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 /****************************************************************************************
19 Portions 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)
26 Permission to distribute, modify and use this file under the standard license
27 terms listed above has been obtained from the copyright holder.
28 ****************************************************************************************/
29 /*
30 
31  Filename: /audio/gsm_amr/c/src/include/d_gain_c.h
32 
33 ------------------------------------------------------------------------------
34  REVISION HISTORY
35 
36  Description: Moved _cplusplus #ifdef after Include section.
37 
38  Who:                       Date:
39  Description:
40 
41 ------------------------------------------------------------------------------
42  INCLUDE DESCRIPTION
43 
44       File          : d_gain_c.h
45       Purpose       : Decode the fixed codebook gain using the received index.
46 
47 ------------------------------------------------------------------------------
48 */
49 
50 #ifndef _D_GAIN_C_H_
51 #define _D_GAIN_C_H_
52 #define d_gain_c_h "$Id $"
53 
54 /*----------------------------------------------------------------------------
55 ; INCLUDES
56 ----------------------------------------------------------------------------*/
57 #include "typedef.h"
58 #include "mode.h"
59 #include "gc_pred.h"
60 
61 /*--------------------------------------------------------------------------*/
62 #ifdef __cplusplus
63 extern "C"
64 {
65 #endif
66 
67     /*----------------------------------------------------------------------------
68     ; MACROS
69     ; [Define module specific macros here]
70     ----------------------------------------------------------------------------*/
71 
72     /*----------------------------------------------------------------------------
73     ; DEFINES
74     ; [Include all pre-processor statements here.]
75     ----------------------------------------------------------------------------*/
76 
77 
78     /*----------------------------------------------------------------------------
79     ; EXTERNAL VARIABLES REFERENCES
80     ; [Declare variables used in this module but defined elsewhere]
81     ----------------------------------------------------------------------------*/
82 
83     /*----------------------------------------------------------------------------
84     ; SIMPLE TYPEDEF'S
85     ----------------------------------------------------------------------------*/
86 
87     /*----------------------------------------------------------------------------
88     ; ENUMERATED TYPEDEF'S
89     ----------------------------------------------------------------------------*/
90 
91     /*----------------------------------------------------------------------------
92     ; STRUCTURES TYPEDEF'S
93     ----------------------------------------------------------------------------*/
94 
95 
96     /*----------------------------------------------------------------------------
97     ; GLOBAL FUNCTION DEFINITIONS
98     ; [List function prototypes here]
99     ----------------------------------------------------------------------------*/
100     /*
101      *  Function    : d_gain_code
102      *  Purpose     : Decode the fixed codebook gain using the received index.
103      *  Description : The received index gives the gain correction factor
104      *                gamma. The quantized gain is given by   g_q = g0 * gamma
105      *                where g0 is the predicted gain. To find g0, 4th order
106      *                MA prediction is applied to the mean-removed innovation
107      *                energy in dB.
108      *  Returns     : void
109      */
110     void d_gain_code(
111         gc_predState *pred_state, /* i/o : MA predictor state               */
112         enum Mode mode,           /* i   : AMR mode                         */
113         Word16 index,             /* i   : received quantization index      */
114         Word16 code[],            /* i   : innovation codevector            */
115         Word16 *gain_code,        /* o   : decoded innovation gain          */
116         Flag   *pOverflow
117     );
118 
119 #ifdef __cplusplus
120 }
121 #endif
122 
123 #endif  /* _D_GAIN_C_H_ */
124 
125 
126