Add the media item to PositionInfo

PiperOrigin-RevId: 392914515

Add the media item to PositionInfo
PiperOrigin-RevId: 392914515
a9913e54 · bachinger · e5a39eca · a9913e54 · a9913e54 · a9913e54
Commit a9913e54 authored Aug 25, 2021 by bachinger
Showing with 451 additions and 37 deletions
extensions/cast/src/main/java/com/google/android/exoplayer2/ext/cast/CastPlayer.java
extensions/cast/src/test/java/com/google/android/exoplayer2/ext/cast/CastPlayerTest.java
extensions/ima/src/test/java/com/google/android/exoplayer2/ext/ima/FakePlayer.java
extensions/ima/src/test/java/com/google/android/exoplayer2/ext/ima/ImaAdsLoaderTest.java
library/common/src/main/java/com/google/android/exoplayer2/Player.java
library/common/src/test/java/com/google/android/exoplayer2/PositionInfoTest.java
library/core/src/main/java/com/google/android/exoplayer2/ExoPlayerImpl.java
library/core/src/test/java/com/google/android/exoplayer2/ExoPlayerTest.java
testutils/src/main/java/com/google/android/exoplayer2/testutil/FakeMediaSourceFactory.java
testutils/src/main/java/com/google/android/exoplayer2/testutil/TestExoPlayerBuilder.java
testutils/src/test/java/com/google/android/exoplayer2/testutil/FakeMediaSourceFactoryTest.java
--- a/extensions/cast/src/main/java/com/google/android/exoplayer2/ext/cast/CastPlayer.java
+++ b/extensions/cast/src/main/java/com/google/android/exoplayer2/ext/cast/CastPlayer.java
@@ -790,6 +790,7 @@ public final class CastPlayer extends BasePlayer {
          new PositionInfo(
              window.uid,
              period.windowIndex,
+              window.mediaItem,
              period.uid,
              period.windowIndex,
              /* positionMs= */ windowDurationMs,
@@ -802,6 +803,7 @@ public final class CastPlayer extends BasePlayer {
          new PositionInfo(
              window.uid,
              period.windowIndex,
+              window.mediaItem,
              period.uid,
              period.windowIndex,
              /* positionMs= */ window.getDefaultPositionMs(),
@@ -904,6 +906,7 @@ public final class CastPlayer extends BasePlayer {
              new PositionInfo(
                  window.uid,
                  period.windowIndex,
+                  window.mediaItem,
                  period.uid,
                  period.windowIndex,
                  getCurrentPosition(),
@@ -1082,17 +1085,19 @@ public final class CastPlayer extends BasePlayer {
  private PositionInfo getCurrentPositionInfo() {
    Timeline currentTimeline = getCurrentTimeline();
-    @Nullable
+    @Nullable Object newPeriodUid = null;
-    Object newPeriodUid =
+    @Nullable Object newWindowUid = null;
-        !currentTimeline.isEmpty()
+    @Nullable MediaItem newMediaItem = null;
-            ? currentTimeline.getPeriod(getCurrentPeriodIndex(), period, /* setIds= */ true).uid
+    if (!currentTimeline.isEmpty()) {
-            : null;
+      newPeriodUid =
-    @Nullable
+          currentTimeline.getPeriod(getCurrentPeriodIndex(), period, /* setIds= */ true).uid;
-    Object newWindowUid =
+      newWindowUid = currentTimeline.getWindow(period.windowIndex, window).uid;
-        newPeriodUid != null ? currentTimeline.getWindow(period.windowIndex, window).uid : null;
+      newMediaItem = window.mediaItem;
+    }
    return new PositionInfo(
        newWindowUid,
        getCurrentWindowIndex(),
+        newMediaItem,
        newPeriodUid,
        getCurrentPeriodIndex(),
        getCurrentPosition(),

--- a/extensions/cast/src/test/java/com/google/android/exoplayer2/ext/cast/CastPlayerTest.java
+++ b/extensions/cast/src/test/java/com/google/android/exoplayer2/ext/cast/CastPlayerTest.java
@@ -380,6 +380,7 @@ public class CastPlayerTest {
        new Player.PositionInfo(
            /* windowUid= */ 2,
            /* windowIndex= */ 1,
+            new MediaItem.Builder().setUri(Uri.EMPTY).setTag(2).build(),
            /* periodUid= */ 2,
            /* periodIndex= */ 1,
            /* positionMs= */ 2000,
@@ -390,6 +391,7 @@ public class CastPlayerTest {
        new Player.PositionInfo(
            /* windowUid= */ 3,
            /* windowIndex= */ 0,
+            new MediaItem.Builder().setUri(Uri.EMPTY).setTag(3).build(),
            /* periodUid= */ 3,
            /* periodIndex= */ 0,
            /* positionMs= */ 1000,
@@ -660,6 +662,7 @@ public class CastPlayerTest {
        new Player.PositionInfo(
            /* windowUid= */ 1,
            /* windowIndex= */ 0,
+            new MediaItem.Builder().setUri(Uri.EMPTY).setTag(1).build(),
            /* periodUid= */ 1,
            /* periodIndex= */ 0,
            /* positionMs= */ 1234,
@@ -670,6 +673,7 @@ public class CastPlayerTest {
        new Player.PositionInfo(
            /* windowUid= */ null,
            /* windowIndex= */ 0,
+            /* mediaItem= */ null,
            /* periodUid= */ null,
            /* periodIndex= */ 0,
            /* positionMs= */ 0,
@@ -744,6 +748,7 @@ public class CastPlayerTest {
        new Player.PositionInfo(
            /* windowUid= */ 1,
            /* windowIndex= */ 0,
+            new MediaItem.Builder().setUri(Uri.EMPTY).setTag(1).build(),
            /* periodUid= */ 1,
            /* periodIndex= */ 0,
            /* positionMs= */ 1234,
@@ -754,6 +759,7 @@ public class CastPlayerTest {
        new Player.PositionInfo(
            /* windowUid= */ 2,
            /* windowIndex= */ 0,
+            new MediaItem.Builder().setUri(Uri.EMPTY).setTag(2).build(),
            /* periodUid= */ 2,
            /* periodIndex= */ 0,
            /* positionMs= */ 0,
@@ -825,6 +831,7 @@ public class CastPlayerTest {
        new Player.PositionInfo(
            /* windowUid= */ 1,
            /* windowIndex= */ 0,
+            new MediaItem.Builder().setUri(Uri.EMPTY).setTag(1).build(),
            /* periodUid= */ 1,
            /* periodIndex= */ 0,
            /* positionMs= */ 0, // position at which we receive the timeline change
@@ -835,6 +842,7 @@ public class CastPlayerTest {
        new Player.PositionInfo(
            /* windowUid= */ 2,
            /* windowIndex= */ 0,
+            new MediaItem.Builder().setUri(Uri.EMPTY).setTag(2).build(),
            /* periodUid= */ 2,
            /* periodIndex= */ 0,
            /* positionMs= */ 0,
@@ -937,6 +945,7 @@ public class CastPlayerTest {
        new Player.PositionInfo(
            /* windowUid= */ 1,
            /* windowIndex= */ 0,
+            new MediaItem.Builder().setUri(Uri.EMPTY).setTag(1).build(),
            /* periodUid= */ 1,
            /* periodIndex= */ 0,
            /* positionMs= */ 0,
@@ -947,6 +956,7 @@ public class CastPlayerTest {
        new Player.PositionInfo(
            /* windowUid= */ 2,
            /* windowIndex= */ 1,
+            new MediaItem.Builder().setUri(Uri.EMPTY).setTag(2).build(),
            /* periodUid= */ 2,
            /* periodIndex= */ 1,
            /* positionMs= */ 1234,
@@ -992,10 +1002,12 @@ public class CastPlayerTest {
    updateTimeLine(mediaItems, mediaQueueItemIds, /* currentItemId= */ 1);
    castPlayer.seekTo(/* windowIndex= */ 0, /* positionMs= */ 1234);
+    MediaItem mediaItem = new MediaItem.Builder().setUri(Uri.EMPTY).setTag(1).build();
    Player.PositionInfo oldPosition =
        new Player.PositionInfo(
            /* windowUid= */ 1,
            /* windowIndex= */ 0,
+            mediaItem,
            /* periodUid= */ 1,
            /* periodIndex= */ 0,
            /* positionMs= */ 0,
@@ -1006,6 +1018,7 @@ public class CastPlayerTest {
        new Player.PositionInfo(
            /* windowUid= */ 1,
            /* windowIndex= */ 0,
+            mediaItem,
            /* periodUid= */ 1,
            /* periodIndex= */ 0,
            /* positionMs= */ 1234,
@@ -1076,6 +1089,7 @@ public class CastPlayerTest {
        new Player.PositionInfo(
            /* windowUid= */ 1,
            /* windowIndex= */ 0,
+            new MediaItem.Builder().setUri(Uri.EMPTY).setTag(1).build(),
            /* periodUid= */ 1,
            /* periodIndex= */ 0,
            /* positionMs= */ 12500,
@@ -1086,6 +1100,7 @@ public class CastPlayerTest {
        new Player.PositionInfo(
            /* windowUid= */ 2,
            /* windowIndex= */ 1,
+            new MediaItem.Builder().setUri(Uri.EMPTY).setTag(2).build(),
            /* periodUid= */ 2,
            /* periodIndex= */ 1,
            /* positionMs= */ 0,
@@ -1120,10 +1135,12 @@ public class CastPlayerTest {
        mediaItems, mediaQueueItemIds, currentItemId, streamTypes, durationsMs, positionMs);
    castPlayer.seekBack();
+    MediaItem mediaItem = new MediaItem.Builder().setUri(Uri.EMPTY).setTag(1).build();
    Player.PositionInfo oldPosition =
        new Player.PositionInfo(
            /* windowUid= */ 1,
            /* windowIndex= */ 0,
+            mediaItem,
            /* periodUid= */ 1,
            /* periodIndex= */ 0,
            /* positionMs= */ 2 * C.DEFAULT_SEEK_BACK_INCREMENT_MS,
@@ -1134,6 +1151,7 @@ public class CastPlayerTest {
        new Player.PositionInfo(
            /* windowUid= */ 1,
            /* windowIndex= */ 0,
+            mediaItem,
            /* periodUid= */ 1,
            /* periodIndex= */ 0,
            /* positionMs= */ C.DEFAULT_SEEK_BACK_INCREMENT_MS,
@@ -1166,10 +1184,12 @@ public class CastPlayerTest {
        mediaItems, mediaQueueItemIds, currentItemId, streamTypes, durationsMs, positionMs);
    castPlayer.seekForward();
+    MediaItem mediaItem = new MediaItem.Builder().setUri(Uri.EMPTY).setTag(1).build();
    Player.PositionInfo oldPosition =
        new Player.PositionInfo(
            /* windowUid= */ 1,
            /* windowIndex= */ 0,
+            mediaItem,
            /* periodUid= */ 1,
            /* periodIndex= */ 0,
            /* positionMs= */ 0,
@@ -1180,6 +1200,7 @@ public class CastPlayerTest {
        new Player.PositionInfo(
            /* windowUid= */ 1,
            /* windowIndex= */ 0,
+            mediaItem,
            /* periodUid= */ 1,
            /* periodIndex= */ 0,
            /* positionMs= */ C.DEFAULT_SEEK_FORWARD_INCREMENT_MS,

--- a/extensions/ima/src/test/java/com/google/android/exoplayer2/ext/ima/FakePlayer.java
+++ b/extensions/ima/src/test/java/com/google/android/exoplayer2/ext/ima/FakePlayer.java
@@ -17,6 +17,7 @@ package com.google.android.exoplayer2.ext.ima;
 import android.os.Looper;
 import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.MediaItem;
 import com.google.android.exoplayer2.Player;
 import com.google.android.exoplayer2.Timeline;
 import com.google.android.exoplayer2.testutil.StubExoPlayer;
@@ -32,6 +33,7 @@ import com.google.android.exoplayer2.util.ListenerSet;
  private final Timeline.Period period;
  private final Object windowUid = new Object();
  private final Object periodUid = new Object();
+  private final MediaItem mediaItem = MediaItem.fromUri("http://google.com/0");
  private Timeline timeline;
  @Player.State private int state;
@@ -72,6 +74,7 @@ import com.google.android.exoplayer2.util.ListenerSet;
        new PositionInfo(
            windowUid,
            /* windowIndex= */ 0,
+            mediaItem,
            periodUid,
            /* periodIndex= */ 0,
            this.positionMs,
@@ -89,6 +92,7 @@ import com.google.android.exoplayer2.util.ListenerSet;
          new PositionInfo(
              windowUid,
              /* windowIndex= */ 0,
+              mediaItem,
              periodUid,
              /* periodIndex= */ 0,
              positionMs,
@@ -119,6 +123,7 @@ import com.google.android.exoplayer2.util.ListenerSet;
        new PositionInfo(
            windowUid,
            /* windowIndex= */ 0,
+            mediaItem,
            periodUid,
            /* periodIndex= */ 0,
            this.positionMs,
@@ -136,6 +141,7 @@ import com.google.android.exoplayer2.util.ListenerSet;
          new PositionInfo(
              windowUid,
              /* windowIndex= */ 0,
+              mediaItem,
              periodUid,
              /* periodIndex= */ 0,
              positionMs,

--- a/extensions/ima/src/test/java/com/google/android/exoplayer2/ext/ima/ImaAdsLoaderTest.java
+++ b/extensions/ima/src/test/java/com/google/android/exoplayer2/ext/ima/ImaAdsLoaderTest.java
@@ -56,6 +56,7 @@ import com.google.ads.interactivemedia.v3.api.player.VideoAdPlayer;
 import com.google.ads.interactivemedia.v3.api.player.VideoProgressUpdate;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.ExoPlaybackException;
+import com.google.android.exoplayer2.MediaItem;
 import com.google.android.exoplayer2.PlaybackException;
 import com.google.android.exoplayer2.Player;
 import com.google.android.exoplayer2.Timeline;
@@ -281,6 +282,7 @@ public final class ImaAdsLoaderTest {
        new Player.PositionInfo(
            /* windowUid= */ new Object(),
            /* windowIndex= */ 0,
+            /* mediaItem= */ MediaItem.fromUri("http://google.com/0"),
            /* periodUid= */ new Object(),
            /* periodIndex= */ 0,
            /* positionMs= */ 10_000,
@@ -290,6 +292,7 @@ public final class ImaAdsLoaderTest {
        new Player.PositionInfo(
            /* windowUid= */ new Object(),
            /* windowIndex= */ 1,
+            /* mediaItem= */ MediaItem.fromUri("http://google.com/1"),
            /* periodUid= */ new Object(),
            /* periodIndex= */ 0,
            /* positionMs= */ 20_000,

--- a/library/common/src/main/java/com/google/android/exoplayer2/Player.java
+++ b/library/common/src/main/java/com/google/android/exoplayer2/Player.java
@@ -32,6 +32,7 @@ import com.google.android.exoplayer2.text.Cue;
 import com.google.android.exoplayer2.trackselection.TrackSelection;
 import com.google.android.exoplayer2.trackselection.TrackSelectionArray;
 import com.google.android.exoplayer2.trackselection.TrackSelectionParameters;
+import com.google.android.exoplayer2.util.BundleableUtils;
 import com.google.android.exoplayer2.util.FlagSet;
 import com.google.android.exoplayer2.util.Util;
 import com.google.android.exoplayer2.video.VideoSize;
@@ -468,13 +469,15 @@ public interface Player {
  final class PositionInfo implements Bundleable {
    /**
-     * The UID of the window, or {@code null}, if the timeline is {@link Timeline#isEmpty() empty}.
+     * The UID of the window, or {@code null} if the timeline is {@link Timeline#isEmpty() empty}.
     */
    @Nullable public final Object windowUid;
    /** The window index. */
    public final int windowIndex;
+    /** The media item, or {@code null} if the timeline is {@link Timeline#isEmpty() empty}. */
+    @Nullable public final MediaItem mediaItem;
    /**
-     * The UID of the period, or {@code null}, if the timeline is {@link Timeline#isEmpty() empty}.
+     * The UID of the period, or {@code null} if the timeline is {@link Timeline#isEmpty() empty}.
     */
    @Nullable public final Object periodUid;
    /** The period index. */
@@ -498,10 +501,37 @@ public interface Player {
     */
    public final int adIndexInAdGroup;
+    /**
+     * @deprecated Use {@link #PositionInfo(Object, int, MediaItem, Object, int, long, long, int,
+     *     int)} instead.
+     */
+    @Deprecated
+    public PositionInfo(
+        @Nullable Object windowUid,
+        int windowIndex,
+        @Nullable Object periodUid,
+        int periodIndex,
+        long positionMs,
+        long contentPositionMs,
+        int adGroupIndex,
+        int adIndexInAdGroup) {
+      this(
+          windowUid,
+          windowIndex,
+          MediaItem.EMPTY,
+          periodUid,
+          periodIndex,
+          positionMs,
+          contentPositionMs,
+          adGroupIndex,
+          adIndexInAdGroup);
+    }
    /** Creates an instance. */
    public PositionInfo(
        @Nullable Object windowUid,
        int windowIndex,
+        @Nullable MediaItem mediaItem,
        @Nullable Object periodUid,
        int periodIndex,
        long positionMs,
@@ -510,6 +540,7 @@ public interface Player {
        int adIndexInAdGroup) {
      this.windowUid = windowUid;
      this.windowIndex = windowIndex;
+      this.mediaItem = mediaItem;
      this.periodUid = periodUid;
      this.periodIndex = periodIndex;
      this.positionMs = positionMs;
@@ -534,7 +565,8 @@ public interface Player {
          && adGroupIndex == that.adGroupIndex
          && adIndexInAdGroup == that.adIndexInAdGroup
          && Objects.equal(windowUid, that.windowUid)
-          && Objects.equal(periodUid, that.periodUid);
+          && Objects.equal(periodUid, that.periodUid)
+          && Objects.equal(mediaItem, that.mediaItem);
    }
    @Override
@@ -542,6 +574,7 @@ public interface Player {
      return Objects.hashCode(
          windowUid,
          windowIndex,
+          mediaItem,
          periodUid,
          periodIndex,
          windowIndex,
@@ -556,6 +589,7 @@ public interface Player {
    @Retention(RetentionPolicy.SOURCE)
    @IntDef({
      FIELD_WINDOW_INDEX,
+      FIELD_MEDIA_ITEM,
      FIELD_PERIOD_INDEX,
      FIELD_POSITION_MS,
      FIELD_CONTENT_POSITION_MS,
@@ -565,11 +599,12 @@ public interface Player {
    private @interface FieldNumber {}
    private static final int FIELD_WINDOW_INDEX = 0;
-    private static final int FIELD_PERIOD_INDEX = 1;
+    private static final int FIELD_MEDIA_ITEM = 1;
-    private static final int FIELD_POSITION_MS = 2;
+    private static final int FIELD_PERIOD_INDEX = 2;
-    private static final int FIELD_CONTENT_POSITION_MS = 3;
+    private static final int FIELD_POSITION_MS = 3;
-    private static final int FIELD_AD_GROUP_INDEX = 4;
+    private static final int FIELD_CONTENT_POSITION_MS = 4;
-    private static final int FIELD_AD_INDEX_IN_AD_GROUP = 5;
+    private static final int FIELD_AD_GROUP_INDEX = 5;
+    private static final int FIELD_AD_INDEX_IN_AD_GROUP = 6;
    /**
     * {@inheritDoc}
@@ -581,6 +616,7 @@ public interface Player {
    public Bundle toBundle() {
      Bundle bundle = new Bundle();
      bundle.putInt(keyForField(FIELD_WINDOW_INDEX), windowIndex);
+      bundle.putBundle(keyForField(FIELD_MEDIA_ITEM), BundleableUtils.toNullableBundle(mediaItem));
      bundle.putInt(keyForField(FIELD_PERIOD_INDEX), periodIndex);
      bundle.putLong(keyForField(FIELD_POSITION_MS), positionMs);
      bundle.putLong(keyForField(FIELD_CONTENT_POSITION_MS), contentPositionMs);
@@ -595,6 +631,10 @@ public interface Player {
    private static PositionInfo fromBundle(Bundle bundle) {
      int windowIndex =
          bundle.getInt(keyForField(FIELD_WINDOW_INDEX), /* defaultValue= */ C.INDEX_UNSET);
+      @Nullable
+      MediaItem mediaItem =
+          BundleableUtils.fromNullableBundle(
+              MediaItem.CREATOR, bundle.getBundle(keyForField(FIELD_MEDIA_ITEM)));
      int periodIndex =
          bundle.getInt(keyForField(FIELD_PERIOD_INDEX), /* defaultValue= */ C.INDEX_UNSET);
      long positionMs =
@@ -608,6 +648,7 @@ public interface Player {
      return new PositionInfo(
          /* windowUid= */ null,
          windowIndex,
+          mediaItem,
          /* periodUid= */ null,
          periodIndex,
          positionMs,

--- a/library/common/src/test/java/com/google/android/exoplayer2/PositionInfoTest.java
+++ b/library/common/src/test/java/com/google/android/exoplayer2/PositionInfoTest.java
@@ -32,6 +32,7 @@ public class PositionInfoTest {
        new PositionInfo(
            /* windowUid= */ null,
            /* windowIndex= */ 23,
+            new MediaItem.Builder().setMediaId("1234").build(),
            /* periodUid= */ null,
            /* periodIndex= */ 11,
            /* positionMs= */ 8787L,
@@ -48,6 +49,7 @@ public class PositionInfoTest {
        new PositionInfo(
            /* windowUid= */ new Object(),
            /* windowIndex= */ 23,
+            MediaItem.fromUri("https://exoplayer.dev"),
            /* periodUid= */ null,
            /* periodIndex= */ 11,
            /* positionMs= */ 8787L,
@@ -65,6 +67,7 @@ public class PositionInfoTest {
        new PositionInfo(
            /* windowUid= */ null,
            /* windowIndex= */ 23,
+            MediaItem.fromUri("https://exoplayer.dev"),
            /* periodUid= */ new Object(),
            /* periodIndex= */ 11,
            /* positionMs= */ 8787L,

--- a/library/core/src/main/java/com/google/android/exoplayer2/ExoPlayerImpl.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/ExoPlayerImpl.java
@@ -1360,6 +1360,7 @@ import java.util.concurrent.CopyOnWriteArraySet;
    @Nullable Object oldPeriodUid = null;
    int oldWindowIndex = oldMaskingWindowIndex;
    int oldPeriodIndex = C.INDEX_UNSET;
+    @Nullable MediaItem oldMediaItem = null;
    Timeline.Period oldPeriod = new Timeline.Period();
    if (!oldPlaybackInfo.timeline.isEmpty()) {
      oldPeriodUid = oldPlaybackInfo.periodId.periodUid;
@@ -1367,6 +1368,7 @@ import java.util.concurrent.CopyOnWriteArraySet;
      oldWindowIndex = oldPeriod.windowIndex;
      oldPeriodIndex = oldPlaybackInfo.timeline.getIndexOfPeriod(oldPeriodUid);
      oldWindowUid = oldPlaybackInfo.timeline.getWindow(oldWindowIndex, window).uid;
+      oldMediaItem = window.mediaItem;
    }
    long oldPositionUs;
    long oldContentPositionUs;
@@ -1397,6 +1399,7 @@ import java.util.concurrent.CopyOnWriteArraySet;
    return new PositionInfo(
        oldWindowUid,
        oldWindowIndex,
+        oldMediaItem,
        oldPeriodUid,
        oldPeriodIndex,
        C.usToMs(oldPositionUs),
@@ -1410,16 +1413,19 @@ import java.util.concurrent.CopyOnWriteArraySet;
    @Nullable Object newPeriodUid = null;
    int newWindowIndex = getCurrentWindowIndex();
    int newPeriodIndex = C.INDEX_UNSET;
+    @Nullable MediaItem newMediaItem = null;
    if (!playbackInfo.timeline.isEmpty()) {
      newPeriodUid = playbackInfo.periodId.periodUid;
      playbackInfo.timeline.getPeriodByUid(newPeriodUid, period);
      newPeriodIndex = playbackInfo.timeline.getIndexOfPeriod(newPeriodUid);
      newWindowUid = playbackInfo.timeline.getWindow(newWindowIndex, window).uid;
+      newMediaItem = window.mediaItem;
    }
    long positionMs = C.usToMs(discontinuityWindowStartPositionUs);
    return new PositionInfo(
        newWindowUid,
        newWindowIndex,
+        newMediaItem,
        newPeriodUid,
        newPeriodIndex,
        positionMs,

--- a/library/core/src/test/java/com/google/android/exoplayer2/ExoPlayerTest.java
+++ b/library/core/src/test/java/com/google/android/exoplayer2/ExoPlayerTest.java
@@ -85,6 +85,8 @@ import androidx.annotation.Nullable;
 import androidx.test.core.app.ApplicationProvider;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 import com.google.android.exoplayer2.Player.DiscontinuityReason;
+import com.google.android.exoplayer2.Player.Listener;
+import com.google.android.exoplayer2.Player.PositionInfo;
 import com.google.android.exoplayer2.Timeline.Window;
 import com.google.android.exoplayer2.analytics.AnalyticsListener;
 import com.google.android.exoplayer2.audio.AudioAttributes;
@@ -120,6 +122,7 @@ import com.google.android.exoplayer2.testutil.FakeDataSource;
 import com.google.android.exoplayer2.testutil.FakeMediaClockRenderer;
 import com.google.android.exoplayer2.testutil.FakeMediaPeriod;
 import com.google.android.exoplayer2.testutil.FakeMediaSource;
+import com.google.android.exoplayer2.testutil.FakeMediaSourceFactory;
 import com.google.android.exoplayer2.testutil.FakeRenderer;
 import com.google.android.exoplayer2.testutil.FakeSampleStream;
 import com.google.android.exoplayer2.testutil.FakeSampleStream.FakeSampleStreamItem;
@@ -142,7 +145,6 @@ import com.google.android.exoplayer2.util.Clock;
 import com.google.android.exoplayer2.util.MimeTypes;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Iterables;
-import com.google.common.collect.Lists;
 import com.google.common.collect.Range;
 import java.io.IOException;
 import java.util.ArrayList;
@@ -9580,6 +9582,7 @@ public final class ExoPlayerTest {
    assertThat(oldPositionInfo.periodUid).isEqualTo(newPositionInfo.periodUid);
    assertThat(oldPositionInfo.periodIndex).isEqualTo(newPositionInfo.periodIndex);
    assertThat(oldPositionInfo.windowIndex).isEqualTo(newPositionInfo.windowIndex);
+    assertThat(oldPositionInfo.mediaItem.playbackProperties.tag).isEqualTo(1);
    assertThat(oldPositionInfo.windowUid).isEqualTo(newPositionInfo.windowUid);
    assertThat(oldPositionInfo.positionMs).isEqualTo(10_000);
    assertThat(oldPositionInfo.contentPositionMs).isEqualTo(10_000);
@@ -9601,6 +9604,7 @@ public final class ExoPlayerTest {
    assertThat(oldPositionInfo.periodUid).isEqualTo(newPositionInfo.periodUid);
    assertThat(oldPositionInfo.periodIndex).isEqualTo(newPositionInfo.periodIndex);
    assertThat(oldPositionInfo.windowIndex).isEqualTo(newPositionInfo.windowIndex);
+    assertThat(oldPositionInfo.mediaItem.playbackProperties.tag).isEqualTo(1);
    assertThat(oldPositionInfo.windowUid).isEqualTo(newPositionInfo.windowUid);
    assertThat(oldPositionInfo.positionMs).isEqualTo(10_000);
    assertThat(oldPositionInfo.contentPositionMs).isEqualTo(10_000);
@@ -9620,6 +9624,7 @@ public final class ExoPlayerTest {
    oldPositionInfo = oldPosition.getValue();
    newPositionInfo = newPosition.getValue();
    assertThat(oldPositionInfo.windowIndex).isEqualTo(1);
+    assertThat(oldPositionInfo.mediaItem.playbackProperties.tag).isEqualTo(2);
    assertThat(oldPositionInfo.windowUid).isNotEqualTo(newPositionInfo.windowUid);
    assertThat(oldPositionInfo.positionMs).isEqualTo(20_000);
    assertThat(oldPositionInfo.contentPositionMs).isEqualTo(20_000);
@@ -9881,7 +9886,7 @@ public final class ExoPlayerTest {
    TimelineWindowDefinition postRollWindow =
        new TimelineWindowDefinition(
            /* periodCount= */ 1,
-            /* id= */ 0,
+            /* id= */ "id-2",
            /* isSeekable= */ true,
            /* isDynamic= */ false,
            /* isLive= */ false,
@@ -9895,7 +9900,7 @@ public final class ExoPlayerTest {
    TimelineWindowDefinition preRollWindow =
        new TimelineWindowDefinition(
            /* periodCount= */ 1,
-            /* id= */ 0,
+            /* id= */ "id-3",
            /* isSeekable= */ true,
            /* isDynamic= */ false,
            /* isLive= */ false,
@@ -9905,11 +9910,13 @@ public final class ExoPlayerTest {
            /* windowOffsetInFirstPeriodUs= */ 0,
            preRollAdPlaybackState);
    player.setMediaSources(
-        Lists.newArrayList(
+        ImmutableList.of(
-            new FakeMediaSource(),
+            createFakeMediaSource(/* id= */ "id-0"),
            new FakeMediaSource(
                new FakeTimeline(
                    new TimelineWindowDefinition(
+                        /* periodCount= */ 1,
+                        /* id= */ "id-1",
                        /* isSeekable= */ true,
                        /* isDynamic= */ false,
                        /* durationUs= */ 15 * C.MICROS_PER_SECOND))),
@@ -9939,6 +9946,7 @@ public final class ExoPlayerTest {
    assertThat(oldPosition.getValue().windowUid)
        .isEqualTo(player.getCurrentTimeline().getWindow(0, window).uid);
    assertThat(oldPosition.getValue().windowIndex).isEqualTo(0);
+    assertThat(oldPosition.getValue().mediaItem.playbackProperties.tag).isEqualTo("id-0");
    assertThat(oldPosition.getValue().positionMs).isEqualTo(10_000);
    assertThat(oldPosition.getValue().contentPositionMs).isEqualTo(10_000);
    assertThat(oldPosition.getValue().adGroupIndex).isEqualTo(-1);
@@ -9946,6 +9954,7 @@ public final class ExoPlayerTest {
    assertThat(newPosition.getValue().windowUid)
        .isEqualTo(player.getCurrentTimeline().getWindow(1, window).uid);
    assertThat(newPosition.getValue().windowIndex).isEqualTo(1);
+    assertThat(newPosition.getValue().mediaItem.playbackProperties.tag).isEqualTo("id-1");
    assertThat(newPosition.getValue().positionMs).isEqualTo(0);
    assertThat(newPosition.getValue().contentPositionMs).isEqualTo(0);
    assertThat(newPosition.getValue().adGroupIndex).isEqualTo(-1);
@@ -9965,11 +9974,13 @@ public final class ExoPlayerTest {
    assertThat(newPosition.getValue().windowUid)
        .isEqualTo(player.getCurrentTimeline().getWindow(2, window).uid);
    assertThat(oldPosition.getValue().windowIndex).isEqualTo(1);
+    assertThat(oldPosition.getValue().mediaItem.playbackProperties.tag).isEqualTo("id-1");
    assertThat(oldPosition.getValue().positionMs).isEqualTo(15_000);
    assertThat(oldPosition.getValue().contentPositionMs).isEqualTo(15_000);
    assertThat(oldPosition.getValue().adGroupIndex).isEqualTo(-1);
    assertThat(oldPosition.getValue().adIndexInAdGroup).isEqualTo(-1);
    assertThat(newPosition.getValue().windowIndex).isEqualTo(2);
+    assertThat(newPosition.getValue().mediaItem.playbackProperties.tag).isEqualTo("id-2");
    assertThat(newPosition.getValue().positionMs).isEqualTo(0);
    assertThat(newPosition.getValue().contentPositionMs).isEqualTo(0);
    assertThat(newPosition.getValue().adGroupIndex).isEqualTo(-1);
@@ -9983,12 +9994,14 @@ public final class ExoPlayerTest {
            newPosition.capture(),
            eq(Player.DISCONTINUITY_REASON_AUTO_TRANSITION));
    assertThat(oldPosition.getValue().windowIndex).isEqualTo(2);
+    assertThat(oldPosition.getValue().mediaItem.playbackProperties.tag).isEqualTo("id-2");
    assertThat(oldPosition.getValue().windowUid).isEqualTo(lastNewWindowUid);
    assertThat(oldPosition.getValue().positionMs).isEqualTo(20_000);
    assertThat(oldPosition.getValue().contentPositionMs).isEqualTo(20_000);
    assertThat(oldPosition.getValue().adGroupIndex).isEqualTo(-1);
    assertThat(oldPosition.getValue().adIndexInAdGroup).isEqualTo(-1);
    assertThat(newPosition.getValue().windowIndex).isEqualTo(2);
+    assertThat(newPosition.getValue().mediaItem.playbackProperties.tag).isEqualTo("id-2");
    assertThat(newPosition.getValue().positionMs).isEqualTo(0);
    assertThat(newPosition.getValue().contentPositionMs).isEqualTo(20_000);
    assertThat(newPosition.getValue().adGroupIndex).isEqualTo(0);
@@ -10003,12 +10016,14 @@ public final class ExoPlayerTest {
            eq(Player.DISCONTINUITY_REASON_AUTO_TRANSITION));
    assertThat(oldPosition.getValue().windowUid).isEqualTo(lastNewWindowUid);
    assertThat(oldPosition.getValue().windowIndex).isEqualTo(2);
+    assertThat(oldPosition.getValue().mediaItem.playbackProperties.tag).isEqualTo("id-2");
    assertThat(oldPosition.getValue().positionMs).isEqualTo(5_000);
    assertThat(oldPosition.getValue().contentPositionMs).isEqualTo(20_000);
    assertThat(oldPosition.getValue().adGroupIndex).isEqualTo(0);
    assertThat(oldPosition.getValue().adIndexInAdGroup).isEqualTo(0);
    assertThat(newPosition.getValue().windowUid).isEqualTo(oldPosition.getValue().windowUid);
    assertThat(newPosition.getValue().windowIndex).isEqualTo(2);
+    assertThat(newPosition.getValue().mediaItem.playbackProperties.tag).isEqualTo("id-2");
    assertThat(newPosition.getValue().positionMs).isEqualTo(19_999);
    assertThat(newPosition.getValue().contentPositionMs).isEqualTo(19_999);
    assertThat(newPosition.getValue().adGroupIndex).isEqualTo(-1);
@@ -10026,12 +10041,14 @@ public final class ExoPlayerTest {
        .onMediaItemTransition(any(), eq(Player.MEDIA_ITEM_TRANSITION_REASON_AUTO));
    assertThat(oldPosition.getValue().windowUid).isEqualTo(lastNewWindowUid);
    assertThat(oldPosition.getValue().windowIndex).isEqualTo(2);
+    assertThat(oldPosition.getValue().mediaItem.playbackProperties.tag).isEqualTo("id-2");
    assertThat(oldPosition.getValue().positionMs).isEqualTo(20_000);
    assertThat(oldPosition.getValue().contentPositionMs).isEqualTo(20_000);
    assertThat(oldPosition.getValue().adGroupIndex).isEqualTo(-1);
    assertThat(oldPosition.getValue().adIndexInAdGroup).isEqualTo(-1);
    assertThat(newPosition.getValue().windowUid).isNotEqualTo(oldPosition.getValue().windowUid);
    assertThat(newPosition.getValue().windowIndex).isEqualTo(3);
+    assertThat(newPosition.getValue().mediaItem.playbackProperties.tag).isEqualTo("id-3");
    assertThat(newPosition.getValue().positionMs).isEqualTo(0);
    assertThat(newPosition.getValue().contentPositionMs).isEqualTo(0);
    assertThat(newPosition.getValue().adGroupIndex).isEqualTo(0);
@@ -10046,12 +10063,14 @@ public final class ExoPlayerTest {
            eq(Player.DISCONTINUITY_REASON_AUTO_TRANSITION));
    assertThat(oldPosition.getValue().windowUid).isEqualTo(lastNewWindowUid);
    assertThat(oldPosition.getValue().windowIndex).isEqualTo(3);
+    assertThat(oldPosition.getValue().mediaItem.playbackProperties.tag).isEqualTo("id-3");
    assertThat(oldPosition.getValue().positionMs).isEqualTo(5_000);
    assertThat(oldPosition.getValue().contentPositionMs).isEqualTo(0);
    assertThat(oldPosition.getValue().adGroupIndex).isEqualTo(0);
    assertThat(oldPosition.getValue().adIndexInAdGroup).isEqualTo(0);
    assertThat(newPosition.getValue().windowUid).isEqualTo(oldPosition.getValue().windowUid);
    assertThat(newPosition.getValue().windowIndex).isEqualTo(3);
+    assertThat(newPosition.getValue().mediaItem.playbackProperties.tag).isEqualTo("id-3");
    assertThat(newPosition.getValue().positionMs).isEqualTo(0);
    assertThat(newPosition.getValue().contentPositionMs).isEqualTo(0);
    assertThat(newPosition.getValue().adGroupIndex).isEqualTo(-1);
@@ -10093,7 +10112,7 @@ public final class ExoPlayerTest {
    player.prepare();
    TestPlayerRunHelper.playUntilPosition(
        player, /* windowIndex= */ 0, /* positionMs= */ 5 * C.MILLIS_PER_SECOND);
-    player.setMediaSources(Lists.newArrayList(secondMediaSource, secondMediaSource));
+    player.setMediaSources(ImmutableList.of(secondMediaSource, secondMediaSource));
    player.play();
    TestPlayerRunHelper.runUntilPlaybackState(player, Player.STATE_ENDED);
@@ -10121,13 +10140,80 @@ public final class ExoPlayerTest {
  }
  @Test
+  public void onPositionDiscontinuity_recursiveStateChange_mediaItemMaskingCorrect()
+      throws Exception {
+    ExoPlayer player = new TestExoPlayerBuilder(context).build();
+    Player.Listener listener = mock(Player.Listener.class);
+    MediaItem[] currentMediaItems = new MediaItem[2];
+    int[] mediaItemCount = new int[2];
+    player.addListener(
+        new Listener() {
+          @Override
+          public void onPositionDiscontinuity(
+              PositionInfo oldPosition, PositionInfo newPosition, int reason) {
+            if (reason == Player.DISCONTINUITY_REASON_AUTO_TRANSITION) {
+              mediaItemCount[0] = player.getMediaItemCount();
+              currentMediaItems[0] = player.getCurrentMediaItem();
+              // This is called before the second listener is called.
+              player.removeMediaItem(/* index= */ 1);
+            }
+          }
+        });
+    player.addListener(
+        new Listener() {
+          @Override
+          public void onPositionDiscontinuity(
+              PositionInfo oldPosition, PositionInfo newPosition, int reason) {
+            if (reason == Player.DISCONTINUITY_REASON_AUTO_TRANSITION) {
+              mediaItemCount[1] = player.getMediaItemCount();
+              currentMediaItems[1] = player.getCurrentMediaItem();
+            }
+          }
+        });
+    player.addListener(listener);
+    player.setMediaSources(
+        ImmutableList.of(
+            createFakeMediaSource(/* id= */ "id-0"), createFakeMediaSource(/* id= */ "id-1")));
+    player.prepare();
+    player.play();
+    TestPlayerRunHelper.runUntilPlaybackState(player, Player.STATE_ENDED);
+    ArgumentCaptor<PositionInfo> newPositionArgumentCaptor =
+        ArgumentCaptor.forClass(PositionInfo.class);
+    InOrder inOrder = inOrder(listener);
+    inOrder
+        .verify(listener)
+        .onPositionDiscontinuity(
+            any(),
+            newPositionArgumentCaptor.capture(),
+            eq(Player.DISCONTINUITY_REASON_AUTO_TRANSITION));
+    inOrder
+        .verify(listener)
+        .onPositionDiscontinuity(
+            any(), newPositionArgumentCaptor.capture(), eq(Player.DISCONTINUITY_REASON_REMOVE));
+    // The state at auto-transition event time.
+    assertThat(mediaItemCount[0]).isEqualTo(2);
+    assertThat(currentMediaItems[0].playbackProperties.tag).isEqualTo("id-1");
+    // The masked state after id-1 has been removed.
+    assertThat(mediaItemCount[1]).isEqualTo(1);
+    assertThat(currentMediaItems[1].playbackProperties.tag).isEqualTo("id-0");
+    // PositionInfo reports the media item at event time.
+    assertThat(newPositionArgumentCaptor.getAllValues().get(0).mediaItem.playbackProperties.tag)
+        .isEqualTo("id-1");
+    assertThat(newPositionArgumentCaptor.getAllValues().get(1).mediaItem.playbackProperties.tag)
+        .isEqualTo("id-0");
+    player.release();
+  }
+  @Test
  public void removeMediaItems_removesPlayingPeriod_callsOnPositionDiscontinuity()
      throws Exception {
    ExoPlayer player = new TestExoPlayerBuilder(context).build();
    Player.Listener listener = mock(Player.Listener.class);
    player.addListener(listener);
    player.setMediaSources(
-        Lists.newArrayList(
+        ImmutableList.of(
            new FakeMediaSource(
                new FakeTimeline(
                    new TimelineWindowDefinition(
@@ -10355,11 +10441,75 @@ public final class ExoPlayerTest {
  }
  @Test
+  public void setMediaItems_callsListenersWithSameInstanceOfMediaItem() throws Exception {
+    ArgumentCaptor<Timeline> timeline = ArgumentCaptor.forClass(Timeline.class);
+    ArgumentCaptor<Player.PositionInfo> oldPosition =
+        ArgumentCaptor.forClass(Player.PositionInfo.class);
+    ArgumentCaptor<Player.PositionInfo> newPosition =
+        ArgumentCaptor.forClass(Player.PositionInfo.class);
+    ArgumentCaptor<MediaItem> currentMediaItem = ArgumentCaptor.forClass(MediaItem.class);
+    Window window = new Timeline.Window();
+    ExoPlayer player =
+        new TestExoPlayerBuilder(context)
+            .setMediaSourceFactory(new FakeMediaSourceFactory())
+            .build();
+    Player.Listener listener = mock(Player.Listener.class);
+    player.addListener(listener);
+    List<MediaItem> playlist =
+        ImmutableList.of(
+            MediaItem.fromUri("http://item-0.com/"), MediaItem.fromUri("http://item-1.com/"));
+    player.setMediaItems(playlist);
+    player.prepare();
+    player.seekTo(/* positionMs= */ 2000);
+    player.play();
+    TestPlayerRunHelper.runUntilPlaybackState(player, Player.STATE_ENDED);
+    InOrder inOrder = inOrder(listener);
+    inOrder
+        .verify(listener)
+        .onTimelineChanged(timeline.capture(), eq(Player.TIMELINE_CHANGE_REASON_PLAYLIST_CHANGED));
+    inOrder
+        .verify(listener)
+        .onMediaItemTransition(
+            currentMediaItem.capture(), eq(Player.MEDIA_ITEM_TRANSITION_REASON_PLAYLIST_CHANGED));
+    inOrder
+        .verify(listener)
+        .onPositionDiscontinuity(
+            oldPosition.capture(), newPosition.capture(), eq(Player.DISCONTINUITY_REASON_SEEK));
+    inOrder
+        .verify(listener)
+        .onPositionDiscontinuity(
+            oldPosition.capture(),
+            newPosition.capture(),
+            eq(Player.DISCONTINUITY_REASON_AUTO_TRANSITION));
+    inOrder
+        .verify(listener)
+        .onMediaItemTransition(
+            currentMediaItem.capture(), eq(Player.MEDIA_ITEM_TRANSITION_REASON_AUTO));
+    inOrder.verify(listener, never()).onPositionDiscontinuity(any(), any(), anyInt());
+    inOrder.verify(listener, never()).onMediaItemTransition(any(), anyInt());
+    assertThat(timeline.getValue().getWindow(0, window).mediaItem)
+        .isSameInstanceAs(playlist.get(0));
+    assertThat(timeline.getValue().getWindow(1, window).mediaItem)
+        .isSameInstanceAs(playlist.get(1));
+    assertThat(oldPosition.getAllValues().get(0).mediaItem).isSameInstanceAs(playlist.get(0));
+    assertThat(newPosition.getAllValues().get(0).mediaItem).isSameInstanceAs(playlist.get(0));
+    assertThat(oldPosition.getAllValues().get(1).mediaItem).isSameInstanceAs(playlist.get(0));
+    assertThat(newPosition.getAllValues().get(1).mediaItem).isSameInstanceAs(playlist.get(1));
+    assertThat(currentMediaItem.getAllValues().get(0)).isSameInstanceAs(playlist.get(0));
+    assertThat(currentMediaItem.getAllValues().get(1)).isSameInstanceAs(playlist.get(1));
+    player.release();
+  }
+  @Test
  public void seekTo_callsOnPositionDiscontinuity() throws Exception {
    ExoPlayer player = new TestExoPlayerBuilder(context).build();
    Player.Listener listener = mock(Player.Listener.class);
    player.addListener(listener);
-    player.setMediaSources(Lists.newArrayList(new FakeMediaSource(), new FakeMediaSource()));
+    player.setMediaSources(
+        ImmutableList.of(
+            createFakeMediaSource(/* id= */ "id-0"), createFakeMediaSource(/* id= */ "id-1")));
    player.prepare();
    TestPlayerRunHelper.playUntilPosition(
@@ -10382,16 +10532,20 @@ public final class ExoPlayerTest {
    List<Player.PositionInfo> newPositions = newPosition.getAllValues();
    assertThat(oldPositions.get(0).windowUid).isEqualTo(newPositions.get(0).windowUid);
    assertThat(newPositions.get(0).windowIndex).isEqualTo(0);
+    assertThat(newPositions.get(0).mediaItem.playbackProperties.tag).isEqualTo("id-0");
    assertThat(oldPositions.get(0).positionMs).isIn(Range.closed(4980L, 5000L));
    assertThat(oldPositions.get(0).contentPositionMs).isIn(Range.closed(4980L, 5000L));
    assertThat(oldPositions.get(0).windowIndex).isEqualTo(0);
+    assertThat(oldPositions.get(0).mediaItem.playbackProperties.tag).isEqualTo("id-0");
    assertThat(newPositions.get(0).positionMs).isEqualTo(7_000);
    assertThat(newPositions.get(0).contentPositionMs).isEqualTo(7_000);
-    assertThat(oldPositions.get(1).windowIndex).isEqualTo(0);
    assertThat(oldPositions.get(1).windowUid).isNotEqualTo(newPositions.get(1).windowUid);
+    assertThat(oldPositions.get(1).windowIndex).isEqualTo(0);
+    assertThat(oldPositions.get(1).mediaItem.playbackProperties.tag).isEqualTo("id-0");
    assertThat(oldPositions.get(1).positionMs).isEqualTo(7_000);
    assertThat(oldPositions.get(1).contentPositionMs).isEqualTo(7_000);
    assertThat(newPositions.get(1).windowIndex).isEqualTo(1);
+    assertThat(newPositions.get(1).mediaItem.playbackProperties.tag).isEqualTo("id-1");
    assertThat(newPositions.get(1).positionMs).isEqualTo(1_000);
    assertThat(newPositions.get(1).contentPositionMs).isEqualTo(1_000);
    player.release();
@@ -10421,6 +10575,7 @@ public final class ExoPlayerTest {
    // a seek from initial state to masked seek position
    assertThat(oldPositions.get(0).windowUid).isNull();
    assertThat(oldPositions.get(0).windowIndex).isEqualTo(0);
+    assertThat(oldPositions.get(0).mediaItem).isNull();
    assertThat(oldPositions.get(0).positionMs).isEqualTo(0);
    assertThat(oldPositions.get(0).contentPositionMs).isEqualTo(0);
    assertThat(newPositions.get(0).windowIndex).isEqualTo(0);
@@ -10430,6 +10585,7 @@ public final class ExoPlayerTest {
    // a seek from masked seek position to another masked position across windows
    assertThat(oldPositions.get(1).windowUid).isNull();
    assertThat(oldPositions.get(1).windowIndex).isEqualTo(0);
+    assertThat(oldPositions.get(1).mediaItem).isNull();
    assertThat(oldPositions.get(1).positionMs).isEqualTo(7_000);
    assertThat(oldPositions.get(1).contentPositionMs).isEqualTo(7_000);
    assertThat(newPositions.get(1).windowUid).isNull();
@@ -10439,6 +10595,7 @@ public final class ExoPlayerTest {
    // a seek from masked seek position to another masked position within window
    assertThat(oldPositions.get(2).windowUid).isNull();
    assertThat(oldPositions.get(2).windowIndex).isEqualTo(1);
+    assertThat(oldPositions.get(2).mediaItem).isNull();
    assertThat(oldPositions.get(2).positionMs).isEqualTo(1_000);
    assertThat(oldPositions.get(2).contentPositionMs).isEqualTo(1_000);
    assertThat(newPositions.get(2).windowUid).isNull();
@@ -10671,7 +10828,7 @@ public final class ExoPlayerTest {
    ExoPlayer player = new TestExoPlayerBuilder(context).build();
    Player.Listener listener = mock(Player.Listener.class);
    player.addListener(listener);
-    player.setMediaSource(new FakeMediaSource());
+    player.setMediaSource(createFakeMediaSource(/* id= */ 123));
    player.prepare();
    TestPlayerRunHelper.playUntilPosition(
@@ -10690,10 +10847,12 @@ public final class ExoPlayerTest {
    List<Player.PositionInfo> oldPositions = oldPosition.getAllValues();
    List<Player.PositionInfo> newPositions = newPosition.getAllValues();
    assertThat(oldPositions.get(0).windowIndex).isEqualTo(0);
+    assertThat(oldPositions.get(0).mediaItem.playbackProperties.tag).isEqualTo(123);
    assertThat(oldPositions.get(0).positionMs).isIn(Range.closed(4980L, 5000L));
    assertThat(oldPositions.get(0).contentPositionMs).isIn(Range.closed(4980L, 5000L));
    assertThat(newPositions.get(0).windowUid).isNull();
    assertThat(newPositions.get(0).windowIndex).isEqualTo(0);
+    assertThat(newPositions.get(0).mediaItem).isNull();
    assertThat(newPositions.get(0).positionMs).isEqualTo(0);
    assertThat(newPositions.get(0).contentPositionMs).isEqualTo(0);
    player.release();
@@ -10851,6 +11010,11 @@ public final class ExoPlayerTest {
            });
  }
+  private static FakeMediaSource createFakeMediaSource(Object id) {
+    return new FakeMediaSource(
+        new FakeTimeline(new TimelineWindowDefinition(/* periodCount= */ 1, id)));
+  }
  private static void deliverBroadcast(Intent intent) {
    ApplicationProvider.getApplicationContext().sendBroadcast(intent);
    shadowOf(Looper.getMainLooper()).idle();

--- a/testutils/src/main/java/com/google/android/exoplayer2/testutil/FakeMediaSourceFactory.java
+++ b/testutils/src/main/java/com/google/android/exoplayer2/testutil/FakeMediaSourceFactory.java
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.testutil;
+import androidx.annotation.Nullable;
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.MediaItem;
+import com.google.android.exoplayer2.drm.DrmSessionManager;
+import com.google.android.exoplayer2.drm.DrmSessionManagerProvider;
+import com.google.android.exoplayer2.source.MediaSource;
+import com.google.android.exoplayer2.source.MediaSourceFactory;
+import com.google.android.exoplayer2.source.ads.AdPlaybackState;
+import com.google.android.exoplayer2.testutil.FakeTimeline.TimelineWindowDefinition;
+import com.google.android.exoplayer2.upstream.HttpDataSource;
+import com.google.android.exoplayer2.upstream.LoadErrorHandlingPolicy;
+/** Fake {@link MediaSourceFactory} that creates a {@link FakeMediaSource}. */
+public class FakeMediaSourceFactory implements MediaSourceFactory {
+  /** The window UID used by media sources that are created by the factory. */
+  public static final Object DEFAULT_WINDOW_UID = new Object();
+  @Override
+  public MediaSourceFactory setDrmSessionManagerProvider(
+      @Nullable DrmSessionManagerProvider drmSessionManagerProvider) {
+    throw new UnsupportedOperationException();
+  }
+  @Deprecated
+  @Override
+  public MediaSourceFactory setDrmSessionManager(@Nullable DrmSessionManager drmSessionManager) {
+    throw new UnsupportedOperationException();
+  }
+  @Deprecated
+  @Override
+  public MediaSourceFactory setDrmHttpDataSourceFactory(
+      @Nullable HttpDataSource.Factory drmHttpDataSourceFactory) {
+    throw new UnsupportedOperationException();
+  }
+  @Deprecated
+  @Override
+  public MediaSourceFactory setDrmUserAgent(@Nullable String userAgent) {
+    throw new UnsupportedOperationException();
+  }
+  @Override
+  public MediaSourceFactory setLoadErrorHandlingPolicy(
+      @Nullable LoadErrorHandlingPolicy loadErrorHandlingPolicy) {
+    throw new UnsupportedOperationException();
+  }
+  @Override
+  public int[] getSupportedTypes() {
+    return new int[] {C.TYPE_OTHER};
+  }
+  @Override
+  public MediaSource createMediaSource(MediaItem mediaItem) {
+    TimelineWindowDefinition timelineWindowDefinition =
+        new TimelineWindowDefinition(
+            /* periodCount= */ 1,
+            /* id= */ DEFAULT_WINDOW_UID,
+            /* isSeekable= */ true,
+            /* isDynamic= */ false,
+            /* isLive= */ false,
+            /* isPlaceholder= */ false,
+            /* durationUs= */ 1000 * C.MICROS_PER_SECOND,
+            /* defaultPositionUs= */ 2 * C.MICROS_PER_SECOND,
+            /* windowOffsetInFirstPeriodUs= */ C.msToUs(123456789),
+            AdPlaybackState.NONE,
+            mediaItem);
+    return new FakeMediaSource(new FakeTimeline(timelineWindowDefinition));
+  }
+}
--- a/testutils/src/main/java/com/google/android/exoplayer2/testutil/TestExoPlayerBuilder.java
+++ b/testutils/src/main/java/com/google/android/exoplayer2/testutil/TestExoPlayerBuilder.java
@@ -28,6 +28,7 @@ import com.google.android.exoplayer2.Renderer;
 import com.google.android.exoplayer2.RenderersFactory;
 import com.google.android.exoplayer2.SimpleExoPlayer;
 import com.google.android.exoplayer2.analytics.AnalyticsCollector;
+import com.google.android.exoplayer2.source.MediaSourceFactory;
 import com.google.android.exoplayer2.trackselection.DefaultTrackSelector;
 import com.google.android.exoplayer2.upstream.BandwidthMeter;
 import com.google.android.exoplayer2.upstream.DefaultBandwidthMeter;
@@ -45,6 +46,7 @@ public class TestExoPlayerBuilder {
  private BandwidthMeter bandwidthMeter;
  @Nullable private Renderer[] renderers;
  @Nullable private RenderersFactory renderersFactory;
+  @Nullable private MediaSourceFactory mediaSourceFactory;
  private boolean useLazyPreparation;
  private @MonotonicNonNull Looper looper;
  private long seekBackIncrementMs;
@@ -220,6 +222,26 @@ public class TestExoPlayerBuilder {
  }
  /**
+   * Returns the {@link MediaSourceFactory} that will be used by the player, or null if no {@link
+   * MediaSourceFactory} has been set yet and no default is available.
+   */
+  @Nullable
+  public MediaSourceFactory getMediaSourceFactory() {
+    return mediaSourceFactory;
+  }
+  /**
+   * Sets the {@link MediaSourceFactory} to be used by the player.
+   *
+   * @param mediaSourceFactory The {@link MediaSourceFactory} to be used by the player.
+   * @return This builder.
+   */
+  public TestExoPlayerBuilder setMediaSourceFactory(MediaSourceFactory mediaSourceFactory) {
+    this.mediaSourceFactory = mediaSourceFactory;
+    return this;
+  }
+  /**
   * Sets the seek back increment to be used by the player.
   *
   * @param seekBackIncrementMs The seek back increment to be used by the player.
@@ -277,16 +299,20 @@ public class TestExoPlayerBuilder {
                  };
    }
-    return new ExoPlayer.Builder(context, playerRenderersFactory)
+    ExoPlayer.Builder builder =
-        .setTrackSelector(trackSelector)
+        new ExoPlayer.Builder(context, playerRenderersFactory)
-        .setLoadControl(loadControl)
+            .setTrackSelector(trackSelector)
-        .setBandwidthMeter(bandwidthMeter)
+            .setLoadControl(loadControl)
-        .setAnalyticsCollector(new AnalyticsCollector(clock))
+            .setBandwidthMeter(bandwidthMeter)
-        .setClock(clock)
+            .setAnalyticsCollector(new AnalyticsCollector(clock))
-        .setUseLazyPreparation(useLazyPreparation)
+            .setClock(clock)
-        .setLooper(looper)
+            .setUseLazyPreparation(useLazyPreparation)
-        .setSeekBackIncrementMs(seekBackIncrementMs)
+            .setLooper(looper)
-        .setSeekForwardIncrementMs(seekForwardIncrementMs)
+            .setSeekBackIncrementMs(seekBackIncrementMs)
-        .build();
+            .setSeekForwardIncrementMs(seekForwardIncrementMs);
+    if (mediaSourceFactory != null) {
+      builder.setMediaSourceFactory(mediaSourceFactory);
+    }
+    return builder.build();
  }
 }
--- a/testutils/src/test/java/com/google/android/exoplayer2/testutil/FakeMediaSourceFactoryTest.java
+++ b/testutils/src/test/java/com/google/android/exoplayer2/testutil/FakeMediaSourceFactoryTest.java
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.testutil;
+import static com.google.common.truth.Truth.assertThat;
+import androidx.annotation.Nullable;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import com.google.android.exoplayer2.MediaItem;
+import com.google.android.exoplayer2.Timeline.Window;
+import com.google.android.exoplayer2.source.MediaSource;
+import java.util.concurrent.atomic.AtomicReference;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+/** Unit test for {@link FakeMediaSourceFactory}. */
+@RunWith(AndroidJUnit4.class)
+public class FakeMediaSourceFactoryTest {
+  @Test
+  public void createMediaSource_mediaItemIsSameInstance() {
+    FakeMediaSourceFactory fakeMediaSourceFactory = new FakeMediaSourceFactory();
+    MediaItem mediaItem = MediaItem.fromUri("http://google.com/0");
+    @Nullable AtomicReference<MediaItem> reportedMediaItem = new AtomicReference<>();
+    MediaSource mediaSource = fakeMediaSourceFactory.createMediaSource(mediaItem);
+    mediaSource.prepareSource(
+        (source, timeline) -> {
+          int firstWindowIndex = timeline.getFirstWindowIndex(/* shuffleModeEnabled= */ false);
+          reportedMediaItem.set(timeline.getWindow(firstWindowIndex, new Window()).mediaItem);
+        },
+        /* mediaTransferListener= */ null);
+    assertThat(reportedMediaItem.get()).isSameInstanceAs(mediaItem);
+    assertThat(mediaSource.getMediaItem()).isSameInstanceAs(mediaItem);
+  }
+}