[FFmpeg-devel] [PATCH] lavfi/WIP: vignette filter.
Clément Bœsch
ubitux at gmail.com
Wed May 29 02:44:34 CEST 2013
On Mon, May 13, 2013 at 12:31:54AM +0200, Michael Niedermayer wrote:
> On Fri, May 10, 2013 at 06:49:22PM +0200, Clément Bœsch wrote:
> > On Thu, Apr 04, 2013 at 05:15:29PM +0200, Clément Bœsch wrote:
> > [...]
> >
> > New version attached.
> [...]
>
> > +typedef struct {
> > + const AVClass *class;
> > + const AVPixFmtDescriptor *desc;
> > + int backward;
> > + enum EvalMode { EVAL_MODE_INIT, EVAL_MODE_FRAME, EVAL_MODE_NB } eval_mode;
> > +#define DEF_EXPR_FIELDS(name) AVExpr *name##_pexpr; char *name##_expr; double name;
> > + DEF_EXPR_FIELDS(a);
> > + DEF_EXPR_FIELDS(x0);
> > + DEF_EXPR_FIELDS(y0);
> > + double var_values[VAR_NB];
>
> > + double *fmap;
>
> isnt double overkill ?
>
Yeah likely. Replaced with float, same for xscale and yscale.
>
> [...]
> > +static double get_natural_factor(const VignetteContext *s, int x, int y)
> > +{
> > + const int xx = (x - s->x0) * s->xscale;
> > + const int yy = (y - s->y0) * s->yscale;
> > + const double dnorm = hypot(xx, yy) / s->dmax;
> > + if (dnorm > 1) {
> > + return 0;
> > + } else {
> > + const double c = cos(s->a * dnorm);
> > + return (c*c)*(c*c); // XXX: do not remove braces, it helps compilers
> > + }
> > +}
>
> this looks a bit unflexible, how well does this work for removing
> actual vignetting from pictures taken with actual lenses ?
>
I looked more closely at the lens correction, but it actually looks like
it would belong in a separate filter to me.
Typically, with lens correction you end up with the following formula:
r = a*r^4 + b*r^3 + c*r^2 + d*r
input r being the distance from the origin of the lens to the current
pixel (radius) and output r is the new radius. Then you likely have to
distort the image to achieve the effect; basically "moving pixels" (barrel
distortion, or its inverse pincushion) which is not what we are doing in
this filter.
The cosine 4 formula I use here seems to be the common way of simulating
the lightning vignetting effect: https://en.wikipedia.org/wiki/Vignetting
more precisely, the Natural Vignetting (which I now mention in the
filter's documentation)
Another lens filter, with different parameters (a, b, c and d) could
re-use the basis of this filter, but I believe it's a different purpose
than what I'm trying to achieve here.
[...]
> > +static int filter_frame(AVFilterLink *inlink, AVFrame *in)
> > +{
> > + unsigned x, y;
> > + AVFilterContext *ctx = inlink->dst;
> > + VignetteContext *s = ctx->priv;
> > + AVFilterLink *outlink = inlink->dst->outputs[0];
> > + AVFrame *out;
> > +
> > + out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
> > + if (!out) {
> > + av_frame_free(&in);
> > + return AVERROR(ENOMEM);
> > + }
> > + av_frame_copy_props(out, in);
> > +
> > + if (s->eval_mode == EVAL_MODE_FRAME)
> > + update_context(s, inlink, in);
> > +
> > + if (s->desc->flags & PIX_FMT_RGB) {
> > + uint8_t *dst = out->data[0];
> > + const uint8_t *src = in ->data[0];
> > + const double *fmap = s->fmap;
> > + const int dst_linesize = out->linesize[0];
> > + const int src_linesize = in ->linesize[0];
> > + const int fmap_linesize = s->fmap_linesize;
> > +
> > + for (y = 0; y < inlink->h; y++) {
> > + uint8_t *dstp = dst;
> > + const uint8_t *srcp = src;
> > +
> > + for (x = 0; x < inlink->w; x++, dstp += 3, srcp += 3) {
> > + const double f = fmap[x];
> > +
> > + dstp[0] = av_clip_uint8(srcp[0] * f);
> > + dstp[1] = av_clip_uint8(srcp[1] * f);
> > + dstp[2] = av_clip_uint8(srcp[2] * f);
>
> i think with just 8bit this kind of filter is prone to banding
> artifacts without dither
>
Yep, you are right, I've added some dithering (taken from mandelbrot,
thank you).
[...]
New patch attached.
--
Clément B.
-------------- next part --------------
From 72d07081bac8d6bb2de4f0428f0068faf9539a3d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cl=C3=A9ment=20B=C5=93sch?= <ubitux at gmail.com>
Date: Tue, 2 Apr 2013 12:48:32 +0200
Subject: [PATCH] lavfi: vignette filter.
TODO: minor bump
---
doc/filters.texi | 98 ++++++++++++++
libavfilter/Makefile | 1 +
libavfilter/allfilters.c | 1 +
libavfilter/vf_vignette.c | 330 ++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 430 insertions(+)
create mode 100644 libavfilter/vf_vignette.c
diff --git a/doc/filters.texi b/doc/filters.texi
index 75a2d6a..65637ea 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -6950,6 +6950,104 @@ For example, to vertically flip a video with @command{ffmpeg}:
ffmpeg -i in.avi -vf "vflip" out.avi
@end example
+ at section vignette
+
+Make or reverse a natural vignetting effect.
+
+The filter accepts the following options:
+
+ at table @option
+ at item angle, a
+Set lens angle expression as a number of radians.
+
+The value is clipped in the @code{[0,PI/2]} range.
+
+Default value: "PI/5"
+
+ at item x0
+ at item y0
+Set center coordinates expressions. Respectively @code{"w/2"} and @code{"h/2"}
+by default.
+
+ at item mode
+Set forward/backward mode.
+
+Available modes are:
+ at table @samp
+ at item forward
+The larger the distance from the central point, the darker the image becomes.
+
+ at item backward
+The larger the distance from the central point, the brighter the image becomes.
+This can be used to reverse a vignette effect, though there is no automatic
+detection to extract the lens @option{angle} and other settings (yet).
+ at end table
+
+Default value is @samp{forward}.
+
+ at item eval
+Set evaluation mode for the expressions (@option{angle}, @option{x0}, @option{y0}).
+
+It accepts the following values:
+ at table @samp
+ at item init
+Evaluate expressions only once during the filter initialization.
+
+ at item frame
+Evaluate expressions for each incoming frame. This is way slower than the
+ at samp{init} mode since it requires all the scalers to be re-computed, but it
+allows advanced dynamic expressions.
+ at end table
+
+Default value is @samp{init}.
+ at end table
+
+ at subsection Expressions
+
+The @option{alpha}, @option{x0} and @option{y0} expressions can contain the
+following parameters.
+
+ at table @option
+ at item w
+ at item h
+input width and height
+
+ at item n
+the number of input frame, starting from 0
+
+ at item pts
+the PTS (Presentation TimeStamp) time of the filtered video frame, expressed in
+ at var{TB} units, NAN if undefined
+
+ at item r
+frame rate of the input video, NAN if the input frame rate is unknown
+
+ at item t
+the PTS (Presentation TimeStamp) of the filtered video frame,
+expressed in seconds, NAN if undefined
+
+ at item tb
+time base of the input video
+ at end table
+
+
+ at subsection Examples
+
+ at itemize
+ at item
+Apply simple strong vignetting effect:
+ at example
+vignette=PI/4
+ at end example
+
+ at item
+Make a flickering vignetting:
+ at example
+vignette='PI/4+random(1)*PI/50':eval=frame
+ at end example
+
+ at end itemize
+
@anchor{yadif}
@section yadif
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 4ee28bf..e1affbf 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -191,6 +191,7 @@ OBJS-$(CONFIG_UNSHARP_FILTER) += vf_unsharp.o
OBJS-$(CONFIG_VFLIP_FILTER) += vf_vflip.o
OBJS-$(CONFIG_VIDSTABDETECT_FILTER) += vidstabutils.o vf_vidstabdetect.o
OBJS-$(CONFIG_VIDSTABTRANSFORM_FILTER) += vidstabutils.o vf_vidstabtransform.o
+OBJS-$(CONFIG_VIGNETTE_FILTER) += vf_vignette.o
OBJS-$(CONFIG_YADIF_FILTER) += vf_yadif.o
OBJS-$(CONFIG_ZMQ_FILTER) += f_zmq.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 58bffc7..6130d09 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -188,6 +188,7 @@ void avfilter_register_all(void)
REGISTER_FILTER(VFLIP, vflip, vf);
REGISTER_FILTER(VIDSTABDETECT, vidstabdetect, vf);
REGISTER_FILTER(VIDSTABTRANSFORM, vidstabtransform, vf);
+ REGISTER_FILTER(VIGNETTE, vignette, vf);
REGISTER_FILTER(YADIF, yadif, vf);
REGISTER_FILTER(ZMQ, zmq, vf);
diff --git a/libavfilter/vf_vignette.c b/libavfilter/vf_vignette.c
new file mode 100644
index 0000000..eb72fae
--- /dev/null
+++ b/libavfilter/vf_vignette.c
@@ -0,0 +1,330 @@
+/*
+ * Copyright (c) 2013 Clément Bœsch
+ *
+ * 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/opt.h"
+#include "libavutil/eval.h"
+#include "libavutil/avassert.h"
+#include "libavutil/pixdesc.h"
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+#include "video.h"
+
+static const char *const var_names[] = {
+ "w", // stream width
+ "h", // stream height
+ "n", // frame count
+ "pts", // presentation timestamp expressed in AV_TIME_BASE units
+ "r", // frame rate
+ "t", // timestamp expressed in seconds
+ "tb", // timebase
+ NULL
+};
+
+enum var_name {
+ VAR_W,
+ VAR_H,
+ VAR_N,
+ VAR_PTS,
+ VAR_R,
+ VAR_T,
+ VAR_TB,
+ VAR_NB
+};
+
+typedef struct {
+ const AVClass *class;
+ const AVPixFmtDescriptor *desc;
+ int backward;
+ enum EvalMode { EVAL_MODE_INIT, EVAL_MODE_FRAME, EVAL_MODE_NB } eval_mode;
+#define DEF_EXPR_FIELDS(name) AVExpr *name##_pexpr; char *name##_expr; double name;
+ DEF_EXPR_FIELDS(angle);
+ DEF_EXPR_FIELDS(x0);
+ DEF_EXPR_FIELDS(y0);
+ double var_values[VAR_NB];
+ float *fmap;
+ int fmap_linesize;
+ double dmax;
+ float xscale, yscale;
+ uint32_t dither;
+ int do_dither;
+} VignetteContext;
+
+#define OFFSET(x) offsetof(VignetteContext, x)
+#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
+static const AVOption vignette_options[] = {
+ { "angle", "set lens angle", OFFSET(angle_expr), AV_OPT_TYPE_STRING, {.str="PI/5"}, .flags = FLAGS },
+ { "a", "set lens angle", OFFSET(angle_expr), AV_OPT_TYPE_STRING, {.str="PI/5"}, .flags = FLAGS },
+ { "x0", "set circle center position on x-axis", OFFSET(x0_expr), AV_OPT_TYPE_STRING, {.str="w/2"}, .flags = FLAGS },
+ { "y0", "set circle center position on y-axis", OFFSET(y0_expr), AV_OPT_TYPE_STRING, {.str="h/2"}, .flags = FLAGS },
+ { "mode", "set forward/backward mode", OFFSET(backward), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, FLAGS, "mode" },
+ { "forward", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 0}, INT_MIN, INT_MAX, FLAGS, "mode"},
+ { "backward", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 1}, INT_MIN, INT_MAX, FLAGS, "mode"},
+ { "eval", "specify when to evaluate expressions", OFFSET(eval_mode), AV_OPT_TYPE_INT, {.i64 = EVAL_MODE_INIT}, 0, EVAL_MODE_NB-1, FLAGS, "eval" },
+ { "init", "eval expressions once during initialization", 0, AV_OPT_TYPE_CONST, {.i64=EVAL_MODE_INIT}, .flags = FLAGS, .unit = "eval" },
+ { "frame", "eval expressions for each frame", 0, AV_OPT_TYPE_CONST, {.i64=EVAL_MODE_FRAME}, .flags = FLAGS, .unit = "eval" },
+ { "dither", "set dithering", OFFSET(do_dither), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, FLAGS },
+ { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(vignette);
+
+static av_cold int init(AVFilterContext *ctx)
+{
+ VignetteContext *s = ctx->priv;
+
+#define PARSE_EXPR(name) do { \
+ int ret = av_expr_parse(&s->name##_pexpr, s->name##_expr, var_names, \
+ NULL, NULL, NULL, NULL, 0, ctx); \
+ if (ret < 0) { \
+ av_log(ctx, AV_LOG_ERROR, "Unable to parse expression for '" \
+ AV_STRINGIFY(name) "'\n"); \
+ return ret; \
+ } \
+} while (0)
+
+ PARSE_EXPR(angle);
+ PARSE_EXPR(x0);
+ PARSE_EXPR(y0);
+ return 0;
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+ VignetteContext *s = ctx->priv;
+ av_freep(&s->fmap);
+ av_expr_free(s->angle_pexpr);
+ av_expr_free(s->x0_pexpr);
+ av_expr_free(s->y0_pexpr);
+}
+
+static int query_formats(AVFilterContext *ctx)
+{
+ static const enum AVPixelFormat pix_fmts[] = {
+ AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV422P,
+ AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV411P,
+ AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV440P,
+ AV_PIX_FMT_RGB24, AV_PIX_FMT_BGR24,
+ AV_PIX_FMT_GRAY8,
+ AV_PIX_FMT_NONE
+ };
+ ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
+ return 0;
+}
+
+static double get_natural_factor(const VignetteContext *s, int x, int y)
+{
+ const int xx = (x - s->x0) * s->xscale;
+ const int yy = (y - s->y0) * s->yscale;
+ const double dnorm = hypot(xx, yy) / s->dmax;
+ if (dnorm > 1) {
+ return 0;
+ } else {
+ const double c = cos(s->angle * dnorm);
+ return (c*c)*(c*c); // do not remove braces, it helps compilers
+ }
+}
+
+#define TS2D(ts) ((ts) == AV_NOPTS_VALUE ? NAN : (double)(ts))
+#define TS2T(ts, tb) ((ts) == AV_NOPTS_VALUE ? NAN : (double)(ts) * av_q2d(tb))
+
+static void update_context(VignetteContext *s, AVFilterLink *inlink, AVFrame *frame)
+{
+ int x, y;
+ float *dst = s->fmap;
+ int dst_linesize = s->fmap_linesize;
+
+ if (frame) {
+ s->var_values[VAR_N] = inlink->frame_count;
+ s->var_values[VAR_T] = TS2T(frame->pts, inlink->time_base);
+ s->var_values[VAR_PTS] = TS2D(frame->pts);
+ } else {
+ s->var_values[VAR_N] = 0;
+ s->var_values[VAR_T] = NAN;
+ s->var_values[VAR_PTS] = NAN;
+ }
+
+ s->angle = av_clipf(av_expr_eval(s->angle_pexpr, s->var_values, NULL), 0, M_PI_2);
+ s->x0 = av_expr_eval(s->x0_pexpr, s->var_values, NULL);
+ s->y0 = av_expr_eval(s->y0_pexpr, s->var_values, NULL);
+
+ if (s->backward) {
+ for (y = 0; y < inlink->h; y++) {
+ for (x = 0; x < inlink->w; x++)
+ dst[x] = 1. / get_natural_factor(s, x, y);
+ dst += dst_linesize;
+ }
+ } else {
+ for (y = 0; y < inlink->h; y++) {
+ for (x = 0; x < inlink->w; x++)
+ dst[x] = get_natural_factor(s, x, y);
+ dst += dst_linesize;
+ }
+ }
+}
+
+static inline double get_dither_value(VignetteContext *s)
+{
+ double dv = 0;
+ if (s->do_dither) {
+ dv = s->dither / (double)(1LL<<32);
+ s->dither = s->dither * 1664525 + 1013904223;
+ }
+ return dv;
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *in)
+{
+ unsigned x, y;
+ AVFilterContext *ctx = inlink->dst;
+ VignetteContext *s = ctx->priv;
+ AVFilterLink *outlink = inlink->dst->outputs[0];
+ AVFrame *out;
+
+ out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
+ if (!out) {
+ av_frame_free(&in);
+ return AVERROR(ENOMEM);
+ }
+ av_frame_copy_props(out, in);
+
+ if (s->eval_mode == EVAL_MODE_FRAME)
+ update_context(s, inlink, in);
+
+ if (s->desc->flags & PIX_FMT_RGB) {
+ uint8_t *dst = out->data[0];
+ const uint8_t *src = in ->data[0];
+ const float *fmap = s->fmap;
+ const int dst_linesize = out->linesize[0];
+ const int src_linesize = in ->linesize[0];
+ const int fmap_linesize = s->fmap_linesize;
+
+ for (y = 0; y < inlink->h; y++) {
+ uint8_t *dstp = dst;
+ const uint8_t *srcp = src;
+
+ for (x = 0; x < inlink->w; x++, dstp += 3, srcp += 3) {
+ const double f = fmap[x];
+
+ dstp[0] = av_clip_uint8(srcp[0] * f + get_dither_value(s));
+ dstp[1] = av_clip_uint8(srcp[1] * f + get_dither_value(s));
+ dstp[2] = av_clip_uint8(srcp[2] * f + get_dither_value(s));
+ }
+ dst += dst_linesize;
+ src += src_linesize;
+ fmap += fmap_linesize;
+ }
+ } else {
+ int plane;
+
+ for (plane = 0; plane < 4 && in->data[plane]; plane++) {
+ uint8_t *dst = out->data[plane];
+ const uint8_t *src = in ->data[plane];
+ const float *fmap = s->fmap;
+ const int dst_linesize = out->linesize[plane];
+ const int src_linesize = in ->linesize[plane];
+ const int fmap_linesize = s->fmap_linesize;
+ const int chroma = plane == 1 || plane == 2;
+ const int hsub = chroma ? s->desc->log2_chroma_w : 0;
+ const int vsub = chroma ? s->desc->log2_chroma_h : 0;
+ const int w = FF_CEIL_RSHIFT(inlink->w, hsub);
+ const int h = FF_CEIL_RSHIFT(inlink->h, vsub);
+
+ for (y = 0; y < h; y++) {
+ uint8_t *dstp = dst;
+ const uint8_t *srcp = src;
+
+ for (x = 0; x < w; x++) {
+ const double dv = get_dither_value(s);
+ if (chroma) *dstp++ = av_clip_uint8(fmap[x << hsub] * (*srcp++ - 127) + 127 + dv);
+ else *dstp++ = av_clip_uint8(fmap[x ] * *srcp++ + dv);
+ }
+ dst += dst_linesize;
+ src += src_linesize;
+ fmap += fmap_linesize << vsub;
+ }
+ }
+ }
+
+ return ff_filter_frame(outlink, out);
+}
+
+static int config_props(AVFilterLink *inlink)
+{
+ VignetteContext *s = inlink->dst->priv;
+
+ s->desc = av_pix_fmt_desc_get(inlink->format);
+ s->var_values[VAR_W] = inlink->w;
+ s->var_values[VAR_H] = inlink->h;
+ s->var_values[VAR_TB] = av_q2d(inlink->time_base);
+ s->var_values[VAR_R] = inlink->frame_rate.num == 0 || inlink->frame_rate.den == 0 ?
+ NAN : av_q2d(inlink->frame_rate);
+
+ if (inlink->sample_aspect_ratio.num > inlink->sample_aspect_ratio.den) {
+ s->xscale = av_q2d(inlink->sample_aspect_ratio);
+ s->yscale = 1;
+ s->dmax = hypot(inlink->w / 2., s->yscale * inlink->h / 2.);
+ } else {
+ s->yscale = av_q2d(inlink->sample_aspect_ratio);
+ s->xscale = 1;
+ s->dmax = hypot(s->xscale * inlink->w / 2., inlink->h / 2.);
+ }
+
+ s->fmap_linesize = FFALIGN(inlink->w, 32);
+ s->fmap = av_malloc(s->fmap_linesize * inlink->h * sizeof(*s->fmap));
+ if (!s->fmap)
+ return AVERROR(ENOMEM);
+
+ if (s->eval_mode == EVAL_MODE_INIT)
+ update_context(s, inlink, NULL);
+
+ return 0;
+}
+
+static const AVFilterPad vignette_inputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .filter_frame = filter_frame,
+ .config_props = config_props,
+ },
+ { NULL }
+};
+
+static const AVFilterPad vignette_outputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ },
+ { NULL }
+};
+
+AVFilter avfilter_vf_vignette = {
+ .name = "vignette",
+ .description = NULL_IF_CONFIG_SMALL("Make or reverse a vignette effect."),
+ .priv_size = sizeof(VignetteContext),
+ .init = init,
+ .uninit = uninit,
+ .query_formats = query_formats,
+ .inputs = vignette_inputs,
+ .outputs = vignette_outputs,
+ .priv_class = &vignette_class,
+ .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
+};
--
1.8.3
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 490 bytes
Desc: not available
URL: <http://ffmpeg.org/pipermail/ffmpeg-devel/attachments/20130529/b23996f5/attachment.asc>
More information about the ffmpeg-devel
mailing list