Fill

Standard render

The fill parameters control what appears in the letterbox or pillarbox region when a video is resized with fit=fill or fit=fillmax. Choose from a solid color, a blurred copy of the video frame, or a custom background image — and optionally animate that image with a slow pan or zoom (Ken Burns effect).

Use case

Reformat a landscape video to portrait for social media, filling the side bars with a blurred copy of the video frame — no additional assets required.

Uses fit=fill with fill=blur to cover-scale and blur a copy of the video behind the resized foreground, with fill-darken=20 to add subtle depth.

https://assets.imgix.net/videos/person-running-01.mp4?fm=mp4&fit=fill&fill=blur&fill-darken=20&w=600&h=1067

ABR Rendition Ladder Fill Background Type