Allow to specify the number of removed ad groups in AdPlaybackState.

This helps to remove old ad groups (e.g. those that fell out
of the live window) to keep the data size of AdPlaybackState small.

Also added this case to some existing unit tests to ensure it's
covered.

PiperOrigin-RevId: 376170653

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

@@ -700,6 +700,14 @@ public abstract class Timeline implements Bundleable {
     }
 
     /**
+     * Returns the number of removed ad groups in the period. Ad groups with indices between {@code
+     * 0} (inclusive) and {@code removedAdGroupCount} (exclusive) will be empty.
+     */
+    public int getRemovedAdGroupCount() {
+      return adPlaybackState.adGroupCount;
+    }
+
+    /**
      * Returns the time of the ad group at index {@code adGroupIndex} in the period, in
      * microseconds.
      *

library/core/src/main/java/com/google/android/exoplayer2/source/ads/ServerSideInsertedAdsMediaSource.java

@@ -121,7 +121,7 @@ public final class ServerSideInsertedAdsMediaSource extends BaseMediaSource
    */
   public void setAdPlaybackState(AdPlaybackState adPlaybackState) {
     checkArgument(adPlaybackState.adGroupCount >= this.adPlaybackState.adGroupCount);
-    for (int i = 0; i < adPlaybackState.adGroupCount; i++) {
+    for (int i = adPlaybackState.removedAdGroupCount; i < adPlaybackState.adGroupCount; i++) {
       AdPlaybackState.AdGroup adGroup = adPlaybackState.getAdGroup(i);
       checkArgument(adGroup.isServerSideInserted);
       if (i < this.adPlaybackState.adGroupCount) {

library/core/src/main/java/com/google/android/exoplayer2/source/ads/ServerSideInsertedAdsUtil.java

@@ -53,7 +53,7 @@ public final class ServerSideInsertedAdsUtil {
     long adGroupInsertionPositionUs =
         getMediaPeriodPositionUsForContent(
             fromPositionUs, /* nextAdGroupIndex= */ C.INDEX_UNSET, adPlaybackState);
-    int insertionIndex = 0;
+    int insertionIndex = adPlaybackState.removedAdGroupCount;
     while (insertionIndex < adPlaybackState.adGroupCount
         && adPlaybackState.getAdGroup(insertionIndex).timeUs != C.TIME_END_OF_SOURCE
         && adPlaybackState.getAdGroup(insertionIndex).timeUs <= adGroupInsertionPositionUs) {
@@ -184,7 +184,7 @@ public final class ServerSideInsertedAdsUtil {
       long positionUs, int adGroupIndex, int adIndexInAdGroup, AdPlaybackState adPlaybackState) {
     AdPlaybackState.AdGroup currentAdGroup = adPlaybackState.getAdGroup(adGroupIndex);
     positionUs += currentAdGroup.timeUs;
-    for (int i = 0; i < adGroupIndex; i++) {
+    for (int i = adPlaybackState.removedAdGroupCount; i < adGroupIndex; i++) {
       AdPlaybackState.AdGroup adGroup = adPlaybackState.getAdGroup(i);
       for (int j = 0; j < getAdCountInGroup(adPlaybackState, /* adGroupIndex= */ i); j++) {
         positionUs += adGroup.durationsUs[j];
@@ -214,7 +214,7 @@ public final class ServerSideInsertedAdsUtil {
       long positionUs, int adGroupIndex, int adIndexInAdGroup, AdPlaybackState adPlaybackState) {
     AdPlaybackState.AdGroup currentAdGroup = adPlaybackState.getAdGroup(adGroupIndex);
     positionUs -= currentAdGroup.timeUs;
-    for (int i = 0; i < adGroupIndex; i++) {
+    for (int i = adPlaybackState.removedAdGroupCount; i < adGroupIndex; i++) {
       AdPlaybackState.AdGroup adGroup = adPlaybackState.getAdGroup(i);
       for (int j = 0; j < getAdCountInGroup(adPlaybackState, /* adGroupIndex= */ i); j++) {
         positionUs -= adGroup.durationsUs[j];
@@ -246,7 +246,7 @@ public final class ServerSideInsertedAdsUtil {
     if (nextAdGroupIndex == C.INDEX_UNSET) {
       nextAdGroupIndex = adPlaybackState.adGroupCount;
     }
-    for (int i = 0; i < nextAdGroupIndex; i++) {
+    for (int i = adPlaybackState.removedAdGroupCount; i < nextAdGroupIndex; i++) {
       AdPlaybackState.AdGroup adGroup = adPlaybackState.getAdGroup(i);
       if (adGroup.timeUs == C.TIME_END_OF_SOURCE || adGroup.timeUs > positionUs) {
         break;
@@ -283,7 +283,7 @@ public final class ServerSideInsertedAdsUtil {
     if (nextAdGroupIndex == C.INDEX_UNSET) {
       nextAdGroupIndex = adPlaybackState.adGroupCount;
     }
-    for (int i = 0; i < nextAdGroupIndex; i++) {
+    for (int i = adPlaybackState.removedAdGroupCount; i < nextAdGroupIndex; i++) {
       AdPlaybackState.AdGroup adGroup = adPlaybackState.getAdGroup(i);
       if (adGroup.timeUs == C.TIME_END_OF_SOURCE
           || adGroup.timeUs > positionUs - totalAdDurationBeforePositionUs) {

library/ui/src/main/java/com/google/android/exoplayer2/ui/PlayerControlView.java

@@ -982,8 +982,9 @@ public class PlayerControlView extends FrameLayout {
         }
         for (int j = window.firstPeriodIndex; j <= window.lastPeriodIndex; j++) {
           timeline.getPeriod(j, period);
-          int periodAdGroupCount = period.getAdGroupCount();
-          for (int adGroupIndex = 0; adGroupIndex < periodAdGroupCount; adGroupIndex++) {
+          int removedGroups = period.getRemovedAdGroupCount();
+          int totalGroups = period.getAdGroupCount();
+          for (int adGroupIndex = removedGroups; adGroupIndex < totalGroups; adGroupIndex++) {
             long adGroupTimeInPeriodUs = period.getAdGroupTimeUs(adGroupIndex);
             if (adGroupTimeInPeriodUs == C.TIME_END_OF_SOURCE) {
               if (period.durationUs == C.TIME_UNSET) {

library/ui/src/main/java/com/google/android/exoplayer2/ui/StyledPlayerControlView.java

@@ -1345,8 +1345,9 @@ public class StyledPlayerControlView extends FrameLayout {
         }
         for (int j = window.firstPeriodIndex; j <= window.lastPeriodIndex; j++) {
           timeline.getPeriod(j, period);
-          int periodAdGroupCount = period.getAdGroupCount();
-          for (int adGroupIndex = 0; adGroupIndex < periodAdGroupCount; adGroupIndex++) {
+          int removedGroups = period.getRemovedAdGroupCount();
+          int totalGroups = period.getAdGroupCount();
+          for (int adGroupIndex = removedGroups; adGroupIndex < totalGroups; adGroupIndex++) {
             long adGroupTimeInPeriodUs = period.getAdGroupTimeUs(adGroupIndex);
             if (adGroupTimeInPeriodUs == C.TIME_END_OF_SOURCE) {
               if (period.durationUs == C.TIME_UNSET) {