libavfilter/vf_removelogo.c File Reference

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

#include "libavutil/imgutils.h"
#include "avfilter.h"
#include "formats.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...

Defines

#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 start_frame (AVFilterLink *inlink, AVFilterBufferRef *inpicref)
static int end_frame (AVFilterLink *inlink)
static void uninit (AVFilterContext *ctx)
static int null_draw_slice (AVFilterLink *link, int y, int h, int slice_dir)

Variables

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.


Define Documentation

#define apply_mask_fudge_factor (  )     (((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 103 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 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 441 of file vf_removelogo.c.

Referenced by end_frame().

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 368 of file vf_removelogo.c.

Referenced by blur_image().

static int config_props_input ( AVFilterLink inlink  )  [static]

Definition at line 339 of file vf_removelogo.c.

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 119 of file vf_removelogo.c.

Referenced by generate_half_size_image(), and init().

static int end_frame ( AVFilterLink inlink  )  [static]

Definition at line 486 of file vf_removelogo.c.

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 240 of file vf_removelogo.c.

Referenced by init().

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

Definition at line 266 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 199 of file vf_removelogo.c.

Referenced by init().

static int null_draw_slice ( AVFilterLink link,
int  y,
int  h,
int  slice_dir 
) [static]

Definition at line 536 of file vf_removelogo.c.

static int query_formats ( AVFilterContext ctx  )  [static]

Definition at line 192 of file vf_removelogo.c.

static int start_frame ( AVFilterLink inlink,
AVFilterBufferRef inpicref 
) [static]

Definition at line 475 of file vf_removelogo.c.

static void uninit ( AVFilterContext ctx  )  [static]

Definition at line 514 of file vf_removelogo.c.


Variable Documentation

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 = (const AVFilterPad[]) {
        { .name             = "default",
          .type             = AVMEDIA_TYPE_VIDEO,
          .get_video_buffer = ff_null_get_video_buffer,
          .config_props     = config_props_input,
          .draw_slice       = null_draw_slice,
          .start_frame      = start_frame,
          .end_frame        = end_frame,
          .min_perms        = AV_PERM_WRITE | AV_PERM_READ },
        { .name = NULL }
    },
    .outputs = (const AVFilterPad[]) {
        { .name             = "default",
          .type             = AVMEDIA_TYPE_VIDEO, },
        { .name = NULL }
    },
}

Definition at line 538 of file vf_removelogo.c.


Generated on Fri Oct 26 02:50:10 2012 for FFmpeg by  doxygen 1.5.8