[FFmpeg-devel] [PATCH v2 1/3] avfilter/x86/vf_exposure: add x86 SIMD optimization
James Almer
jamrial at gmail.com
Sat Nov 20 18:46:08 EET 2021
On 11/4/2021 1:18 AM, Wu Jianhua wrote:
> Performance data(Less is better):
> exposure_c: 857394
> exposure_sse: 327589
>
> Signed-off-by: Wu Jianhua <jianhua.wu at intel.com>
> ---
> libavfilter/exposure.h | 36 +++++++++++++++++++
> libavfilter/vf_exposure.c | 36 +++++++++----------
> libavfilter/x86/Makefile | 2 ++
> libavfilter/x86/vf_exposure.asm | 55 ++++++++++++++++++++++++++++++
> libavfilter/x86/vf_exposure_init.c | 36 +++++++++++++++++++
> 5 files changed, 147 insertions(+), 18 deletions(-)
> create mode 100644 libavfilter/exposure.h
> create mode 100644 libavfilter/x86/vf_exposure.asm
> create mode 100644 libavfilter/x86/vf_exposure_init.c
>
> diff --git a/libavfilter/exposure.h b/libavfilter/exposure.h
> new file mode 100644
> index 0000000000..e76a517826
> --- /dev/null
> +++ b/libavfilter/exposure.h
> @@ -0,0 +1,36 @@
> +/*
> + * 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
> + */
> +
> +#ifndef AVFILTER_EXPOSURE_H
> +#define AVFILTER_EXPOSURE_H
> +#include "avfilter.h"
> +
> +typedef struct ExposureContext {
> + const AVClass *class;
> +
> + float exposure;
> + float black;
> + float scale;
> +
> + void (*exposure_func)(float *ptr, int length, float black, float scale);
> +} ExposureContext;
> +
> +void ff_exposure_init(ExposureContext *s);
> +void ff_exposure_init_x86(ExposureContext *s);
> +
> +#endif
> diff --git a/libavfilter/vf_exposure.c b/libavfilter/vf_exposure.c
> index 108fba7930..045ae710d3 100644
> --- a/libavfilter/vf_exposure.c
> +++ b/libavfilter/vf_exposure.c
> @@ -26,23 +26,20 @@
> #include "formats.h"
> #include "internal.h"
> #include "video.h"
> +#include "exposure.h"
>
> -typedef struct ExposureContext {
> - const AVClass *class;
> -
> - float exposure;
> - float black;
> +static void exposure_c(float *ptr, int length, float black, float scale)
> +{
> + int i;
>
> - float scale;
> - int (*do_slice)(AVFilterContext *s, void *arg,
> - int jobnr, int nb_jobs);
> -} ExposureContext;
> + for (i = 0; i < length; i++)
> + ptr[i] = (ptr[i] - black) * scale;
> +}
>
> static int exposure_slice(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
> {
> ExposureContext *s = ctx->priv;
> AVFrame *frame = arg;
> - const int width = frame->width;
> const int height = frame->height;
> const int slice_start = (height * jobnr) / nb_jobs;
> const int slice_end = (height * (jobnr + 1)) / nb_jobs;
> @@ -52,24 +49,27 @@ static int exposure_slice(AVFilterContext *ctx, void *arg, int jobnr, int nb_job
> for (int p = 0; p < 3; p++) {
> const int linesize = frame->linesize[p] / 4;
> float *ptr = (float *)frame->data[p] + slice_start * linesize;
> - for (int y = slice_start; y < slice_end; y++) {
> - for (int x = 0; x < width; x++)
> - ptr[x] = (ptr[x] - black) * scale;
> -
> - ptr += linesize;
> - }
> + s->exposure_func(ptr, linesize * (slice_end - slice_start), black, scale);
> }
>
> return 0;
> }
>
> +void ff_exposure_init(ExposureContext *s)
> +{
> + s->exposure_func = exposure_c;
> +
> + if (ARCH_X86)
> + ff_exposure_init_x86(s);
> +}
> +
> static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
> {
> AVFilterContext *ctx = inlink->dst;
> ExposureContext *s = ctx->priv;
>
> s->scale = 1.f / (exp2f(-s->exposure) - s->black);
> - ff_filter_execute(ctx, s->do_slice, frame, NULL,
> + ff_filter_execute(ctx, exposure_slice, frame, NULL,
> FFMIN(frame->height, ff_filter_get_nb_threads(ctx)));
>
> return ff_filter_frame(ctx->outputs[0], frame);
> @@ -80,7 +80,7 @@ static av_cold int config_input(AVFilterLink *inlink)
> AVFilterContext *ctx = inlink->dst;
> ExposureContext *s = ctx->priv;
>
> - s->do_slice = exposure_slice;
> + ff_exposure_init(s);
>
> return 0;
> }
> diff --git a/libavfilter/x86/Makefile b/libavfilter/x86/Makefile
> index a29941eaeb..e84a388aa5 100644
> --- a/libavfilter/x86/Makefile
> +++ b/libavfilter/x86/Makefile
> @@ -8,6 +8,7 @@ OBJS-$(CONFIG_BWDIF_FILTER) += x86/vf_bwdif_init.o
> OBJS-$(CONFIG_COLORSPACE_FILTER) += x86/colorspacedsp_init.o
> OBJS-$(CONFIG_CONVOLUTION_FILTER) += x86/vf_convolution_init.o
> OBJS-$(CONFIG_EQ_FILTER) += x86/vf_eq_init.o
> +OBJS-$(CONFIG_EXPOSURE_FILTER) += x86/vf_exposure_init.o
> OBJS-$(CONFIG_FSPP_FILTER) += x86/vf_fspp_init.o
> OBJS-$(CONFIG_GBLUR_FILTER) += x86/vf_gblur_init.o
> OBJS-$(CONFIG_GRADFUN_FILTER) += x86/vf_gradfun_init.o
> @@ -49,6 +50,7 @@ X86ASM-OBJS-$(CONFIG_BWDIF_FILTER) += x86/vf_bwdif.o
> X86ASM-OBJS-$(CONFIG_COLORSPACE_FILTER) += x86/colorspacedsp.o
> X86ASM-OBJS-$(CONFIG_CONVOLUTION_FILTER) += x86/vf_convolution.o
> X86ASM-OBJS-$(CONFIG_EQ_FILTER) += x86/vf_eq.o
> +X86ASM-OBJS-$(CONFIG_EXPOSURE_FILTER) += x86/vf_exposure.o
> X86ASM-OBJS-$(CONFIG_FRAMERATE_FILTER) += x86/vf_framerate.o
> X86ASM-OBJS-$(CONFIG_FSPP_FILTER) += x86/vf_fspp.o
> X86ASM-OBJS-$(CONFIG_GBLUR_FILTER) += x86/vf_gblur.o
> diff --git a/libavfilter/x86/vf_exposure.asm b/libavfilter/x86/vf_exposure.asm
> new file mode 100644
> index 0000000000..3351c6fb3b
> --- /dev/null
> +++ b/libavfilter/x86/vf_exposure.asm
> @@ -0,0 +1,55 @@
> +;*****************************************************************************
> +;* x86-optimized functions for exposure filter
> +;*
> +;* 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
> +;******************************************************************************
> +
> +%include "libavutil/x86/x86util.asm"
> +
> +SECTION .text
> +
> +;*******************************************************************************
> +; void ff_exposure(float *ptr, int length, float black, float scale);
> +;*******************************************************************************
> +%macro EXPOSURE 0
> +cglobal exposure, 2, 2, 4, ptr, length, black, scale
> + movsxdifnidn lengthq, lengthd
> +%if WIN64
> + VBROADCASTSS m0, xmm2
> + VBROADCASTSS m1, xmm3
> +%else
> + VBROADCASTSS m0, xmm0
> + VBROADCASTSS m1, xmm1
> +%endif
> +
> +.loop:
> + movu m2, [ptrq]
> + subps m2, m2, m0
> + mulps m2, m2, m1
> + movu [ptrq], m2
> + add ptrq, mmsize
> + sub lengthq, mmsize/4
> +
> + jg .loop
> +
> + RET
> +%endmacro
> +
> +%if ARCH_X86_64
Why x86_64 only?
> +INIT_XMM sse
> +EXPOSURE
Is it not possible to add an AVX version to process eight floats per
loop? The function is already written in a way that you would only need
to do
%if HAVE_AVX_EXTERNAL
INIT_YMM avx
EXPOSURE
%endif
For it. And ptr alignment is not a problem seeing you're using unaligned
movs.
> +%endif
> diff --git a/libavfilter/x86/vf_exposure_init.c b/libavfilter/x86/vf_exposure_init.c
> new file mode 100644
> index 0000000000..de1b360f6c
> --- /dev/null
> +++ b/libavfilter/x86/vf_exposure_init.c
> @@ -0,0 +1,36 @@
> +/*
> + * 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
> + */
> +
> +#include "config.h"
> +
> +#include "libavutil/attributes.h"
> +#include "libavutil/cpu.h"
> +#include "libavutil/x86/cpu.h"
> +#include "libavfilter/exposure.h"
> +
> +void ff_exposure_sse(float *ptr, int length, float black, float scale);
> +
> +av_cold void ff_exposure_init_x86(ExposureContext *s)
> +{
> + int cpu_flags = av_get_cpu_flags();
> +
> +#if ARCH_X86_64
> + if (EXTERNAL_SSE(cpu_flags))
> + s->exposure_func = ff_exposure_sse;
> +#endif
> +}
>
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