In ads_manager.js
, define a wrapper class for the IMA SDK StreamManager that
makes stream requests, gets the ad pod manifest, listens to IMA stream events,
and passes emsg events to the IMA SDK.
In ads_manager.js
, the IMA HbbTV sample app sets up the following methods:
requestStream()
onStreamEvent()
onEmsgEvent()
loadAdPodManifest()
Initialize ads manager
Initialize the ads manager class and set listeners for the IMA stream events. In
this call, set the emsg event handler with the
VideoPlayer.setEmsgEventHandler()
method.
/** * Wraps IMA SDK ad stream manager. * @param {!VideoPlayer} videoPlayer Reference an instance of the wrapper from * video_player.js. */ var AdManager = function(videoPlayer) { this.streamData = null; this.videoPlayer = videoPlayer; // Ad UI is not supported for HBBTV, so no 'adUiElement' is passed in the // StreamManager constructor. this.streamManager = new google.ima.dai.api.StreamManager( this.videoPlayer.videoElement); this.streamManager.addEventListener( [ google.ima.dai.api.StreamEvent.Type.STREAM_INITIALIZED, google.ima.dai.api.StreamEvent.Type.ERROR, google.ima.dai.api.StreamEvent.Type.CLICK, google.ima.dai.api.StreamEvent.Type.STARTED, google.ima.dai.api.StreamEvent.Type.FIRST_QUARTILE, google.ima.dai.api.StreamEvent.Type.MIDPOINT, google.ima.dai.api.StreamEvent.Type.THIRD_QUARTILE, google.ima.dai.api.StreamEvent.Type.COMPLETE, google.ima.dai.api.StreamEvent.Type.AD_BREAK_STARTED, google.ima.dai.api.StreamEvent.Type.AD_BREAK_ENDED, google.ima.dai.api.StreamEvent.Type.AD_PROGRESS, google.ima.dai.api.StreamEvent.Type.PAUSED, google.ima.dai.api.StreamEvent.Type.RESUMED ], this.onStreamEvent.bind(this), false); this.videoPlayer.setEmsgEventHandler(this.onEmsgEvent, this); };
Make a request for an ad pod stream
Create the AdManager.requestStream()
method to create a PodStreamRequest
object using your Google Ad Manager network code and the stream's custom asset
key. Test your HbbTV app using the IMA sample DASH pod serving stream with the
following stream parameters:
- Network code:
'21775744923'
- Custom asset key:
'hbbtv-dash'
/** * Makes a pod stream request. * @param {string} networkCode The network code. * @param {string} customAssetKey The custom asset key. */ AdManager.prototype.requestStream = function(networkCode, customAssetKey) { var streamRequest = new google.ima.dai.api.PodStreamRequest(); streamRequest.networkCode = networkCode; streamRequest.customAssetKey = customAssetKey; streamRequest.format = 'dash'; debugView.log('AdsManager: make PodStreamRequest'); this.streamManager.requestStream(streamRequest); };
Listen to ad stream events
Create the AdManager.onStreamEvent()
method to handle your app's response to
the IMA stream events, STREAM_INITIALIZED
, AD_BREAK_STARTED
, and
AD_BREAK_ENDED
.
/** * Handles IMA playback events. * @param {!Event} event The event object. */ AdManager.prototype.onStreamEvent = function(event) { switch (event.type) { // Once the stream response data is received, generate pod manifest url // for the video stream. case google.ima.dai.api.StreamEvent.Type.STREAM_INITIALIZED: debugView.log('IMA SDK: stream initialized'); this.streamData = event.getStreamData(); break; case google.ima.dai.api.StreamEvent.Type.ERROR: break; // Hide video controls while ad is playing. case google.ima.dai.api.StreamEvent.Type.AD_BREAK_STARTED: debugView.log('IMA SDK: ad break started'); this.adPlaying = true; this.adBreakStarted = true; break; // Show video controls when ad ends. case google.ima.dai.api.StreamEvent.Type.AD_BREAK_ENDED: debugView.log('IMA SDK: ad break ended'); this.adPlaying = false; this.adBreakStarted = false; break; // Update ad countdown timers. case google.ima.dai.api.StreamEvent.Type.AD_PROGRESS: break; default: debugView.log('IMA SDK: ' + event.type); break; } };
Handle ad stream metadata
To pass the emsg event info to IMA, create the AdManager.onEmsgEvent()
method
using the StreamManager.processMetadata()
method. The video player class calls
this method with the VideoPlayer.setEmsgEventHandler()
method.
/** * Callback on Emsg event. * Instructs IMA SDK to fire back VAST events accordingly. * @param {!Event} event The event object. */ AdManager.prototype.onEmsgEvent = function(event) { var data = event.event.messageData; var pts = event.event.calculatedPresentationTime; if ((data instanceof Uint8Array) && data.byteLength > 0) { this.streamManager.processMetadata('ID3', data, pts); } };
Load the ad pod manifest
Create the AdManager.loadAdPodManifest()
method to preload the ad pod manifest
with the video player. Construct the manifest URL using the structure in
Method: DASH pod manifest.
/** * Creates DAI pod url and instructs video player to load manifest. * @param {string} networkCode The network code. * @param {string} customAssetKey The custom asset key. * @param {number} podDuration The duration of the ad pod. */ AdManager.prototype.loadAdPodManifest = function(networkCode, customAssetKey, podDuration) { if (!this.streamData) { debugView.log('IMA SDK: No DAI pod session registered.'); return; } var MANIFEST_BASE_URL = 'https://dai.google.com/linear/pods/v1/dash/network/'; // Method: DASH pod manifest reference docs: // https://developers.google.com/ad-manager/dynamic-ad-insertion/api/pod-serving/reference/live#method_dash_pod_manifest var manifestUrl = MANIFEST_BASE_URL + networkCode + '/custom_asset/' + customAssetKey + '/stream/' + this.streamData.streamId + '/pod/' + this.getPodId() + '/manifest.mpd?pd=' + podDuration; this.videoPlayer.preload(manifestUrl); };
The
HbbTV sample app
uses a randomly generated unique podId
. In production apps, the podId
is an
integer that starts at one, and increments by one for each ad break. Ensure the
podId
is the same value for all viewers of the ad break. To get a podId
, we
recommend using the
Early ad break notifications
(EABN) API. In a production environment, include the podId
and podDuration
in the HbbTV stream event AD_BREAK_ANNOUNCE
.
Next, create the main application class for your HbbTV app that interacts with the HbbTV broadcast.