1 files changed, 184 insertions, 0 deletions
diff --git a/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/source/MergingMediaSource.java b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/source/MergingMediaSource.java
new file mode 100644
index 0000000000..ac2ef3c7da
--- /dev/null
+++ b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/source/MergingMediaSource.java
@@ -0,0 +1,184 @@
+/*
+ * Copyright (C) 2016 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 org.mozilla.thirdparty.com.google.android.exoplayer2.source;
+
+import androidx.annotation.IntDef;
+import androidx.annotation.Nullable;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.Timeline;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.upstream.Allocator;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.upstream.TransferListener;
+import java.io.IOException;
+import java.lang.annotation.Documented;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+
+/**
+ * Merges multiple {@link MediaSource}s.
+ *
+ * <p>The {@link Timeline}s of the sources being merged must have the same number of periods.
+ */
+public final class MergingMediaSource extends CompositeMediaSource<Integer> {
+
+  /**
+   * Thrown when a {@link MergingMediaSource} cannot merge its sources.
+   */
+  public static final class IllegalMergeException extends IOException {
+
+    /** The reason the merge failed. One of {@link #REASON_PERIOD_COUNT_MISMATCH}. */
+    @Documented
+    @Retention(RetentionPolicy.SOURCE)
+    @IntDef({REASON_PERIOD_COUNT_MISMATCH})
+    public @interface Reason {}
+    /**
+     * The sources have different period counts.
+     */
+    public static final int REASON_PERIOD_COUNT_MISMATCH = 0;
+
+    /**
+     * The reason the merge failed.
+     */
+    @Reason public final int reason;
+
+    /**
+     * @param reason The reason the merge failed.
+     */
+    public IllegalMergeException(@Reason int reason) {
+      this.reason = reason;
+    }
+
+  }
+
+  private static final int PERIOD_COUNT_UNSET = -1;
+
+  private final MediaSource[] mediaSources;
+  private final Timeline[] timelines;
+  private final ArrayList<MediaSource> pendingTimelineSources;
+  private final CompositeSequenceableLoaderFactory compositeSequenceableLoaderFactory;
+
+  private int periodCount;
+  @Nullable private IllegalMergeException mergeError;
+
+  /**
+   * @param mediaSources The {@link MediaSource}s to merge.
+   */
+  public MergingMediaSource(MediaSource... mediaSources) {
+    this(new DefaultCompositeSequenceableLoaderFactory(), mediaSources);
+  }
+
+  /**
+   * @param compositeSequenceableLoaderFactory A factory to create composite
+   *     {@link SequenceableLoader}s for when this media source loads data from multiple streams
+   *     (video, audio etc...).
+   * @param mediaSources The {@link MediaSource}s to merge.
+   */
+  public MergingMediaSource(CompositeSequenceableLoaderFactory compositeSequenceableLoaderFactory,
+      MediaSource... mediaSources) {
+    this.mediaSources = mediaSources;
+    this.compositeSequenceableLoaderFactory = compositeSequenceableLoaderFactory;
+    pendingTimelineSources = new ArrayList<>(Arrays.asList(mediaSources));
+    periodCount = PERIOD_COUNT_UNSET;
+    timelines = new Timeline[mediaSources.length];
+  }
+
+  @Override
+  @Nullable
+  public Object getTag() {
+    return mediaSources.length > 0 ? mediaSources[0].getTag() : null;
+  }
+
+  @Override
+  protected void prepareSourceInternal(@Nullable TransferListener mediaTransferListener) {
+    super.prepareSourceInternal(mediaTransferListener);
+    for (int i = 0; i < mediaSources.length; i++) {
+      prepareChildSource(i, mediaSources[i]);
+    }
+  }
+
+  @Override
+  public void maybeThrowSourceInfoRefreshError() throws IOException {
+    if (mergeError != null) {
+      throw mergeError;
+    }
+    super.maybeThrowSourceInfoRefreshError();
+  }
+
+  @Override
+  public MediaPeriod createPeriod(MediaPeriodId id, Allocator allocator, long startPositionUs) {
+    MediaPeriod[] periods = new MediaPeriod[mediaSources.length];
+    int periodIndex = timelines[0].getIndexOfPeriod(id.periodUid);
+    for (int i = 0; i < periods.length; i++) {
+      MediaPeriodId childMediaPeriodId =
+          id.copyWithPeriodUid(timelines[i].getUidOfPeriod(periodIndex));
+      periods[i] = mediaSources[i].createPeriod(childMediaPeriodId, allocator, startPositionUs);
+    }
+    return new MergingMediaPeriod(compositeSequenceableLoaderFactory, periods);
+  }
+
+  @Override
+  public void releasePeriod(MediaPeriod mediaPeriod) {
+    MergingMediaPeriod mergingPeriod = (MergingMediaPeriod) mediaPeriod;
+    for (int i = 0; i < mediaSources.length; i++) {
+      mediaSources[i].releasePeriod(mergingPeriod.periods[i]);
+    }
+  }
+
+  @Override
+  protected void releaseSourceInternal() {
+    super.releaseSourceInternal();
+    Arrays.fill(timelines, null);
+    periodCount = PERIOD_COUNT_UNSET;
+    mergeError = null;
+    pendingTimelineSources.clear();
+    Collections.addAll(pendingTimelineSources, mediaSources);
+  }
+
+  @Override
+  protected void onChildSourceInfoRefreshed(
+      Integer id, MediaSource mediaSource, Timeline timeline) {
+    if (mergeError == null) {
+      mergeError = checkTimelineMerges(timeline);
+    }
+    if (mergeError != null) {
+      return;
+    }
+    pendingTimelineSources.remove(mediaSource);
+    timelines[id] = timeline;
+    if (pendingTimelineSources.isEmpty()) {
+      refreshSourceInfo(timelines[0]);
+    }
+  }
+
+  @Override
+  @Nullable
+  protected MediaPeriodId getMediaPeriodIdForChildMediaPeriodId(
+      Integer id, MediaPeriodId mediaPeriodId) {
+    return id == 0 ? mediaPeriodId : null;
+  }
+
+  @Nullable
+  private IllegalMergeException checkTimelineMerges(Timeline timeline) {
+    if (periodCount == PERIOD_COUNT_UNSET) {
+      periodCount = timeline.getPeriodCount();
+    } else if (timeline.getPeriodCount() != periodCount) {
+      return new IllegalMergeException(IllegalMergeException.REASON_PERIOD_COUNT_MISMATCH);
+    }
+    return null;
+  }
+
+}