[FFmpeg-devel] [PATCH] Port FFT domain filter.
Michael Niedermayer
michaelni at gmx.at
Sat Feb 28 12:00:07 CET 2015
On Sat, Feb 28, 2015 at 04:00:36PM +0530, arwa arif wrote:
> On Sat, Feb 28, 2015 at 2:42 PM, Carl Eugen Hoyos <cehoyos at ag.or.at> wrote:
>
> > arwa arif <arwaarif1994 <at> gmail.com> writes:
> >
> > > * FFmpeg is free software; you can redistribute it and/or modify
> > > * it under the terms of the GNU General Public License as published by
> >
> > If you want this filter to be licensed under GPL you
> > have to add a line to configure.
> >
> >
> I am sorry I didn't pay attention to the licensing part. I have updated it
> to LGPL.
>
>
> > Carl Eugen
> >
> > _______________________________________________
> > ffmpeg-devel mailing list
> > ffmpeg-devel at ffmpeg.org
> > http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> >
> Makefile | 1
> allfilters.c | 1
> vf_fftfilt.c | 238 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 240 insertions(+)
> c188c2ed10576d2cc68771bee64a02782bff29de 0001-Port-FFT-domain-filter.patch
> From 63bd20d116464dc37db1a02b714a934a7d1ca912 Mon Sep 17 00:00:00 2001
> From: Arwa Arif <arwaarif1994 at gmail.com>
> Date: Tue, 24 Feb 2015 12:17:30 +0530
> Subject: [PATCH] Port FFT domain filter.
>
> ---
> libavfilter/Makefile | 1 +
> libavfilter/allfilters.c | 1 +
> libavfilter/vf_fftfilt.c | 238 ++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 240 insertions(+)
> create mode 100644 libavfilter/vf_fftfilt.c
>
> diff --git a/libavfilter/Makefile b/libavfilter/Makefile
> index 289c63b..b184f07 100644
> --- a/libavfilter/Makefile
> +++ b/libavfilter/Makefile
> @@ -120,6 +120,7 @@ OBJS-$(CONFIG_EDGEDETECT_FILTER) += vf_edgedetect.o
> OBJS-$(CONFIG_EQ_FILTER) += vf_eq.o
> OBJS-$(CONFIG_EXTRACTPLANES_FILTER) += vf_extractplanes.o
> OBJS-$(CONFIG_FADE_FILTER) += vf_fade.o
> +OBJS-$(CONFIG_FFTFILT_FILTER) += vf_fftfilt.o
> OBJS-$(CONFIG_FIELD_FILTER) += vf_field.o
> OBJS-$(CONFIG_FIELDMATCH_FILTER) += vf_fieldmatch.o
> OBJS-$(CONFIG_FIELDORDER_FILTER) += vf_fieldorder.o
> diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
> index 55de154..043ac56 100644
> --- a/libavfilter/allfilters.c
> +++ b/libavfilter/allfilters.c
> @@ -136,6 +136,7 @@ void avfilter_register_all(void)
> REGISTER_FILTER(EQ, eq, vf);
> REGISTER_FILTER(EXTRACTPLANES, extractplanes, vf);
> REGISTER_FILTER(FADE, fade, vf);
> + REGISTER_FILTER(FFTFILT, fftfilt, vf);
> REGISTER_FILTER(FIELD, field, vf);
> REGISTER_FILTER(FIELDMATCH, fieldmatch, vf);
> REGISTER_FILTER(FIELDORDER, fieldorder, vf);
> diff --git a/libavfilter/vf_fftfilt.c b/libavfilter/vf_fftfilt.c
> new file mode 100644
> index 0000000..a9dc107
> --- /dev/null
> +++ b/libavfilter/vf_fftfilt.c
> @@ -0,0 +1,238 @@
> +/*
> + * Copyright (c) 2015 Arwa Arif <arwaarif1994 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
> + * FFT domain filtering.
> + */
> +
> +#include "libavfilter/internal.h"
> +#include "libavutil/common.h"
> +#include "libavutil/imgutils.h"
> +#include "libavutil/opt.h"
> +#include "libavutil/pixdesc.h"
> +#include "libavcodec/avfft.h"
> +#include "libavutil/eval.h"
> +
> +typedef struct {
> + const AVClass *class;
> +
> + RDFTContext *rdft;
> + int rdft_hbits;
> + int rdft_vbits;
> + size_t rdft_vlen;
> + FFTSample *rdft_hdata;
> + FFTSample *rdft_vdata;
> +
> + int dc;
> + char *lum_str;
> + AVExpr *lum_expr;
> +
> +} FFTFILTContext;
> +
> +static const char *const var_names[] = { "X", "Y", "W", "H", NULL };
> +enum { VAR_X, VAR_Y, VAR_W, VAR_H, VAR_VARS_NB };
> +
> +#define OFFSET(x) offsetof(FFTFILTContext, x)
> +#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
> +
> +static const AVOption fftfilt_options[] = {
> + { "dc", "adjust gain", OFFSET(dc), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1000, FLAGS },
> + { "lum", "set luminance expression", OFFSET(lum_str), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },
> + {NULL},
> +};
> +
> +AVFILTER_DEFINE_CLASS(fftfilt);
> +
> +static inline double lum(void *priv, double x, double y)
> +{
> + FFTFILTContext *fftfilt = priv;
> + FFTSample *rdft_data = fftfilt->rdft_vdata;
> + size_t rdft_vlen = fftfilt->rdft_vlen;
> +
> + return rdft_data[(int)x * rdft_vlen + (int)y];
> +}
> +
> +static av_cold int initialize(AVFilterContext *ctx)
> +{
> + FFTFILTContext *fftfilt = ctx->priv;
> + int ret = 0;
> +
> + static double (*p[])(void *, double, double) = {lum};
> + const char *const func2_names[] = {"lum", NULL };
> + double (*func2[])(void *, double, double) = {lum, p[0], NULL };
> + ret = av_expr_parse(&fftfilt->lum_expr, fftfilt->lum_str, var_names, NULL, NULL, func2_names, func2, 0, ctx);
> + return ret;
> +}
> +
> +static int filter_frame(AVFilterLink *inlink, AVFrame *in)
> +{
> + AVFilterContext *ctx = inlink->dst;
> + AVFilterLink *outlink = inlink->dst->outputs[0];
> + FFTFILTContext *fftfilt = ctx->priv;
> + AVFrame *out;
> + int i, j, rdft_hbits, rdft_vbits;
> + size_t rdft_hlen, rdft_vlen, w, h;
> + double values[VAR_VARS_NB];
> +
> + w = inlink->w;
> + h = inlink->h;
> +
> + /* RDFT - Array initialization for Horizontal pass*/
> + for (rdft_hbits = 1; 1 << rdft_hbits < w; rdft_hbits++);
> + rdft_hlen = 1 << rdft_hbits;
> + if (!(fftfilt->rdft_hdata = av_malloc_array(h, rdft_hlen * sizeof(FFTSample))))
> + return AVERROR(ENOMEM);
> +
> + /* RDFT - Array initialization for Vertical pass*/
> + for (rdft_vbits = 1; 1 << rdft_vbits < h; rdft_vbits++);
> + rdft_vlen = 1 << rdft_vbits;
> + if (!(fftfilt->rdft_vdata = av_malloc_array(rdft_hlen, rdft_vlen * sizeof(FFTSample))))
> + return AVERROR(ENOMEM);
> + fftfilt->rdft_vlen = rdft_vlen;
> +
> + out = ff_get_video_buffer(outlink, inlink->w, inlink->h);
> + if (!out)
> + return AVERROR(ENOMEM);
> +
> + av_frame_copy_props(out, in);
> +
> + /*Horizontal pass - RDFT*/
> + fftfilt->rdft = av_rdft_init(rdft_hbits, DFT_R2C);
> + for (i = 0; i < h; i++)
> + {
> + memset(fftfilt->rdft_hdata + i * rdft_hlen, 0, rdft_hlen * sizeof(*fftfilt->rdft_hdata));
> + for (j = 0; j < w; j++)
> + fftfilt->rdft_hdata[i * rdft_hlen + j] = *(in->data[0] + in->linesize[0] * i + j);
> + }
> +
> + for (i = 0; i < h; i++)
> + av_rdft_calc(fftfilt->rdft, fftfilt->rdft_hdata + i * rdft_hlen);
> +
> + av_rdft_end(fftfilt->rdft);
> +
> + /*Vertical pass - RDFT*/
> + fftfilt->rdft = av_rdft_init(rdft_vbits, DFT_R2C);
> + for (i = 0; i < rdft_hlen; i++)
> + {
> + memset(fftfilt->rdft_vdata + i * rdft_vlen, 0, rdft_vlen * sizeof(*fftfilt->rdft_vdata));
> + for (j = 0; j < h; j++)
> + fftfilt->rdft_vdata[i * rdft_vlen + j] = fftfilt->rdft_hdata[j * rdft_hlen + i];
> + }
> +
> + for (i = 0; i < rdft_hlen; i++)
> + av_rdft_calc(fftfilt->rdft, fftfilt->rdft_vdata + i * rdft_vlen);
> +
> + av_rdft_end(fftfilt->rdft);
> +
> + /*Change user defined parameters*/
> + values[VAR_W] = w;
> + values[VAR_H] = h;
> +
> + for (i = 0; i < rdft_hlen; i++)
> + {
> + values[VAR_X] = i;
> + for (j = 0; j < rdft_vlen; j++)
> + {
> + values[VAR_Y] = j;
> + fftfilt->rdft_vdata[i * rdft_vlen + j] *= av_expr_eval(fftfilt->lum_expr, values, fftfilt);
> + }
> + }
the return values from av_expr_eval() could be stored in a
rdft_hlen * rdft_vlen array in the context and calculated only once
av_expr_eval() is somewhat timeconsuming, so this would speed the
code up.
Also a check for fftfilt->lum_str == NULL is needed because if no
lum=... is specified then it would otherwise crash
[...]
--
Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
Republics decline into democracies and democracies degenerate into
despotisms. -- Aristotle
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