if defined(__cplusplus)
+/* C++ doesn't seem to have sane rounding functions/macros yet */
+#ifndef _MSC_VER
+#define lrint(x) ((long int) (x))
+#define lrintf(x) ((long int) (x))
+#endif
+#endif
+
+#endif
+/*- End of file ------------------------------------------------------------*/