[FFmpeg-devel] [PATCH V1] lavfi/superfastblur: add superfastblur filter
Jun Zhao
mypopydev at gmail.com
Tue Nov 12 09:51:31 EET 2019
From: Jun Zhao <barryjzhao at tencent.com>
add superfastblur filter
Signed-off-by: Jun Zhao <barryjzhao at tencent.com>
---
doc/filters.texi | 15 ++
libavfilter/Makefile | 1 +
libavfilter/allfilters.c | 1 +
libavfilter/vf_superfastblur.c | 275 ++++++++++++++++++++++++++++++++++++++++
4 files changed, 292 insertions(+), 0 deletions(-)
create mode 100644 libavfilter/vf_superfastblur.c
diff --git a/doc/filters.texi b/doc/filters.texi
index 6800124..c7d1893 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -17453,6 +17453,21 @@ Interpolate) pixel art scaling algorithm.
Useful for enlarging pixel art images without reducing sharpness.
+ at section superfastblur
+
+Blur the input image with super fast blur algorithm, multiple invocations of this
+filter with a small radius will approximate a gaussian blur quite well.
+
+This filter accepts the following options:
+
+ at table @option
+ at item radius
+ at item r
+Set the blurring box radius. The option value must be a int number in
+the range [1, 10] that specifies the blur box size of the superfast blur filter
+used to blur the image. Default value is @code{2}..
+ at end table
+
@section swaprect
Swap two rectangular objects in video.
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index fce9303..db4d5e6 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -396,6 +396,7 @@ OBJS-$(CONFIG_STEREO3D_FILTER) += vf_stereo3d.o
OBJS-$(CONFIG_STREAMSELECT_FILTER) += f_streamselect.o framesync.o
OBJS-$(CONFIG_SUBTITLES_FILTER) += vf_subtitles.o
OBJS-$(CONFIG_SUPER2XSAI_FILTER) += vf_super2xsai.o
+OBJS-$(CONFIG_SUPEREQUALIZER_FILTER) += vf_superfastblur.o
OBJS-$(CONFIG_SWAPRECT_FILTER) += vf_swaprect.o
OBJS-$(CONFIG_SWAPUV_FILTER) += vf_swapuv.o
OBJS-$(CONFIG_TBLEND_FILTER) += vf_blend.o framesync.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 7c1e19e..d507bc5 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -377,6 +377,7 @@ extern AVFilter ff_vf_stereo3d;
extern AVFilter ff_vf_streamselect;
extern AVFilter ff_vf_subtitles;
extern AVFilter ff_vf_super2xsai;
+extern AVFilter ff_vf_superfastblur;
extern AVFilter ff_vf_swaprect;
extern AVFilter ff_vf_swapuv;
extern AVFilter ff_vf_tblend;
diff --git a/libavfilter/vf_superfastblur.c b/libavfilter/vf_superfastblur.c
new file mode 100644
index 0000000..a6428cf
--- /dev/null
+++ b/libavfilter/vf_superfastblur.c
@@ -0,0 +1,275 @@
+/*
+ * Copyright (c) 2019 Jun Zhao
+ *
+ * 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
+ * Super fast blur filter
+ *
+ * @see http://incubator.quasimondo.com/processing/superfast_blur.php
+ */
+
+#include "libavutil/avassert.h"
+#include "libavutil/imgutils.h"
+#include "libavutil/opt.h"
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+#include "video.h"
+
+typedef struct SuperFastBlurContext {
+ const AVClass *class;
+
+ int radius;
+
+ uint32_t *vMIN;
+ uint32_t *vMAX;
+
+ uint8_t *r;
+ uint8_t *g;
+ uint8_t *b;
+
+ uint8_t *dv;
+} SuperFastBlurContext;
+
+#define OFFSET(x) offsetof(SuperFastBlurContext, x)
+#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
+static const AVOption superfastblur_options[] = {
+ { "radius", "Radius of the super fast blurring box", OFFSET(radius), AV_OPT_TYPE_INT, {.i64 = 2}, 1, 10, FLAGS },
+ { "r", "Radius of the super fast blurring box", OFFSET(radius), AV_OPT_TYPE_INT, {.i64 = 2}, 1, 10, FLAGS },
+ { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(superfastblur);
+
+static av_cold int init(AVFilterContext *ctx)
+{
+ SuperFastBlurContext *s = ctx->priv;
+
+ // This line precalculates a lookup table for all the possible
+ // mean values that can occur. This is to avoid costly division
+ // in the inner loop. On some systems doing the division directly
+ // instead of a doing an array lookup might actually be faster
+ // nowadays.
+ uint32_t div = 2 * s->radius + 1;
+ s->dv = av_malloc(sizeof(*s->dv) * 256 * div);
+ if (!s->dv)
+ return AVERROR(ENOMEM);
+ for (int i = 0; i < 256 * div; i++)
+ s->dv[i] = (i / div);
+
+ return 0;
+}
+
+static int query_formats(AVFilterContext *ctx)
+{
+ static const enum AVPixelFormat pix_fmts[] = {
+ AV_PIX_FMT_RGB24, AV_PIX_FMT_BGR24,
+
+ AV_PIX_FMT_NONE
+ };
+
+ AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
+ if (!fmts_list)
+ return AVERROR(ENOMEM);
+ return ff_set_common_formats(ctx, fmts_list);
+}
+
+static int config_props(AVFilterLink *inlink)
+{
+ AVFilterContext *ctx = inlink->dst;
+ SuperFastBlurContext *s = ctx->priv;
+
+ uint32_t wm = inlink->w - 1;
+ uint32_t wh = inlink->w * inlink->h;
+
+ s->vMIN = av_malloc(sizeof(wm) * FFMAX(inlink->w, inlink->h));
+ s->vMAX = av_malloc(sizeof(wm) * FFMAX(inlink->w, inlink->h));
+ s->r = av_malloc(sizeof(*s->r) * wh);
+ s->g = av_malloc(sizeof(*s->g) * wh);
+ s->b = av_malloc(sizeof(*s->b) * wh);
+
+ if (!s->vMIN || !s->vMAX || !s->r || !s->g || !s->b)
+ return AVERROR(ENOMEM);
+
+ return 0;
+}
+
+/*
+ * Super Fast Blur v1.1+
+ * by Mario Klingemann <http://incubator.quasimondo.com>
+ * Original address: http://incubator.quasimondo.com/processing/superfastblur.pde
+ *
+ * Tip: Multiple invocations of this filter with a small
+ * radius will approximate a gaussian blur quite well.
+ */
+static void superfast_blur(SuperFastBlurContext *s, uint8_t *pix, int w, int h, int nb_comps)
+{
+ uint32_t wm, hm;
+ uint32_t *vMIN, *vMAX;
+ uint8_t *r, *g, *b, *dv;
+ uint32_t rsum, gsum, bsum;
+ uint32_t p, p1, p2, yi, yw;
+
+ int radius;
+
+ int x, y, i, yp;
+
+ wm = w - 1;
+ hm = h - 1;
+
+ vMIN = s->vMIN;
+ vMAX = s->vMAX;
+ r = s->r;
+ g = s->g;
+ b = s->b;
+
+ dv = s->dv;
+
+ radius = s->radius;
+
+ yw = yi = 0;
+ for (y = 0; y < h; y++) {
+ rsum = gsum = bsum = 0;
+ // The reason why this algorithm is fast is that it uses a sliding
+ // window and thus reduces the number of required pixel lookups.
+ // The window slides from the left edge to the right (and in the
+ // second pass from top to bottom) and only adds one pixel at the
+ // right and removes one from the left. The code above initializes
+ // the window by prefilling the window with the leftmost edge pixel
+ // depending on the kernel size.
+ for (i = -radius; i <= radius; i++) {
+ p = (yi + FFMIN(wm, FFMAX(i, 0))) * nb_comps;
+ rsum += pix[p];
+ gsum += pix[p + 1];
+ bsum += pix[p + 2];
+ }
+
+ for (x = 0; x < w; x++) {
+ r[yi] = dv[rsum];
+ g[yi] = dv[gsum];
+ b[yi] = dv[bsum];
+
+ // adds a new pixel but at the same time handles the border
+ // conditions (when the window tries to read or remove pixels
+ // outside the bitmap).
+ if (y == 0) {
+ vMIN[x] = FFMIN(x + radius + 1, wm);
+ vMAX[x] = FFMAX(x - radius, 0);
+ }
+ p1 = (yw + vMIN[x]) * nb_comps;
+ p2 = (yw + vMAX[x]) * nb_comps;
+ rsum += pix[p1] - pix[p2];
+ gsum += pix[p1 + 1] - pix[p2 + 1];
+ bsum += pix[p1 + 2] - pix[p2 + 2];
+ yi++;
+ }
+ yw += w;
+ }
+
+ for (x = 0; x < w; x++) {
+ rsum = gsum = bsum = 0;
+ yp = -radius * w;
+ for (i = -radius; i <= radius; i++) {
+ yi = FFMAX(0, yp) + x;
+ rsum += r[yi];
+ gsum += g[yi];
+ bsum += b[yi];
+ yp += w;
+ }
+
+ yi = x;
+ for (y = 0; y < h; y++) {
+ pix[yi * nb_comps] = dv[bsum];
+ pix[yi * nb_comps + 1] = dv[gsum];
+ pix[yi * nb_comps + 2] = dv[rsum];
+
+ if (x == 0) {
+ vMIN[y] = FFMIN(y + radius + 1, hm) * w;
+ vMAX[y] = FFMAX(y - radius, 0) * w;
+ }
+ p1 = x + vMIN[y];
+ p2 = x + vMAX[y];
+
+ // rsum, gsum and bsum is the accumulated sum of pixels inside
+ // the sliding window. What you see is the new pixel on the
+ // right side being added to the sum and the leftmost pixel
+ // i nthe window being removed from the sum.
+ rsum += r[p1] - r[p2];
+ gsum += g[p1] - g[p2];
+ bsum += b[p1] - b[p2];
+ yi += w;
+ }
+ }
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *in)
+{
+ AVFilterContext *ctx = inlink->dst;
+ SuperFastBlurContext *s = ctx->priv;
+ AVFilterLink *outlink = ctx->outputs[0];
+ const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
+
+ superfast_blur(s, in->data[0], inlink->w, inlink->h, desc->nb_components);
+
+ return ff_filter_frame(outlink, in);
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+ SuperFastBlurContext *s = ctx->priv;
+
+ av_freep(&s->r);
+ av_freep(&s->g);
+ av_freep(&s->b);
+ av_freep(&s->vMIN);
+ av_freep(&s->vMAX);
+ av_freep(&s->dv);
+}
+
+static const AVFilterPad superfastblur_inputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .config_props = config_props,
+ .filter_frame = filter_frame,
+ },
+ { NULL }
+};
+
+static const AVFilterPad superfastblur_outputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ },
+ { NULL }
+};
+
+AVFilter ff_vf_superfastblur = {
+ .name = "superfastblur",
+ .description = NULL_IF_CONFIG_SMALL("Blur the input with super fast blur algorithm."),
+ .priv_size = sizeof(SuperFastBlurContext),
+ .init = init,
+ .uninit = uninit,
+ .query_formats = query_formats,
+ .inputs = superfastblur_inputs,
+ .outputs = superfastblur_outputs,
+ .priv_class = &superfastblur_class,
+ .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
+};
--
1.7.1
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