Motion

Change a clip's playback speed

Play the source faster or slower. 2 is double speed, and the clip lasts half as long.

Shown on Rafting on the Rogue River, on a studio backdrop

Before · the same request without it
After · rendered from the request below

The entry

Put it on the clip itself, beside its asset.

{
  "speed": 2
}

Run it

The whole request behind the render above. Paste it as it is, or swap the file for your own.

job.ts
import { createClient, outputUrl } from "@rendobar/sdk";


const rb = createClient({ apiKey: process.env.RENDOBAR_API_KEY });


const job = await rb.jobs.run({
  type: "compose",
  params: {
    schemaVersion: 1,
    output: {
      format: "mp4",
      resolution: {
        width: 960,
        height: 540
      }
    },
    timeline: {
      tracks: [
        {
          clips: [
            {
              asset: {
                type: "shape",
                shape: "rect",
                color: [
                  "#1B2A26",
                  "#070D0B"
                ],
                gradient: "radial"
              },
              start: 0,
              length: 3
            }
          ]
        },
        {
          clips: [
            {
              asset: {
                type: "video",
                src: "https://cdn.rendobar.com/compose/showcase/media/river.mp4"
              },
              start: 0,
              length: 3,
              transform: {
                scale: 0.62
              },
              speed: 2
            }
          ]
        }
      ]
    }
  },
});


console.log(outputUrl(job));

Install with npm i @rendobar/sdk. jobs.run() submits and waits, so it returns the finished job in one call.

terminal
curl https://api.rendobar.com/jobs \
  -H "Authorization: Bearer $RENDOBAR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"type":"compose","params":{"schemaVersion":1,"output":{"format":"mp4","resolution":{"width":960,"height":540}},"timeline":{"tracks":[{"clips":[{"asset":{"type":"shape","shape":"rect","color":["#1B2A26","#070D0B"],"gradient":"radial"},"start":0,"length":3}]},{"clips":[{"asset":{"type":"video","src":"https://cdn.rendobar.com/compose/showcase/media/river.mp4"},"start":0,"length":3,"transform":{"scale":0.62},"speed":2}]}]}}}'

Returns immediately with a job id. Poll GET /jobs/{id} or register a webhook rather than blocking on the request.

Questions

What does the speed effect do in compose?

Play the source faster or slower. 2 is double speed, and the clip lasts half as long.

How do I add speed to a video with an API?

Send a compose job to the Rendobar API with this entry in the timeline: {"speed":2}. Put it on the clip itself, beside its asset. The request on this page is complete and renders as shown.

Footage and sound

More in the reference

Keyframes A Ken Burns push on a still photo. The box scales from 1 to 1.15 across the clip, eased in and out, so a photograph becomes a shot. Color A warm cinematic grade: the light pulled towards gold, contrast and color lifted a little, skin left believable. LUT A film grade from a LUT file: shadows toward teal, skin and highlights toward orange, the look a colourist hands over as a .cube. Looks The whole archive look in one word: sepia, grain, dust, scratches, projector flicker and a vignette together. Blur Knock the footage back so a title over it stays readable. Sharpen Crisp up footage that is slightly out of focus. Look at the rocks and the life jackets.

See all 77 in the effects reference →