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/*
* dvb-math provides some complex fixed-point math
* operations shared between the dvb related stuff
*
* Copyright (C) 2006 Christoph Pfister (christophpfister@gmail.com)
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef __DVB_MATH_H
#define __DVB_MATH_H
#include <linux/types.h>
/**
* computes log2 of a value; the result is shifted left by 24 bits
*
* to use rational values you can use the following method:
* intlog2(value) = intlog2(value * 2^x) - x * 2^24
*
* example: intlog2(8) will give 3 << 24 = 3 * 2^24
* example: intlog2(9) will give 3 << 24 + ... = 3.16... * 2^24
* example: intlog2(1.5) = intlog2(3) - 2^24 = 0.584... * 2^24
*
* @param value The value (must be != 0)
* @return log2(value) * 2^24
*/
extern unsigned int intlog2(u32 value);
/**
* computes log10 of a value; the result is shifted left by 24 bits
*
* to use rational values you can use the following method:
* intlog10(value) = intlog10(value * 10^x) - x * 2^24
*
* example: intlog10(1000) will give 3 << 24 = 3 * 2^24
* due to the implementation intlog10(1000) might be not exactly 3 * 2^24
*
* look at intlog2 for similar examples
*
* @param value The value (must be != 0)
* @return log10(value) * 2^24
*/
extern unsigned int intlog10(u32 value);
#endif
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