vf_edgedetect.c File Reference

Edge detection filter. More...

#include "libavutil/avassert.h"
#include "libavutil/opt.h"
#include "avfilter.h"
#include "formats.h"
#include "internal.h"
#include "video.h"

Go to the source code of this file.

Data Structures
struct	plane_info
struct	EdgeDetectContext

Macros
#define	OFFSET(x)   offsetof(EdgeDetectContext, x)
#define	FLAGS   AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
#define	COPY_MAXIMA(ay, ax, by, bx)

Enumerations
enum	FilterMode {   FILTER_8TAP_SMOOTH, FILTER_8TAP_REGULAR, FILTER_8TAP_SHARP, FILTER_BILINEAR,   N_FILTERS, FILTER_SWITCHABLE = N_FILTERS, MODE_WIRES, MODE_COLORMIX,   NB_MODE, MODE_NONE, MODE_INTERLEAVE, MODE_DEINTERLEAVE,   FILTER_NONE = -1, FILTER_TOUT, FILTER_VREP, FILTER_BRNG,   FILT_NUMB }
enum	{ DIRECTION_45UP, DIRECTION_45DOWN, DIRECTION_HORIZONTAL, DIRECTION_VERTICAL }

Functions
	AVFILTER_DEFINE_CLASS (edgedetect)
static av_cold int	init (AVFilterContext *ctx)
static int	query_formats (AVFilterContext *ctx)
static int	config_props (AVFilterLink *inlink)
static void	gaussian_blur (AVFilterContext *ctx, int w, int h, uint8_t *dst, int dst_linesize, const uint8_t *src, int src_linesize)
static int	get_rounded_direction (int gx, int gy)
static void	sobel (int w, int h, uint16_t *dst, int dst_linesize, int8_t *dir, int dir_linesize, const uint8_t *src, int src_linesize)
static void	non_maximum_suppression (int w, int h, uint8_t *dst, int dst_linesize, const int8_t *dir, int dir_linesize, const uint16_t *src, int src_linesize)
static void	double_threshold (int low, int high, int w, int h, uint8_t *dst, int dst_linesize, const uint8_t *src, int src_linesize)
static void	color_mix (int w, int h, uint8_t *dst, int dst_linesize, const uint8_t *src, int src_linesize)
static int	filter_frame (AVFilterLink *inlink, AVFrame *in)
static av_cold void	uninit (AVFilterContext *ctx)

Variables
static const AVOption	edgedetect_options []
static const AVFilterPad	edgedetect_inputs []
static const AVFilterPad	edgedetect_outputs []
AVFilter	ff_vf_edgedetect

Detailed Description

Edge detection filter.

See also

https://en.wikipedia.org/wiki/Canny_edge_detector

Definition in file vf_edgedetect.c.

Macro Definition Documentation

OFFSET

#define OFFSET

(

x

)

offsetof(EdgeDetectContext, x)

Definition at line 56 of file vf_edgedetect.c.

FLAGS

#define FLAGS   AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM

Definition at line 57 of file vf_edgedetect.c.

COPY_MAXIMA

#define COPY_MAXIMA	(		ay,
			ax,
			by,
			bx
	)

Value:

do {                \
    if (src[i] > src[(ay)*src_linesize + i+(ax)] &&     \
        src[i] > src[(by)*src_linesize + i+(bx)])       \
        dst[i] = av_clip_uint8(src[i]);                 \
} while (0)

Referenced by non_maximum_suppression().

Enumeration Type Documentation

FilterMode

enum FilterMode

Enumerator
FILTER_8TAP_SMOOTH
FILTER_8TAP_REGULAR
FILTER_8TAP_SHARP
FILTER_BILINEAR
N_FILTERS
FILTER_SWITCHABLE
MODE_WIRES
MODE_COLORMIX
NB_MODE
MODE_NONE
MODE_INTERLEAVE
MODE_DEINTERLEAVE
FILTER_NONE
FILTER_TOUT
FILTER_VREP
FILTER_BRNG
FILT_NUMB

Definition at line 35 of file vf_edgedetect.c.

anonymous enum

anonymous enum

Enumerator
DIRECTION_45UP
DIRECTION_45DOWN
DIRECTION_HORIZONTAL
DIRECTION_VERTICAL

Definition at line 159 of file vf_edgedetect.c.

Function Documentation

AVFILTER_DEFINE_CLASS()

AVFILTER_DEFINE_CLASS

(

edgedetect

)

init()

static av_cold int init ( AVFilterContext *  ctx )

static

Definition at line 69 of file vf_edgedetect.c.

query_formats()

static int query_formats ( AVFilterContext *  ctx )

static

Definition at line 78 of file vf_edgedetect.c.

config_props()

static int config_props ( AVFilterLink *  inlink )

static

Definition at line 99 of file vf_edgedetect.c.

gaussian_blur()

static void gaussian_blur ( AVFilterContext *  ctx, int  w, int  h, uint8_t *  dst, int  dst_linesize, const uint8_t *  src, int  src_linesize  )

static

Definition at line 118 of file vf_edgedetect.c.

Referenced by filter_frame().

get_rounded_direction()

static int get_rounded_direction ( int  gx, int  gy  )

static

Definition at line 166 of file vf_edgedetect.c.

Referenced by sobel().

sobel()

static void sobel ( int  w, int  h, uint16_t *  dst, int  dst_linesize, int8_t *  dir, int  dir_linesize, const uint8_t *  src, int  src_linesize  )

static

Definition at line 193 of file vf_edgedetect.c.

Referenced by filter_frame().

non_maximum_suppression()

static void non_maximum_suppression ( int  w, int  h, uint8_t *  dst, int  dst_linesize, const int8_t *  dir, int  dir_linesize, const uint16_t *  src, int  src_linesize  )

static

Definition at line 220 of file vf_edgedetect.c.

Referenced by filter_frame().

double_threshold()

static void double_threshold ( int  low, int  high, int  w, int  h, uint8_t *  dst, int  dst_linesize, const uint8_t *  src, int  src_linesize  )

static

Definition at line 248 of file vf_edgedetect.c.

Referenced by filter_frame().

color_mix()

static void color_mix ( int  w, int  h, uint8_t *  dst, int  dst_linesize, const uint8_t *  src, int  src_linesize  )

static

Definition at line 280 of file vf_edgedetect.c.

Referenced by filter_frame().

filter_frame()

static int filter_frame ( AVFilterLink *  inlink, AVFrame *  in  )

static

Definition at line 294 of file vf_edgedetect.c.

uninit()

static av_cold void uninit ( AVFilterContext *  ctx )

static

Definition at line 357 of file vf_edgedetect.c.

Variable Documentation

edgedetect_options

const AVOption edgedetect_options[]

static

Initial value:

= {
    { "high", "set high threshold", OFFSET(high), AV_OPT_TYPE_DOUBLE, {.dbl=50/255.}, 0, 1, FLAGS },
    { "low",  "set low threshold",  OFFSET(low),  AV_OPT_TYPE_DOUBLE, {.dbl=20/255.}, 0, 1, FLAGS },
    { "mode", "set mode", OFFSET(mode), AV_OPT_TYPE_INT, {.i64=MODE_WIRES}, 0, NB_MODE-1, FLAGS, "mode" },
        { "wires",    "white/gray wires on black",  0, AV_OPT_TYPE_CONST, {.i64=MODE_WIRES},    INT_MIN, INT_MAX, FLAGS, "mode" },
        { "colormix", "mix colors",                 0, AV_OPT_TYPE_CONST, {.i64=MODE_COLORMIX}, INT_MIN, INT_MAX, FLAGS, "mode" },
    { NULL }
}

Definition at line 58 of file vf_edgedetect.c.

edgedetect_inputs

const AVFilterPad edgedetect_inputs[]

static

Initial value:

= {
    {
        .name         = "default",
        .type         = AVMEDIA_TYPE_VIDEO,
        .config_props = config_props,
        .filter_frame = filter_frame,
    },
    { NULL }
}

Definition at line 370 of file vf_edgedetect.c.

edgedetect_outputs

const AVFilterPad edgedetect_outputs[]

static

Initial value:

= {
    {
        .name = "default",
        .type = AVMEDIA_TYPE_VIDEO,
    },
    { NULL }
}

Definition at line 380 of file vf_edgedetect.c.

ff_vf_edgedetect

AVFilter ff_vf_edgedetect

Initial value:

= {
    .name          = "edgedetect",
    .description   = NULL_IF_CONFIG_SMALL("Detect and draw edge."),
    .priv_size     = sizeof(EdgeDetectContext),
    .init          = init,
    .uninit        = uninit,
    .query_formats = query_formats,
    .inputs        = edgedetect_inputs,
    .outputs       = edgedetect_outputs,
    .priv_class    = &edgedetect_class,
    .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
}

Definition at line 388 of file vf_edgedetect.c.