If your scene uses a video background, its duration cannot be extended.
This is because it’s not possible to generate additional video content beyond the original footage.
When can the duration be extended?
Solid color or image background:
The scene duration can be freely extended or shortened.Video background:
❌ Can only be shortened
❌ Cannot be extended
How to check if your scene is a video:
Click the scene in the timeline at the bottom
Look at the top toolbar: If you see a “Speed” option, it means the scene uses a video background (You can reduce the playback speed of a video to make the scene appear longer, but the actual video length itself cannot be extended.)
