--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/spandsp-0.0.6pre17/src/spandsp/private/dtmf.h	Fri Jun 25 15:50:58 2010 +0200
@@ -0,0 +1,111 @@
+/*
+ * SpanDSP - a series of DSP components for telephony
+ *
+ * private/dtmf.h - DTMF tone generation and detection 
+ *
+ * Written by Steve Underwood <steveu@coppice.org>
+ *
+ * Copyright (C) 2001, 2005 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: dtmf.h,v 1.1 2008/10/13 13:14:01 steveu Exp $
+ */
+
+#if !defined(_SPANDSP_PRIVATE_DTMF_H_)
+#define _SPANDSP_PRIVATE_DTMF_H_
+
+/*!
+    DTMF generator state descriptor. This defines the state of a single
+    working instance of a DTMF generator.
+*/
+struct dtmf_tx_state_s
+{
+    tone_gen_state_t tones;
+    float low_level;
+    float high_level;
+    int on_time;
+    int off_time;
+    union
+    {
+        queue_state_t queue;
+        uint8_t buf[QUEUE_STATE_T_SIZE(MAX_DTMF_DIGITS)];
+    } queue;
+};
+
+/*!
+    DTMF digit detector descriptor.
+*/
+struct dtmf_rx_state_s
+{
+    /*! Optional callback funcion to deliver received digits. */
+    digits_rx_callback_t digits_callback;
+    /*! An opaque pointer passed to the callback function. */
+    void *digits_callback_data;
+    /*! Optional callback funcion to deliver real time digit state changes. */
+    tone_report_func_t realtime_callback;
+    /*! An opaque pointer passed to the real time callback function. */
+    void *realtime_callback_data;
+    /*! TRUE if dialtone should be filtered before processing */
+    int filter_dialtone;
+#if defined(SPANDSP_USE_FIXED_POINT)
+    /*! 350Hz filter state for the optional dialtone filter. */
+    float z350[2];
+    /*! 440Hz filter state for the optional dialtone filter. */
+    float z440[2];
+    /*! Maximum acceptable "normal" (lower bigger than higher) twist ratio. */
+    float normal_twist;
+    /*! Maximum acceptable "reverse" (higher bigger than lower) twist ratio. */
+    float reverse_twist;
+    /*! Minimum acceptable tone level for detection. */
+    int32_t threshold;
+    /*! The accumlating total energy on the same period over which the Goertzels work. */
+    int32_t energy;
+#else
+    /*! 350Hz filter state for the optional dialtone filter. */
+    float z350[2];
+    /*! 440Hz filter state for the optional dialtone filter. */
+    float z440[2];
+    /*! Maximum acceptable "normal" (lower bigger than higher) twist ratio. */
+    float normal_twist;
+    /*! Maximum acceptable "reverse" (higher bigger than lower) twist ratio. */
+    float reverse_twist;
+    /*! Minimum acceptable tone level for detection. */
+    float threshold;
+    /*! The accumlating total energy on the same period over which the Goertzels work. */
+    float energy;
+#endif
+    /*! Tone detector working states for the row tones. */
+    goertzel_state_t row_out[4];
+    /*! Tone detector working states for the column tones. */
+    goertzel_state_t col_out[4];
+    /*! The result of the last tone analysis. */
+    uint8_t last_hit;
+    /*! The confirmed digit we are currently receiving */
+    uint8_t in_digit;
+    /*! The current sample number within a processing block. */
+    int current_sample;
+
+    /*! The number of digits which have been lost due to buffer overflows. */
+    int lost_digits;
+    /*! The number of digits currently in the digit buffer. */
+    int current_digits;
+    /*! The received digits buffer. This is a NULL terminated string. */
+    char digits[MAX_DTMF_DIGITS + 1];
+};
+
+#endif
+/*- End of file ------------------------------------------------------------*/