Dolby Millicast Interactivity SDK

This project is an SDK built on top of the @millicast/sdk library to provide an easier way to manage bi-directional communications on the Dolby Millicast platform.

Getting Started

To get started, install this SDK into your web application. The @millicast/sdk library will be installed as a dependency.

npm install @millicast/sdk-interactivity

To import this SDK via script, you will need to load the SDK as UMD as well as the Millicast SDK. An example is provided in the example folder of this repository.

<script src="https://cdn.jsdelivr.net/npm/@millicast/sdk/dist/millicast.umd.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/@millicast/sdk-interactivity/dist/millicast-sdk-interactivity.min.js"></script>

Then you can use the SDK using the variable MillicastInteractivity.

Events

The SDK can trigger the following events:

• publisherJoined - Event triggered when a new publisher starts publishing to the stream.
• publisherLeft - Event triggered when a publisher stops publishing to the stream.
• sourceAdded - Event triggered when a new source is being published to the stream.
• sourceRemoved - Event triggered when a source stopped being published.
• viewercount - Event triggered from time to time to indicate the number of viewers connected to the stream.

import { Publisher, Room, Source } from '@millicast/sdk-interactivity';

const room = new Room({
    streamName,
    streamAccountId,
});

room.on('viewercount', (count: number) => console.log('Viewer count is', count));

room.on('sourceAdded', async (publisher: Publisher, source: Source) => {
    const { identifier } = source;
    console.log(`New ${identifier.sourceType} source: ${identifier.sourceName}`);
    console.log(`is available from ${publisher.name}.`);

    // Request to receive the source
    await source.receive();

    // Display the source on the UI
    const videoElement = document.getElementById('video');
    videoElement.srcObject = new MediaStream([source.videoTrack]);
    videoElement.play();
});

Connect to a stream

To publish your camera into a stream and listen to the available sources, call the connect function. Once connected, the SDK will trigger a series of publisherJoined and sourceAdded events that you must subscribe to in order to get the audio / video streams coming from the platform, and display them on your web page.

import { Publisher, Room, Source } from '@millicast/sdk-interactivity';

const room = new Room({
    streamName,
    streamAccountId,
});

room.on('publisherJoined', (publisher: Publisher) => {
    console.log(`${publisher.name} joined.`);
});
room.on('sourceAdded', (publisher: Publisher, source: Source) => {
    const { identifier } = source;
    console.log(`New ${identifier.sourceType} source: ${identifier.sourceName}`);
    console.log(`is available from ${publisher.name}.`);
});

// Let the SDK handle the getUserMedia
const publishedSource = await room.connect({
    publishToken,
    publisherName,
    constraints: {
        // Set WebRTC Media Stream constraints
        audio: true,
        video: true,
    },
});

// If you want to provide your own media stream, use the following code
const customPublishedSource = await room.connect({
    publishToken,
    publisherName,
    mediaStream,
});

// Stop publishing sources
room.unpublish(publishedSource);
room.unpublish(customPublishedSource);

Watch to a stream

To watch a stream, call the watch function. Once connected, the SDK will trigger a series of publisherJoined and sourceAdded events that you must subscribe to in order to get the audio / video streams coming from the platform, and display them on your web page.

import { Publisher, Room, Source } from '@millicast/sdk-interactivity';

const room = new Room({
    streamName,
    streamAccountId,
});

room.on('publisherJoined', (publisher: Publisher) => {
    console.log(`${publisher.name} joined.`);
});
room.on('sourceAdded', (publisher: Publisher, source: Source) => {
    const { identifier } = source;
    console.log(`New ${identifier.sourceType} source: ${identifier.sourceName}`);
    console.log(`is available from ${publisher.name}.`);
});

await room.watch();

Publish a new source to a stream

To publish another source into a stream, call the publish function.

// Will publish another source
await room.publish({
    publishToken,
    constraints: {
        // Set WebRTC Media Stream constraints
        audio: true,
        video: true,
    },
});

To publish a screenshare into the stream, call the getDisplayMedia function to get the screenshare stream. and the publish function.

import { SourceType } from '@millicast/sdk-interactivity';

// Prompts the user to select and grant permission to capture the contents
// of a display or portion thereof (such as a window).
const mediaStream = await navigator.mediaDevices.getDisplayMedia({});

const source = await room.publish({
    mediaStream,
    releaseOnLeave: true,
    publishToken,
    sourceType: SourceType.Screenshare,
    sourceName: 'My Screenshare',
});

// Display the screenshare on the page
const videoElement = document.getElementById('screenshare');
videoElement.srcObject = new MediaStream([source.videoTrack]);
videoElement.play();

How to

The unit tests are built on Jest, to execute the tests, run the following command.

npm run test

Create distribution package:

npm run build

The documentation is built on TypeDoc, to generate the doc, run the following command. You will find the HTML files in the docs folder.

npm run docs

You can also print the logs in the console and select the log level by using the following code.

import { Logger } from '@millicast/sdk-interactivity';

Logger.useDefaults({
    defaultLevel: Logger.TRACE,
});

Related Projects

• Dolby.io WebRTC Statistics
• Millicast SDK
• js-logger
• TypeDoc
• Jest