122 lines
4.3 KiB
C
122 lines
4.3 KiB
C
/*
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* Copyright (c) 1999-2000 Image Power, Inc. and the University of
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* British Columbia.
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* Copyright (c) 2001-2002 Michael David Adams.
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* All rights reserved.
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*/
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/* __START_OF_JASPER_LICENSE__
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*
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* JasPer License Version 2.0
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*
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* Copyright (c) 2001-2006 Michael David Adams
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* Copyright (c) 1999-2000 Image Power, Inc.
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* Copyright (c) 1999-2000 The University of British Columbia
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*
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* All rights reserved.
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*
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* Permission is hereby granted, free of charge, to any person (the
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* "User") obtaining a copy of this software and associated documentation
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* files (the "Software"), to deal in the Software without restriction,
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* including without limitation the rights to use, copy, modify, merge,
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* publish, distribute, and/or sell copies of the Software, and to permit
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* persons to whom the Software is furnished to do so, subject to the
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* following conditions:
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*
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* 1. The above copyright notices and this permission notice (which
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* includes the disclaimer below) shall be included in all copies or
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* substantial portions of the Software.
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*
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* 2. The name of a copyright holder shall not be used to endorse or
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* promote products derived from the Software without specific prior
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* written permission.
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*
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* THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL PART OF THIS
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* LICENSE. NO USE OF THE SOFTWARE IS AUTHORIZED HEREUNDER EXCEPT UNDER
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* THIS DISCLAIMER. THE SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS
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* "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
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* BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
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* PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS. IN NO
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* EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL
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* INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING
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* FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
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* NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
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* WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. NO ASSURANCES ARE
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* PROVIDED BY THE COPYRIGHT HOLDERS THAT THE SOFTWARE DOES NOT INFRINGE
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* THE PATENT OR OTHER INTELLECTUAL PROPERTY RIGHTS OF ANY OTHER ENTITY.
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* EACH COPYRIGHT HOLDER DISCLAIMS ANY LIABILITY TO THE USER FOR CLAIMS
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* BROUGHT BY ANY OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL
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* PROPERTY RIGHTS OR OTHERWISE. AS A CONDITION TO EXERCISING THE RIGHTS
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* GRANTED HEREUNDER, EACH USER HEREBY ASSUMES SOLE RESPONSIBILITY TO SECURE
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* ANY OTHER INTELLECTUAL PROPERTY RIGHTS NEEDED, IF ANY. THE SOFTWARE
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* IS NOT FAULT-TOLERANT AND IS NOT INTENDED FOR USE IN MISSION-CRITICAL
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* SYSTEMS, SUCH AS THOSE USED IN THE OPERATION OF NUCLEAR FACILITIES,
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* AIRCRAFT NAVIGATION OR COMMUNICATION SYSTEMS, AIR TRAFFIC CONTROL
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* SYSTEMS, DIRECT LIFE SUPPORT MACHINES, OR WEAPONS SYSTEMS, IN WHICH
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* THE FAILURE OF THE SOFTWARE OR SYSTEM COULD LEAD DIRECTLY TO DEATH,
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* PERSONAL INJURY, OR SEVERE PHYSICAL OR ENVIRONMENTAL DAMAGE ("HIGH
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* RISK ACTIVITIES"). THE COPYRIGHT HOLDERS SPECIFICALLY DISCLAIM ANY
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* EXPRESS OR IMPLIED WARRANTY OF FITNESS FOR HIGH RISK ACTIVITIES.
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*
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* __END_OF_JASPER_LICENSE__
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*/
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/*
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* Math Library
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*
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* $Id: jpc_math.c,v 1.2 2008-05-26 09:40:52 vp153 Exp $
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*/
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/******************************************************************************\
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* Includes
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\******************************************************************************/
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#include <assert.h>
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#include <stdio.h>
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#include <string.h>
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#include <math.h>
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#include <stdlib.h>
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#include <stdarg.h>
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#include "jpc_math.h"
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/******************************************************************************\
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* Miscellaneous Functions
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\******************************************************************************/
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/* Calculate the integer quantity floor(log2(x)), where x is a positive
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integer. */
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int jpc_floorlog2(int x)
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{
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int y;
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/* The argument must be positive. */
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assert(x > 0);
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y = 0;
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while (x > 1) {
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x >>= 1;
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++y;
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}
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return y;
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}
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/* Calculate the bit position of the first leading one in a nonnegative
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integer. */
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/* This function is the basically the same as ceillog2(x), except that the
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allowable range for x is slightly different. */
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int jpc_firstone(int x)
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{
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int n;
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/* The argument must be nonnegative. */
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assert(x >= 0);
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n = -1;
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while (x > 0) {
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x >>= 1;
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++n;
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}
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return n;
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}
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