--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/spandsp-0.0.6pre17/src/spandsp/lpc10.h	Fri Jun 25 15:50:58 2010 +0200
@@ -0,0 +1,120 @@
+/*
+ * SpanDSP - a series of DSP components for telephony
+ *
+ * lpc10.h - LPC10 low bit rate speech codec.
+ *
+ * Written by Steve Underwood <steveu@coppice.org>
+ *
+ * Copyright (C) 2006 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: lpc10.h,v 1.22 2009/04/11 18:11:19 steveu Exp $
+ */
+
+#if !defined(_SPANDSP_LPC10_H_)
+#define _SPANDSP_LPC10_H_
+
+/*! \page lpc10_page LPC10 encoding and decoding
+\section lpc10_page_sec_1 What does it do?
+The LPC10 module implements the US Department of Defense LPC10
+codec. This codec produces compressed data at 2400bps. At such
+a low rate high fidelity cannot be expected. However, the speech
+clarity is quite good, and this codec is unencumbered by patent
+or other restrictions.
+
+\section lpc10_page_sec_2 How does it work?
+???.
+*/
+
+#define LPC10_SAMPLES_PER_FRAME 180
+#define LPC10_BITS_IN_COMPRESSED_FRAME 54
+
+/*!
+    LPC10 codec unpacked frame.
+*/
+typedef struct
+{
+    /*! Pitch */
+    int32_t ipitch;
+    /*! Energy */
+    int32_t irms;
+    /*! Reflection coefficients */
+    int32_t irc[10];
+} lpc10_frame_t;
+
+/*!
+    LPC10 codec encoder state descriptor. This defines the state of
+    a single working instance of the LPC10 encoder.
+*/
+typedef struct lpc10_encode_state_s lpc10_encode_state_t;
+
+/*!
+    LPC10 codec decoder state descriptor. This defines the state of
+    a single working instance of the LPC10 decoder.
+*/
+typedef struct lpc10_decode_state_s lpc10_decode_state_t;
+
+#if defined(__cplusplus)
+extern "C"
+{
+#endif
+
+/*! Initialise an LPC10e encode context.
+    \param s The LPC10e context
+    \param error_correction ???
+    \return A pointer to the LPC10e context, or NULL for error. */
+SPAN_DECLARE(lpc10_encode_state_t *) lpc10_encode_init(lpc10_encode_state_t *s, int error_correction);
+
+SPAN_DECLARE(int) lpc10_encode_release(lpc10_encode_state_t *s);
+
+SPAN_DECLARE(int) lpc10_encode_free(lpc10_encode_state_t *s);
+
+/*! Encode a buffer of linear PCM data to LPC10e.
+    \param s The LPC10e context.
+    \param ima_data The LPC10e data produced.
+    \param amp The audio sample buffer.
+    \param len The number of samples in the buffer. This must be a multiple of 180, as
+           this is the number of samples on a frame.
+    \return The number of bytes of LPC10e data produced. */
+SPAN_DECLARE(int) lpc10_encode(lpc10_encode_state_t *s, uint8_t code[], const int16_t amp[], int len);
+
+/*! Initialise an LPC10e decode context.
+    \param s The LPC10e context
+    \param error_correction ???
+    \return A pointer to the LPC10e context, or NULL for error. */
+SPAN_DECLARE(lpc10_decode_state_t *) lpc10_decode_init(lpc10_decode_state_t *st, int error_correction);
+
+SPAN_DECLARE(int) lpc10_decode_release(lpc10_decode_state_t *s);
+
+SPAN_DECLARE(int) lpc10_decode_free(lpc10_decode_state_t *s);
+
+/*! Decode a buffer of LPC10e data to linear PCM.
+    \param s The LPC10e context.
+    \param amp The audio sample buffer.
+    \param code The LPC10e data.
+    \param len The number of bytes of LPC10e data to be decoded. This must be a multiple of 7,
+           as each frame is packed into 7 bytes.
+    \return The number of samples returned. */
+SPAN_DECLARE(int) lpc10_decode(lpc10_decode_state_t *s, int16_t amp[], const uint8_t code[], int len);
+
+
+#if defined(__cplusplus)
+}
+#endif
+
+#endif
+/*- End of include ---------------------------------------------------------*/