Crop 9:16 to 16:9 for TikTok horizontal: height 0.3164 is 1080x608

To turn a 1080x1920 (9:16) clip into 16:9, keep the full width and crop the height to 0.31640625, which is 607.5 of 1920 pixels and rounds to an even 608. Centered, y is 0.3418. TikTok's in-feed page lists 16:9 horizontal with a 960 x 540 minimum, and a 1080x608 crop clears both edges.

The numbers

A 16:9 frame at 1080 wide is 607.5 tall, so the compiler rounds to 608. 608 divided by 1920 is about 0.3167, and the exact fraction 0.31640625 is what the width-to-height math gives. The crop keeps 32 percent of the vertical frame.

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-9x16-to-16x9-001" \
  -d '{
    "video_url": "https://media.sume.com/artifacts/artf_demo/talk.mp4",
    "ops": [{ "op": "crop", "x": 0, "y": 0.3418, "width": 1, "height": 0.3164 }]
  }'

When not to do this

A 16:9 crop of a vertical clip throws away two thirds of the picture, and most vertical framing has the subject spread over the full height. TikTok lists 9:16 as the recommended vertical ratio, so keep the vertical master for the feed. Use the crop only when a placement asks for horizontal and a new generation is not an option.

If you are generating, ask for 16:9 directly. The video generation docs list 16:9 among the ratios, and each model shows its own subset.

Cost is small either way: one $0.02 crop job, plus a $0.10 per output minute Timeline render if you want a different canvas size. The cost that matters is the picture you lose, so view the cropped frame before you spend on the render. If the subject sits outside the middle third, move y toward it instead of centering.