From 60c25a4beb1d0df699104ecb8a536d9a09703d2f Mon Sep 17 00:00:00 2001 From: Kenan Gillet Date: Fri, 24 Oct 2008 21:20:29 +0000 Subject: Rename acelp_math.[ch] to celp_math.[ch] to prepare for QCELP decoder merge. patch by Kenan Gillet, kenan.gillet gmail com Originally committed as revision 15679 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/celp_math.h | 86 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 86 insertions(+) create mode 100644 libavcodec/celp_math.h (limited to 'libavcodec/celp_math.h') diff --git a/libavcodec/celp_math.h b/libavcodec/celp_math.h new file mode 100644 index 0000000000..029b5310af --- /dev/null +++ b/libavcodec/celp_math.h @@ -0,0 +1,86 @@ +/* + * Various fixed-point math operations + * + * Copyright (c) 2008 Vladimir Voroshilov + * + * This file is part of FFmpeg. + * + * FFmpeg 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. + * + * FFmpeg 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 FFmpeg; 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 + +/** + * 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); + +/** + * Calculates log2(x). + * @param value function argument, 0 < value <= 7fff ffff + * + * @return value of (1<<15) * log2(value) + */ +int ff_log2(uint32_t value); + +/** + * returns the dot product. + * @param a input data array + * @param b input data array + * @param length number of elements + * @param shift right shift by this value will be done after multiplication + * + * @return dot product = sum of elementwise products + */ +static int dot_product(const int16_t* a, const int16_t* b, int length, int shift) +{ + int sum = 0; + int i; + + for(i=0; i> shift; + + return sum; +} + +/** + * 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; +} + +#endif /* AVCODEC_CELP_MATH_H */ -- cgit v1.2.3