Framing

Anchor a clip to a point

What `position` points at. With topLeft the clip's corner lands on the point instead of its middle.

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.

{
  "transform": {
    "scale": 0.62,
    "position": {
      "x": "30%",
      "y": "30%"
    },
    "anchor": "topLeft"
  }
}

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: 6
            }
          ]
        },
        {
          clips: [
            {
              asset: {
                type: "video",
                src: "https://cdn.rendobar.com/compose/showcase/media/river.mp4"
              },
              start: 0,
              transform: {
                scale: 0.62,
                position: {
                  x: "30%",
                  y: "30%"
                },
                anchor: "topLeft"
              }
            }
          ]
        }
      ]
    }
  },
});


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":6}]},{"clips":[{"asset":{"type":"video","src":"https://cdn.rendobar.com/compose/showcase/media/river.mp4"},"start":0,"transform":{"scale":0.62,"position":{"x":"30%","y":"30%"},"anchor":"topLeft"}}]}]}}}'

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

Questions

What does the anchor effect do in compose?

What `position` points at. With topLeft the clip's corner lands on the point instead of its middle.

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

Send a compose job to the Rendobar API with this entry in the timeline: {"transform":{"scale":0.62,"position":{"x":"30%","y":"30%"},"anchor":"topLeft"}}. 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

Position Where the clip sits in the frame. x and y are the clip's centre by default, as a percent of the frame or in pixels. Scale How big the clip is drawn, as a multiple of its natural size. 0.34 makes it a picture in picture. Rotate Turn the clip, in degrees, about its anchor. A few degrees reads as a photograph laid on a desk. Size The clip's own box, in percent or pixels. Give it a shape the source does not have and `fit: "cover"` crops the picture into it, which is how a wide shot becomes a tall panel. Corner pin Pin the clip's four corners to four points, so footage sits on a surface in the shot. Here the river plays on the laptop screen. Rounded corners Round the corners of what the crop keeps, 0 square to 1 fully round. The corners ride the transform, so a scaled-down clip becomes a rounded card.

See all 77 in the effects reference →