Lavalier

A video editing toolkit for TypeScript.

Usage

import { video } from "lavalier"

await video("input.mp4")
  .trim({ start: 2, end: 8 })
  .scale({ width: 1280 })
  .fps(30)
  .rotate(90)
  .volume(0.8)
  .export("output.mp4")

Lavalier requires ffmpeg to be installed and available on your PATH.

API

video(input)

Create an editable video from an input path.

const clip = video("input.mp4")

trim(options)

Trim by seconds. Provide start, end, or both.

video("input.mp4").trim({ end: 5 })
video("input.mp4").trim({ start: 10 })
video("input.mp4").trim({ start: 2, end: 8 })

If start is omitted, it defaults to 0. If end is omitted, the clip runs to the end.

volume(level)

Adjust audio volume. 1 keeps the original volume, 0.5 halves it, 2 doubles it, and 0 makes it silent.

video("input.mp4").volume(0)

fps(rate)

Set the output frame rate.

video("input.mp4").fps(30)

rotate(degrees)

Rotate the video frame. Degrees must be 90, 180, or 270.

video("input.mp4").rotate(90)

flip(direction)

Flip the video frame horizontally or vertically.

video("input.mp4").flip("horizontal")
video("input.mp4").flip("vertical")

speed(factor)

Change playback speed. 2 is twice as fast, and 0.5 is half speed.

video("input.mp4").speed(2)

crop(options)

Crop the video frame.

video("input.mp4").crop({ x: 10, y: 20, width: 640, height: 360 })

scale(options)

Resize the video frame. Provide both dimensions for an exact resize, or one dimension to preserve aspect ratio.

video("input.mp4").scale({ width: 1280, height: 720 })
video("input.mp4").scale({ width: 1280 })
video("input.mp4").scale({ height: 720 })

concat(...videos)

Append videos in order.

await video("intro.mp4").concat(video("main.mp4"), video("outro.mp4")).export("output.mp4")

export(output)

Render the video to an output path.

await video("input.mp4").export("output.mp4")