1 /* ------------------------------------------------------------------
2 * Copyright (C) 1998-2009 PacketVideo
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
8 * http://www.apache.org/licenses/LICENSE-2.0
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
14 * See the License for the specific language governing permissions
15 * and limitations under the License.
16 * -------------------------------------------------------------------
18 /****************************************************************************************
19 Portions of this file are derived from the following 3GPP standard:
22 ANSI-C code for the Adaptive Multi-Rate (AMR) speech codec
23 Available from http://www.3gpp.org
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 ****************************************************************************************/
33 ------------------------------------------------------------------------------
37 Purpose : Decode the fixed codebook gain using the received index.
39 ------------------------------------------------------------------------------
44 #define d_gain_c_h "$Id $"
46 /*----------------------------------------------------------------------------
48 ----------------------------------------------------------------------------*/
53 /*--------------------------------------------------------------------------*/
59 /*----------------------------------------------------------------------------
61 ; [Define module specific macros here]
62 ----------------------------------------------------------------------------*/
64 /*----------------------------------------------------------------------------
66 ; [Include all pre-processor statements here.]
67 ----------------------------------------------------------------------------*/
70 /*----------------------------------------------------------------------------
71 ; EXTERNAL VARIABLES REFERENCES
72 ; [Declare variables used in this module but defined elsewhere]
73 ----------------------------------------------------------------------------*/
75 /*----------------------------------------------------------------------------
77 ----------------------------------------------------------------------------*/
79 /*----------------------------------------------------------------------------
80 ; ENUMERATED TYPEDEF'S
81 ----------------------------------------------------------------------------*/
83 /*----------------------------------------------------------------------------
84 ; STRUCTURES TYPEDEF'S
85 ----------------------------------------------------------------------------*/
88 /*----------------------------------------------------------------------------
89 ; GLOBAL FUNCTION DEFINITIONS
90 ; [List function prototypes here]
91 ----------------------------------------------------------------------------*/
93 * Function : d_gain_code
94 * Purpose : Decode the fixed codebook gain using the received index.
95 * Description : The received index gives the gain correction factor
96 * gamma. The quantized gain is given by g_q = g0 * gamma
97 * where g0 is the predicted gain. To find g0, 4th order
98 * MA prediction is applied to the mean-removed innovation
103 gc_predState *pred_state, /* i/o : MA predictor state */
104 enum Mode mode, /* i : AMR mode */
105 Word16 index, /* i : received quantization index */
106 Word16 code[], /* i : innovation codevector */
107 const Word16* qua_gain_code_ptr, /* i : Pointer to read-only table */
108 Word16 *gain_code, /* o : decoded innovation gain */
116 #endif /* _D_GAIN_C_H_ */