Monitor Chromecast

Mux Data is the best way to monitor video streaming performance.

Integration is easy - just initialize the Mux SDK, pass in some metadata, and you're up and running in minutes.

This documents integration instructions for Chromecast. For other players, see the additional Integration Guides.

Features

The following data can be collected by the Mux Data SDK when you use the Chromecast SDK, as described below.

Supported Features:

• Engagement metrics
• Quality of Experience Metrics
• Web metrics such as Player Startup Time, Page Load Time, etc
• Average Bitrate metrics and renditionchange events
• Request metrics
• Customizable Error Tracking
• Custom Beacon Domain

Average Bitrate metrics available in v4.2.11 and newer.

1Include the Mux Data SDK

Mux supports Chromecast applications that are built on top of the Cast Application Framework CAF Receiver SDK. The CAF Receiver SDK supports the following streaming protocols.

A Chromecast application contains two main components: a sender and a receiver. The Mux Data SDK is integrated at the receiver side; include the chromecast-mux.js JavaScript file within your custom receiver application. You can use the Mux-hosted version of the script to receive automatic updates. (The API will not change within major versions, as in chromecast/MAJOR_VERSION/chromecast-mux.js).

npm install --save @mux/mux-data-chromecast

2Initialize Mux Data

Get your ENV_KEY from the Mux environments dashboard.

To monitor video playback within your Chromecast application, pass the PlayerManager instance to initChromecastMux along with SDK options and metadata.

You can initialize within a message interceptor for the LOAD event, or immediately on app load as before. This suggestion changed in version 4.0.0 and newer.

import initChromecastMux from '@mux/mux-data-chromecast';

var app = {
  init: function () {
    const context = cast.framework.CastReceiverContext.getInstance();
    const playerManager = context.getPlayerManager();
    let firstPlay = true;
    let playerInitTime = initChromecastMux.utils.now();

    playerManager.setMessageInterceptor(cast.framework.messages.MessageType.LOAD, loadRequestData => {
      if (firstPlay) {
        initChromecastMux(playerManager, {
          debug: false,
          data : {
            env_key: 'ENV_KEY', // required

            // Metadata
            player_name: 'Custom Player', // ex: 'My Main Player'
            player_init_time: playerInitTime,

            // ... additional metadata
          }
        });
      }

      return loadRequestData;
    });

    context.start();
  }
};

$(document).ready(function () {
  app.init();
});

After you've finished integration, the quickest way to see that the SDK is loaded is to pass debug: true in the options passed to the SDK. With this flag enabled, you can open the debug console, and you should start seeing debug statements from [mux] when you click play on the video.

After playing a video, a few minutes after you stop watching, you'll see the results in your Mux account. We'll also email you when your first video view has been recorded. Log in to the dashboard and find the environment that corresponds to your env_key and look for video views.

Note that it may take a few minutes for views to show up in the Mux Data dashboard.

3Make your data actionable

Detailed Documentation

Options are provided via the data object passed in the call to initChromecastMux.

All metadata details except for env_key are optional, however you'll be able to compare and see more interesting results as you include more details. This gives you more metrics and metadata about video streaming, and allows you to search and filter on important fields like the player version, CDN, and video title.

For more information, see the Metadata Guide.

4Set or update metadata after initialization

There are some cases where you may not have the full set of metadata until after the video playback has started. In this case, you should omit the values when you first call initChromecastMux. Then, once you have the metadata, you can update the metadata with the updateData method.

playerManager.mux.updateData({ video_title: 'My Updated Great Video' });

5Changing the video

There are two cases where the underlying tracking of the video view need to be reset:

1. New source: When you load a new source URL into an existing player.
2. New program: When the program within a singular stream changes (such as a program change within a continuous live stream).

Note: You do not need to change the video info when changing to a different source of the same video content (e.g. different resolution or video format).

New source

If your application plays multiple videos back-to-back in the same video player, you need to signal when a new video starts to the Mux SDK. Examples of when this is needed are:

• The player advances to the next video in a playlist
• The user selects a different video to play

In order to signal the Mux SDK that a new view is starting, you will need to emit a videochange event, along with metadata about the new video. See metadata in Make your data actionable for the full list of video details you can provide. You can include any metadata when changing the video but you should only need to update the values that start with video_.

It's best to change the video info immediately after telling the player which new source to play.

The source change should be done by intercepting the cast.framework.messages.MessageType.LOAD message and doing the following:

playerManager.setMessageInterceptor(cast.framework.messages.MessageType.LOAD, loadRequestData => {
  // It's important to only call this on subsequent videos being loaded, not
  // the first playback (where you call `initChromecastMux`).
  if (!firstVideo) {
    playerManager.mux.emit('videochange', { ... });
  }

  return loadRequestData;
});

New program

In some cases, you may have the program change within a stream, and you may want to track each program as a view on its own. An example of this is a live stream that streams multiple programs back to back, with no interruptions.

In this case, you emit a programchange event, including the updated metadata for the new program within the continuous stream. This will remove all previous video data and reset all metrics for the video view, creating a new video view. See Metadata for the list of video details you can provide. You can include any metadata when changing the video but you should only need to update the values that start with video.

Note: The programchange event is intended to be used only while the player is currently not paused. If you emit this event while the player is paused, the resulting view will not track video startup time correctly, and may also have incorrect watch time. Do not emit this event while the player is paused.

6Advanced options

Customize error tracking behavior

By default, @mux/mux-data-chromecast will track errors emitted from the video element as fatal errors. If a fatal error happens outside of the context of the player, you can emit a custom error to the mux monitor.

playerManager.mux.emit('error', {
  player_error_code: 100,
  player_error_message: 'Description of error',
  player_error_context: 'Additional context for the error'
});

When triggering an error event, it is important to provide values for player_error_code and player_error_message. The player_error_message should provide a generalized description of the error as it happened. The player_error_code must be an integer, and should provide a category of the error. If the errors match up with the HTML Media Element Error, you can use the same codes as the corresponding HTML errors. However, for custom errors, you should choose a number greater than or equal to 100.

In general you should not send a distinct code for each possible error message, but rather group similar errors under the same code. For instance, if your library has two different conditions for network errors, both should have the same player_error_code but different messages.

The error message and code are combined together and aggregated with all errors that occur in your environment in order to find the most common errors that occur. To make error aggregation as useful as possible, these values should be general enough to provide useful information but not specific to each individual error (such as stack trace).

You can use player_error_context to provide instance-specific information derived from the error such as stack trace or segment-ids where an error occurred. This value is not aggregated with other errors and can be used to provide detailed information. Note: Please do not include any personally identifiable information from the viewer in this data.

Error translator

If your player emits error events that are not fatal to playback or the errors are unclear and/or do not have helpful information in the default error message and codes you might find it helpful to use an error translator or disable automatic error tracking all together.

function errorTranslator (error) {
  return {
    player_error_code: translateCode(error.player_error_code),
    player_error_message: translateMessage(error.player_error_message),
    player_error_context: translateContext(error.player_error_context)
  };
}

initChromecastMux(playerManager, {
  debug: false,
  errorTranslator: errorTranslator,
  data : {
    env_key: 'ENV_KEY', // required
    // Metadata
    player_name: 'Custom Player', // ex: 'My Main Player'
    // ... additional metadata
  }
});

If you return false from your errorTranslator function then the error will not be tracked. Do this for non-fatal errors that you want to ignore. If your errorTranslator function itself raises an error, then it will be silenced and the player's original error will be used.

Disable automatic error tracking

In the case that you want full control over what errors are counted as fatal or not, you may want to consider turning off Mux's automatic error tracking completely. This can be done by passing automaticErrorTracking: false in the configuration object.

initChromecastMux(playerManager, {
  debug: false,
  automaticErrorTracking: false,
  data : {
    env_key: 'ENV_KEY', // required
    // Metadata
    player_name: 'Custom Player', // ex: 'My Main Player'
    // ... additional metadata
  }
});

Customize beacon collection domain

If you have integrated a custom domain for Data collection, specify your custom domain by setting beaconCollectionDomain.

initChromecastMux(playerManager, {
  debug: false,
  beaconCollectionDomain: 'CUSTOM_DOMAIN', // ex: 'foo.bar.com'
  data: {
    env_key: "ENV_KEY",
    // ...
  }
});

Destroying the Monitor

There are certain use cases where you want to stop monitoring playback within a player (for instance if the player is no longer being used, you are recycling players, or you are shutting down the application). In this case, you should make sure to destroy the monitor. This can be done by simply calling playerManager.mux.destroy().