Advanced blur-based logo removing filter. More...

#include "libavutil/imgutils.h"
#include "avfilter.h"
#include "formats.h"
#include "internal.h"
#include "video.h"
#include "bbox.h"
#include "lavfutils.h"
#include "lswsutils.h"

Data Structures
struct	RemovelogoContext
	This code implements a filter to remove annoying TV logos and other annoying images placed onto a video stream. More...

Macros
#define	apply_mask_fudge_factor(x) (((x) >> 2) + x)
	Choose a slightly larger mask size to improve performance.

#define	SHOW_LOGO_INFO(mask_type)

Functions
static void	convert_mask_to_strength_mask (uint8_t data, int linesize, int w, int h, int min_val, int max_mask_size)
	Pre-process an image to give distance information.

static int	query_formats (AVFilterContext *ctx)

static int	load_mask (uint8_t *mask, int w, int h, const char filename, void *log_ctx)

static void	generate_half_size_image (const uint8_t src_data, int src_linesize, uint8_t dst_data, int dst_linesize, int src_w, int src_h, int *max_mask_size)
	Generate a scaled down image with half width, height, and intensity.

static av_cold int	init (AVFilterContext ctx, const char args)

static int	config_props_input (AVFilterLink *inlink)

static unsigned int	blur_pixel (int **mask, const uint8_t mask_data, int mask_linesize, uint8_t *image_data, int image_linesize, int w, int h, int x, int y)
	Blur image.

static void	blur_image (int **mask, const uint8_t src_data, int src_linesize, uint8_t dst_data, int dst_linesize, const uint8_t mask_data, int mask_linesize, int w, int h, int direct, FFBoundingBox *bbox)
	Blur image plane using a mask.

static int	filter_frame (AVFilterLink inlink, AVFilterBufferRef inpicref)

static void	uninit (AVFilterContext *ctx)

Variables
static const AVFilterPad	removelogo_inputs []

static const AVFilterPad	removelogo_outputs []

AVFilter	avfilter_vf_removelogo

Detailed Description

Advanced blur-based logo removing filter.

This filter loads an image mask file showing where a logo is and uses a blur transform to remove the logo.

Based on the libmpcodecs remove-logo filter by Robert Edele.

Definition in file vf_removelogo.c.

Macro Definition Documentation

#define apply_mask_fudge_factor ( x ) (((x) >> 2) + x)

Choose a slightly larger mask size to improve performance.

This function maps the absolute minimum mask size needed to the mask size we'll actually use. f(x) = x (the smallest that will work) will produce the sharpest results, but will be quite jittery. f(x) = 1.25x (what I'm using) is a good tradeoff in my opinion. This will calculate only at init-time, so you can put a long expression here without effecting performance.

Definition at line 104 of file vf_removelogo.c.

Referenced by convert_mask_to_strength_mask().

#define SHOW_LOGO_INFO ( mask_type )

Value:

av_log(ctx, AV_LOG_VERBOSE, #mask_type " x1:%d x2:%d y1:%d y2:%d max_mask_size:%d\n", \
           removelogo->mask_type##_mask_bbox.x1, removelogo->mask_type##_mask_bbox.x2, \
           removelogo->mask_type##_mask_bbox.y1, removelogo->mask_type##_mask_bbox.y2, \
           mask_type##_max_mask_size);

Referenced by init().

Function Documentation

static void convert_mask_to_strength_mask	(	uint8_t *	data,
		int	linesize,
		int	w,
		int	h,
		int	min_val,
		int *	max_mask_size
	)

static

Pre-process an image to give distance information.

This function takes a bitmap image and converts it in place into a distance image. A distance image is zero for pixels outside of the logo and is the Manhattan distance (|dx| + |dy|) from the logo edge for pixels inside of the logo. This will overestimate the distance, but that is safe, and is far easier to implement than a proper pythagorean distance since I'm using a modified erosion algorithm to compute the distances.

Parameters

mask	image which will be converted from a greyscale image into a distance image.

Definition at line 120 of file vf_removelogo.c.

Referenced by generate_half_size_image(), and init().

static int query_formats ( AVFilterContext * ctx )

static

Definition at line 193 of file vf_removelogo.c.

static int load_mask	(	uint8_t **	mask,
		int *	w,
		int *	h,
		const char *	filename,
		void *	log_ctx
	)

static

Definition at line 200 of file vf_removelogo.c.

Referenced by init().

static void generate_half_size_image	(	const uint8_t *	src_data,
		int	src_linesize,
		uint8_t *	dst_data,
		int	dst_linesize,
		int	src_w,
		int	src_h,
		int *	max_mask_size
	)

static

Generate a scaled down image with half width, height, and intensity.

This function not only scales down an image, but halves the value in each pixel too. The purpose of this is to produce a chroma filter image out of a luma filter image. The pixel values store the distance to the edge of the logo and halving the dimensions halves the distance. This function rounds up, because a downwards rounding error could cause the filter to fail, but an upwards rounding error will only cause a minor amount of excess blur in the chroma planes.

Definition at line 241 of file vf_removelogo.c.

Referenced by init().

static av_cold int init	(	AVFilterContext *	ctx,
		const char *	args
	)

static

Definition at line 267 of file vf_removelogo.c.

static int config_props_input ( AVFilterLink * inlink )

static

Definition at line 340 of file vf_removelogo.c.

static unsigned int blur_pixel	(	int ***	mask,
		const uint8_t *	mask_data,
		int	mask_linesize,
		uint8_t *	image_data,
		int	image_linesize,
		int	w,
		int	h,
		int	x,
		int	y
	)

static

Blur image.

It takes a pixel that is inside the mask and blurs it. It does so by finding the average of all the pixels within the mask and outside of the mask.

Parameters

mask_data	the mask plane to use for averaging
image_data	the image plane to blur
w	width of the image
h	height of the image
x	x-coordinate of the pixel to blur
y	y-coordinate of the pixel to blur

Definition at line 369 of file vf_removelogo.c.

Referenced by blur_image().

static void blur_image	(	int ***	mask,
		const uint8_t *	src_data,
		int	src_linesize,
		uint8_t *	dst_data,
		int	dst_linesize,
		const uint8_t *	mask_data,
		int	mask_linesize,
		int	w,
		int	h,
		int	direct,
		FFBoundingBox *	bbox
	)

static

Blur image plane using a mask.

Parameters

source	The image to have it's logo removed.
destination	Where the output image will be stored.
source_stride	How far apart (in memory) two consecutive lines are.
destination	Same as source_stride, but for the destination image.
width	Width of the image. This is the same for source and destination.
height	Height of the image. This is the same for source and destination.
is_image_direct	If the image is direct, then source and destination are the same and we can save a lot of time by not copying pixels that haven't changed.
filter	The image that stores the distance to the edge of the logo for each pixel.
logo_start_x	smallest x-coordinate that contains at least 1 logo pixel.
logo_start_y	smallest y-coordinate that contains at least 1 logo pixel.
logo_end_x	largest x-coordinate that contains at least 1 logo pixel.
logo_end_y	largest y-coordinate that contains at least 1 logo pixel.

This function processes an entire plane. Pixels outside of the logo are copied to the output without change, and pixels inside the logo have the de-blurring function applied.

Definition at line 442 of file vf_removelogo.c.

Referenced by filter_frame().

static int filter_frame	(	AVFilterLink *	inlink,
		AVFilterBufferRef *	inpicref
	)

static

Definition at line 476 of file vf_removelogo.c.

static void uninit ( AVFilterContext * ctx )

static

Definition at line 517 of file vf_removelogo.c.

Variable Documentation

const AVFilterPad removelogo_inputs[]

static

Initial value:

= {
    {
        .name             = "default",
        .type             = AVMEDIA_TYPE_VIDEO,
        .get_video_buffer = ff_null_get_video_buffer,
        .config_props     = config_props_input,
        .filter_frame     = filter_frame,
        .min_perms        = AV_PERM_READ,
    },
    { NULL }
}

Definition at line 539 of file vf_removelogo.c.

const AVFilterPad removelogo_outputs[]

static

Initial value:

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

Definition at line 551 of file vf_removelogo.c.

AVFilter avfilter_vf_removelogo

Initial value:

= {
    .name          = "removelogo",
    .description   = NULL_IF_CONFIG_SMALL("Remove a TV logo based on a mask image."),
    .priv_size     = sizeof(RemovelogoContext),
    .init          = init,
    .uninit        = uninit,
    .query_formats = query_formats,
    .inputs        = removelogo_inputs,
    .outputs       = removelogo_outputs,
}

Definition at line 559 of file vf_removelogo.c.

Data Structures

Macros

Functions

Variables

Detailed Description

Macro Definition Documentation

Function Documentation

Variable Documentation