log2.h

Trolltech公司发布的图形界面操作系统。可在qt-embedded-2.3.10平台上编译为嵌入式图形界面操作系统。

/**********************************************************************
** Copyright (C) 2000-2005 Trolltech AS and its licensors.
** All rights reserved.
**
** This file is part of the Qtopia Environment.
**
** This file may be distributed and/or modified under the terms of the
** GNU General Public License version 2 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
** See http://www.trolltech.com/gpl/ for GPL licensing information.
** See below for additional copyright and license information
**
** Contact [e-mail] if any conditions of this licensing are
** not clear to you.
**
**********************************************************************/
/*
********************************************************************************
*
*      GSM AMR-NB speech codec   R98   Version 7.6.0   December 12, 2001
*                                R99   Version 3.3.0                
*                                REL-4 Version 4.1.0                
*
********************************************************************************
*
*      File             : log2.h
*      Purpose          : Computes log2(L_x)
*
********************************************************************************
*/
#ifndef log2_h
#define log2_h "$Id $"
 
/*
********************************************************************************
*                         INCLUDE FILES
********************************************************************************
*/
#include "typedef.h"
 
/*
********************************************************************************
*                         DEFINITION OF DATA TYPES
********************************************************************************
*/
 
/*
********************************************************************************
*                         DECLARATION OF PROTOTYPES
********************************************************************************
*/
void Log2 (
    Word32 L_x,        /* (i) : input value                                 */
    Word16 *exponent,  /* (o) : Integer part of Log2.   (range: 0<=val<=30) */
    Word16 *fraction   /* (o) : Fractional part of Log2. (range: 0<=val<1)*/
);

void Log2_norm (
    Word32 L_x,         /* (i) : input value (normalized)                    */
    Word16 exp,         /* (i) : norm_l (L_x)                                */
    Word16 *exponent,   /* (o) : Integer part of Log2.   (range: 0<=val<=30) */
    Word16 *fraction    /* (o) : Fractional part of Log2. (range: 0<=val<1)  */
);

#endif