[FFmpeg-devel] [PATCH] lavfi/WIP: vignette filter.

Stefano Sabatini stefasab at gmail.com
Sun May 12 15:40:25 CEST 2013


On date Friday 2013-05-10 18:49:22 +0200, Clément Bœsch encoded:
> On Thu, Apr 04, 2013 at 05:15:29PM +0200, Clément Bœsch wrote:
> [...]
> 
> New version attached.
> 
> -- 
> Clément B.

> From 9c88f51e80929efed15a432d2fb8dab26a77f84e 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 | 306 ++++++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 406 insertions(+)
>  create mode 100644 libavfilter/vf_vignette.c
> 
> diff --git a/doc/filters.texi b/doc/filters.texi
> index fe38b7f..1866988 100644
> --- a/doc/filters.texi
> +++ b/doc/filters.texi
> @@ -6667,6 +6667,104 @@ 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 vignette effect.
> +
> +The filter accepts the following options:
> +
> + at table @option
> + at item angle, a
> +Set lens angle expression.

... as a number of radians, or people will invariably try to use silly
1/360 degrees.

> +
> +The value is clipped in the @code{[0,PI/2]} range.
> +
> +Default value: "PI/5"

An explanation of the meaning of this angle would be welcome.

> +
> + 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) of the filtered video frame,
> +expressed in @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

technically a time is not a PTS, more accurate:
the PTS (Presentation TimeStamp) *time*

> +
> + at item tb
> +time base of the input video
> + at end table
> +
> +
> + at subsection Examples
> +
> + at itemize

> + at item
> +Simple strong vignetting effect:

Apply simple ...

> + at example
> +vignette=PI/4
> + at end example
> +
> + at item
> +Flickering vignetting:

Apply flickering ...

> + 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 73a24dd..a715f91 100644
> --- a/libavfilter/Makefile
> +++ b/libavfilter/Makefile
> @@ -185,6 +185,7 @@ 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_CELLAUTO_FILTER)               += vsrc_cellauto.o
> diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
> index b8f273d..3b6047c 100644
> --- a/libavfilter/allfilters.c
> +++ b/libavfilter/allfilters.c
> @@ -182,6 +182,7 @@ 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(CELLAUTO,       cellauto,       vsrc);
> diff --git a/libavfilter/vf_vignette.c b/libavfilter/vf_vignette.c
> new file mode 100644
> index 0000000..6d92abc
> --- /dev/null
> +++ b/libavfilter/vf_vignette.c
> @@ -0,0 +1,306 @@
> +/*
> + * 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(a);
> +    DEF_EXPR_FIELDS(x0);
> +    DEF_EXPR_FIELDS(y0);
> +    double var_values[VAR_NB];
> +    double *fmap;
> +    int fmap_linesize;
> +    double dmax;
> +    double xscale, yscale;
> +} 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(a_expr), AV_OPT_TYPE_STRING, {.str="PI/5"}, .flags = FLAGS },
> +    { "a",     "set lens angle", OFFSET(a_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" },
> +    { NULL }
> +};
> +
> +AVFILTER_DEFINE_CLASS(vignette);
> +

> +static av_cold int init(AVFilterContext *ctx)
> +{
> +    int ret;
> +    VignetteContext *s = ctx->priv;
> +
> +    if ((ret = av_expr_parse(&s->a_pexpr,  s->a_expr,  var_names, NULL, NULL, NULL, NULL, 0, ctx)) < 0 ||
> +        (ret = av_expr_parse(&s->x0_pexpr, s->x0_expr, var_names, NULL, NULL, NULL, NULL, 0, ctx)) < 0 ||
> +        (ret = av_expr_parse(&s->y0_pexpr, s->y0_expr, var_names, NULL, NULL, NULL, NULL, 0, ctx)) < 0)

You could create a macro to specify the name of expression which
failed.

> +        return ret;
> +    return 0;
> +}
> +
> +static av_cold void uninit(AVFilterContext *ctx)
> +{
> +    VignetteContext *s = ctx->priv;
> +    av_freep(&s->fmap);
> +    av_expr_free(s->a_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->a * dnorm);
> +        return (c*c)*(c*c); // XXX: 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))

we may move these to a common header...

> +
> +static void update_context(VignetteContext *s, AVFilterLink *inlink, AVFrame *frame)
> +{
> +    int x, y;
> +    double *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->a = av_clipf(av_expr_eval(s->a_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 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);
> +            }
> +            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 double *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++)
> +                    if (chroma) *dstp++ = av_clip_uint8(fmap[x << hsub] * (*srcp++ - 127) + 127);
> +                    else        *dstp++ = av_clip_uint8(fmap[x        ] *  *srcp++);
> +                dst += dst_linesize;
> +                src += src_linesize;
> +                fmap += fmap_linesize << vsub;
> +            }
> +        }
> +    }
> +
> +    return ff_filter_frame(outlink, out);
> +}
> +

> +static int config_props(AVFilterLink *inlink)

nit: move this before filter_frame()

> +{
> +    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));

check for int overflow?

> +    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,
> +};

No more comments from me, thanks.
-- 
FFmpeg = Fiendish Furious Mega Portable Easy Goblin


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