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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 17:32:43 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 17:32:43 +0000 |
commit | 6bf0a5cb5034a7e684dcc3500e841785237ce2dd (patch) | |
tree | a68f146d7fa01f0134297619fbe7e33db084e0aa /media/ffvpx/libavutil/ffmath.h | |
parent | Initial commit. (diff) | |
download | thunderbird-6bf0a5cb5034a7e684dcc3500e841785237ce2dd.tar.xz thunderbird-6bf0a5cb5034a7e684dcc3500e841785237ce2dd.zip |
Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | media/ffvpx/libavutil/ffmath.h | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/media/ffvpx/libavutil/ffmath.h b/media/ffvpx/libavutil/ffmath.h new file mode 100644 index 0000000000..aad1347f26 --- /dev/null +++ b/media/ffvpx/libavutil/ffmath.h @@ -0,0 +1,67 @@ +/* + * copyright (c) 2016 Ganesh Ajjanagadde <gajjanag@gmail.com> + * + * 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 + */ + +/** + * @file + * internal math functions header + */ + +#ifndef AVUTIL_FFMATH_H +#define AVUTIL_FFMATH_H + +#include "attributes.h" +#include "libm.h" + +/** + * Compute 10^x for floating point values. Note: this function is by no means + * "correctly rounded", and is meant as a fast, reasonably accurate approximation. + * For instance, maximum relative error for the double precision variant is + * ~ 1e-13 for very small and very large values. + * This is ~2x faster than GNU libm's approach, which is still off by 2ulp on + * some inputs. + * @param x exponent + * @return 10^x + */ +static av_always_inline double ff_exp10(double x) +{ + return exp2(M_LOG2_10 * x); +} + +static av_always_inline float ff_exp10f(float x) +{ + return exp2f(M_LOG2_10 * x); +} + +/** + * Compute x^y for floating point x, y. Note: this function is faster than the + * libm variant due to mainly 2 reasons: + * 1. It does not handle any edge cases. In particular, this is only guaranteed + * to work correctly for x > 0. + * 2. It is not as accurate as a standard nearly "correctly rounded" libm variant. + * @param x base + * @param y exponent + * @return x^y + */ +static av_always_inline float ff_fast_powf(float x, float y) +{ + return expf(logf(x) * y); +} + +#endif /* AVUTIL_FFMATH_H */ |