1 
2 /*
3  ** Copyright 2003-2010, VisualOn, Inc.
4  **
5  ** Licensed under the Apache License, Version 2.0 (the "License");
6  ** you may not use this file except in compliance with the License.
7  ** You may obtain a copy of the License at
8  **
9  **     http://www.apache.org/licenses/LICENSE-2.0
10  **
11  ** Unless required by applicable law or agreed to in writing, software
12  ** distributed under the License is distributed on an "AS IS" BASIS,
13  ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  ** See the License for the specific language governing permissions and
15  ** limitations under the License.
16  */
17 
18 
19 /********************************************************************************
20 *
21 *      File             : log2.h
22 *      Purpose          : Computes log2(L_x)
23 *
24 ********************************************************************************
25 */
26 #ifndef __LOG2_H__
27 #define __LOG2_H__
28 
29 /*
30 ********************************************************************************
31 *                         INCLUDE FILES
32 ********************************************************************************
33 */
34 #include "typedef.h"
35 
36 /*
37 ********************************************************************************
38 *                         DEFINITION OF DATA TYPES
39 ********************************************************************************
40 */
41 
42 /*
43 ********************************************************************************
44 *                         DECLARATION OF PROTOTYPES
45 ********************************************************************************
46 */
47 void Log2 (
48         Word32 L_x,        /* (i) : input value                                 */
49         Word16 *exponent,  /* (o) : Integer part of Log2.   (range: 0<=val<=30) */
50         Word16 *fraction   /* (o) : Fractional part of Log2. (range: 0<=val<1)*/
51       );
52 
53 void Log2_norm (
54         Word32 L_x,         /* (i) : input value (normalized)                    */
55         Word16 exp,         /* (i) : norm_l (L_x)                                */
56         Word16 *exponent,   /* (o) : Integer part of Log2.   (range: 0<=val<=30) */
57         Word16 *fraction    /* (o) : Fractional part of Log2. (range: 0<=val<1)  */
58            );
59 
60 #endif  //__LOG2_H__
61 
62 
63