Serving VAST ads via Revma

One of Revma’s main functions is the ability to serve VAST ads to listeners. These ads are requested received from the respective content provider (e.g. Triton). For this media to be served to listeners via Revma, one of the three needs to apply:

1. The ad is served as a pre-roll

2. The ad is served as a mid-roll spot replacement

3. The ad is served as a mid-roll spot insertion

Pre-roll

In order for a VAST ad to be served as a pre-roll, a listener needs to simply connect to the stream. To achieve having pre-rolls for streams and targeted listeners, the VAST action that applies for the respective rule requires to have the “Enable PreRoll” option selected. Here is more information on this.

Keep in mind that a pre-roll prevention time can be set per account or stream, in order to avoid having the same listener receive pre-rolls upon every connection. Here is more information on this: 

Pre-rolls always consist of one media file

Ad Replacement

With ad replacement, VAST ads are served to the listener mid-stream, replacing the stream’s content for the duration of this mid-roll. For ads to be served as a spot replacement, a certain metadata trigger needs to be sent from the broadcaster’s end: “ADBREAK_LENGTH_{duration}” will trigger the ad replacement starting point while including its requested duration and “ADBREAK_END” marks the end of that duration in order to define the point of return to the stream. When Revma receives the spot start metadata trigger, it will call for ads from the ad provider. 

As mentioned, the duration of the ads that Revma will try to fetch and serve for each listener is included in the metadata trigger and the stream’s content will be “overlapped” with ads for the listeners that will receive a mid-roll. However, a provider will not necessarily provide ads whose duration is equal to the duration requested by the spot start metadata trigger. If the replacement’s combination of ad media turn out to be longer than what was requested and the listener receives longer duration, they will then be returned to the stream at the point that the mid-roll was “intended” to end, which is defined by the “ADBREAK_END” point. As this will mean that listeners will be “behind” the real-time stream, this is limited up to a certain duration equal to the “overfill limit” setting (as set on the stream configuration settings section of the station).

More specifically, in regards to the metadata triggers: the broadcaster will need to send them via the broadcasting tool in use. The metadata trigger is ADBREAK_LENGTH_{duration} where the duration is in milliseconds. So, if the broadcaster wants to send a request to the provider for 60 seconds of ads, the metadata trigger will need to be ADBREAK_LENGTH_60000.

Here are some more examples:

ADBREAK_LENGTH_60000, for 60 seconds of ads

ADBREAK_LENGTH_120000, for 120 seconds of ads

ADBREAK_LENGTH_240000, for 240 seconds of ads

At the point that the duration ends, the broadcaster will need to send the metadata ADBREAK_END. For example, if the broadcaster sends metadata trigger ADBREAK_LENGTH_60000 from the encoder, the metadata ADBREAK_END will need to follow after 60 seconds.

The ADBREAK_END metadata trigger should be sent at all cases.

The metadata trigger will need to be sent via the "title" or "song" field of the broadcasting tool in use.

Not to be confused with a pre-roll, if a listener enters the stream while a spot replacement mid-roll is triggered, they will enter “mid-break” and they will receive the remaining time of the ad replacement media and then return to the stream accordingly. The “mid-break” has priority over a pre-roll, meaning that, even if enabled, a pre-roll will not be received when the listener enters “mid-break” to a spot replacement mid-roll.

Spot Insertion

To enable spot insertion for streams, please contact your RCS support representative.

With spot insertion, rather than replacing the stream’s content, the VAST ads are injected while the live audio is "paused" for each listener during the mid-roll. Upon completion, live playback resumes from the exact point it was “paused” on; as a result, listeners do not miss any part of the live broadcast.

For ads to be served as a spot insertion, a certain metadata trigger needs to be sent from the broadcaster’s end: “ADINJECT_LENGTH_{duration}” will trigger the spot insertion’s starting point while including its requested duration. Spot insertion requires no trigger to mark its ending point, as the listener should always return at the point that the spot began, which is the same as the spot start metadata trigger. 

More specifically, in regards to the metadata triggers: the broadcaster will need to send them via the broadcasting tool in use. The metadata trigger is ADINJECT_LENGTH_{duration} where the duration is in milliseconds. So, if the broadcaster wants to send a request to the provider for 60 seconds of ads, the metadata trigger will need to be ADINJECT_LENGTH_60000.

Here are some more examples:

ADINJECT_LENGTH_60000, for 60 seconds of ads

ADINJECT_LENGTH_120000, for 120 seconds of ads

ADINJECT_LENGTH_240000, for 240 seconds of ads

With every spot insertion during a session, the listener will go further “behind” the real-time stream. This is limited up to a certain duration equal to the “overfill limit” setting (as set on the stream configuration settings section of the station). Therefore, streams that utilise spot insertion will usually need to have larger “overfill limit” than the default or that required for a ad replacement, in order to facilitate its requirements. Before adjusting this setting, keep in mind that the “stream history” setting should always be set to 30 seconds higher than the “overfill limit”.

Revma has a mechanism preventing ad media files from being interrupted. Listeners will either receive an ad media file from start to end before returning to the stream or the media will be dropped entirely.

A listener cannot enter “mid-break” to a spot insertion as they would during a spot replacement. In such cases, they will either enter the stream with no ad or receive a pre-roll (if enabled).

Ad replacement and insertion can both be used even for the same stream and session. If a spot insertion metadata is triggered while another mid-roll (insertion or replacement) is currently running, it will be ignored. This also applies for spot replacement triggers.

The Provider/Action/Rule setup for spot insertion and replacement does not differ in any way. The VAST provider url that will be used for the mid-roll will in both cases be the “Midroll URL” if any or the “URL” if the “Midroll URL” is empty.