Track video metrics

Last Updated: December 5, 2018

When viewers interact with a video player on your site, their actions trigger player events. Some of the player events return video metrics that you can use to analyze and improve your viewers' video experiences.

Below is a visual representation of player events in a timeline. The table below explains all the bold items. The gray events are included as reference points.

player event metrics

This timeline does not include all events. The events listed may not appear for all player setups.

Event Metric Description
setupError Error Use the setupError event to track critical errors in the player setup process.

All setupError codes are listed in the Errors Reference.
buffer N/A Use the buffer event to track how often the player enters a buffering state and evaluate the quality of your adaptive stream. Since this event fires when the player enters a buffering state, this event may fire multiple times during a session.

Use the reason property of the buffer event to differentiate normal buffering ("reason": "buffering") from stalls ("reason": "stalled").
adError Error Use the adError event to track critical errors in the ad process.

All adError codes are listed in the Ads Errors Reference.
adImpression Ad impressions Use the adImpression event to track the number of raw ad impressions. After an ad has rendered and begun playback, the adImpression event fires.
adViewableImpression Ad viewable impressions Use the adViewableImpression to track the viewability of your ad impressions. The adViewableImpression event fires only when both of the following conditions are met:

- Ad has played for two consecutive seconds
- At least 50% of the player is in the viewport.

The ad viewable impressions metric is comparable to Google's TrueView viewable impression metric.
autostartNotAllowed 8.2.0 + N/A Use the autostartNotAllowed to understand if autostarting videos with sound is permitted for a viewer's video experience.

In environments that prohibit autostarting a video with sound, the player defaults to click-to-play. When this occurs, the player emits an autostartNotAllowed event.
error Error Use the error event to track critical errors that prevent or interrupt playback.

All error codes are listed in the Errors Reference.
firstFrame Plays Use the firstFrame event to track video starts, or plays. The firstFrame event fires once per media item, when playback has begun.

We do not suggest using the play event. The play event can be fired several times per media item. For example, when a view pauses and resumes content, resuming the content triggers a play event.
visualQuality N/A Use the visualQuality event to evaluate your quality of service (QoS). This event fires when the rendition of an adaptive stream changes. The visualQuality event has two relevant properties:

- mode: The mode property returns one of two values that correspond to how the visual quality has been changed: "manual" or "auto". To evaluate the quality of your stream, track when "auto" is the value returned. When "manual" is the value that is returned, a user has manually changed the visual quality. When "auto" is the value that is returned, the visual quality has been changed automatically by the player, based on bandwidth calculations.

- level: The level property returns characteristics of the new rendition, like bitrate, width, and height.
time Quartiles Use the time event to track quartiles on video on demand (VOD) assets. You can use the duration and currentTime properties of this event to calculate the percentage of the video viewed. Then, you can determine quartile events.

When tracking the time event, be sure that the analytics ping is dispatched only once. Since the time event is fired frequently, use a flag or another mechanism to prevent multiple firings.

NOTE: Live streams do not have a duration. Therefore, you cannot track quartile events.