/* * Various fixed-point math operations * * Copyright (c) 2008 Vladimir Voroshilov * * This file is part of Libav. * * Libav 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. * * Libav 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 Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #ifndef AVCODEC_CELP_MATH_H#define AVCODEC_CELP_MATH_H #include <stdint.h> /** * fixed-point implementation of cosine in [0; PI) domain. * @param arg fixed-point cosine argument, 0 <= arg < 0x4000 * * @return value of (1<<15) * cos(arg * PI / (1<<14)), -0x8000 <= result <= 0x7fff */int16_t ff_cos(uint16_t arg); /** * fixed-point implementation of exp2(x) in [0; 1] domain. * @param power argument to exp2, 0 <= power <= 0x7fff * * @return value of (1<<20) * exp2(power / (1<<15)) *         0x8000c <= result <= 0xfffea */int ff_exp2(uint16_t power); /** * Calculate log2(x). * @param value function argument, 0 < value <= 7fff ffff * * @return value of (1<<15) * log2(value) */int ff_log2(uint32_t value); /** * Shift value left or right depending on sign of offset parameter. * @param value value to shift * @param offset shift offset * * @return value << offset, if offset>=0; value >> -offset - otherwise */static inline int bidir_sal(int value, int offset){    if(offset < 0) return value >> -offset;    else           return value <<  offset;} /** * Return the dot product. * @param a input data array * @param b input data array * @param length number of elements * * @return dot product = sum of elementwise products */float ff_dot_productf(const float* a, const float* b, int length); #endif /* AVCODEC_CELP_MATH_H */