[FFmpeg-devel] [PATCHv3 2/2] all: move ff_exp10, ff_exp10f, ff_fast_powf to lavu/ffmath.h
Ganesh Ajjanagadde
gajjanag at gmail.com
Fri Mar 18 15:59:04 CET 2016
On Mon, Mar 14, 2016 at 7:05 PM, Ganesh Ajjanagadde <gajjanag at gmail.com> wrote:
> The idea is to use ffmath.h for internal implementations of math functions.
> Currently, it is used for variants of libm functions, but is by no means
> limited to such things.
>
> Note that this is not exported; use lavu/mathematics for such purposes.
>
> Suggested-by: Ronald S. Bultje <rsbultje at gmail.com>
> Signed-off-by: Ganesh Ajjanagadde <gajjanag at gmail.com>
> ---
> libavcodec/aacenc_utils.h | 2 +-
> libavcodec/aacpsy.c | 3 +-
> libavcodec/acelp_pitch_delay.c | 3 +-
> libavcodec/cngdec.c | 2 +-
> libavcodec/dcaenc.c | 2 +-
> libavcodec/imc.c | 2 +-
> libavcodec/on2avc.c | 2 +-
> libavcodec/opus.c | 2 +-
> libavcodec/wmadec.c | 3 +-
> libavcodec/wmaenc.c | 2 +-
> libavcodec/wmaprodec.c | 2 +-
> libavfilter/af_anequalizer.c | 1 +
> libavfilter/af_compand.c | 1 +
> libavfilter/af_volume.c | 1 +
> libavfilter/f_ebur128.c | 1 +
> libavfilter/vaf_spectrumsynth.c | 1 +
> libavfilter/vsrc_testsrc.c | 1 +
> libavutil/eval.c | 1 +
> libavutil/ffmath.h | 67 +++++++++++++++++++++++++++++++++++++++++
> libavutil/internal.h | 36 ----------------------
> 20 files changed, 85 insertions(+), 50 deletions(-)
> create mode 100644 libavutil/ffmath.h
>
> diff --git a/libavcodec/aacenc_utils.h b/libavcodec/aacenc_utils.h
> index 07f7337..bb1dcb4 100644
> --- a/libavcodec/aacenc_utils.h
> +++ b/libavcodec/aacenc_utils.h
> @@ -28,7 +28,7 @@
> #ifndef AVCODEC_AACENC_UTILS_H
> #define AVCODEC_AACENC_UTILS_H
>
> -#include "libavutil/internal.h"
> +#include "libavutil/ffmath.h"
> #include "aac.h"
> #include "aacenctab.h"
> #include "aactab.h"
> diff --git a/libavcodec/aacpsy.c b/libavcodec/aacpsy.c
> index 8643fe7..0898baf 100644
> --- a/libavcodec/aacpsy.c
> +++ b/libavcodec/aacpsy.c
> @@ -25,8 +25,7 @@
> */
>
> #include "libavutil/attributes.h"
> -#include "libavutil/internal.h"
> -#include "libavutil/libm.h"
> +#include "libavutil/ffmath.h"
>
> #include "avcodec.h"
> #include "aactab.h"
> diff --git a/libavcodec/acelp_pitch_delay.c b/libavcodec/acelp_pitch_delay.c
> index c2533b1..8ec1ba3 100644
> --- a/libavcodec/acelp_pitch_delay.c
> +++ b/libavcodec/acelp_pitch_delay.c
> @@ -21,9 +21,8 @@
> */
>
> #include "libavutil/common.h"
> +#include "libavutil/ffmath.h"
> #include "libavutil/float_dsp.h"
> -#include "libavutil/internal.h"
> -#include "libavutil/libm.h"
> #include "libavutil/mathematics.h"
> #include "avcodec.h"
> #include "acelp_pitch_delay.h"
> diff --git a/libavcodec/cngdec.c b/libavcodec/cngdec.c
> index 0251086..34f8814 100644
> --- a/libavcodec/cngdec.c
> +++ b/libavcodec/cngdec.c
> @@ -22,7 +22,7 @@
> #include <math.h>
>
> #include "libavutil/common.h"
> -#include "libavutil/internal.h"
> +#include "libavutil/ffmath.h"
> #include "avcodec.h"
> #include "celp_filters.h"
> #include "internal.h"
> diff --git a/libavcodec/dcaenc.c b/libavcodec/dcaenc.c
> index 70e9230..ab40e37 100644
> --- a/libavcodec/dcaenc.c
> +++ b/libavcodec/dcaenc.c
> @@ -24,7 +24,7 @@
> #include "libavutil/avassert.h"
> #include "libavutil/channel_layout.h"
> #include "libavutil/common.h"
> -#include "libavutil/internal.h"
> +#include "libavutil/ffmath.h"
> #include "avcodec.h"
> #include "dca.h"
> #include "dcadata.h"
> diff --git a/libavcodec/imc.c b/libavcodec/imc.c
> index 085ec09..850bc9d 100644
> --- a/libavcodec/imc.c
> +++ b/libavcodec/imc.c
> @@ -35,9 +35,9 @@
> #include <stdio.h>
>
> #include "libavutil/channel_layout.h"
> +#include "libavutil/ffmath.h"
> #include "libavutil/float_dsp.h"
> #include "libavutil/internal.h"
> -#include "libavutil/libm.h"
> #include "avcodec.h"
> #include "bswapdsp.h"
> #include "get_bits.h"
> diff --git a/libavcodec/on2avc.c b/libavcodec/on2avc.c
> index 62c71cc..3064c6f 100644
> --- a/libavcodec/on2avc.c
> +++ b/libavcodec/on2avc.c
> @@ -21,8 +21,8 @@
> */
>
> #include "libavutil/channel_layout.h"
> +#include "libavutil/ffmath.h"
> #include "libavutil/float_dsp.h"
> -#include "libavutil/internal.h"
> #include "avcodec.h"
> #include "bytestream.h"
> #include "fft.h"
> diff --git a/libavcodec/opus.c b/libavcodec/opus.c
> index f2b8ecc..47f2657 100644
> --- a/libavcodec/opus.c
> +++ b/libavcodec/opus.c
> @@ -27,7 +27,7 @@
> #include <stdint.h>
>
> #include "libavutil/error.h"
> -#include "libavutil/internal.h"
> +#include "libavutil/ffmath.h"
>
> #include "opus.h"
> #include "vorbis.h"
> diff --git a/libavcodec/wmadec.c b/libavcodec/wmadec.c
> index 1a84323..7130bf6 100644
> --- a/libavcodec/wmadec.c
> +++ b/libavcodec/wmadec.c
> @@ -34,8 +34,7 @@
> */
>
> #include "libavutil/attributes.h"
> -#include "libavutil/internal.h"
> -#include "libavutil/libm.h"
> +#include "libavutil/ffmath.h"
>
> #include "avcodec.h"
> #include "internal.h"
> diff --git a/libavcodec/wmaenc.c b/libavcodec/wmaenc.c
> index d0727e6..418e958 100644
> --- a/libavcodec/wmaenc.c
> +++ b/libavcodec/wmaenc.c
> @@ -20,7 +20,7 @@
> */
>
> #include "libavutil/attributes.h"
> -#include "libavutil/internal.h"
> +#include "libavutil/ffmath.h"
>
> #include "avcodec.h"
> #include "internal.h"
> diff --git a/libavcodec/wmaprodec.c b/libavcodec/wmaprodec.c
> index 2ea59e9..2cc1b09 100644
> --- a/libavcodec/wmaprodec.c
> +++ b/libavcodec/wmaprodec.c
> @@ -88,8 +88,8 @@
>
> #include <inttypes.h>
>
> +#include "libavutil/ffmath.h"
> #include "libavutil/float_dsp.h"
> -#include "libavutil/internal.h"
> #include "libavutil/intfloat.h"
> #include "libavutil/intreadwrite.h"
> #include "avcodec.h"
> diff --git a/libavfilter/af_anequalizer.c b/libavfilter/af_anequalizer.c
> index a344c77..2403460 100644
> --- a/libavfilter/af_anequalizer.c
> +++ b/libavfilter/af_anequalizer.c
> @@ -21,6 +21,7 @@
>
> #include "libavutil/intreadwrite.h"
> #include "libavutil/avstring.h"
> +#include "libavutil/ffmath.h"
> #include "libavutil/opt.h"
> #include "libavutil/parseutils.h"
> #include "avfilter.h"
> diff --git a/libavfilter/af_compand.c b/libavfilter/af_compand.c
> index b746364..0bb719f 100644
> --- a/libavfilter/af_compand.c
> +++ b/libavfilter/af_compand.c
> @@ -29,6 +29,7 @@
>
> #include "libavutil/avassert.h"
> #include "libavutil/avstring.h"
> +#include "libavutil/ffmath.h"
> #include "libavutil/opt.h"
> #include "libavutil/samplefmt.h"
> #include "audio.h"
> diff --git a/libavfilter/af_volume.c b/libavfilter/af_volume.c
> index 3913e7b..4d6b916 100644
> --- a/libavfilter/af_volume.c
> +++ b/libavfilter/af_volume.c
> @@ -27,6 +27,7 @@
> #include "libavutil/channel_layout.h"
> #include "libavutil/common.h"
> #include "libavutil/eval.h"
> +#include "libavutil/ffmath.h"
> #include "libavutil/float_dsp.h"
> #include "libavutil/intreadwrite.h"
> #include "libavutil/opt.h"
> diff --git a/libavfilter/f_ebur128.c b/libavfilter/f_ebur128.c
> index c4b30b4..59eaedd 100644
> --- a/libavfilter/f_ebur128.c
> +++ b/libavfilter/f_ebur128.c
> @@ -33,6 +33,7 @@
> #include "libavutil/avstring.h"
> #include "libavutil/channel_layout.h"
> #include "libavutil/dict.h"
> +#include "libavutil/ffmath.h"
> #include "libavutil/xga_font_data.h"
> #include "libavutil/opt.h"
> #include "libavutil/timestamp.h"
> diff --git a/libavfilter/vaf_spectrumsynth.c b/libavfilter/vaf_spectrumsynth.c
> index 8d4014e..ee394b4 100644
> --- a/libavfilter/vaf_spectrumsynth.c
> +++ b/libavfilter/vaf_spectrumsynth.c
> @@ -27,6 +27,7 @@
> #include "libavcodec/avfft.h"
> #include "libavutil/avassert.h"
> #include "libavutil/channel_layout.h"
> +#include "libavutil/ffmath.h"
> #include "libavutil/opt.h"
> #include "libavutil/parseutils.h"
> #include "avfilter.h"
> diff --git a/libavfilter/vsrc_testsrc.c b/libavfilter/vsrc_testsrc.c
> index a75dd4c..f0c0985 100644
> --- a/libavfilter/vsrc_testsrc.c
> +++ b/libavfilter/vsrc_testsrc.c
> @@ -37,6 +37,7 @@
>
> #include "libavutil/avassert.h"
> #include "libavutil/common.h"
> +#include "libavutil/ffmath.h"
> #include "libavutil/opt.h"
> #include "libavutil/imgutils.h"
> #include "libavutil/intreadwrite.h"
> diff --git a/libavutil/eval.c b/libavutil/eval.c
> index 2acbbb4..37b8511 100644
> --- a/libavutil/eval.c
> +++ b/libavutil/eval.c
> @@ -31,6 +31,7 @@
> #include "avutil.h"
> #include "common.h"
> #include "eval.h"
> +#include "ffmath.h"
> #include "internal.h"
> #include "log.h"
> #include "mathematics.h"
> diff --git a/libavutil/ffmath.h b/libavutil/ffmath.h
> new file mode 100644
> index 0000000..aad1347
> --- /dev/null
> +++ b/libavutil/ffmath.h
> @@ -0,0 +1,67 @@
> +/*
> + * copyright (c) 2016 Ganesh Ajjanagadde <gajjanag at 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 */
> diff --git a/libavutil/internal.h b/libavutil/internal.h
> index 340e18b..61784b5 100644
> --- a/libavutil/internal.h
> +++ b/libavutil/internal.h
> @@ -295,42 +295,6 @@ static av_always_inline av_const int64_t ff_rint64_clip(double a, int64_t amin,
> }
>
> /**
> - * 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);
> -}
> -
> -
> -/**
> * A wrapper for open() setting O_CLOEXEC.
> */
> av_warn_unused_result
> --
> 2.7.3
>
Ping, not sure if Ronald's comment counts as an ack on this. Thanks.
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