aboutsummaryrefslogtreecommitdiffstats
path: root/trunk/codecs/g722/g722.h
diff options
context:
space:
mode:
Diffstat (limited to 'trunk/codecs/g722/g722.h')
-rw-r--r--trunk/codecs/g722/g722.h148
1 files changed, 148 insertions, 0 deletions
diff --git a/trunk/codecs/g722/g722.h b/trunk/codecs/g722/g722.h
new file mode 100644
index 000000000..f57b1c882
--- /dev/null
+++ b/trunk/codecs/g722/g722.h
@@ -0,0 +1,148 @@
+/*
+ * 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
+ *
+ * Despite my general liking of the GPL, I place my own contributions
+ * to this code in the public domain for the benefit of all mankind -
+ * even the slimy ones who might try to proprietize my work and use it
+ * to my detriment.
+ *
+ * Based on a single channel G.722 codec which is:
+ *
+ ***** Copyright (c) CMU 1993 *****
+ * Computer Science, Speech Group
+ * Chengxiang Lu and Alex Hauptmann
+ *
+ * $Id$
+ */
+
+
+/*! \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
+};
+
+#ifndef INT16_MAX
+#define INT16_MAX 32767
+#endif
+#ifndef INT16_MIN
+#define INT16_MIN (-32768)
+#endif
+
+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
+
+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);
+int g722_encode(g722_encode_state_t *s, uint8_t g722_data[], const int16_t amp[], int len);
+
+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);
+int g722_decode(g722_decode_state_t *s, int16_t amp[], const uint8_t g722_data[], int len);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif