--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/spandsp-0.0.6pre17/src/spandsp/v42bis.h	Fri Jun 25 15:50:58 2010 +0200
@@ -0,0 +1,143 @@
+/*
+ * SpanDSP - a series of DSP components for telephony
+ *
+ * v42bis.h
+ *
+ * Written by Steve Underwood <steveu@coppice.org>
+ *
+ * Copyright (C) 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: v42bis.h,v 1.27 2009/04/11 18:11:19 steveu Exp $
+ */
+
+/*! \page v42bis_page V.42bis modem data compression
+\section v42bis_page_sec_1 What does it do?
+The v.42bis specification defines a data compression scheme, to work in
+conjunction with the error correction scheme defined in V.42.
+
+\section v42bis_page_sec_2 How does it work?
+*/
+
+#if !defined(_SPANDSP_V42BIS_H_)
+#define _SPANDSP_V42BIS_H_
+
+#define V42BIS_MAX_BITS         12
+#define V42BIS_MAX_CODEWORDS    4096    /* 2^V42BIS_MAX_BITS */
+#define V42BIS_TABLE_SIZE       5021    /* This should be a prime >(2^V42BIS_MAX_BITS) */
+#define V42BIS_MAX_STRING_SIZE  250
+
+enum
+{
+    V42BIS_P0_NEITHER_DIRECTION = 0,
+    V42BIS_P0_INITIATOR_RESPONDER,
+    V42BIS_P0_RESPONDER_INITIATOR,
+    V42BIS_P0_BOTH_DIRECTIONS
+};
+
+enum
+{
+    V42BIS_COMPRESSION_MODE_DYNAMIC = 0,
+    V42BIS_COMPRESSION_MODE_ALWAYS,
+    V42BIS_COMPRESSION_MODE_NEVER
+};
+
+typedef void (*v42bis_frame_handler_t)(void *user_data, const uint8_t *pkt, int len);
+typedef void (*v42bis_data_handler_t)(void *user_data, const uint8_t *buf, int len);
+
+/*!
+    V.42bis compression/decompression descriptor. This defines the working state for a
+    single instance of V.42bis compress/decompression.
+*/
+typedef struct v42bis_state_s v42bis_state_t;
+
+#if defined(__cplusplus)
+extern "C"
+{
+#endif
+
+/*! Compress a block of octets.
+    \param s The V.42bis context.
+    \param buf The data to be compressed.
+    \param len The length of the data buffer.
+    \return 0 */
+SPAN_DECLARE(int) v42bis_compress(v42bis_state_t *s, const uint8_t *buf, int len);
+
+/*! Flush out any data remaining in a compression buffer.
+    \param s The V.42bis context.
+    \return 0 */
+SPAN_DECLARE(int) v42bis_compress_flush(v42bis_state_t *s);
+
+/*! Decompress a block of octets.
+    \param s The V.42bis context.
+    \param buf The data to be decompressed.
+    \param len The length of the data buffer.
+    \return 0 */
+SPAN_DECLARE(int) v42bis_decompress(v42bis_state_t *s, const uint8_t *buf, int len);
+    
+/*! Flush out any data remaining in the decompression buffer.
+    \param s The V.42bis context.
+    \return 0 */
+SPAN_DECLARE(int) v42bis_decompress_flush(v42bis_state_t *s);
+
+/*! Set the compression mode.
+    \param s The V.42bis context.
+    \param mode One of the V.42bis compression modes -
+            V42BIS_COMPRESSION_MODE_DYNAMIC,
+            V42BIS_COMPRESSION_MODE_ALWAYS,
+            V42BIS_COMPRESSION_MODE_NEVER */
+SPAN_DECLARE(void) v42bis_compression_control(v42bis_state_t *s, int mode);
+
+/*! Initialise a V.42bis context.
+    \param s The V.42bis context.
+    \param negotiated_p0 The negotiated P0 parameter, from the V.42bis spec.
+    \param negotiated_p1 The negotiated P1 parameter, from the V.42bis spec.
+    \param negotiated_p2 The negotiated P2 parameter, from the V.42bis spec.
+    \param frame_handler Frame callback handler.
+    \param frame_user_data An opaque pointer passed to the frame callback handler.
+    \param max_frame_len The maximum length that should be passed to the frame handler.
+    \param data_handler data callback handler.
+    \param data_user_data An opaque pointer passed to the data callback handler.
+    \param max_data_len The maximum length that should be passed to the data handler.
+    \return The V.42bis context. */
+SPAN_DECLARE(v42bis_state_t *) v42bis_init(v42bis_state_t *s,
+                                           int negotiated_p0,
+                                           int negotiated_p1,
+                                           int negotiated_p2,
+                                           v42bis_frame_handler_t frame_handler,
+                                           void *frame_user_data,
+                                           int max_frame_len,
+                                           v42bis_data_handler_t data_handler,
+                                           void *data_user_data,
+                                           int max_data_len);
+
+/*! Release a V.42bis context.
+    \param s The V.42bis context.
+    \return 0 if OK */
+SPAN_DECLARE(int) v42bis_release(v42bis_state_t *s);
+
+/*! Free a V.42bis context.
+    \param s The V.42bis context.
+    \return 0 if OK */
+SPAN_DECLARE(int) v42bis_free(v42bis_state_t *s);
+
+#if defined(__cplusplus)
+}
+#endif
+
+#endif
+/*- End of file ------------------------------------------------------------*/