mirror of
https://github.com/nyanmisaka/ffmpeg-rockchip.git
synced 2025-10-31 12:36:41 +08:00
85 lines
3.0 KiB
C
85 lines
3.0 KiB
C
/*
|
|
* Copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at>
|
|
*
|
|
* 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 of the License, or (at your option) any later version.
|
|
*
|
|
* This library 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
/**
|
|
* @file mathematics.c
|
|
* Miscellaneous math routines and tables.
|
|
*/
|
|
|
|
#include "common.h"
|
|
#include "integer.h"
|
|
#include "mathematics.h"
|
|
|
|
const uint8_t ff_sqrt_tab[128]={
|
|
0, 1, 1, 1, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5,
|
|
5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
|
|
8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
|
|
9, 9, 9, 9,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,11,11,11,11,11,11,11
|
|
};
|
|
|
|
const uint8_t ff_log2_tab[256]={
|
|
0,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
|
|
5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
|
|
6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
|
|
6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
|
|
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
|
|
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
|
|
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
|
|
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7
|
|
};
|
|
|
|
int64_t ff_gcd(int64_t a, int64_t b){
|
|
if(b) return ff_gcd(b, a%b);
|
|
else return a;
|
|
}
|
|
|
|
int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding rnd){
|
|
AVInteger ai;
|
|
int64_t r=0;
|
|
assert(c > 0);
|
|
assert(b >=0);
|
|
assert(rnd >=0 && rnd<=5 && rnd!=4);
|
|
|
|
if(a<0 && a != INT64_MIN) return -av_rescale_rnd(-a, b, c, rnd ^ ((rnd>>1)&1));
|
|
|
|
if(rnd==AV_ROUND_NEAR_INF) r= c/2;
|
|
else if(rnd&1) r= c-1;
|
|
|
|
if(b<=INT_MAX && c<=INT_MAX){
|
|
if(a<=INT_MAX)
|
|
return (a * b + r)/c;
|
|
else
|
|
return a/c*b + (a%c*b + r)/c;
|
|
}
|
|
|
|
ai= av_mul_i(av_int2i(a), av_int2i(b));
|
|
ai= av_add_i(ai, av_int2i(r));
|
|
|
|
return av_i2int(av_div_i(ai, av_int2i(c)));
|
|
}
|
|
|
|
int64_t av_rescale(int64_t a, int64_t b, int64_t c){
|
|
return av_rescale_rnd(a, b, c, AV_ROUND_NEAR_INF);
|
|
}
|
|
|
|
int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq){
|
|
int64_t b= bq.num * (int64_t)cq.den;
|
|
int64_t c= cq.num * (int64_t)bq.den;
|
|
return av_rescale_rnd(a, b, c, AV_ROUND_NEAR_INF);
|
|
}
|