Crop 9:16 to 4:5 for Facebook feed: height 0.703125, y 0.148

To turn a 1080x1920 (9:16) clip into 4:5, keep the full width and crop the height to 0.703125, which is 1350 of 1920 pixels. Centered, that means y of 0.1484375. Meta's Facebook feed video page lists 4:5 at 1440 x 1800, so the cropped 1080x1350 clip then goes through a Timeline render at 1440x1800.

The numbers

A 4:5 frame at 1080 wide is 1350 tall. 1350 divided by 1920 is 0.703125. The most you can shift the window is 1 minus 0.703125, or 0.296875. Faces in phone video sit above center, so a y of 0.08 to 0.12 usually keeps more headroom than the centered 0.1484.

The request

Crop fractions are applied to the source frame, so the pixel result depends on the source size. The video filter docs require x and y in [0, 1], width and height in [0.05, 1], x + width at most 1 and y + height at most 1, and the compiler rounds to even values. One crop is one $0.02 encode job, the check is free, the source must be 300 seconds or shorter, and the request needs an Idempotency-Key. Sume does not auto-detect faces or subjects, so you choose the offset.

curl -X POST https://api.sume.com/v1/video-filter \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: crop-4x5-001" \
  -d '{
    "video_url": "https://media.sume.com/artifacts/artf_demo/talk.mp4",
    "ops": [{ "op": "crop", "x": 0, "y": 0.1, "width": 1, "height": 0.7031 }]
  }'

Then size it for Meta

The cropped clip is about 1080x1350. The Facebook page lists 1440 x 1800, which Timeline allows because both edges are even and within 256 to 2160. Under the default cover fit, the clip scales up to fill the canvas, which adds pixels but no detail. A Timeline 1.0 render costs $0.10 per output minute, rounded up.

What you give up

Cropping to 4:5 removes 30 percent of the height. Burned captions or product text near the top or bottom of the vertical master will be cut, so run captions after the crop, not before.

A habit that saves money: run the free check on the crop request first. It validates the fractions without creating a job, so a typo like a height of 0.75 with a y of 0.3 (which exceeds 1 in total) is caught before the $0.02 encode. After the crop, put the returned MP4 into a Timeline video slot, as the video filter docs describe.