Contact Support | System Status
Page Contents

    Brightcove Player Sample: Automatically Set Audio Track Language

    In this topic, you will learn how to set the default audio track language based on the browser language.

    Player example

    When you start video playback, you will hear the narration in the same language as the browser, with the limitation that the video has only English and Spanish audio tracks.

    See the Pen Automatically Set Audio Track Language by Brightcove Learning Services (@rcrooks1969) on CodePen.

    Source code

    View the complete solution on GitHub.

    Using the CodePen

    Here are some tips to effectively use the above CodePen:

    • Toggle the actual display of the player by clicking the Result button.
    • Click the HTML/CSS/JS buttons to display ONE of the code types.
    • Later in this document the logic, flow and styling used in the application will be discussed in the Player/HTML configuration, Application flow and Application styling sections. The best way to follow along with the information in those sections is to:
      1. Click the EDIT ON CODEPEN button in the CodePen and have the code available in one browser/browser tab.
      2. In CodePen, adjust what code you want displayed. You can change the width of different code sections within CodePen.
      3. View the Player/HTML configuration, Application flow and/or Application styling sections in another browser/browser tab. You will now be able to follow the code explanations and at the same time view the code.

    Development sequence

    Here is the recommended development sequence:

    1. Use the In-Page embed player implementation to test the functionality of your player, plugin and CSS (if CSS is needed)
    2. Put the plugin's JavaScript and CSS into separate files for local testing
    3. Deploy the plugin code and CSS to your server once you have worked out any errors
    4. Use Studio to add the plugin and CSS to your player
    5. Replace the In-Page embed player implementation if you determine that the iframe implementation is a better fit (detailed in next section)

    For details about these steps, review the Step-by-Step: Plugin Development guide.

    iframe or In-Page embed

    When developing enhancements for the Brightcove Player you will need to decide if the code is a best fit for the iframe or In-Page embed implementation. The best practice recommendation is to build a plugin for use with an iframe implementation. The advantages of using the iframe player are:

    • No collisions with existing JavaScript and/or CSS
    • Automatically responsive
    • The iframe eases use in social media apps (or whenever the video will need to "travel" into other apps)

    Although integrating the In-Page embed player can be more complex, there are times when you will plan your code around that implementation. To generalize, this approach is best when the containing page needs to communicate to the player. Specifically, here are some examples:

    • Code in the containing page needs to listen for and act on player events
    • The player uses styles from the containing page
    • The iframe will cause app logic to fail, like a redirect from the containing page

    Even if your final implementation does not use the iframe code, you can still use the In-Page embed code with a plugin for your JavaScript and a separate file for your CSS. This encapsulates your logic so that you can easily use it in multiple players.

    API/Plugin resources used

    API Methods API Events
    on() loadedmetadata

    Player/HTML configuration

    This section details any special configuration needed during player creation. In addition, other HTML elements that must be added to the page, beyond the in-page embed player implementation code, are described.

    Player configuration

    No special configuration is required for the Brightcove Player you create for this sample.

    Other HTML

    No other HTML elements are added to the page.

    Application flow

    The basic logic behind this application is:

    • Get the browser language
    • Retrieve the audio tracks
    • Loop over the audio tracks
    • Enable the correct audio track

    Get the browser language

    Find the code which is labeled:

    // +++ Get the browser language +++

    Use navigator.language to determine the language being used in the browser. Check for navigator.userLanguage with IE browsers earlier than 10.

    Retrieve the audio tracks

    Find the code which is labeled:

    // +++ Get the audio tracks +++

    Use the myPlayer.audioTracks() method to retrieve all the available audio tracks. The object view of the audioTracks object is shown here:


    Notice that the object contains both the country label and country code (language). In the JavaScript code, we are searching for the language since it is possible that the label could be translated by the browser.

    Loop over the audio tracks

    Find the code which is labeled:

    // +++ Loop through the audio tracks +++

    Loop over the available audio tracks.

    Enable the correct audio track

    Find the code which is labeled:

    // +++ Set the enabled audio track language +++

    When the audio track language is equal to the browser language, then enable that boolean property to true. Note that when one audio track is enabled the others are automatically disabled.

    Application styling

    No CSS is needed for this sample.

    Plugin code

    Normally when converting the JavaScript into a Brightcove Player plugin nominal changes are needed. One required change is to replace the standard use of the ready() method with the code that defines a plugin.

    Here is the very commonly used start to JavaScript code that will work with the player:

    videojs.getPlayer('myPlayerID').ready(function() {
    var myPlayer = this;

    You will change the first line to use the standard syntax to start a Brightcove Player plugin:

    videojs.registerPlugin('pluginName', function(options) {
    var myPlayer = this;

    As mentioned earlier, you can see the plugin's JavaScript code in this document's corresponding GitHub repo: auto-audio-track.js.

    Using the plugin with a player

    Once you have the plugin's CSS and JavaScript files stored in an Internet accessible location, you can use the plugin with a player. In Studio's PLAYERS module you can choose a player, then in the PLUGINS section add the URLs to the CSS and JavaScript files, and also add the Name and Options, if options are needed.

    Page last updated on 03 Jul 2021