--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/spandsp-0.0.3/spandsp-0.0.3/src/spandsp/g722.h	Fri Jun 25 16:00:21 2010 +0200
@@ -0,0 +1,179 @@
+/*
+ * SpanDSP - a series of DSP components for telephony
+ *
+ * g722.h - The ITU G.722 codec.
+ *
+ * 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 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.
+ *
+ * Based on a single channel G.722 codec which is:
+ *
+ *****    Copyright (c) CMU    1993      *****
+ * Computer Science, Speech Group
+ * Chengxiang Lu and Alex Hauptmann
+ *
+ * $Id: g722.h,v 1.13 2006/10/24 13:45:28 steveu Exp $
+ */
+
+
+/*! \file */
+
+#if !defined(_G722_H_)
+#define _G722_H_
+
+/*! \page g722_page G.722 encoding and decoding
+\section g722_page_sec_1 What does it do?
+The G.722 module is a bit exact implementation of the ITU G.722 specification for all three
+specified bit rates - 64000bps, 56000bps and 48000bps. It passes the ITU tests.
+
+To allow fast and flexible interworking with narrow band telephony, the encoder and decoder
+support an option for the linear audio to be an 8k samples/second stream. In this mode the
+codec is considerably faster, and still fully compatible with wideband terminals using G.722.
+
+\section g722_page_sec_2 How does it work?
+???.
+*/
+
+enum
+{
+    G722_SAMPLE_RATE_8000 = 0x0001,
+    G722_PACKED = 0x0002
+};
+
+typedef struct
+{
+    /*! TRUE if the operating in the special ITU test mode, with the band split filters
+             disabled. */
+    int itu_test_mode;
+    /*! TRUE if the G.722 data is packed */
+    int packed;
+    /*! TRUE if encode from 8k samples/second */
+    int eight_k;
+    /*! 6 for 48000kbps, 7 for 56000kbps, or 8 for 64000kbps. */
+    int bits_per_sample;
+
+    /*! Signal history for the QMF */
+    int x[24];
+
+    struct
+    {
+        int s;
+        int sp;
+        int sz;
+        int r[3];
+        int a[3];
+        int ap[3];
+        int p[3];
+        int d[7];
+        int b[7];
+        int bp[7];
+        int sg[7];
+        int nb;
+        int det;
+    } band[2];
+
+    unsigned int in_buffer;
+    int in_bits;
+    unsigned int out_buffer;
+    int out_bits;
+} g722_encode_state_t;
+
+typedef struct
+{
+    /*! TRUE if the operating in the special ITU test mode, with the band split filters
+             disabled. */
+    int itu_test_mode;
+    /*! TRUE if the G.722 data is packed */
+    int packed;
+    /*! TRUE if decode to 8k samples/second */
+    int eight_k;
+    /*! 6 for 48000kbps, 7 for 56000kbps, or 8 for 64000kbps. */
+    int bits_per_sample;
+
+    /*! Signal history for the QMF */
+    int x[24];
+
+    struct
+    {
+        int s;
+        int sp;
+        int sz;
+        int r[3];
+        int a[3];
+        int ap[3];
+        int p[3];
+        int d[7];
+        int b[7];
+        int bp[7];
+        int sg[7];
+        int nb;
+        int det;
+    } band[2];
+    
+    unsigned int in_buffer;
+    int in_bits;
+    unsigned int out_buffer;
+    int out_bits;
+} g722_decode_state_t;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*! Initialise an G.722 encode context.
+    \param s The G.722 encode context.
+    \param rate The required bit rate for the G.722 data.
+           The valid rates are 64000, 56000 and 48000.
+    \param options
+    \return A pointer to the G.722 encode context, or NULL for error. */
+g722_encode_state_t *g722_encode_init(g722_encode_state_t *s, int rate, int options);
+
+int g722_encode_release(g722_encode_state_t *s);
+
+/*! Encode a buffer of linear PCM data to G.722
+    \param s The G.722 context.
+    \param g722_data The G.722 data produced.
+    \param amp The audio sample buffer.
+    \param len The number of samples in the buffer.
+    \return The number of bytes of G.722 data produced. */
+int g722_encode(g722_encode_state_t *s, uint8_t g722_data[], const int16_t amp[], int len);
+
+/*! Initialise an G.722 decode context.
+    \param s The G.722 decode context.
+    \param rate The bit rate of the G.722 data.
+           The valid rates are 64000, 56000 and 48000.
+    \param options
+    \return A pointer to the G.722 decode context, or NULL for error. */
+g722_decode_state_t *g722_decode_init(g722_decode_state_t *s, int rate, int options);
+
+int g722_decode_release(g722_decode_state_t *s);
+
+/*! Decode a buffer of G.722 data to linear PCM.
+    \param s The G.722 context.
+    \param amp The audio sample buffer.
+    \param g722_data
+    \param len
+    \return The number of samples returned. */
+int g722_decode(g722_decode_state_t *s, int16_t amp[], const uint8_t g722_data[], int len);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif