vf_removelogo.c File Reference

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

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

Go to the source code of this file.

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	OFFSET(x)   offsetof(RemovelogoContext, x)
#define	FLAGS   AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
#define	apply_mask_fudge_factor(x)   (((x) >> 2) + (x))
	Choose a slightly larger mask size to improve performance. More...
#define	SHOW_LOGO_INFO(mask_type)

Functions
	AVFILTER_DEFINE_CLASS (removelogo)
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. More...
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. More...
static av_cold int	init (AVFilterContext *ctx)
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. More...
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. More...
static int	filter_frame (AVFilterLink *inlink, AVFrame *inpicref)
static av_cold void	uninit (AVFilterContext *ctx)

Variables
static const AVOption	removelogo_options []
static const AVFilterPad	removelogo_inputs []
static const AVFilterPad	removelogo_outputs []
AVFilter	ff_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

OFFSET

#define OFFSET

(

x

)

offsetof(RemovelogoContext, x)

Definition at line 97 of file vf_removelogo.c.

FLAGS

#define FLAGS   AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM

Definition at line 98 of file vf_removelogo.c.

apply_mask_fudge_factor

#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 117 of file vf_removelogo.c.

Referenced by convert_mask_to_strength_mask().

SHOW_LOGO_INFO

#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", \
           s->mask_type##_mask_bbox.x1, s->mask_type##_mask_bbox.x2, \
           s->mask_type##_mask_bbox.y1, s->mask_type##_mask_bbox.y2, \
           mask_type##_max_mask_size);

Referenced by init().

Function Documentation

AVFILTER_DEFINE_CLASS()

AVFILTER_DEFINE_CLASS

(

removelogo

)

convert_mask_to_strength_mask()

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 133 of file vf_removelogo.c.

Referenced by generate_half_size_image(), and init().

query_formats()

static int query_formats ( AVFilterContext *  ctx )

static

Definition at line 206 of file vf_removelogo.c.

load_mask()

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

static

Definition at line 215 of file vf_removelogo.c.

Referenced by init().

generate_half_size_image()

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 256 of file vf_removelogo.c.

Referenced by init().

init()

static av_cold int init ( AVFilterContext *  ctx )

static

Definition at line 282 of file vf_removelogo.c.

config_props_input()

static int config_props_input ( AVFilterLink *  inlink )

static

Definition at line 359 of file vf_removelogo.c.

blur_pixel()

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 388 of file vf_removelogo.c.

Referenced by blur_image().

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 461 of file vf_removelogo.c.

Referenced by filter_frame().

filter_frame()

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

static

Definition at line 495 of file vf_removelogo.c.

uninit()

static av_cold void uninit ( AVFilterContext *  ctx )

static

Definition at line 536 of file vf_removelogo.c.

Variable Documentation

removelogo_options

const AVOption removelogo_options[]

static

Initial value:

= {
    { "filename", "set bitmap filename", OFFSET(filename), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
    { "f",        "set bitmap filename", OFFSET(filename), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
    { NULL }
}

Definition at line 99 of file vf_removelogo.c.

removelogo_inputs

const AVFilterPad removelogo_inputs[]

static

Initial value:

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

Definition at line 558 of file vf_removelogo.c.

removelogo_outputs

const AVFilterPad removelogo_outputs[]

static

Initial value:

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

Definition at line 568 of file vf_removelogo.c.

ff_vf_removelogo

AVFilter ff_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,
    .priv_class    = &removelogo_class,
    .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
}

Definition at line 576 of file vf_removelogo.c.