How to Use FFmpeg Delogo Filter to Remove Video Logos

This article provides a straightforward guide on how to use the FFmpeg delogo filter to remove or blur unwanted logos, watermarks, and on-screen graphics from your videos. You will learn the basic command syntax, how to identify the correct coordinates for the logo, and how to apply the filter to achieve a clean result.

Understanding the Delogo Filter

The delogo filter in FFmpeg removes an unwanted logo by interpolating the surrounding pixels. Instead of detecting the logo automatically, you define a rectangular bounding box over the logo. FFmpeg then blends the pixels within that box with the surrounding image to make the logo less noticeable.

The Basic Command Syntax

The basic syntax for the delogo filter is as follows:

ffmpeg -i input.mp4 -vf "delogo=x=X:y=Y:w=W:h=H" output.mp4

Parameter Breakdown:

• x: The horizontal position of the top-left corner of the logo (in pixels) from the left edge of the video.
• y: The vertical position of the top-left corner of the logo (in pixels) from the top edge of the video.
• w: The width of the logo bounding box (in pixels).
• h: The height of the logo bounding box (in pixels).

Step-by-Step Guide

Step 1: Find the Logo Coordinates and Dimensions

To use the filter, you must first find the exact pixel coordinates (x, y) and size (w, h) of the logo. 1. Take a screenshot of your video containing the logo. 2. Open the screenshot in an image editor (such as Photoshop, GIMP, or Paint). 3. Use the selection tool to highlight the logo. 4. Note the X and Y coordinates of the top-left corner of your selection, as well as the Width and Height of the selection.

Step 2: Run the FFmpeg Command

Suppose your video is 1920x1080, and you found a logo in the top-right corner with the following measurements: * X coordinate (x): 1700 * Y coordinate (y): 50 * Width (w): 150 * Height (h): 75

You would run the following command to blur the logo:

ffmpeg -i input.mp4 -vf "delogo=x=1700:y=50:w=150:h=75" -c:a copy output.mp4

(Note: -c:a copy is added to copy the audio stream without re-encoding it, which saves processing time.)

Advanced Settings

Adjusting the Blend Border

The delogo filter has an optional parameter called band which specifies the thickness of the fuzzy edge (in pixels) around the coordinates. This helps blend the interpolated area into the video. The default value is 4. You can increase this if the edges of the blurred area look too sharp.

Example with a custom band thickness of 10:

ffmpeg -i input.mp4 -vf "delogo=x=1700:y=50:w=150:h=75:band=10" -c:a copy output.mp4

Visualizing the Bounding Box

To ensure you have the correct coordinates before rendering the entire video, you can use the show parameter. Setting show=1 draws a green rectangle around the specified coordinates.

Example for testing:

ffmpeg -i input.mp4 -vf "delogo=x=1700:y=50:w=150:h=75:show=1" -c:a copy test_output.mp4

Once you verify that the green box covers the logo perfectly, run the final command without :show=1 to apply the actual blur.