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