Use content timeline to get ad group index and ad index in ad group

The timeline used to map ad groups to periods needs to report the original content period duration without subtracting the serverside inserted ad duration. When marking played ads in onPositionDiscontinuity, the public timeline has been used which crashed the app when the ads media source is playing on a window index different to zero (in a playlist).

#minor-release

PiperOrigin-RevId: 428465833

libraries/exoplayer_ima/src/main/java/androidx/media3/exoplayer/ima/ImaServerSideAdInsertionMediaSource.java

@@ -93,6 +93,7 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import org.checkerframework.checker.nullness.qual.EnsuresNonNull;
 import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
 
 /**
@@ -476,6 +477,7 @@ private void setAdPlaybackState(AdPlaybackState adPlaybackState) {
   }
 
   @MainThread
+  @EnsuresNonNull("contentTimeline")
   private void setContentTimeline(Timeline contentTimeline) {
     if (contentTimeline.equals(this.contentTimeline)) {
       return;
@@ -640,7 +642,9 @@ public void onPositionDiscontinuity(
           // Map adGroupIndex and adIndexInAdGroup to multi-period window.
           Pair<Integer, Integer> adGroupIndexAndAdIndexInAdGroup =
               getAdGroupAndIndexInMultiPeriodWindow(
-                  oldPosition.periodIndex, adPlaybackState, timeline);
+                  oldPosition.periodIndex - window.firstPeriodIndex,
+                  adPlaybackState,
+                  checkNotNull(contentTimeline));
           adGroupIndex = adGroupIndexAndAdIndexInAdGroup.first;
           adIndexInAdGroup = adGroupIndexAndAdIndexInAdGroup.second;
         }

libraries/exoplayer_ima/src/main/java/androidx/media3/exoplayer/ima/ImaUtil.java

@@ -475,11 +475,11 @@ private static AdPlaybackState splitAdGroupForPeriod(
    *
    * @param adPeriodIndex The period index of the ad period.
    * @param adPlaybackState The ad playback state that holds the ad group and ad information.
-   * @param timeline The timeline that contains the ad period.
+   * @param contentTimeline The timeline that contains the ad period.
    * @return A pair with the ad group index (first) and the ad index in that ad group (second).
    */
   public static Pair<Integer, Integer> getAdGroupAndIndexInMultiPeriodWindow(
-      int adPeriodIndex, AdPlaybackState adPlaybackState, Timeline timeline) {
+      int adPeriodIndex, AdPlaybackState adPlaybackState, Timeline contentTimeline) {
     Timeline.Period period = new Timeline.Period();
     int periodIndex = 0;
     long totalElapsedContentDurationUs = 0;
@@ -488,8 +488,8 @@ public static Pair<Integer, Integer> getAdGroupAndIndexInMultiPeriodWindow(
       AdPlaybackState.AdGroup adGroup = adPlaybackState.getAdGroup(/* adGroupIndex= */ i);
       long adGroupDurationUs = sum(adGroup.durationsUs);
       long elapsedAdGroupAdDurationUs = 0;
-      for (int j = periodIndex; j < timeline.getPeriodCount(); j++) {
-        timeline.getPeriod(j, period, /* setIds= */ true);
+      for (int j = periodIndex; j < contentTimeline.getPeriodCount(); j++) {
+        contentTimeline.getPeriod(j, period, /* setIds= */ true);
         // TODO(b/192231683) Remove subtracted US from ad group time when we can upgrade the SDK.
         // Subtract one microsecond to work around rounding errors with adGroup.timeUs.
         if (totalElapsedContentDurationUs < adGroup.timeUs - 1) {