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 ****************************************************************************************/
30 ------------------------------------------------------------------------------
36 ------------------------------------------------------------------------------
40 Purpose : Convert from direct form coefficients to
41 reflection coefficients
43 ------------------------------------------------------------------------------
48 #define a_refl_h "$Id $"
50 /*----------------------------------------------------------------------------
52 ----------------------------------------------------------------------------*/
55 /*--------------------------------------------------------------------------*/
61 /*----------------------------------------------------------------------------
63 ; Define module specific macros here
64 ----------------------------------------------------------------------------*/
66 /*----------------------------------------------------------------------------
68 ; Include all pre-processor statements here.
69 ----------------------------------------------------------------------------*/
71 /*----------------------------------------------------------------------------
72 ; EXTERNAL VARIABLES REFERENCES
73 ; Declare variables used in this module but defined elsewhere
74 ----------------------------------------------------------------------------*/
76 /*----------------------------------------------------------------------------
78 ----------------------------------------------------------------------------*/
80 /*----------------------------------------------------------------------------
81 ; ENUMERATED TYPEDEF'S
82 ----------------------------------------------------------------------------*/
84 /*----------------------------------------------------------------------------
85 ; STRUCTURES TYPEDEF'S
86 ----------------------------------------------------------------------------*/
88 /*----------------------------------------------------------------------------
89 ; GLOBAL FUNCTION DEFINITIONS
90 ; Function Prototype declaration
91 ----------------------------------------------------------------------------*/
94 * PURPOSE: Convert from direct form coefficients to reflection coefficients
96 * Directform coeffs in Q12 are converted to
97 * reflection coefficients Q15
100 Word16 a[], /* i : Directform coefficients */
101 Word16 refl[], /* o : Reflection coefficients */
105 /*----------------------------------------------------------------------------
107 ----------------------------------------------------------------------------*/
112 #endif /* _A_REFL_H_ */