[FFmpeg-devel] [PATCH] histogram filter
Stefano Sabatini
stefasab at gmail.com
Mon Dec 31 17:01:22 CET 2012
On date Monday 2012-12-31 15:16:06 +0000, Paul B Mahol encoded:
> Signed-off-by: Paul B Mahol <onemda at gmail.com>
> ---
> doc/filters.texi | 57 +++++++++
> libavfilter/Makefile | 1 +
> libavfilter/allfilters.c | 1 +
> libavfilter/vf_histogram.c | 290 +++++++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 349 insertions(+)
> create mode 100644 libavfilter/vf_histogram.c
Reminder: minor bump
> diff --git a/doc/filters.texi b/doc/filters.texi
> index 76e8fb5..cbf49a5 100644
> --- a/doc/filters.texi
> +++ b/doc/filters.texi
> @@ -2664,6 +2664,63 @@ For example to horizontally flip the input video with @command{ffmpeg}:
> ffmpeg -i in.avi -vf "hflip" out.avi
> @end example
>
> + at section histogram
> +
> +Compute and draw an histogram.
This could be expanded a bit. What does the drawn histogram represent?
> +
> +The filter accepts the following named parameters:
> +
> + at table @option
> + at item graph
> +Draw histogram graph, defaults to enabled.
Specify what it does otherwise.
> +
> + at item size
> +Set the video size, the value must be a valid abbreviation or in the
> +form @var{width}x at var{height}.
> +
> + at item fg
> +Set foreground histogram color.
> +
> + at item bg
> +Set background histogram color.
> + at end table
> +
> +Following options specify which color components are used in histogram calculation:
> +
> + at table @option
> + at item @var{y} (Y/luminance component)
> + at item @var{u} (U/Cb component)
> + at item @var{v} (V/Cr component)
> + at item @var{a} (alpha component)
> + at item @var{r} (red component)
> + at item @var{g} (green component)
> + at item @var{b} (blue component)
> + at end table
Missing: All components are enabled by default.
> +
> + at subsection Examples
> +
> + at itemize
> +
> + at item
> +Calculate and draw histogram for luma plane:
> + at example
> +ffplay -i yuvinput -vf histogram=fg=yellow:bg=white
> + at end example
> +
> + at item
> +Calculate and draw histogram for chroma planes:
> + at example
> +ffplay -i yuvinput -vf histogram=y=0:u=1:v=1:a=0
> + at end example
> +
> + at item
> +Calculate and draw histogram for green plane only:
> + at example
> +ffplay -i rgbinput -vf histogram=r=0:g=1:b=0:a=0
> + at end example
Looks OK, although maybe a more generic example (not relying on the
ffplay syntax) may be more suited.
Example:
format=rgb24,histogram=r=0:g=1:b=0:a=0
> +
> + at end itemize
> +
> @section hqdn3d
>
> High precision/quality 3d denoise filter. This filter aims to reduce
> diff --git a/libavfilter/Makefile b/libavfilter/Makefile
> index d84bf5d..450b65f 100644
> --- a/libavfilter/Makefile
> +++ b/libavfilter/Makefile
> @@ -111,6 +111,7 @@ OBJS-$(CONFIG_FREI0R_FILTER) += vf_frei0r.o
> OBJS-$(CONFIG_GEQ_FILTER) += vf_geq.o
> OBJS-$(CONFIG_GRADFUN_FILTER) += vf_gradfun.o
> OBJS-$(CONFIG_HFLIP_FILTER) += vf_hflip.o
> +OBJS-$(CONFIG_HISTOGRAM_FILTER) += vf_histogram.o
> OBJS-$(CONFIG_HQDN3D_FILTER) += vf_hqdn3d.o
> OBJS-$(CONFIG_HUE_FILTER) += vf_hue.o
> OBJS-$(CONFIG_IDET_FILTER) += vf_idet.o
> diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
> index 4458917..fc603aa 100644
> --- a/libavfilter/allfilters.c
> +++ b/libavfilter/allfilters.c
> @@ -105,6 +105,7 @@ void avfilter_register_all(void)
> REGISTER_FILTER(GEQ, geq, vf);
> REGISTER_FILTER(GRADFUN, gradfun, vf);
> REGISTER_FILTER(HFLIP, hflip, vf);
> + REGISTER_FILTER(HISTOGRAM, histogram, vf);
> REGISTER_FILTER(HQDN3D, hqdn3d, vf);
> REGISTER_FILTER(HUE, hue, vf);
> REGISTER_FILTER(IDET, idet, vf);
> diff --git a/libavfilter/vf_histogram.c b/libavfilter/vf_histogram.c
> new file mode 100644
> index 0000000..4d3e679
> --- /dev/null
> +++ b/libavfilter/vf_histogram.c
> @@ -0,0 +1,290 @@
> +/*
> + * Copyright (c) 2012 Paul B Mahol
> + *
> + * 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/parseutils.h"
> +#include "libavutil/pixdesc.h"
> +#include "avfilter.h"
> +#include "formats.h"
> +#include "drawutils.h"
> +#include "internal.h"
> +#include "video.h"
> +
> +typedef struct HistogramContext {
> + const AVClass *class; ///< AVClass context for log and options purpose
> + unsigned histogram[1 << 16];
> + unsigned histogram_size;
> + unsigned max_hval;
> + int comp_yuv[4], comp_rgb[4];
> + uint8_t rgba_map[4];
> + int ncomp;
> + int do_graph;
> + int w, h;
> + FFDrawContext draw;
> + FFDrawColor bg, fg;
> + char *fg_color_str, *bg_color_str;
> + uint8_t fg_color_rgba[4], bg_color_rgba[4];
> +} HistogramContext;
> +
> +#define Y 0
> +#define U 1
> +#define V 2
> +#define R 0
> +#define G 1
> +#define B 2
> +#define A 3
> +
> +#define OFFSET(x) offsetof(HistogramContext, x)
> +#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
> +
> +static const AVOption histogram_options[] = {
> + { "graph", "show histogram graph", OFFSET(do_graph), AV_OPT_TYPE_INT, {.i64=1}, 0, 1, FLAGS},
> + { "size", "set histogram graph video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = "256x200"}, 0, 0, FLAGS },
> + { "fg", "set histogram foreground color", OFFSET(fg_color_str), AV_OPT_TYPE_STRING, {.str = "white"}, CHAR_MIN, CHAR_MAX, FLAGS },
> + { "bg", "set histogram background color", OFFSET(bg_color_str), AV_OPT_TYPE_STRING, {.str = "black"}, CHAR_MIN, CHAR_MAX, FLAGS },
> + { "y", "use Y component", OFFSET(comp_yuv[Y]), AV_OPT_TYPE_INT, {.i64=1}, 0, 1, FLAGS},
> + { "u", "use U component", OFFSET(comp_yuv[U]), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS},
> + { "v", "use V component", OFFSET(comp_yuv[V]), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS},
> + { "a", "use A component", OFFSET(comp_yuv[A]), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS},
> + { "r", "use R component", OFFSET(comp_rgb[R]), AV_OPT_TYPE_INT, {.i64=1}, 0, 1, FLAGS},
> + { "g", "use G component", OFFSET(comp_rgb[G]), AV_OPT_TYPE_INT, {.i64=1}, 0, 1, FLAGS},
> + { "b", "use B component", OFFSET(comp_rgb[B]), AV_OPT_TYPE_INT, {.i64=1}, 0, 1, FLAGS},
> + { NULL },
> +};
> +
> +AVFILTER_DEFINE_CLASS(histogram);
> +
> +static av_cold int init(AVFilterContext *ctx, const char *args)
> +{
> + HistogramContext *h = ctx->priv;
> + int ret;
> +
> + h->class = &histogram_class;
> + av_opt_set_defaults(h);
> +
> + if ((ret = (av_set_options_string(h, args, "=", ":"))) < 0)
> + return ret;
> +
> + if ((ret = av_parse_color(h->fg_color_rgba, h->fg_color_str, -1, ctx)) < 0 ||
> + (ret = av_parse_color(h->bg_color_rgba, h->bg_color_str, -1, ctx)) < 0 )
> + return ret;
> +
> + h->comp_rgb[A] = h->comp_yuv[A];
> + if (!h->comp_rgb[R] && !h->comp_rgb[G] && !h->comp_rgb[B] && !h->comp_rgb[A] &&
> + !h->comp_yuv[Y] && !h->comp_yuv[U] && !h->comp_yuv[V] && !h->comp_yuv[A])
> + return AVERROR(EINVAL);
> +
> + return 0;
> +}
> +
> +static int query_formats(AVFilterContext *ctx)
> +{
> + static const enum AVPixelFormat pix_fmts[] = {
> + AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUVJ444P,
> + AV_PIX_FMT_BGR24, AV_PIX_FMT_RGB24,
> + AV_PIX_FMT_ABGR, AV_PIX_FMT_0BGR,
> + AV_PIX_FMT_ARGB, AV_PIX_FMT_0RGB,
> + AV_PIX_FMT_BGRA, AV_PIX_FMT_BGR0,
> + AV_PIX_FMT_RGBA, AV_PIX_FMT_RGB0,
> + AV_PIX_FMT_GRAY8, AV_PIX_FMT_GRAY8A,
> + AV_PIX_FMT_NONE
> + };
> +
> + ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
> +
> + return 0;
> +}
> +
> +static int config_input(AVFilterLink *inlink)
> +{
> + HistogramContext *h = inlink->dst->priv;
> + const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
> +
> + h->histogram_size = 1 << desc->comp[0].depth_minus1 + 1;
Nit:
(desc->comp[0].depth_minus1 + 1)
may help readability (and I always discard operator binding priority
rules).
> + h->ncomp = desc->nb_components;
> + ff_fill_rgba_map(h->rgba_map, inlink->format);
> +
> + return 0;
> +}
> +
> +static int config_output(AVFilterLink *outlink)
> +{
> + AVFilterContext *ctx = outlink->src;
> + HistogramContext *h = ctx->priv;
> +
> + if (!h->do_graph)
> + return 0;
> +
> + outlink->w = h->w;
> + outlink->h = h->h;
> +
> + outlink->sample_aspect_ratio = (AVRational){1,1};
> +
> + ff_draw_init(&h->draw, outlink->format, 0);
> + ff_draw_color(&h->draw, &h->bg, h->bg_color_rgba);
> + ff_draw_color(&h->draw, &h->fg, h->fg_color_rgba);
> +
> + return 0;
> +}
> +
> +static int filter_frame(AVFilterLink *link, AVFilterBufferRef *in)
Nit: inlink for enhanced readability.
> +{
> + HistogramContext *h = link->dst->priv;
> + AVFilterContext *ctx = link->dst;
> + AVFilterLink *outlink = ctx->outputs[0];
> + const uint8_t *src;
> + int i, j, k, ret;
> +
> + switch (in->format) {
> + case AV_PIX_FMT_0BGR:
> + case AV_PIX_FMT_0RGB:
> + case AV_PIX_FMT_ABGR:
> + case AV_PIX_FMT_ARGB:
> + case AV_PIX_FMT_BGR0:
> + case AV_PIX_FMT_BGR24:
> + case AV_PIX_FMT_BGRA:
> + case AV_PIX_FMT_RGB0:
> + case AV_PIX_FMT_RGB24:
> + case AV_PIX_FMT_RGBA:
if (is_packed_rgb) { ... } else { ... }?
Should simplify the code in case more formats are added.
> + src = in->data[0];
> + for (i = 0; i < in->video->h; i++) {
> + for (j = 0; j < in->video->w * h->ncomp; j += h->ncomp) {
> + unsigned v = 0, used = 0;
> +
> + for (k = 0; k < h->ncomp; k++) {
> + if (h->comp_rgb[k]) {
> + v += src[j + h->rgba_map[k]];
> + used++;
> + }
> + }
> +
> + if (used)
> + h->histogram[v / used]++;
> + }
> + src += in->linesize[0];
> + }
> + break;
> + case AV_PIX_FMT_YUVA444P:
> + case AV_PIX_FMT_YUV444P:
> + case AV_PIX_FMT_YUVJ444P:
> + case AV_PIX_FMT_GRAY8:
> + case AV_PIX_FMT_GRAY8A:
> + for (i = 0; i < in->video->h; i++) {
> + for (j = 0; j < in->video->w; j++) {
> + unsigned v = 0, used = 0;
> +
> + for (k = 0; k < h->ncomp; k++) {
> + if (h->comp_yuv[k]) {
> + src = in->data[k] + i * in->linesize[k];
> + v += src[j];
> + used++;
> + }
> + }
> +
> + if (used)
> + h->histogram[v / used]++;
> + }
> + }
> + break;
default: assert()?
> + }
> +
> + for (i = 0; i < h->histogram_size; i++) {
> + h->max_hval = FFMAX(h->max_hval, h->histogram[i]);
> + if (h->histogram[i])
> + av_log(ctx, h->do_graph ? AV_LOG_VERBOSE : AV_LOG_INFO, "i:%d c:%d\n", i, h->histogram[i]);
> + }
Maybe a complete histogram could be printed here, although I have not
good ideas about how to represent it.
> +
> + if (h->do_graph) {
> + AVFilterBufferRef *outpicref;
> + int col_width = h->w / h->histogram_size;
> +
> + outpicref = ff_get_video_buffer(outlink, AV_PERM_WRITE, outlink->w, outlink->h);
> + if (!outpicref) {
> + avfilter_unref_bufferp(&in);
> + return AVERROR(ENOMEM);
> + }
> +
> + outpicref->pts = in->pts;
> + outpicref->pos = in->pos;
> +
> + ff_fill_rectangle(&h->draw, &h->bg, outpicref->data, outpicref->linesize, 0, 0, h->w, h->h);
> + for (i = 0; i < h->histogram_size; i++) {
> + int col_height = (float) h->histogram[i] / h->max_hval * h->h;
> +
> + ff_fill_rectangle(&h->draw, &h->fg, outpicref->data, outpicref->linesize,
> + i * col_width,
> + h->h - col_height,
> + col_width,
> + col_height);
> + }
> +
> + ret = ff_filter_frame(outlink, outpicref);
> + avfilter_unref_bufferp(&in);
> + if (ret < 0)
> + return ret;
> + } else {
> + ret = ff_filter_frame(outlink, in);
> + if (ret < 0)
> + return ret;
> + }
> + memset(h->histogram, 0, h->histogram_size * sizeof(*h->histogram));
> + h->max_hval = 0;
> +
> + return 0;
> +}
> +
[...]
LGTM otherwise.
--
FFmpeg = Fundamental & Faithless Mournful Problematic Ecstatic Game
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