IMA SDK 可用于通过直播和视频点播创收。 对于直播,您需要为每个广告插播时间点发出新的广告请求。 错开这些请求,确保不会让所有观看者同时请求广告,导致广告服务器无法运行。
为帮助完成此任务,IMA SDK 具有 AdsRequest.liveStreamPrefetchSeconds
属性。此属性用于指定在您调用 AdsLoader.requestAds()
后,SDK 在与广告服务器通信之前应等待的最大秒数。实际请求时间是随机的。例如,如果您将 AdsRequest.liveStreamPrefetchSeconds
设置为 30,在您调用 AdsLoader.requestAds()
以实际向服务器发出请求后,SDK 会等待 0 到 30 秒。
直播预提取的实际运用
我们建议在广告插播结束后立即预提取下一个广告插播时间点。 这样可以确保预取窗口具有最长的时间长度。假设您的广告插播时间点之间有 5 分钟的间隔时间。广告插播结束后,您可以请求将预提取时长设置为 290 秒(5 分钟减去 10 秒,以确保在预提取窗口结束时发送的请求有足够的时间进行解析)的下一个广告插播时间点:
这些代码段展示了如何将直播预提取功能添加到高级示例中,但这种方法也适用于其他 IMA 实现。
VideoPlayerController.java
/** Ads logic for handling the IMA SDK integration code and events. */ public class VideoPlayerController { // 5 minutes == 300 seconds. Include a 10 second buffer private float AD_INTERVAL = 290; private double AD_TIMEOUT = 300; ... adsManager.addAdEventListener( new AdEvent.AdEventListener() { /** Responds to AdEvents. */ @Override public void onAdEvent(AdEvent adEvent) { ... case ALL_ADS_COMPLETED: if (adsManager != null) { adsManager.destroy(); adsManager = null; } // When pre-fetching for live streams, be sure to destroy the current AdsManager, // in case the tag you requested previously contains post-rolls // (you don't want to play those now). // Pre-fetch the next ad break. // Play those ads in ~5 minutes. In a real-world implementation, // this will likely be done as the result of a message from your // streaming server, not a via the playAdsAfterThisTime parameter // of requestAndPlayAds(). requestAndPlayAds(AD_TIMEOUT); break; default: break; } } ... public void requestAndPlayAds(double playAdsAfterThisTime) { if (currentAdTagUrl == null || currentAdTagUrl == "") { log("No VAST ad tag URL specified"); resumeContent(); return; } // Since you're switching to a new video, tell the SDK the previous video is finished. if (adsManager != null) { adsManager.destroy(); } playButton.setVisibility(View.GONE); // Create the ads request. AdsRequest request = sdkFactory.createAdsRequest(); request.setAdTagUrl(currentAdTagUrl); request.setContentProgressProvider(videoPlayerWithAdPlayback.getContentProgressProvider()); request.setLiveStreamPrefetchSeconds(AD_INTERVAL); playAdsAfterTime = playAdsAfterThisTime; // Request the ad. After the ad is loaded, onAdsManagerLoaded() will be called. adsLoader.requestAds(request); }