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/*
* 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
*/
static inline double hermite_interpolation(double x, double x0, double x1,
double p0, double p1,
double m0, double m1)
{
double width = x1 - x0;
double t = (x - x0) / width;
double t2, t3;
double ct0, ct1, ct2, ct3;
m0 *= width;
m1 *= width;
t2 = t*t;
t3 = t2*t;
ct0 = p0;
ct1 = m0;
ct2 = -3 * p0 - 2 * m0 + 3 * p1 - m1;
ct3 = 2 * p0 + m0 - 2 * p1 + m1;
return ct3 * t3 + ct2 * t2 + ct1 * t + ct0;
}
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