Methods to Add and Remove Video Watermarks with FFmpeg

Video Watermark Overview

Video watermarks are an important means of protecting video copyright and enhancing brand recognition. Whether text watermarks or image watermarks, FFmpeg can implement them with simple commands. This article comprehensively introduces various methods of watermark processing in FFmpeg, including practical techniques for adding, positioning, animation effects, and removing watermarks.

Adding Text Watermarks

Use FFmpeg's drawtext filter to add text watermarks on videos, supporting rich style settings.

Basic Text Watermark

The simplest way to add a text watermark, specifying text content, font size, and color:

ffmpeg -i input.mp4 -vf "drawtext=text='CGJU':fontsize=24:fontcolor=white:x=10:y=10" output.mp4

Setting Font and Style

You can specify font file, font size, color, shadow, and other effects:

ffmpeg -i input.mp4 -vf "drawtext=text='@CGJU':fontfile=msyh.ttf:fontsize=32:fontcolor=white:shadowx=2:shadowy=2:shadowcolor=black@0.5:x=20:y=20" output.mp4

Adding Image Watermarks

Use the overlay filter to superimpose images (such as logos) onto videos as watermarks.

Basic Image Watermark

ffmpeg -i input.mp4 -i logo.png -filter_complex "overlay=10:10" output.mp4

Adjusting Watermark Size

First use the scale filter to adjust the watermark image size, then overlay it onto the video:

ffmpeg -i input.mp4 -i logo.png -filter_complex "[1:v]scale=100:-1[logo];[0:v][logo]overlay=20:20" output.mp4

Watermark Position Settings: 9 Standard Positions

FFmpeg provides convenient positioning variables that allow you to easily implement watermark layouts in 9 standard positions.

Four Corner Positions

# Top-left corner
overlay=10:10

# Top-right corner
overlay=W-w-10:10

# Bottom-left corner
overlay=10:H-h-10

# Bottom-right corner
overlay=W-w-10:H-h-10

Edge Center Positions

# Top center
overlay=(W-w)/2:10

# Bottom center
overlay=(W-w)/2:H-h-10

# Left center
overlay=10:(H-h)/2

# Right center
overlay=W-w-10:(H-h)/2

Center Position

# Center
overlay=(W-w)/2:(H-h)/2

Where W and H represent the width and height of the main video, and w and h represent the width and height of the watermark.

Watermark Animation Effects

By using the time variable t in the overlay filter, you can achieve dynamic watermark effects.

Horizontal Scrolling Watermark

# Scroll from left to right
ffmpeg -i input.mp4 -i logo.png -filter_complex "overlay=x='t*100':y=50" output.mp4

# Scroll from right to left
ffmpeg -i input.mp4 -i logo.png -filter_complex "overlay=x='W-w-t*100':y=50" output.mp4

Bouncing Watermark

Use the sine function to achieve up and down bouncing effects:

ffmpeg -i input.mp4 -i logo.png -filter_complex "overlay=x=50:y='50+abs(sin(t*2))*100'" output.mp4

Watermark Opacity Settings

Adjusting watermark opacity can make the watermark less obtrusive while retaining copyright protection.

Image Watermark Opacity

Use format and colorchannelmixer filters to adjust opacity:

# 50% opacity
ffmpeg -i input.mp4 -i logo.png -filter_complex "[1:v]format=rgba,colorchannelmixer=aa=0.5[logo];[0:v][logo]overlay=W-w-20:H-h-20" output.mp4

Text Watermark Opacity

Text watermarks can directly specify opacity in fontcolor:

ffmpeg -i input.mp4 -vf "drawtext=text='CGJU':fontsize=24:fontcolor=white@0.5:x=W-tw-20:y=H-th-20" output.mp4

Watermark Removal/Blurring Methods

Sometimes you need to remove watermarks from videos. FFmpeg provides several methods to achieve different levels of removal effects.

Blurring Watermark Area

Use the boxblur filter to blur the watermark area:

# Blur the top-left watermark area (x:y:w:h)
ffmpeg -i input.mp4 -vf "delogo=x=10:y=10:w=200:h=80:show=0" output.mp4

Using the delogo Filter

delogo is a filter specifically for removing station logos and watermarks, with more natural results than blurring:

ffmpeg -i input.mp4 -vf "delogo=x=50:y=50:w=150:h=60:band=3" output.mp4

Using the remove logo Filter

The removelogo filter fills the watermark area by analyzing surrounding pixels:

# Need to create a watermark mask image first
ffmpeg -i input.mp4 -vf "removelogo=mask.png" output.mp4

Batch Watermark Addition

In practical work, it's often necessary to batch process multiple videos. Here are methods for batch adding watermarks.

Windows Batch Processing

@echo off
for %%i in (*.mp4) do (
    ffmpeg -i "%%i" -i logo.png -filter_complex "overlay=W-w-20:H-h-20" -c:a copy "output\%%~ni_watermark.mp4"
)

Linux/Mac Shell Script

#!/bin/bash
for file in *.mp4; do
    ffmpeg -i "$file" -i logo.png -filter_complex "overlay=W-w-20:H-h-20" -c:a copy "output/${file%.mp4}_watermark.mp4"
done

Summary

FFmpeg provides powerful and flexible watermark processing capabilities, from simple text watermarks to complex animated watermarks, from addition to removal, all can be done efficiently. Mastering these techniques will allow you to handle video copyright protection, brand promotion, and other scenarios with ease.

It should be noted that removing watermarks from others' videos may involve copyright issues. Please ensure you use these technologies under legal and compliant premises.