The IMA SDK can be used to monetize live streams as well as video-on-demand. For live streams, you need to make a new ad request for each ad break. Stagger these requests to ensure that all of your viewers aren't requesting ads at the same time and bogging down the ad server(s).
To help with this, the IMA SDK has the AdsRequest.liveStreamPrefetchSeconds
property. This property specifies the maximum number of seconds the SDK
should wait before reaching out to the ad server after you call
AdsLoader.requestAds(). The actual request time will be randomized. For
example, if you set AdsRequest.liveStreamPrefetchSeconds to 30, the SDK
waits 0 to 30 seconds after you call AdsLoader.requestAds() to actually
make the request to the server.
Live stream pre-fetch in practice
We recommend pre-fetching your next ad break as soon as an ad break completes. This ensures the maximum length of time is available for your pre-fetch window. Suppose you have 5 minutes between ad breaks. When an ad break completes, you can request your next ad break with a pre-fetch window of 290 seconds (5 minutes minus 10 seconds, to make sure the requests sent at the end of the pre-fetch window have enough time to resolve):
Objective-C
- (void)adsManager:(IMAAdsManager *)adsManager didReceiveAdEvent:(IMAAdEvent *)event {
...
switch (event.type) {
...
case kIMAAdEvent_ALL_ADS_COMPLETED:
IMAAdsRequest *request = [[IMAAdsRequest alloc]
initWithAdTagUrl: self.adTagUrl
adDisplayContainer: self.adDisplayContainer
avPlayerVideoDisplay: self.avPlayerVideoDisplay
pictureInPictureProxy: self.pictureInPictureProxy
userContext: nil];
// set a delay between the end of the last ad
// in the last request, and the first ad from
// the new request
Float64 adGap = 30;
// make sure the request occurs at least five
// seconds before starting the new set of ads
request.liveStreamPrefetchSeconds = adGap - 5;
[self.adsLoader requestAdsWithRequest:request];
// start new ads after adGap seconds have elapsed
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, adGap * NSEC_PER_SEC), dispatch_get_main_queue(), ^{
[adsManager start];
});
break;
...
}
...
}
Swift
func adsManager(_ adsManager: IMAAdsManager!, didReceive event: IMAAdEvent!) {
switch event.type {
...
case IMAAdEventType.ALL_ADS_COMPLETED:
let request = IMAAdsRequest(
adTagUrl: AdTagUrl,
adDisplayContainer: adDisplayContainer,
contentPlayhead: contentPlayhead,
userContext: nil)
// set a delay between the end of the last ad
// in the last request, and the first ad from
// the new request
let adGap = 30
// make sure the request occurs at least five
// seconds before starting the new set of ads
request.liveStreamPrefetchSeconds = adGap - 5
adsLoader.requestAds(with: request)
// start new ads after adGap seconds have elapsed
DispatchQueue.main.asyncAfter(deadline: .now() + adGap) {
adsManager.start()
}
break
...
}
}