IMA Extension PODs with empty positions in the middle

[MajDroid]

Issue description

IMA Extension when dealing with a POD (pre-roll/mid-roll) with fixed size (like 4) and one or more of the positions in the middle happen to be empty.
As soon as IMA Extension spots an empty position (AdEvent LOG), it decides to mark the rest of the unplayed ads with error as seen in method handleAdGroupLoadError:

    for (int i = 0; i < adGroup.count; i++) {
        if (adGroup.states[i] == AdPlaybackState.AD_STATE_UNAVAILABLE) {
            if (DEBUG) {
                Log.d(TAG, "Removing ad " + i + " in ad group " + adGroupIndex);
            }
            adPlaybackState = adPlaybackState.withAdLoadError(adGroupIndex, i);
        }
     }

and skips the rest of unplayed ads

Version of ExoPlayer being used

2.8.0 and 2.7.3

Expected Behavior

IMA Extension should continue withe rest of the positions in a POD even if it found an empty one (or more) in the middle

[andrewlewis]

Please could you provide your ad tag (here or via email to dev.exoplayer@gmail.com)?

[MajDroid]

Unfortunately i do not have a publicly available ad tag for your to test.

Just to clarify what i mean with an empty position, it's an AdEvent LOG as follows:
onAdEvent: LOG
adEvent: AdEvent[type=LOG, ad=null, adData={type: adLoadError, errorCode: 1009, errorMessage: The response does not contain any valid ads.}]

[andrewlewis]

Without the ad tag it's difficult to see if this is a bug in the extension, in the IMA SDK or a problem with the ad tag.

Please could you look in the ad tag and the pods it links to and describe which specific files are empty/non-empty? Or, even better, download the ad tags, remove information you can't share and attach the result?

[MajDroid]

To summarize our ads setup, we serve the ads in VMAP (Ad Playlist), attached a sample for your reference.

In each Ad Pod (such as Preroll), DFP reserves 4 slots for ads as, these slots might have ads or they might not, this is determined once the DFP receives a request.
So IMA requests each Ad, DFP determines whether that slot should return an ad or not.

Now IMA-Extension becomes unreliable and does not play all ads once one or more of those ad slots return empty result (attached is a sample of an empty ad response).
So In one case, where ads fail to play at in the preroll:
Slot #1 NoAd
Slot #2 NoAd
Slot #3 HasAnAd
Slot #4 NoAd

another scenario:
Slot #1 NoAd
Slot #2 HasAnAd
Slot #3 NoAd
Slot #4 HasAnAd

or another scenario:
Slot #1 NoAd
Slot #2 HasAnAd
Slot #3 HasAnAd
Slot #4 NoAd

Now results vary with different combination but during my investigation, i noticed that IMA Extension as soon as it receives a LOG event (in other words, an empty ad), it decides to mark the remaining ads with no state as "error".

Attached is a sample VMAP, Empty Ad and Filled Ad

[MajDroid]

@andrewlewis is my description in the last post sufficient? if there are more details that i can provide, please don't hesitate to ask

[andrewlewis]

It looks sufficient to investigate though I probably won't get round to it for a while. Thanks for your patience.

[andrewlewis]

To fix this I think we need the IMA SDK to surface more information with adLoadErrors about exactly which ad/ad break is empty. I've filed [Internal: b/112349460] for this feature request and will update this issue when I have more information.

[ojw28]

Please give the latest dev-v2 branch a try, and let us know whether this is fixed. Thanks!