2 * This file is part of FFmpeg.
4 * FFmpeg is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
9 * FFmpeg is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with FFmpeg; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 #ifndef AVFILTER_HERMITE_H
20 #define AVFILTER_HERMITE_H
22 static inline double hermite_interpolation(double x, double x0, double x1,
26 double width = x1 - x0;
27 double t = (x - x0) / width;
29 double ct0, ct1, ct2, ct3;
39 ct2 = -3 * p0 - 2 * m0 + 3 * p1 - m1;
40 ct3 = 2 * p0 + m0 - 2 * p1 + m1;
42 return ct3 * t3 + ct2 * t2 + ct1 * t + ct0;
45 #endif /* AVFILTER_HERMITE_H */