FFmpeg Cookbook
FFmpeg Fade & xfade Filters — Crossfade Transitions
Add fade-in/fade-out with FFmpeg's fade filter and crossfade between two clips with the xfade filter. Covers built-in transition effects, timing control with offset/duration, chaining multiple clips, and audio crossfades — with primary sources.
Audio Fade-In and Fade-Out with the afade Filter
Create smooth audio fades in FFmpeg with the afade filter. Covers start time, duration, curve types, applying fades to video audio tracks, and combining fade-in with fade-out in one command.