vf_histeq.c File Reference

Histogram equalization filter, based on the VirtualDub filter by Donald A. More...

#include "libavutil/common.h"
#include "libavutil/internal.h"
#include "libavutil/opt.h"
#include "libavutil/pixdesc.h"
#include "avfilter.h"
#include "drawutils.h"
#include "formats.h"
#include "internal.h"
#include "video.h"

Classes
struct	HisteqContext

Macros
#define	LCG_A   4096
#define	LCG_C   150889
#define	LCG_M   714025
#define	LCG(x)   (((x) * LCG_A + LCG_C) % LCG_M)
#define	LCG_SEED   739187
#define	OFFSET(x)   offsetof(HisteqContext, x)
#define	FLAGS   AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
#define	CONST(name, help, val, unit)   { name, help, 0, AV_OPT_TYPE_CONST, {.i64=val}, INT_MIN, INT_MAX, FLAGS, unit }
#define	R   0
#define	G   1
#define	B   2
#define	A   3
#define	GET_RGB_VALUES(r, g, b, src, map)

Typedefs
typedef struct HisteqContext	HisteqContext

Enumerations
enum	HisteqAntibanding { HISTEQ_ANTIBANDING_NONE = 0, HISTEQ_ANTIBANDING_WEAK = 1, HISTEQ_ANTIBANDING_STRONG = 2, HISTEQ_ANTIBANDING_NB }

Functions
	AVFILTER_DEFINE_CLASS (histeq)

Variables
AVFilter	ff_vf_histeq

Detailed Description

Histogram equalization filter, based on the VirtualDub filter by Donald A.

Graft <neuron2 at="" home="" dot="" com>="">. Implements global automatic contrast adjustment by means of histogram equalization.

Macro Definition Documentation

GET_RGB_VALUES

#define GET_RGB_VALUES	(		r,
			g,
			b,
			src,
			map
	)

Value:

do { \
    r = src[x + map[R]];                       \
    g = src[x + map[G]];                       \
    b = src[x + map[B]];                       \
} while (0)

Variable Documentation

ff_vf_histeq

AVFilter ff_vf_histeq

Initial value:

= {
    .name          = "histeq",
    .description   = NULL_IF_CONFIG_SMALL("Apply global color histogram equalization."),
    .priv_size     = sizeof(HisteqContext),
    .init          = init,
    .query_formats = query_formats,
    .inputs        = histeq_inputs,
    .outputs       = histeq_outputs,
    .priv_class    = &histeq_class,
    .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
}