bgnscd.h revision 4f1efc098cb5791c3e9f483f2af84aef70d2d0a0 
1/* ------------------------------------------------------------------
2 * Copyright (C) 1998-2009 PacketVideo
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
13 * express or implied.
14 * See the License for the specific language governing permissions
15 * and limitations under the License.
16 * -------------------------------------------------------------------
17 */
18/****************************************************************************************
19Portions of this file are derived from the following 3GPP standard:
20
21    3GPP TS 26.073
22    ANSI-C code for the Adaptive Multi-Rate (AMR) speech codec
23    Available from http://www.3gpp.org
24
25(C) 2004, 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TTA, TTC)
26Permission to distribute, modify and use this file under the standard license
27terms listed above has been obtained from the copyright holder.
28****************************************************************************************/
29/*
30------------------------------------------------------------------------------
31
32
33
34 Filename: /audio/gsm_amr/c/src/include/bgnscd.h
35
36     Date: 12/29/2002
37
38------------------------------------------------------------------------------
39 REVISION HISTORY
40
41 Description: Moved _cplusplus #ifdef after Include section.
42
43 Description:
44
45------------------------------------------------------------------------------
46 INCLUDE DESCRIPTION
47
48      File             : bgnscd.h
49      Purpose          : Background noise source charateristic detector (SCD)
50
51------------------------------------------------------------------------------
52*/
53
54#ifndef _BGNSCD_H_
55#define _BGNSCD_H_
56
57/*----------------------------------------------------------------------------
58; INCLUDES
59----------------------------------------------------------------------------*/
60#include "typedef.h"
61#include "cnst.h"
62
63/*--------------------------------------------------------------------------*/
64#ifdef __cplusplus
65extern "C"
66{
67#endif
68
69    /*----------------------------------------------------------------------------
70    ; MACROS
71    ; [Define module specific macros here]
72    ----------------------------------------------------------------------------*/
73
74    /*----------------------------------------------------------------------------
75    ; DEFINES
76    ; [Include all pre-processor statements here.]
77    ----------------------------------------------------------------------------*/
78#define L_ENERGYHIST 60
79#define INV_L_FRAME 102
80
81
82    /* 2*(160*x)^2 / 65536  where x is FLP values 150,5 and 50 */
83#define FRAMEENERGYLIMIT  17578         /* 150 */
84#define LOWERNOISELIMIT      20         /*   5 */
85#define UPPERNOISELIMIT    1953         /*  50 */
86
87
88    /*----------------------------------------------------------------------------
89    ; EXTERNAL VARIABLES REFERENCES
90    ; [Declare variables used in this module but defined elsewhere]
91    ----------------------------------------------------------------------------*/
92
93    /*----------------------------------------------------------------------------
94    ; SIMPLE TYPEDEF'S
95    ----------------------------------------------------------------------------*/
96
97    /*----------------------------------------------------------------------------
98    ; ENUMERATED TYPEDEF'S
99    ----------------------------------------------------------------------------*/
100
101    /*----------------------------------------------------------------------------
102    ; STRUCTURES TYPEDEF'S
103    ----------------------------------------------------------------------------*/
104    typedef struct
105    {
106        /* history vector of past synthesis speech energy */
107        Word16 frameEnergyHist[L_ENERGYHIST];
108
109        /* state flags */
110        Word16 bgHangover; /* counter; number of frames after last speech frame */
111
112    } Bgn_scdState;
113
114    /*----------------------------------------------------------------------------
115    ; GLOBAL FUNCTION DEFINITIONS
116    ; [List function prototypes here]
117    ----------------------------------------------------------------------------*/
118    /*
119     *  Function    : Bgn_scd_init
120     *  Purpose     : Allocates initializes state memory
121     *  Description : Stores pointer to filter status struct in *st. This
122     *                pointer has to be passed to Bgn_scd in each call.
123     *  Returns     : 0 on success
124     */
125    Word16 Bgn_scd_init(Bgn_scdState **st);
126
127    /*
128     *  Function    : Bgn_scd_reset
129     *  Purpose     : Resets state memory
130     *  Returns     : 0 on success
131     */
132    Word16 Bgn_scd_reset(Bgn_scdState *st);
133
134    /*
135     *  Function    : Bgn_scd_exit
136     *  Purpose     : The memory used for state memory is freed
137     *  Description : Stores NULL in *s
138     *  Returns     : void
139     */
140    void Bgn_scd_exit(Bgn_scdState **st);
141
142    /*
143     *  Function    : Bgn_scd
144     *  Purpose     : Charaterice synthesis speech and detect background noise
145     *  Returns     : background noise decision; 0 = bgn, 1 = no bgn
146     */
147    Word16 Bgn_scd(Bgn_scdState *st,       /* i : State variables for bgn SCD         */
148                   Word16 ltpGainHist[],  /* i : LTP gain history                    */
149                   Word16 speech[],       /* o : synthesis speech frame              */
150                   Word16 *voicedHangover,/* o : # of frames after last voiced frame */
151                   Flag   *pOverflow
152                  );
153
154
155#ifdef __cplusplus
156}
157#endif
158
159#endif  /* _BGNSCD_H_ */
160