[FFmpeg-devel] [PATCH] Add 'drawgrid' video filter

[Stefano Sabatini]

On date Saturday 2013-05-11 17:02:49 +0300, Andrey Utkin encoded:
> Fixed nits pointed by Clement, thanks to him for review.
> Also fixed remaining 'drawbox' mention in texi
> ---8<---
> ---
>  doc/filters.texi          |  39 +++++++++
>  libavfilter/Makefile      |   1 +
>  libavfilter/allfilters.c  |   1 +
>  libavfilter/vf_drawgrid.c | 206 ++++++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 247 insertions(+)
>  create mode 100644 libavfilter/vf_drawgrid.c
> 
> diff --git a/doc/filters.texi b/doc/filters.texi
> index fe38b7f..2beb471 100644
> --- a/doc/filters.texi
> +++ b/doc/filters.texi
> @@ -2877,6 +2877,45 @@ drawbox=x=10:y=10:w=100:h=100:color=pink@@0.5:t=max
>  @end example
>  @end itemize
>  
> + at section drawgrid
> +
> +Draw a grid on the input image.
> +
> +This filter accepts the following options:
> +
> + at table @option
> + at item x
> + at item y
> +Specify the coordinates of some point of grid intersection (meant to configure offset). Both default to 0.
> +
> + at item width, w
> + at item height, h
> +Specify the width and height of the grid cell, if 0 they are interpreted as the
> +input width and height, respectively, minus @code{thickness}, so image gets
> +framed. Default to 0.
> +
> + at item color, c
> +Specify the color of the grid, it can be the name of a color
> +(case insensitive match) or a 0xRRGGBB[AA] sequence. If the special
> +value @code{invert} is used, the grid color is the same as the
> +video with inverted luma.
> +Note that you can append opacity value (in range of 0.0 - 1.0)
> +to color name after @@ sign.
> +
> + at item thickness, t
> +Set the thickness of the grid line. Default value is @code{1}.
> + at end table
> +
> + at subsection Examples
> +
> + at itemize
> + at item
> +Draw a grid with cell 100x100 pixels, thickness 2 pixels, with color red and an opacity of 50%:
> + at example
> +drawgrid=width=100:height=100:thickness=2:color=red@@0.5
> + at end example
> + at end itemize
> +
>  @anchor{drawtext}
>  @section drawtext
>  
> diff --git a/libavfilter/Makefile b/libavfilter/Makefile
> index f0e703e..5d571ad 100644
> --- a/libavfilter/Makefile
> +++ b/libavfilter/Makefile
> @@ -119,6 +119,7 @@ OBJS-$(CONFIG_DECIMATE_FILTER)               += vf_decimate.o
>  OBJS-$(CONFIG_DELOGO_FILTER)                 += vf_delogo.o
>  OBJS-$(CONFIG_DESHAKE_FILTER)                += vf_deshake.o
>  OBJS-$(CONFIG_DRAWBOX_FILTER)                += vf_drawbox.o
> +OBJS-$(CONFIG_DRAWGRID_FILTER)               += vf_drawgrid.o
>  OBJS-$(CONFIG_DRAWTEXT_FILTER)               += vf_drawtext.o
>  OBJS-$(CONFIG_EDGEDETECT_FILTER)             += vf_edgedetect.o
>  OBJS-$(CONFIG_EXTRACTPLANES_FILTER)          += vf_extractplanes.o
> diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
> index b8f273d..413dc54 100644
> --- a/libavfilter/allfilters.c
> +++ b/libavfilter/allfilters.c
> @@ -117,6 +117,7 @@ void avfilter_register_all(void)
>      REGISTER_FILTER(DELOGO,         delogo,         vf);
>      REGISTER_FILTER(DESHAKE,        deshake,        vf);
>      REGISTER_FILTER(DRAWBOX,        drawbox,        vf);
> +    REGISTER_FILTER(DRAWGRID,       drawgrid,       vf);
>      REGISTER_FILTER(DRAWTEXT,       drawtext,       vf);
>      REGISTER_FILTER(EDGEDETECT,     edgedetect,     vf);
>      REGISTER_FILTER(EXTRACTPLANES,  extractplanes,  vf);
> diff --git a/libavfilter/vf_drawgrid.c b/libavfilter/vf_drawgrid.c
> new file mode 100644
> index 0000000..3be47e2
> --- /dev/null
> +++ b/libavfilter/vf_drawgrid.c
> @@ -0,0 +1,206 @@
> +/*
> + * Copyright (c) 2008 Affine Systems, Inc (Michael Sullivan, Bobby Impollonia)
> + * Copyright (c) 2013 Andrey Utkin <andrey.krieger.utkin 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
> + * Grid drawing filter.
> + * Code derived from drawbox filter.
> + */
> +
> +#include "libavutil/colorspace.h"
> +#include "libavutil/common.h"
> +#include "libavutil/opt.h"
> +#include "libavutil/pixdesc.h"
> +#include "libavutil/parseutils.h"
> +#include "avfilter.h"
> +#include "formats.h"
> +#include "internal.h"
> +#include "video.h"
> +

> +enum { Y, U, V, A };
> +
> +typedef struct {
> +    const AVClass *class;
> +    int x, y, w, h, thickness;
> +    char *color_str;
> +    unsigned char yuv_color[4];
> +    int invert_color; ///< invert luma color
> +    int vsub, hsub;   ///< chroma subsampling
> +} DrawGridContext;
> +
> +static av_cold int init(AVFilterContext *ctx)
> +{
> +    DrawGridContext *drawgrid = ctx->priv;
> +    uint8_t rgba_color[4];
> +
> +    if (!strcmp(drawgrid->color_str, "invert"))
> +        drawgrid->invert_color = 1;
> +    else if (av_parse_color(rgba_color, drawgrid->color_str, -1, ctx) < 0)
> +        return AVERROR(EINVAL);
> +
> +    if (!drawgrid->invert_color) {
> +        drawgrid->yuv_color[Y] = RGB_TO_Y_CCIR(rgba_color[0], rgba_color[1], rgba_color[2]);
> +        drawgrid->yuv_color[U] = RGB_TO_U_CCIR(rgba_color[0], rgba_color[1], rgba_color[2], 0);
> +        drawgrid->yuv_color[V] = RGB_TO_V_CCIR(rgba_color[0], rgba_color[1], rgba_color[2], 0);
> +        drawgrid->yuv_color[A] = rgba_color[3];
> +    }
> +
> +    return 0;
> +}
> +
> +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_YUVJ444P, AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ420P,
> +        AV_PIX_FMT_YUV440P,  AV_PIX_FMT_YUVJ440P,
> +        AV_PIX_FMT_NONE
> +    };
> +
> +    ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
> +    return 0;
> +}
> +
> +static int config_input(AVFilterLink *inlink)
> +{
> +    DrawGridContext *drawgrid = inlink->dst->priv;
> +    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
> +
> +    drawgrid->hsub = desc->log2_chroma_w;
> +    drawgrid->vsub = desc->log2_chroma_h;
> +
> +    if (drawgrid->w == 0) drawgrid->w = inlink->w - drawgrid->thickness;
> +    if (drawgrid->h == 0) drawgrid->h = inlink->h - drawgrid->thickness;
> +
> +    av_log(inlink->dst, AV_LOG_VERBOSE, "x:%d y:%d w:%d h:%d color:0x%02X%02X%02X%02X\n",
> +           drawgrid->x, drawgrid->y, drawgrid->w, drawgrid->h,
> +           drawgrid->yuv_color[Y], drawgrid->yuv_color[U], drawgrid->yuv_color[V], drawgrid->yuv_color[A]);
> +
> +    return 0;
> +}
> +

I see this code is mostly duplicated from vf_drawbox.c. What about
defining the code in vf_drawbox.c, so that it can be factorized?

[...]
-- 
FFmpeg = Faithless Furious Marvellous Plastic Eretic Gadget