How to Use FFmpeg xfade Filter for Video Transitions

This guide explains how to apply transition effects between two video files using the FFmpeg xfade filter. You will learn the fundamental command structure, how to calculate the correct transition timing, how to handle accompanying audio, and how to choose from various transition styles to create seamless video cuts.

The xfade Filter Syntax

The xfade (cross-fade) filter merges two video streams using a specified transition effect. To use it successfully, you must define three primary parameters:

• transition: The name of the transition effect (e.g., fade, wipeleft, slideup).
• duration: The length of the transition effect in seconds.
• offset: The exact timestamp (in seconds) in the first video where the transition should begin.

How to Calculate the Offset

The most critical step in using xfade is calculating the offset. If your first video is 10 seconds long and you want a 1-second transition, the transition must start at the 9-second mark.

The formula is:
offset = (Duration of Video 1) - (Transition Duration)

Basic Command Example

To apply a 1-second fade transition between video1.mp4 (which is 10 seconds long) and video2.mp4, use the following command:

ffmpeg -i video1.mp4 -i video2.mp4 -filter_complex "[0:v][1:v]xfade=transition=fade:duration=1:offset=9[v]" -map "[v]" output.mp4

Here is a breakdown of the command: * -i video1.mp4 -i video2.mp4: Imports the two input videos. * -filter_complex: Invokes FFmpeg’s complex filtergraph. * [0:v][1:v]: Selects the video streams of the first and second inputs. * xfade=transition=fade:duration=1:offset=9: Applies the fade transition for 1 second starting at second 9. * [v]: Labels the output video stream. * -map "[v]": Ensures the processed video stream is mapped to the output file.

Adding Audio Transitions

The xfade filter only processes video. To prevent the audio from cutting off abruptly, you must cross-fade the audio streams using the acrossfade filter.

Here is the complete command combining both video and audio transitions:

ffmpeg -i video1.mp4 -i video2.mp4 -filter_complex "[0:v][1:v]xfade=transition=fade:duration=1:offset=9[v];[0:a][1:a]acrossfade=d=1[a]" -map "[v]" -map "[a]" output.mp4

In this command, acrossfade=d=1 cross-fades the audio streams for a duration (d) of 1 second at the end of the first clip.

Available Transition Effects

FFmpeg supports dozens of transition effects. You can substitute transition=fade in the command with any of the following popular options:

• Wipes: wipeleft, wiperight, wipeup, wipedown
• Slides: slideleft, slideright, slideup, slidedown
• Shapes: circlecrop, rectcrop
• Dissolves: dissolve, pixelize