FFmpeg
Data Structures | Macros | Enumerations | Functions | Variables
vf_histeq.c File Reference
#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"

Go to the source code of this file.

Data Structures

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)
 

Enumerations

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

Functions

 AVFILTER_DEFINE_CLASS (histeq)
 
static av_cold int init (AVFilterContext *ctx)
 
static int query_formats (AVFilterContext *ctx)
 
static int config_input (AVFilterLink *inlink)
 
static int filter_frame (AVFilterLink *inlink, AVFrame *inpic)
 

Variables

static const AVOption histeq_options []
 
static const AVFilterPad histeq_inputs []
 
static const AVFilterPad histeq_outputs []
 
const 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.

Definition in file vf_histeq.c.

Macro Definition Documentation

◆ LCG_A

#define LCG_A   4096

Definition at line 44 of file vf_histeq.c.

◆ LCG_C

#define LCG_C   150889

Definition at line 45 of file vf_histeq.c.

◆ LCG_M

#define LCG_M   714025

Definition at line 46 of file vf_histeq.c.

◆ LCG

#define LCG (   x)    (((x) * LCG_A + LCG_C) % LCG_M)

Definition at line 47 of file vf_histeq.c.

◆ LCG_SEED

#define LCG_SEED   739187

Definition at line 48 of file vf_histeq.c.

◆ OFFSET

#define OFFSET (   x)    offsetof(HisteqContext, x)

Definition at line 69 of file vf_histeq.c.

◆ FLAGS

Definition at line 70 of file vf_histeq.c.

◆ CONST

#define CONST (   name,
  help,
  val,
  unit 
)    { name, help, 0, AV_OPT_TYPE_CONST, {.i64=val}, INT_MIN, INT_MAX, FLAGS, unit }

Definition at line 71 of file vf_histeq.c.

◆ R

#define R   0

Definition at line 121 of file vf_histeq.c.

◆ G

#define G   1

Definition at line 122 of file vf_histeq.c.

◆ B

#define B   2

Definition at line 123 of file vf_histeq.c.

◆ A

#define A   3

Definition at line 124 of file vf_histeq.c.

◆ 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)

Definition at line 126 of file vf_histeq.c.

Enumeration Type Documentation

◆ HisteqAntibanding

Enumerator
HISTEQ_ANTIBANDING_NONE 
HISTEQ_ANTIBANDING_WEAK 
HISTEQ_ANTIBANDING_STRONG 
HISTEQ_ANTIBANDING_NB 

Definition at line 50 of file vf_histeq.c.

Function Documentation

◆ AVFILTER_DEFINE_CLASS()

AVFILTER_DEFINE_CLASS ( histeq  )

◆ init()

static av_cold int init ( AVFilterContext ctx)
static

Definition at line 85 of file vf_histeq.c.

◆ query_formats()

static int query_formats ( AVFilterContext ctx)
static

Definition at line 96 of file vf_histeq.c.

◆ config_input()

static int config_input ( AVFilterLink inlink)
static

Definition at line 109 of file vf_histeq.c.

◆ filter_frame()

static int filter_frame ( AVFilterLink inlink,
AVFrame inpic 
)
static

Definition at line 132 of file vf_histeq.c.

Variable Documentation

◆ histeq_options

const AVOption histeq_options[]
static
Initial value:
= {
{ "strength", "set the strength", OFFSET(strength), AV_OPT_TYPE_FLOAT, {.dbl=0.2}, 0, 1, FLAGS },
{ "intensity", "set the intensity", OFFSET(intensity), AV_OPT_TYPE_FLOAT, {.dbl=0.21}, 0, 1, FLAGS },
{ "antibanding", "set the antibanding level", OFFSET(antibanding), AV_OPT_TYPE_INT, {.i64=HISTEQ_ANTIBANDING_NONE}, 0, HISTEQ_ANTIBANDING_NB-1, FLAGS, "antibanding" },
CONST("none", "apply no antibanding", HISTEQ_ANTIBANDING_NONE, "antibanding"),
CONST("weak", "apply weak antibanding", HISTEQ_ANTIBANDING_WEAK, "antibanding"),
CONST("strong", "apply strong antibanding", HISTEQ_ANTIBANDING_STRONG, "antibanding"),
{ NULL }
}

Definition at line 73 of file vf_histeq.c.

◆ histeq_inputs

const AVFilterPad histeq_inputs[]
static
Initial value:
= {
{
.name = "default",
.config_props = config_input,
.filter_frame = filter_frame,
},
{ NULL }
}

Definition at line 255 of file vf_histeq.c.

◆ histeq_outputs

const AVFilterPad histeq_outputs[]
static
Initial value:
= {
{
.name = "default",
},
{ NULL }
}

Definition at line 265 of file vf_histeq.c.

◆ ff_vf_histeq

const AVFilter ff_vf_histeq
Initial value:
= {
.name = "histeq",
.description = NULL_IF_CONFIG_SMALL("Apply global color histogram equalization."),
.priv_size = sizeof(HisteqContext),
.init = init,
.priv_class = &histeq_class,
}

Definition at line 273 of file vf_histeq.c.

HISTEQ_ANTIBANDING_WEAK
@ HISTEQ_ANTIBANDING_WEAK
Definition: vf_histeq.c:52
B
#define B
Definition: vf_histeq.c:123
histeq_outputs
static const AVFilterPad histeq_outputs[]
Definition: vf_histeq.c:265
inputs
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several inputs
Definition: filter_design.txt:243
outputs
static const AVFilterPad outputs[]
Definition: af_acontrast.c:203
NULL
#define NULL
Definition: coverity.c:32
init
static av_cold int init(AVFilterContext *ctx)
Definition: vf_histeq.c:85
src
#define src
Definition: vp8dsp.c:255
HISTEQ_ANTIBANDING_NONE
@ HISTEQ_ANTIBANDING_NONE
Definition: vf_histeq.c:51
CONST
#define CONST(name, help, val, unit)
Definition: vf_histeq.c:71
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
histeq_inputs
static const AVFilterPad histeq_inputs[]
Definition: vf_histeq.c:255
query_formats
static int query_formats(AVFilterContext *ctx)
Definition: vf_histeq.c:96
HisteqContext
Definition: vf_histeq.c:57
AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC
#define AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC
Some filters support a generic "enable" expression option that can be used to enable or disable a fil...
Definition: avfilter.h:126
AV_OPT_TYPE_FLOAT
@ AV_OPT_TYPE_FLOAT
Definition: opt.h:228
R
#define R
Definition: vf_histeq.c:121
config_input
static int config_input(AVFilterLink *inlink)
Definition: vf_histeq.c:109
OFFSET
#define OFFSET(x)
Definition: vf_histeq.c:69
G
#define G
Definition: vf_histeq.c:122
AV_OPT_TYPE_INT
@ AV_OPT_TYPE_INT
Definition: opt.h:225
filter_frame
static int filter_frame(AVFilterLink *inlink, AVFrame *inpic)
Definition: vf_histeq.c:132
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
FLAGS
#define FLAGS
Definition: vf_histeq.c:70
map
const VDPAUPixFmtMap * map
Definition: hwcontext_vdpau.c:71
HISTEQ_ANTIBANDING_STRONG
@ HISTEQ_ANTIBANDING_STRONG
Definition: vf_histeq.c:53
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:561
HISTEQ_ANTIBANDING_NB
@ HISTEQ_ANTIBANDING_NB
Definition: vf_histeq.c:54