/*
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
/**
* computes log2 of a value; the result is shifted left by 16 bits
*
* to use rational values you can use the following method:
* intlog2(value) = intlog2(value * 2^x) - x * 2^16
*
* example: intlog2(8) will give 3 << 16 = 3 * 2^16 = 196608
* example: intlog2(9) will give 3 << 16 + ... = 207744 (rounded)
* example: intlog2(1.5) = intlog2(3) - 2^16 = 38336 (rounded)
*
* @param value The value [ 0 gives a wrong result ]
* @return log2(value) * 2^16
*/
extern unsigned int intlog2(unsigned int value);
/**
* computes log10 of a value; the result is shifted left by 28 bits
*
* to use rational values you can use the following method:
* intlog10(value) = intlog10(value * 10^x) - x * 2^28
*
* example: intlog10(1000) will give 3 << 28 = 3 * 2^28
* due to the implementation intlog10(1000) might be not exactly 3 * 2^28
*
* look at intlog2 for similar examples
*
* @param value The value [ 0 gives a wrong result ]
* @return log10(value) * 2^28
*/
extern unsigned int intlog10(unsigned int value);
#endif