--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/spandsp-0.0.6pre17/src/spandsp/v22bis.h	Fri Jun 25 15:50:58 2010 +0200
@@ -0,0 +1,225 @@
+/*
+ * SpanDSP - a series of DSP components for telephony
+ *
+ * v22bis.h - ITU V.22bis modem
+ *
+ * Written by Steve Underwood <steveu@coppice.org>
+ *
+ * Copyright (C) 2004 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: v22bis.h,v 1.46 2009/11/04 15:52:06 steveu Exp $
+ */
+
+/*! \file */
+
+/*! \page v22bis_page The V.22bis modem
+\section v22bis_page_sec_1 What does it do?
+The V.22bis modem is a duplex modem for general data use on the PSTN, at rates
+of 1200 and 2400 bits/second. It is a compatible extension of the V.22 modem,
+which is a 1200 bits/second only design. It is a band-split design, using carriers
+of 1200Hz and 2400Hz. It is the fastest PSTN modem in general use which does not
+use echo-cancellation.
+
+\section v22bis__page_sec_2 How does it work?
+V.22bis uses 4PSK modulation at 1200 bits/second or 16QAM modulation at 2400
+bits/second. At 1200bps the symbols are so long that a fixed compromise equaliser
+is sufficient to recover the 4PSK signal reliably. At 2400bps an adaptive
+equaliser is necessary.
+
+The V.22bis training sequence includes sections which allow the modems to determine
+if the far modem can support (or is willing to support) 2400bps operation. The
+modems will automatically use 2400bps if both ends are willing to use that speed,
+or 1200bps if one or both ends to not acknowledge that 2400bps is OK.
+*/
+
+#if !defined(_SPANDSP_V22BIS_H_)
+#define _SPANDSP_V22BIS_H_
+
+enum
+{
+    V22BIS_GUARD_TONE_NONE,
+    V22BIS_GUARD_TONE_550HZ,
+    V22BIS_GUARD_TONE_1800HZ
+};
+
+/*!
+    V.22bis modem descriptor. This defines the working state for a single instance
+    of a V.22bis modem.
+*/
+typedef struct v22bis_state_s v22bis_state_t;
+
+extern const complexf_t v22bis_constellation[16];
+
+#if defined(__cplusplus)
+extern "C"
+{
+#endif
+
+/*! Process a block of received V.22bis modem audio samples.
+    \brief Process a block of received V.22bis modem audio samples.
+    \param s The modem context.
+    \param amp The audio sample buffer.
+    \param len The number of samples in the buffer.
+    \return The number of samples unprocessed. */
+SPAN_DECLARE_NONSTD(int) v22bis_rx(v22bis_state_t *s, const int16_t amp[], int len);
+
+/*! Fake processing of a missing block of received V.22bis modem audio samples.
+    (e.g due to packet loss).
+    \brief Fake processing of a missing block of received V.22bis modem audio samples.
+    \param s The modem context.
+    \param len The number of samples to fake.
+    \return The number of samples unprocessed. */
+SPAN_DECLARE(int) v22bis_rx_fillin(v22bis_state_t *s, int len);
+
+/*! Get a snapshot of the current equalizer coefficients.
+    \brief Get a snapshot of the current equalizer coefficients.
+    \param coeffs The vector of complex coefficients.
+    \return The number of coefficients in the vector. */
+SPAN_DECLARE(int) v22bis_rx_equalizer_state(v22bis_state_t *s, complexf_t **coeffs);
+
+/*! Get the current received carrier frequency.
+    \param s The modem context.
+    \return The frequency, in Hertz. */
+SPAN_DECLARE(float) v22bis_rx_carrier_frequency(v22bis_state_t *s);
+
+/*! Get the current symbol timing correction since startup.
+    \param s The modem context.
+    \return The correction. */
+SPAN_DECLARE(float) v22bis_rx_symbol_timing_correction(v22bis_state_t *s);
+
+/*! Get a current received signal power.
+    \param s The modem context.
+    \return The signal power, in dBm0. */
+SPAN_DECLARE(float) v22bis_rx_signal_power(v22bis_state_t *s);
+
+/*! Set the power level at which the carrier detection will cut in
+    \param s The modem context.
+    \param cutoff The signal cutoff power, in dBm0. */
+SPAN_DECLARE(void) v22bis_rx_signal_cutoff(v22bis_state_t *s, float cutoff);
+
+/*! Set a handler routine to process QAM status reports
+    \param s The modem context.
+    \param handler The handler routine.
+    \param user_data An opaque pointer passed to the handler routine. */
+SPAN_DECLARE(void) v22bis_rx_set_qam_report_handler(v22bis_state_t *s, qam_report_handler_t handler, void *user_data);
+
+/*! Generate a block of V.22bis modem audio samples.
+    \brief Generate a block of V.22bis modem audio samples.
+    \param s The modem context.
+    \param amp The audio sample buffer.
+    \param len The number of samples to be generated.
+    \return The number of samples actually generated. */
+SPAN_DECLARE_NONSTD(int) v22bis_tx(v22bis_state_t *s, int16_t amp[], int len);
+
+/*! Adjust a V.22bis modem transmit context's power output.
+    \brief Adjust a V.22bis modem transmit context's output power.
+    \param s The modem context.
+    \param power The power level, in dBm0 */
+SPAN_DECLARE(void) v22bis_tx_power(v22bis_state_t *s, float power);
+
+/*! Reinitialise an existing V.22bis modem context, so it may be reused.
+    \brief Reinitialise an existing V.22bis modem context.
+    \param s The modem context.
+    \param bit_rate The bit rate of the modem. Valid values are 1200 and 2400.
+    \return 0 for OK, -1 for bad parameter. */
+SPAN_DECLARE(int) v22bis_restart(v22bis_state_t *s, int bit_rate);
+
+/*! Request a retrain for a V.22bis modem context. A rate change may also be requested.
+    \brief Request a retrain for a V.22bis modem context.
+    \param s The modem context.
+    \param bit_rate The bit rate of the modem. Valid values are 1200 and 2400.
+    \return 0 for OK, -1 for request rejected. */
+SPAN_DECLARE(int) v22bis_request_retrain(v22bis_state_t *s, int bit_rate);
+
+/*! Request a loopback 2 for a V.22bis modem context.
+    \brief Request a loopback 2 for a V.22bis modem context.
+    \param s The modem context.
+    \param enable TRUE to enable loopback, or FALSE to disable it.
+    \return 0 for OK, -1 for request reject. */
+SPAN_DECLARE(int) v22bis_remote_loopback(v22bis_state_t *s, int enable);
+
+/*! Report the current operating bit rate of a V.22bis modem context.
+    \brief Report the current operating bit rate of a V.22bis modem context
+    \param s The modem context. */
+SPAN_DECLARE(int) v22bis_current_bit_rate(v22bis_state_t *s);
+
+/*! Initialise a V.22bis modem context. This must be called before the first
+    use of the context, to initialise its contents.
+    \brief Initialise a V.22bis modem context.
+    \param s The modem context.
+    \param bit_rate The bit rate of the modem. Valid values are 1200 and 2400.
+    \param guard The guard tone option. 0 = none, 1 = 550Hz, 2 = 1800Hz.
+    \param calling_party TRUE if this is the calling modem.
+    \param get_bit The callback routine used to get the data to be transmitted.
+    \param put_bit The callback routine used to get the data to be transmitted.
+    \param user_data An opaque pointer, passed in calls to the get and put routines.
+    \return A pointer to the modem context, or NULL if there was a problem. */
+SPAN_DECLARE(v22bis_state_t *) v22bis_init(v22bis_state_t *s,
+                                           int bit_rate,
+                                           int guard,
+                                           int calling_party,
+                                           get_bit_func_t get_bit,
+                                           void *get_bit_user_data,
+                                           put_bit_func_t put_bit,
+                                           void *put_bit_user_data);
+
+/*! Release a V.22bis modem receive context.
+    \brief Release a V.22bis modem receive context.
+    \param s The modem context.
+    \return 0 for OK */
+SPAN_DECLARE(int) v22bis_release(v22bis_state_t *s);
+
+/*! Free a V.22bis modem receive context.
+    \brief Free a V.22bis modem receive context.
+    \param s The modem context.
+    \return 0 for OK */
+SPAN_DECLARE(int) v22bis_free(v22bis_state_t *s);
+
+/*! Get the logging context associated with a V.22bis modem context.
+    \brief Get the logging context associated with a V.22bis modem context.
+    \param s The modem context.
+    \return A pointer to the logging context */
+SPAN_DECLARE(logging_state_t *) v22bis_get_logging_state(v22bis_state_t *s);
+
+/*! Change the get_bit function associated with a V.22bis modem context.
+    \brief Change the get_bit function associated with a V.22bis modem context.
+    \param s The modem context.
+    \param get_bit The callback routine used to get the data to be transmitted.
+    \param user_data An opaque pointer. */
+SPAN_DECLARE(void) v22bis_set_get_bit(v22bis_state_t *s, get_bit_func_t get_bit, void *user_data);
+
+/*! Change the get_bit function associated with a V.22bis modem context.
+    \brief Change the put_bit function associated with a V.22bis modem context.
+    \param s The modem context.
+    \param put_bit The callback routine used to process the data received.
+    \param user_data An opaque pointer. */
+SPAN_DECLARE(void) v22bis_set_put_bit(v22bis_state_t *s, put_bit_func_t put_bit, void *user_data);
+
+/*! Change the modem status report function associated with a V.22bis modem receive context.
+    \brief Change the modem status report function associated with a V.22bis modem receive context.
+    \param s The modem context.
+    \param handler The callback routine used to report modem status changes.
+    \param user_data An opaque pointer. */
+SPAN_DECLARE(void) v22bis_set_modem_status_handler(v22bis_state_t *s, modem_rx_status_func_t handler, void *user_data);
+
+#if defined(__cplusplus)
+}
+#endif
+
+#endif
+/*- End of file ------------------------------------------------------------*/