Etro

Etro is a typescript framework for programmatically editing videos. It lets you composite layers and add filters (effects). Etro comes shipped with text, video, audio and image layers, along with a bunch of GLSL effects. You can also define your own layers and effects with javascript and GLSL.

Features

Composite video and audio layers
Use built-in hardware accelerated effects
Write your own effects in JavaScript and GLSL
Manipulate audio with the web audio API (audio effects coming soon)
Define layer and effect parameters as keyframes or custom functions
Render to a blob in realtime (offline rendering coming soon)

Installation

npm i etro

System Dependencies

node-canvas

If you have problems while installing etro you may need to manually install additional dependencies. See: compiling node-canvas

Basic Usage

Let's look at an example:

import etro from 'etro'

var movie = new etro.Movie({ canvas: outputCanvas })
var layer = new etro.layer.Video({ startTime: 0, source: videoElement })  // the layer starts at 0s
movie.addLayer(layer)

movie.record({ frameRate: 24 })  // or just `play` if you don't need to save it
    .then(blob => ...)

The blob could then be downloaded as a video file or displayed using a <video> element.

See the documentation for a list of all built-in layers.

Effects

Effects can transform the output of a layer or movie:

var layer = new etro.layer.Video({ startTime: 0, source: videoElement })
    .addEffect(new etro.effect.Brightness({ brightness: +100) }))

See the documentation for a list of all built-in effects.

Dynamic Properties

Most properties also support keyframes and functions:

// Keyframes
layer.effects[0].brightness = new etro.KeyFrame(
  [0, -75],  // brightness == -75 at 0 seconds
  [2, +75]  // +75 at 2 seconds
)

// Function
layer.effects[0].brightness = () => 100 * Math.random() - 50

See the documentation for more info.

Using in Node

To use Etro in Node, see the wrapper:

Running the Examples

Start the development server (only used for convenience while developing; you don't need a server to use Etro):

npm i
npm run build
npm start

Now you can open any example (such as http://127.0.0.1:8080/examples/introduction/hello-world1.html).

Contributing

See the contributing guide

License

Distributed under GNU General Public License v3. See LICENSE for more information.

etro-js / etro

readme