Select your video layer. Go to Effects > Magic Bullet > Instant 4K .
Right-click your comp > Composition Settings > Change Width to 3840 and Height to 2160. Do not scale the layer yet. You will see a tiny box of footage in a sea of black. instant 4k plugin after effects
For vector layers, turn off Texture Recovery . You don't want to add "grain" to a corporate logo. Set the plugin to "Graphics Mode" (if available in your version) for mathematically perfect scale. Part 5: The "AI vs. Optical Flow" Debate You might wonder: Why can't I just use the "Frame Blending" or "Pixel Motion" in After Effects? Select your video layer