Mixing 24 fps Seedance clips with 30 fps footage in Sume Timeline

When a holiday ad mixes AI clips with phone footage, set output.fps explicitly in Sume Timeline 1.0. The allowed values are 24, 25, 30 and 60. Without it, the job matches the sources, and if they differ it returns the warning output_fps_resamples_sources with the rate the sources wanted.

What the docs say

From the Timeline docs, as of 2026-10-08.

Picking a rate

Seedance renders at 24 fps in Sume's cost model, and many phone clips are 30. Choose the rate of the majority of the footage, or the rate the destination wants. 30 suits social placements, 24 suits a film look, and 60 is for UI captures. Shopify's help page recommends 60, 30 or 25 fps for product video (read 2026-10-08), so 30 fits both a Seedance mix and a store page.

• Run the plan endpoint first; it costs nothing and shows warnings.
• Treat output_fps_resamples_sources as a decision prompt, not an error.
• Use fit: cover for full-bleed, blur for letterbox backgrounds.

Checks before a batch

Join two clips with a plan call, read the warnings, then render. Once the rate is set, fix it in your template so 1,200 renders carry the same value.

Where it goes wrong

The common mistake is leaving fps unset and letting a 24 fps clip and a 60 fps screen recording fight over the output rate. The warning tells you the rate the sources wanted, so read it and decide, rather than accepting what the job picked.

Another is mixing sizes. fit controls how a clip that differs from the output frame is placed: cover crops, contain letterboxes, stretch distorts and blur fills the bars with a blurred copy.

• Plan call first; it is not billed.
• Set output.fps in the template.
• Keep one fit value for the whole timeline unless a clip is an exception.

Before you scale

A fixed template also makes batch cost predictable. Because Timeline bills $0.10 per ceil output minute, a 45-second render and a 60-second render cost the same, and a 61-second render costs $0.20. Trim to just under the minute where the ad allows it, and set the fps and the size once so every SKU renders under the same rules.