JavaScript Player SDK Overview

The Twilio Live Player SDK allows you to play a live stream in your web application. Please check out the documentation for more details.

License

The Twilio Live Player SDK is distributed under the Twilio Terms of Service.

Browser support

Prerequisites

• Node.js (v14+)
• NPM (v6+)

Installing the SDK

NPM

You can install the SDK as a dependency of your app by running the following command:

npm install @twilio/live-player-sdk

You can now import the SDK to your project as shown below:

TypeScript or ES Modules

import { Player } from '@twilio/live-player-sdk';

CommonJS

const { Player } = require('@twilio/live-player-sdk');

Script Tag

You can deploy node_modules/@twilio/live-player-sdk/dist/build/twilio-live-player.min.js with your application. Once you include it in a <script> tag, you can access the SDK APIs in window scope as shown below:

const { Player } = Twilio.Live;

Live Streaming a Video Room

Please refer to the Twilio Live docs docs for starting a live stream of a Video Room from your application server. At the end, you will have an AccessToken which you can use to join the live stream.

Checking for Browser Support

You can check whether the SDK supports the browser on which the application is running as shown below:

import { Player } from '@twilio/live-player-sdk';

if (Player.isSupported) {
  /* Load your application */
} else {
  /* Inform the user that the browser is not supported */
}

Joining a Live Stream

You can now join the live stream from your application using the AccessToken as shown below:

import { Player } from '@twilio/live-player-sdk';

const {
  host,
  protocol,
} = window.location;

// Join a live stream.
const player = await Player.connect('$accessToken', {
  playerWasmAssetsPath: `${protocol}//${host}/path/to/hosted/player/assets`,
});

In order for the SDK to run, your application must host the following artifacts which are available in node_modules/@twilio/live-player-sdk/dist/build:

• twilio-live-player-wasmworker-x-y-z.min.wasm
• twilio-live-player-wasmworker-x-y-z.min.js

where x.y.z is the version of the SDK assets.

Handling Player Events

After joining the live stream, you can listen to events on the Player as shown below:

player.on(Player.Event.StateChanged, (state: Player.State) => {
  switch (state) {
    case Player.State.Buffering:
      /**
       * The player is buffering content.
       */
    case Player.State.Ended:
      /**
       * The stream has ended.
       */
    case Player.State.Idle:
      /**
       * The player has successfully authenticated and is loading the stream. This
       * state is also reached as a result of calling player.pause().
       */
    case Player.State.Playing:
      /**
       * The player is now playing a stream. This state occurs as a result of calling
       * player.play().
       */
    case Player.State.Ready:
      /**
       * The player is ready to play back the stream.
       */
  }
});

Live Stream Playback

You can perform the following playback actions on the live stream:

// Call this method after the Player transitions to the Player.State.Ready state.
player.play();

// Pause playback.
player.pause();

// Mute audio.
player.isMuted = true;

// Unmute audio.
player.isMuted = false;

// Set volume.
player.setVolume(0.5);

Handling the Browser's Autoplay Policy

If your application plays the live stream on page load without a user action, then the browser's autoplay policy may come into effect, in which case the audio will be muted. You can detect when this happens by listening to the Player.Event.VolumeChanged event on the Player as shown below:

player.on(Player.Event.VolumeChanged, () => {
  if (player.isMuted) {
    /* Show the unmute button */
  } else {
    /* Hide the unmute button */
  }
});

Rendering the Live Stream

In order to render the live stream, you can use the default HTMLVideoElement created by the Player in your application as shown below:

const container = document.querySelector('div#container');
container.appendChild(player.videoElement);

Alternatively, if you want to render the live stream in your own HTMLVideoElement, you can do so as shown below:

const videoElement = document.querySelector('div#container > video');
// This is required for inline playback on iOS.
videoElement.playsInline = true;
player.attach(videoElement);

Handling Timed Metadata

When a Media Extension inserts TimedMetadata into a stream, you can receive them by listening to the Player.Event.TimedMetadataReceived event as shown below:

player.on(Player.Event.TimedMetadataReceived, (metadata: Player.TimedMetadata) => {
  /**
   * Handle the data.
   */
});

The Player will receive only the TimedMetadata that is inserted to the stream while it is in the Player.State.Playing state. All other TimedMetadata will be dropped.

Disconnecting from the Live Stream

You can disconnect from the live stream as shown below:

player.disconnect();

This is a terminal operation on the Player, which is no longer useful to the application.

Known Issues

Android Chrome

• Cannot resume playback of a paused live stream.
• The video of a live stream sometimes flickers.

Desktop Firefox

• The Player takes a few seconds longer than usual to reach the ended state after a live stream is stopped by ending a MediaProcessor.

iOS Chrome

• The parameters of Player.stats are always either 0 or null.
• Cannot change the volume of a live stream's audio.
• The live latency of a stream is always greater than 3 seconds and is generally 7-10 seconds.

iOS Safari

• The parameters of Player.stats are always either 0 or null.
• Cannot change the volume of a live stream's audio.
• The live latency of a stream is always greater than 3 seconds and is generally 7-10 seconds.