Don't drop updates of the playing period for skipped SSI ads

Before this change ExpPlayerImplInternal dropped a change of the playing period when a change in the timeline occurred that actually changed the playing period but we don't want to update the period queue. This logic also dropped the update of a skipped server side inserted preroll ad for which we want the periodQueue to 'seek' to the stream position after the preroll ad and trigger a SKIP discontinuity.

This change now introduces an exception so that a skipped SSI ad is still causing an update in the period queue which leads to a 'seek' and a discontinuity of type SKIP.

PiperOrigin-RevId: 411607299

library/common/src/main/java/com/google/android/exoplayer2/Timeline.java

@@ -15,6 +15,7 @@
  */
 package com.google.android.exoplayer2;
 
+import static com.google.android.exoplayer2.source.ads.AdPlaybackState.AD_STATE_UNAVAILABLE;
 import static com.google.android.exoplayer2.util.Assertions.checkArgument;
 import static com.google.android.exoplayer2.util.Assertions.checkState;
 import static java.lang.Math.max;
@@ -815,6 +816,21 @@ public abstract class Timeline implements Bundleable {
       return adGroup.count != C.LENGTH_UNSET ? adGroup.durationsUs[adIndexInAdGroup] : C.TIME_UNSET;
     }
 
+    /**
+     * Returns the state of the ad at index {@code adIndexInAdGroup} in the ad group at {@code
+     * adGroupIndex}, or {@link AdPlaybackState#AD_STATE_UNAVAILABLE} if not yet known.
+     *
+     * @param adGroupIndex The ad group index.
+     * @return The state of the ad, or {@link AdPlaybackState#AD_STATE_UNAVAILABLE} if not yet
+     *     known.
+     */
+    public int getAdState(int adGroupIndex, int adIndexInAdGroup) {
+      AdPlaybackState.AdGroup adGroup = adPlaybackState.getAdGroup(adGroupIndex);
+      return adGroup.count != C.LENGTH_UNSET
+          ? adGroup.states[adIndexInAdGroup]
+          : AD_STATE_UNAVAILABLE;
+    }
+
     /**
      * Returns the position offset in the first unplayed ad at which to begin playback, in
      * microseconds.

library/core/src/main/java/com/google/android/exoplayer2/ExoPlayerImplInternal.java

@@ -44,6 +44,7 @@ import com.google.android.exoplayer2.source.MediaSource.MediaPeriodId;
 import com.google.android.exoplayer2.source.SampleStream;
 import com.google.android.exoplayer2.source.ShuffleOrder;
 import com.google.android.exoplayer2.source.TrackGroupArray;
+import com.google.android.exoplayer2.source.ads.AdPlaybackState;
 import com.google.android.exoplayer2.text.TextRenderer;
 import com.google.android.exoplayer2.trackselection.ExoTrackSelection;
 import com.google.android.exoplayer2.trackselection.TrackSelector;
@@ -2648,15 +2649,14 @@ import java.util.concurrent.atomic.AtomicBoolean;
             && earliestCuePointIsUnchangedOrLater;
     // Drop update if the change is from/to server-side inserted ads at the same content position to
     // avoid any unintentional renderer reset.
-    timeline.getPeriodByUid(newPeriodUid, period);
     boolean isInStreamAdChange =
-        sameOldAndNewPeriodUid
+        isIgnorableServerSideAdInsertionPeriodChange(
-            && !isUsingPlaceholderPeriod
+            isUsingPlaceholderPeriod,
-            && oldContentPositionUs == newContentPositionUs
+            oldPeriodId,
-            && ((periodIdWithAds.isAd()
+            oldContentPositionUs,
-                    && period.isServerSideInsertedAdGroup(periodIdWithAds.adGroupIndex))
+            periodIdWithAds,
-                || (oldPeriodId.isAd()
+            timeline.getPeriodByUid(newPeriodUid, period),
-                    && period.isServerSideInsertedAdGroup(oldPeriodId.adGroupIndex)));
+            newContentPositionUs);
     MediaPeriodId newPeriodId =
         onlyNextAdGroupIndexIncreased || isInStreamAdChange ? oldPeriodId : periodIdWithAds;
 
@@ -2682,6 +2682,30 @@ import java.util.concurrent.atomic.AtomicBoolean;
         setTargetLiveOffset);
   }
 
+  private static boolean isIgnorableServerSideAdInsertionPeriodChange(
+      boolean isUsingPlaceholderPeriod,
+      MediaPeriodId oldPeriodId,
+      long oldContentPositionUs,
+      MediaPeriodId newPeriodId,
+      Timeline.Period newPeriod,
+      long newContentPositionUs) {
+    if (isUsingPlaceholderPeriod
+        || oldContentPositionUs != newContentPositionUs
+        || !oldPeriodId.periodUid.equals(newPeriodId.periodUid)) {
+      // The period position changed.
+      return false;
+    }
+    if (oldPeriodId.isAd() && newPeriod.isServerSideInsertedAdGroup(oldPeriodId.adGroupIndex)) {
+      // Whether the old period was a server side ad that doesn't need skipping to the content.
+      return newPeriod.getAdState(oldPeriodId.adGroupIndex, oldPeriodId.adIndexInAdGroup)
+              != AdPlaybackState.AD_STATE_ERROR
+          && newPeriod.getAdState(oldPeriodId.adGroupIndex, oldPeriodId.adIndexInAdGroup)
+              != AdPlaybackState.AD_STATE_SKIPPED;
+    }
+    // If the new period is a server side inserted ad, we can just continue playing.
+    return newPeriodId.isAd() && newPeriod.isServerSideInsertedAdGroup(newPeriodId.adGroupIndex);
+  }
+
   private static boolean isUsingPlaceholderPeriod(
       PlaybackInfo playbackInfo, Timeline.Period period) {
     MediaPeriodId periodId = playbackInfo.periodId;