Kling motion control: a 2.4-second driver is billed as 3 seconds

Sume bills Kling 3.0 Motion Control per whole second, rounded up, so a 2.4-second driving video is charged as 3 seconds: 3 x $0.1575 = $0.4725. The catalog describes the price as per ceil(motion video second) after Sume's margin.

The rounding rule

The catalog entry reads: priced per ceil(motion video second), output length follows the driving video, duration 1 to 30 seconds. In the request body, you declare duration_seconds as a number from 1 to 30 so that Sume can reserve the right amount before the job runs. The provider itself has no duration setting; Sume uses the number for admission and pricing only.

Practical consequences

Trim your driver to a whole second if you can, because a driver of 7.01 seconds bills as 8. Trimming costs a flat $0.02 per job on Sume's video trim route, which pays for itself only if it saves more than $0.02, and one second of Kling motion control is $0.1575, so trimming a few tenths of a second off a clip that just crossed a whole-second line is worth it.

Measure the driver before you submit. Sume has a video inspect route for that. Declare the measured length, not a guess; the output follows the driving video no matter what you declare, so declaring too short only risks a mismatch at the reservation.

Budget for a batch

Forty drivers of 2.4 seconds each reserve 40 x $0.4725 = $18.90. If they were trimmed to exactly 2 seconds they would cost 40 x 2 x $0.1575 = $12.60, a difference of $6.30 for the batch.

A tiny rounding calculator

If you prefer to compute the bill in your own code before submitting, the arithmetic is one line. The rate comes from the catalog, so read it from there rather than hard-coding it where you can. The ceiling matters for floats: a measured length of 7.0000001 seconds will bill as 8, so round measured lengths to a sensible number of decimals first, for example to milliseconds.

Expected values at $0.1575 per second: 1 s = $0.1575, 2 s = $0.315, 3 s = $0.4725, 8 s = $1.26, 15 s = $2.3625, 30 s = $4.725.

The reservation is rounded up to cents, so these appear as 16, 32, 48, 126, 237 and 473 cents on your balance until the job captures the Sume price.