Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 858 insertions, 0 deletions

diff --git a/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/source/hls/HlsMediaPeriod.java b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/source/hls/HlsMediaPeriod.java
new file mode 100644
index 0000000000..60aa5298c3
--- /dev/null
+++ b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/source/hls/HlsMediaPeriod.java
@@ -0,0 +1,858 @@
+/*
+ * 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.hls;
+
+import android.net.Uri;
+import android.text.TextUtils;
+import androidx.annotation.Nullable;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.C;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.Format;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.SeekParameters;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.drm.DrmInitData;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.drm.DrmSession;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.drm.DrmSessionManager;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.Extractor;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.metadata.Metadata;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.offline.StreamKey;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.source.CompositeSequenceableLoaderFactory;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.source.MediaPeriod;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.source.MediaSourceEventListener.EventDispatcher;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.source.SampleStream;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.source.SequenceableLoader;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.source.TrackGroup;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.source.TrackGroupArray;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.source.hls.playlist.HlsMasterPlaylist;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.source.hls.playlist.HlsMasterPlaylist.Rendition;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.source.hls.playlist.HlsMasterPlaylist.Variant;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.source.hls.playlist.HlsPlaylistTracker;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.trackselection.TrackSelection;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.upstream.Allocator;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.upstream.DataSource;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.upstream.LoadErrorHandlingPolicy;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.upstream.TransferListener;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.util.Assertions;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.util.MimeTypes;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.util.Util;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.IdentityHashMap;
+import java.util.List;
+import java.util.Map;
+import org.checkerframework.checker.nullness.compatqual.NullableType;
+import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
+
+/**
+ * A {@link MediaPeriod} that loads an HLS stream.
+ */
+public final class HlsMediaPeriod implements MediaPeriod, HlsSampleStreamWrapper.Callback,
+    HlsPlaylistTracker.PlaylistEventListener {
+
+  private final HlsExtractorFactory extractorFactory;
+  private final HlsPlaylistTracker playlistTracker;
+  private final HlsDataSourceFactory dataSourceFactory;
+  @Nullable private final TransferListener mediaTransferListener;
+  private final DrmSessionManager<?> drmSessionManager;
+  private final LoadErrorHandlingPolicy loadErrorHandlingPolicy;
+  private final EventDispatcher eventDispatcher;
+  private final Allocator allocator;
+  private final IdentityHashMap<SampleStream, Integer> streamWrapperIndices;
+  private final TimestampAdjusterProvider timestampAdjusterProvider;
+  private final CompositeSequenceableLoaderFactory compositeSequenceableLoaderFactory;
+  private final boolean allowChunklessPreparation;
+  private final @HlsMediaSource.MetadataType int metadataType;
+  private final boolean useSessionKeys;
+
+  @Nullable private Callback callback;
+  private int pendingPrepareCount;
+  private @MonotonicNonNull TrackGroupArray trackGroups;
+  private HlsSampleStreamWrapper[] sampleStreamWrappers;
+  private HlsSampleStreamWrapper[] enabledSampleStreamWrappers;
+  // Maps sample stream wrappers to variant/rendition index by matching array positions.
+  private int[][] manifestUrlIndicesPerWrapper;
+  private SequenceableLoader compositeSequenceableLoader;
+  private boolean notifiedReadingStarted;
+
+  /**
+   * Creates an HLS media period.
+   *
+   * @param extractorFactory An {@link HlsExtractorFactory} for {@link Extractor}s for the segments.
+   * @param playlistTracker A tracker for HLS playlists.
+   * @param dataSourceFactory An {@link HlsDataSourceFactory} for {@link DataSource}s for segments
+   *     and keys.
+   * @param mediaTransferListener The transfer listener to inform of any media data transfers. May
+   *     be null if no listener is available.
+   * @param drmSessionManager The {@link DrmSessionManager} to acquire {@link DrmSession
+   *     DrmSessions} with.
+   * @param loadErrorHandlingPolicy A {@link LoadErrorHandlingPolicy}.
+   * @param eventDispatcher A dispatcher to notify of events.
+   * @param allocator An {@link Allocator} from which to obtain media buffer allocations.
+   * @param compositeSequenceableLoaderFactory A factory to create composite {@link
+   *     SequenceableLoader}s for when this media source loads data from multiple streams.
+   * @param allowChunklessPreparation Whether chunkless preparation is allowed.
+   * @param useSessionKeys Whether to use #EXT-X-SESSION-KEY tags.
+   */
+  public HlsMediaPeriod(
+      HlsExtractorFactory extractorFactory,
+      HlsPlaylistTracker playlistTracker,
+      HlsDataSourceFactory dataSourceFactory,
+      @Nullable TransferListener mediaTransferListener,
+      DrmSessionManager<?> drmSessionManager,
+      LoadErrorHandlingPolicy loadErrorHandlingPolicy,
+      EventDispatcher eventDispatcher,
+      Allocator allocator,
+      CompositeSequenceableLoaderFactory compositeSequenceableLoaderFactory,
+      boolean allowChunklessPreparation,
+      @HlsMediaSource.MetadataType int metadataType,
+      boolean useSessionKeys) {
+    this.extractorFactory = extractorFactory;
+    this.playlistTracker = playlistTracker;
+    this.dataSourceFactory = dataSourceFactory;
+    this.mediaTransferListener = mediaTransferListener;
+    this.drmSessionManager = drmSessionManager;
+    this.loadErrorHandlingPolicy = loadErrorHandlingPolicy;
+    this.eventDispatcher = eventDispatcher;
+    this.allocator = allocator;
+    this.compositeSequenceableLoaderFactory = compositeSequenceableLoaderFactory;
+    this.allowChunklessPreparation = allowChunklessPreparation;
+    this.metadataType = metadataType;
+    this.useSessionKeys = useSessionKeys;
+    compositeSequenceableLoader =
+        compositeSequenceableLoaderFactory.createCompositeSequenceableLoader();
+    streamWrapperIndices = new IdentityHashMap<>();
+    timestampAdjusterProvider = new TimestampAdjusterProvider();
+    sampleStreamWrappers = new HlsSampleStreamWrapper[0];
+    enabledSampleStreamWrappers = new HlsSampleStreamWrapper[0];
+    manifestUrlIndicesPerWrapper = new int[0][];
+    eventDispatcher.mediaPeriodCreated();
+  }
+
+  public void release() {
+    playlistTracker.removeListener(this);
+    for (HlsSampleStreamWrapper sampleStreamWrapper : sampleStreamWrappers) {
+      sampleStreamWrapper.release();
+    }
+    callback = null;
+    eventDispatcher.mediaPeriodReleased();
+  }
+
+  @Override
+  public void prepare(Callback callback, long positionUs) {
+    this.callback = callback;
+    playlistTracker.addListener(this);
+    buildAndPrepareSampleStreamWrappers(positionUs);
+  }
+
+  @Override
+  public void maybeThrowPrepareError() throws IOException {
+    for (HlsSampleStreamWrapper sampleStreamWrapper : sampleStreamWrappers) {
+      sampleStreamWrapper.maybeThrowPrepareError();
+    }
+  }
+
+  @Override
+  public TrackGroupArray getTrackGroups() {
+    // trackGroups will only be null if period hasn't been prepared or has been released.
+    return Assertions.checkNotNull(trackGroups);
+  }
+
+  // TODO: When the master playlist does not de-duplicate variants by URL and allows Renditions with
+  // null URLs, this method must be updated to calculate stream keys that are compatible with those
+  // that may already be persisted for offline.
+  @Override
+  public List<StreamKey> getStreamKeys(List<TrackSelection> trackSelections) {
+    // See HlsMasterPlaylist.copy for interpretation of StreamKeys.
+    HlsMasterPlaylist masterPlaylist = Assertions.checkNotNull(playlistTracker.getMasterPlaylist());
+    boolean hasVariants = !masterPlaylist.variants.isEmpty();
+    int audioWrapperOffset = hasVariants ? 1 : 0;
+    // Subtitle sample stream wrappers are held last.
+    int subtitleWrapperOffset = sampleStreamWrappers.length - masterPlaylist.subtitles.size();
+
+    TrackGroupArray mainWrapperTrackGroups;
+    int mainWrapperPrimaryGroupIndex;
+    int[] mainWrapperVariantIndices;
+    if (hasVariants) {
+      HlsSampleStreamWrapper mainWrapper = sampleStreamWrappers[0];
+      mainWrapperVariantIndices = manifestUrlIndicesPerWrapper[0];
+      mainWrapperTrackGroups = mainWrapper.getTrackGroups();
+      mainWrapperPrimaryGroupIndex = mainWrapper.getPrimaryTrackGroupIndex();
+    } else {
+      mainWrapperVariantIndices = new int[0];
+      mainWrapperTrackGroups = TrackGroupArray.EMPTY;
+      mainWrapperPrimaryGroupIndex = 0;
+    }
+
+    List<StreamKey> streamKeys = new ArrayList<>();
+    boolean needsPrimaryTrackGroupSelection = false;
+    boolean hasPrimaryTrackGroupSelection = false;
+    for (TrackSelection trackSelection : trackSelections) {
+      TrackGroup trackSelectionGroup = trackSelection.getTrackGroup();
+      int mainWrapperTrackGroupIndex = mainWrapperTrackGroups.indexOf(trackSelectionGroup);
+      if (mainWrapperTrackGroupIndex != C.INDEX_UNSET) {
+        if (mainWrapperTrackGroupIndex == mainWrapperPrimaryGroupIndex) {
+          // Primary group in main wrapper.
+          hasPrimaryTrackGroupSelection = true;
+          for (int i = 0; i < trackSelection.length(); i++) {
+            int variantIndex = mainWrapperVariantIndices[trackSelection.getIndexInTrackGroup(i)];
+            streamKeys.add(new StreamKey(HlsMasterPlaylist.GROUP_INDEX_VARIANT, variantIndex));
+          }
+        } else {
+          // Embedded group in main wrapper.
+          needsPrimaryTrackGroupSelection = true;
+        }
+      } else {
+        // Audio or subtitle group.
+        for (int i = audioWrapperOffset; i < sampleStreamWrappers.length; i++) {
+          TrackGroupArray wrapperTrackGroups = sampleStreamWrappers[i].getTrackGroups();
+          int selectedTrackGroupIndex = wrapperTrackGroups.indexOf(trackSelectionGroup);
+          if (selectedTrackGroupIndex != C.INDEX_UNSET) {
+            int groupIndexType =
+                i < subtitleWrapperOffset
+                    ? HlsMasterPlaylist.GROUP_INDEX_AUDIO
+                    : HlsMasterPlaylist.GROUP_INDEX_SUBTITLE;
+            int[] selectedWrapperUrlIndices = manifestUrlIndicesPerWrapper[i];
+            for (int trackIndex = 0; trackIndex < trackSelection.length(); trackIndex++) {
+              int renditionIndex =
+                  selectedWrapperUrlIndices[trackSelection.getIndexInTrackGroup(trackIndex)];
+              streamKeys.add(new StreamKey(groupIndexType, renditionIndex));
+            }
+            break;
+          }
+        }
+      }
+    }
+    if (needsPrimaryTrackGroupSelection && !hasPrimaryTrackGroupSelection) {
+      // A track selection includes a variant-embedded track, but no variant is added yet. We use
+      // the valid variant with the lowest bitrate to reduce overhead.
+      int lowestBitrateIndex = mainWrapperVariantIndices[0];
+      int lowestBitrate = masterPlaylist.variants.get(mainWrapperVariantIndices[0]).format.bitrate;
+      for (int i = 1; i < mainWrapperVariantIndices.length; i++) {
+        int variantBitrate =
+            masterPlaylist.variants.get(mainWrapperVariantIndices[i]).format.bitrate;
+        if (variantBitrate < lowestBitrate) {
+          lowestBitrate = variantBitrate;
+          lowestBitrateIndex = mainWrapperVariantIndices[i];
+        }
+      }
+      streamKeys.add(new StreamKey(HlsMasterPlaylist.GROUP_INDEX_VARIANT, lowestBitrateIndex));
+    }
+    return streamKeys;
+  }
+
+  @Override
+  public long selectTracks(
+      @NullableType TrackSelection[] selections,
+      boolean[] mayRetainStreamFlags,
+      @NullableType SampleStream[] streams,
+      boolean[] streamResetFlags,
+      long positionUs) {
+    // Map each selection and stream onto a child period index.
+    int[] streamChildIndices = new int[selections.length];
+    int[] selectionChildIndices = new int[selections.length];
+    for (int i = 0; i < selections.length; i++) {
+      streamChildIndices[i] = streams[i] == null ? C.INDEX_UNSET
+          : streamWrapperIndices.get(streams[i]);
+      selectionChildIndices[i] = C.INDEX_UNSET;
+      if (selections[i] != null) {
+        TrackGroup trackGroup = selections[i].getTrackGroup();
+        for (int j = 0; j < sampleStreamWrappers.length; j++) {
+          if (sampleStreamWrappers[j].getTrackGroups().indexOf(trackGroup) != C.INDEX_UNSET) {
+            selectionChildIndices[i] = j;
+            break;
+          }
+        }
+      }
+    }
+
+    boolean forceReset = false;
+    streamWrapperIndices.clear();
+    // Select tracks for each child, copying the resulting streams back into a new streams array.
+    SampleStream[] newStreams = new SampleStream[selections.length];
+    @NullableType SampleStream[] childStreams = new SampleStream[selections.length];
+    @NullableType TrackSelection[] childSelections = new TrackSelection[selections.length];
+    int newEnabledSampleStreamWrapperCount = 0;
+    HlsSampleStreamWrapper[] newEnabledSampleStreamWrappers =
+        new HlsSampleStreamWrapper[sampleStreamWrappers.length];
+    for (int i = 0; i < sampleStreamWrappers.length; i++) {
+      for (int j = 0; j < selections.length; j++) {
+        childStreams[j] = streamChildIndices[j] == i ? streams[j] : null;
+        childSelections[j] = selectionChildIndices[j] == i ? selections[j] : null;
+      }
+      HlsSampleStreamWrapper sampleStreamWrapper = sampleStreamWrappers[i];
+      boolean wasReset = sampleStreamWrapper.selectTracks(childSelections, mayRetainStreamFlags,
+          childStreams, streamResetFlags, positionUs, forceReset);
+      boolean wrapperEnabled = false;
+      for (int j = 0; j < selections.length; j++) {
+        SampleStream childStream = childStreams[j];
+        if (selectionChildIndices[j] == i) {
+          // Assert that the child provided a stream for the selection.
+          Assertions.checkNotNull(childStream);
+          newStreams[j] = childStream;
+          wrapperEnabled = true;
+          streamWrapperIndices.put(childStream, i);
+        } else if (streamChildIndices[j] == i) {
+          // Assert that the child cleared any previous stream.
+          Assertions.checkState(childStream == null);
+        }
+      }
+      if (wrapperEnabled) {
+        newEnabledSampleStreamWrappers[newEnabledSampleStreamWrapperCount] = sampleStreamWrapper;
+        if (newEnabledSampleStreamWrapperCount++ == 0) {
+          // The first enabled wrapper is responsible for initializing timestamp adjusters. This
+          // way, if enabled, variants are responsible. Else audio renditions. Else text renditions.
+          sampleStreamWrapper.setIsTimestampMaster(true);
+          if (wasReset || enabledSampleStreamWrappers.length == 0
+              || sampleStreamWrapper != enabledSampleStreamWrappers[0]) {
+            // The wrapper responsible for initializing the timestamp adjusters was reset or
+            // changed. We need to reset the timestamp adjuster provider and all other wrappers.
+            timestampAdjusterProvider.reset();
+            forceReset = true;
+          }
+        } else {
+          sampleStreamWrapper.setIsTimestampMaster(false);
+        }
+      }
+    }
+    // Copy the new streams back into the streams array.
+    System.arraycopy(newStreams, 0, streams, 0, newStreams.length);
+    // Update the local state.
+    enabledSampleStreamWrappers =
+        Util.nullSafeArrayCopy(newEnabledSampleStreamWrappers, newEnabledSampleStreamWrapperCount);
+    compositeSequenceableLoader =
+        compositeSequenceableLoaderFactory.createCompositeSequenceableLoader(
+            enabledSampleStreamWrappers);
+    return positionUs;
+  }
+
+  @Override
+  public void discardBuffer(long positionUs, boolean toKeyframe) {
+    for (HlsSampleStreamWrapper sampleStreamWrapper : enabledSampleStreamWrappers) {
+      sampleStreamWrapper.discardBuffer(positionUs, toKeyframe);
+    }
+  }
+
+  @Override
+  public void reevaluateBuffer(long positionUs) {
+    compositeSequenceableLoader.reevaluateBuffer(positionUs);
+  }
+
+  @Override
+  public boolean continueLoading(long positionUs) {
+    if (trackGroups == null) {
+      // Preparation is still going on.
+      for (HlsSampleStreamWrapper wrapper : sampleStreamWrappers) {
+        wrapper.continuePreparing();
+      }
+      return false;
+    } else {
+      return compositeSequenceableLoader.continueLoading(positionUs);
+    }
+  }
+
+  @Override
+  public boolean isLoading() {
+    return compositeSequenceableLoader.isLoading();
+  }
+
+  @Override
+  public long getNextLoadPositionUs() {
+    return compositeSequenceableLoader.getNextLoadPositionUs();
+  }
+
+  @Override
+  public long readDiscontinuity() {
+    if (!notifiedReadingStarted) {
+      eventDispatcher.readingStarted();
+      notifiedReadingStarted = true;
+    }
+    return C.TIME_UNSET;
+  }
+
+  @Override
+  public long getBufferedPositionUs() {
+    return compositeSequenceableLoader.getBufferedPositionUs();
+  }
+
+  @Override
+  public long seekToUs(long positionUs) {
+    if (enabledSampleStreamWrappers.length > 0) {
+      // We need to reset all wrappers if the one responsible for initializing timestamp adjusters
+      // is reset. Else each wrapper can decide whether to reset independently.
+      boolean forceReset = enabledSampleStreamWrappers[0].seekToUs(positionUs, false);
+      for (int i = 1; i < enabledSampleStreamWrappers.length; i++) {
+        enabledSampleStreamWrappers[i].seekToUs(positionUs, forceReset);
+      }
+      if (forceReset) {
+        timestampAdjusterProvider.reset();
+      }
+    }
+    return positionUs;
+  }
+
+  @Override
+  public long getAdjustedSeekPositionUs(long positionUs, SeekParameters seekParameters) {
+    return positionUs;
+  }
+
+  // HlsSampleStreamWrapper.Callback implementation.
+
+  @Override
+  public void onPrepared() {
+    if (--pendingPrepareCount > 0) {
+      return;
+    }
+
+    int totalTrackGroupCount = 0;
+    for (HlsSampleStreamWrapper sampleStreamWrapper : sampleStreamWrappers) {
+      totalTrackGroupCount += sampleStreamWrapper.getTrackGroups().length;
+    }
+    TrackGroup[] trackGroupArray = new TrackGroup[totalTrackGroupCount];
+    int trackGroupIndex = 0;
+    for (HlsSampleStreamWrapper sampleStreamWrapper : sampleStreamWrappers) {
+      int wrapperTrackGroupCount = sampleStreamWrapper.getTrackGroups().length;
+      for (int j = 0; j < wrapperTrackGroupCount; j++) {
+        trackGroupArray[trackGroupIndex++] = sampleStreamWrapper.getTrackGroups().get(j);
+      }
+    }
+    trackGroups = new TrackGroupArray(trackGroupArray);
+    callback.onPrepared(this);
+  }
+
+  @Override
+  public void onPlaylistRefreshRequired(Uri url) {
+    playlistTracker.refreshPlaylist(url);
+  }
+
+  @Override
+  public void onContinueLoadingRequested(HlsSampleStreamWrapper sampleStreamWrapper) {
+    callback.onContinueLoadingRequested(this);
+  }
+
+  // PlaylistListener implementation.
+
+  @Override
+  public void onPlaylistChanged() {
+    callback.onContinueLoadingRequested(this);
+  }
+
+  @Override
+  public boolean onPlaylistError(Uri url, long blacklistDurationMs) {
+    boolean noBlacklistingFailure = true;
+    for (HlsSampleStreamWrapper streamWrapper : sampleStreamWrappers) {
+      noBlacklistingFailure &= streamWrapper.onPlaylistError(url, blacklistDurationMs);
+    }
+    callback.onContinueLoadingRequested(this);
+    return noBlacklistingFailure;
+  }
+
+  // Internal methods.
+
+  private void buildAndPrepareSampleStreamWrappers(long positionUs) {
+    HlsMasterPlaylist masterPlaylist = Assertions.checkNotNull(playlistTracker.getMasterPlaylist());
+    Map<String, DrmInitData> overridingDrmInitData =
+        useSessionKeys
+            ? deriveOverridingDrmInitData(masterPlaylist.sessionKeyDrmInitData)
+            : Collections.emptyMap();
+
+    boolean hasVariants = !masterPlaylist.variants.isEmpty();
+    List<Rendition> audioRenditions = masterPlaylist.audios;
+    List<Rendition> subtitleRenditions = masterPlaylist.subtitles;
+
+    pendingPrepareCount = 0;
+    ArrayList<HlsSampleStreamWrapper> sampleStreamWrappers = new ArrayList<>();
+    ArrayList<int[]> manifestUrlIndicesPerWrapper = new ArrayList<>();
+
+    if (hasVariants) {
+      buildAndPrepareMainSampleStreamWrapper(
+          masterPlaylist,
+          positionUs,
+          sampleStreamWrappers,
+          manifestUrlIndicesPerWrapper,
+          overridingDrmInitData);
+    }
+
+    // TODO: Build video stream wrappers here.
+
+    buildAndPrepareAudioSampleStreamWrappers(
+        positionUs,
+        audioRenditions,
+        sampleStreamWrappers,
+        manifestUrlIndicesPerWrapper,
+        overridingDrmInitData);
+
+    // Subtitle stream wrappers. We can always use master playlist information to prepare these.
+    for (int i = 0; i < subtitleRenditions.size(); i++) {
+      Rendition subtitleRendition = subtitleRenditions.get(i);
+      HlsSampleStreamWrapper sampleStreamWrapper =
+          buildSampleStreamWrapper(
+              C.TRACK_TYPE_TEXT,
+              new Uri[] {subtitleRendition.url},
+              new Format[] {subtitleRendition.format},
+              null,
+              Collections.emptyList(),
+              overridingDrmInitData,
+              positionUs);
+      manifestUrlIndicesPerWrapper.add(new int[] {i});
+      sampleStreamWrappers.add(sampleStreamWrapper);
+      sampleStreamWrapper.prepareWithMasterPlaylistInfo(
+          new TrackGroup[] {new TrackGroup(subtitleRendition.format)},
+          /* primaryTrackGroupIndex= */ 0);
+    }
+
+    this.sampleStreamWrappers = sampleStreamWrappers.toArray(new HlsSampleStreamWrapper[0]);
+    this.manifestUrlIndicesPerWrapper = manifestUrlIndicesPerWrapper.toArray(new int[0][]);
+    pendingPrepareCount = this.sampleStreamWrappers.length;
+    // Set timestamp master and trigger preparation (if not already prepared)
+    this.sampleStreamWrappers[0].setIsTimestampMaster(true);
+    for (HlsSampleStreamWrapper sampleStreamWrapper : this.sampleStreamWrappers) {
+      sampleStreamWrapper.continuePreparing();
+    }
+    // All wrappers are enabled during preparation.
+    enabledSampleStreamWrappers = this.sampleStreamWrappers;
+  }
+
+  /**
+   * This method creates and starts preparation of the main {@link HlsSampleStreamWrapper}.
+   *
+   * <p>The main sample stream wrapper is the first element of {@link #sampleStreamWrappers}. It
+   * provides {@link SampleStream}s for the variant urls in the master playlist. It may be adaptive
+   * and may contain multiple muxed tracks.
+   *
+   * <p>If chunkless preparation is allowed, the media period will try preparation without segment
+   * downloads. This is only possible if variants contain the CODECS attribute. If not, traditional
+   * preparation with segment downloads will take place. The following points apply to chunkless
+   * preparation:
+   *
+   * <ul>
+   *   <li>A muxed audio track will be exposed if the codecs list contain an audio entry and the
+   *       master playlist either contains an EXT-X-MEDIA tag without the URI attribute or does not
+   *       contain any EXT-X-MEDIA tag.
+   *   <li>Closed captions will only be exposed if they are declared by the master playlist.
+   *   <li>An ID3 track is exposed preemptively, in case the segments contain an ID3 track.
+   * </ul>
+   *
+   * @param masterPlaylist The HLS master playlist.
+   * @param positionUs If preparation requires any chunk downloads, the position in microseconds at
+   *     which downloading should start. Ignored otherwise.
+   * @param sampleStreamWrappers List to which the built main sample stream wrapper should be added.
+   * @param manifestUrlIndicesPerWrapper List to which the selected variant indices should be added.
+   * @param overridingDrmInitData Overriding {@link DrmInitData}, keyed by protection scheme type
+   *     (i.e. {@link DrmInitData#schemeType}).
+   */
+  private void buildAndPrepareMainSampleStreamWrapper(
+      HlsMasterPlaylist masterPlaylist,
+      long positionUs,
+      List<HlsSampleStreamWrapper> sampleStreamWrappers,
+      List<int[]> manifestUrlIndicesPerWrapper,
+      Map<String, DrmInitData> overridingDrmInitData) {
+    int[] variantTypes = new int[masterPlaylist.variants.size()];
+    int videoVariantCount = 0;
+    int audioVariantCount = 0;
+    for (int i = 0; i < masterPlaylist.variants.size(); i++) {
+      Variant variant = masterPlaylist.variants.get(i);
+      Format format = variant.format;
+      if (format.height > 0 || Util.getCodecsOfType(format.codecs, C.TRACK_TYPE_VIDEO) != null) {
+        variantTypes[i] = C.TRACK_TYPE_VIDEO;
+        videoVariantCount++;
+      } else if (Util.getCodecsOfType(format.codecs, C.TRACK_TYPE_AUDIO) != null) {
+        variantTypes[i] = C.TRACK_TYPE_AUDIO;
+        audioVariantCount++;
+      } else {
+        variantTypes[i] = C.TRACK_TYPE_UNKNOWN;
+      }
+    }
+    boolean useVideoVariantsOnly = false;
+    boolean useNonAudioVariantsOnly = false;
+    int selectedVariantsCount = variantTypes.length;
+    if (videoVariantCount > 0) {
+      // We've identified some variants as definitely containing video. Assume variants within the
+      // master playlist are marked consistently, and hence that we have the full set. Filter out
+      // any other variants, which are likely to be audio only.
+      useVideoVariantsOnly = true;
+      selectedVariantsCount = videoVariantCount;
+    } else if (audioVariantCount < variantTypes.length) {
+      // We've identified some variants, but not all, as being audio only. Filter them out to leave
+      // the remaining variants, which are likely to contain video.
+      useNonAudioVariantsOnly = true;
+      selectedVariantsCount = variantTypes.length - audioVariantCount;
+    }
+    Uri[] selectedPlaylistUrls = new Uri[selectedVariantsCount];
+    Format[] selectedPlaylistFormats = new Format[selectedVariantsCount];
+    int[] selectedVariantIndices = new int[selectedVariantsCount];
+    int outIndex = 0;
+    for (int i = 0; i < masterPlaylist.variants.size(); i++) {
+      if ((!useVideoVariantsOnly || variantTypes[i] == C.TRACK_TYPE_VIDEO)
+          && (!useNonAudioVariantsOnly || variantTypes[i] != C.TRACK_TYPE_AUDIO)) {
+        Variant variant = masterPlaylist.variants.get(i);
+        selectedPlaylistUrls[outIndex] = variant.url;
+        selectedPlaylistFormats[outIndex] = variant.format;
+        selectedVariantIndices[outIndex++] = i;
+      }
+    }
+    String codecs = selectedPlaylistFormats[0].codecs;
+    HlsSampleStreamWrapper sampleStreamWrapper =
+        buildSampleStreamWrapper(
+            C.TRACK_TYPE_DEFAULT,
+            selectedPlaylistUrls,
+            selectedPlaylistFormats,
+            masterPlaylist.muxedAudioFormat,
+            masterPlaylist.muxedCaptionFormats,
+            overridingDrmInitData,
+            positionUs);
+    sampleStreamWrappers.add(sampleStreamWrapper);
+    manifestUrlIndicesPerWrapper.add(selectedVariantIndices);
+    if (allowChunklessPreparation && codecs != null) {
+      boolean variantsContainVideoCodecs = Util.getCodecsOfType(codecs, C.TRACK_TYPE_VIDEO) != null;
+      boolean variantsContainAudioCodecs = Util.getCodecsOfType(codecs, C.TRACK_TYPE_AUDIO) != null;
+      List<TrackGroup> muxedTrackGroups = new ArrayList<>();
+      if (variantsContainVideoCodecs) {
+        Format[] videoFormats = new Format[selectedVariantsCount];
+        for (int i = 0; i < videoFormats.length; i++) {
+          videoFormats[i] = deriveVideoFormat(selectedPlaylistFormats[i]);
+        }
+        muxedTrackGroups.add(new TrackGroup(videoFormats));
+
+        if (variantsContainAudioCodecs
+            && (masterPlaylist.muxedAudioFormat != null || masterPlaylist.audios.isEmpty())) {
+          muxedTrackGroups.add(
+              new TrackGroup(
+                  deriveAudioFormat(
+                      selectedPlaylistFormats[0],
+                      masterPlaylist.muxedAudioFormat,
+                      /* isPrimaryTrackInVariant= */ false)));
+        }
+        List<Format> ccFormats = masterPlaylist.muxedCaptionFormats;
+        if (ccFormats != null) {
+          for (int i = 0; i < ccFormats.size(); i++) {
+            muxedTrackGroups.add(new TrackGroup(ccFormats.get(i)));
+          }
+        }
+      } else if (variantsContainAudioCodecs) {
+        // Variants only contain audio.
+        Format[] audioFormats = new Format[selectedVariantsCount];
+        for (int i = 0; i < audioFormats.length; i++) {
+          audioFormats[i] =
+              deriveAudioFormat(
+                  /* variantFormat= */ selectedPlaylistFormats[i],
+                  masterPlaylist.muxedAudioFormat,
+                  /* isPrimaryTrackInVariant= */ true);
+        }
+        muxedTrackGroups.add(new TrackGroup(audioFormats));
+      } else {
+        // Variants contain codecs but no video or audio entries could be identified.
+        throw new IllegalArgumentException("Unexpected codecs attribute: " + codecs);
+      }
+
+      TrackGroup id3TrackGroup =
+          new TrackGroup(
+              Format.createSampleFormat(
+                  /* id= */ "ID3",
+                  MimeTypes.APPLICATION_ID3,
+                  /* codecs= */ null,
+                  /* bitrate= */ Format.NO_VALUE,
+                  /* drmInitData= */ null));
+      muxedTrackGroups.add(id3TrackGroup);
+
+      sampleStreamWrapper.prepareWithMasterPlaylistInfo(
+          muxedTrackGroups.toArray(new TrackGroup[0]),
+          /* primaryTrackGroupIndex= */ 0,
+          /* optionalTrackGroupsIndices= */ muxedTrackGroups.indexOf(id3TrackGroup));
+    }
+  }
+
+  private void buildAndPrepareAudioSampleStreamWrappers(
+      long positionUs,
+      List<Rendition> audioRenditions,
+      List<HlsSampleStreamWrapper> sampleStreamWrappers,
+      List<int[]> manifestUrlsIndicesPerWrapper,
+      Map<String, DrmInitData> overridingDrmInitData) {
+    ArrayList<Uri> scratchPlaylistUrls =
+        new ArrayList<>(/* initialCapacity= */ audioRenditions.size());
+    ArrayList<Format> scratchPlaylistFormats =
+        new ArrayList<>(/* initialCapacity= */ audioRenditions.size());
+    ArrayList<Integer> scratchIndicesList =
+        new ArrayList<>(/* initialCapacity= */ audioRenditions.size());
+    HashSet<String> alreadyGroupedNames = new HashSet<>();
+    for (int renditionByNameIndex = 0;
+        renditionByNameIndex < audioRenditions.size();
+        renditionByNameIndex++) {
+      String name = audioRenditions.get(renditionByNameIndex).name;
+      if (!alreadyGroupedNames.add(name)) {
+        // This name already has a corresponding group.
+        continue;
+      }
+
+      boolean renditionsHaveCodecs = true;
+      scratchPlaylistUrls.clear();
+      scratchPlaylistFormats.clear();
+      scratchIndicesList.clear();
+      // Group all renditions with matching name.
+      for (int renditionIndex = 0; renditionIndex < audioRenditions.size(); renditionIndex++) {
+        if (Util.areEqual(name, audioRenditions.get(renditionIndex).name)) {
+          Rendition rendition = audioRenditions.get(renditionIndex);
+          scratchIndicesList.add(renditionIndex);
+          scratchPlaylistUrls.add(rendition.url);
+          scratchPlaylistFormats.add(rendition.format);
+          renditionsHaveCodecs &= rendition.format.codecs != null;
+        }
+      }
+
+      HlsSampleStreamWrapper sampleStreamWrapper =
+          buildSampleStreamWrapper(
+              C.TRACK_TYPE_AUDIO,
+              scratchPlaylistUrls.toArray(Util.castNonNullTypeArray(new Uri[0])),
+              scratchPlaylistFormats.toArray(new Format[0]),
+              /* muxedAudioFormat= */ null,
+              /* muxedCaptionFormats= */ Collections.emptyList(),
+              overridingDrmInitData,
+              positionUs);
+      manifestUrlsIndicesPerWrapper.add(Util.toArray(scratchIndicesList));
+      sampleStreamWrappers.add(sampleStreamWrapper);
+
+      if (allowChunklessPreparation && renditionsHaveCodecs) {
+        Format[] renditionFormats = scratchPlaylistFormats.toArray(new Format[0]);
+        sampleStreamWrapper.prepareWithMasterPlaylistInfo(
+            new TrackGroup[] {new TrackGroup(renditionFormats)}, /* primaryTrackGroupIndex= */ 0);
+      }
+    }
+  }
+
+  private HlsSampleStreamWrapper buildSampleStreamWrapper(
+      int trackType,
+      Uri[] playlistUrls,
+      Format[] playlistFormats,
+      @Nullable Format muxedAudioFormat,
+      @Nullable List<Format> muxedCaptionFormats,
+      Map<String, DrmInitData> overridingDrmInitData,
+      long positionUs) {
+    HlsChunkSource defaultChunkSource =
+        new HlsChunkSource(
+            extractorFactory,
+            playlistTracker,
+            playlistUrls,
+            playlistFormats,
+            dataSourceFactory,
+            mediaTransferListener,
+            timestampAdjusterProvider,
+            muxedCaptionFormats);
+    return new HlsSampleStreamWrapper(
+        trackType,
+        /* callback= */ this,
+        defaultChunkSource,
+        overridingDrmInitData,
+        allocator,
+        positionUs,
+        muxedAudioFormat,
+        drmSessionManager,
+        loadErrorHandlingPolicy,
+        eventDispatcher,
+        metadataType);
+  }
+
+  private static Map<String, DrmInitData> deriveOverridingDrmInitData(
+      List<DrmInitData> sessionKeyDrmInitData) {
+    ArrayList<DrmInitData> mutableSessionKeyDrmInitData = new ArrayList<>(sessionKeyDrmInitData);
+    HashMap<String, DrmInitData> drmInitDataBySchemeType = new HashMap<>();
+    for (int i = 0; i < mutableSessionKeyDrmInitData.size(); i++) {
+      DrmInitData drmInitData = sessionKeyDrmInitData.get(i);
+      String scheme = drmInitData.schemeType;
+      // Merge any subsequent drmInitData instances that have the same scheme type. This is valid
+      // due to the assumptions documented on HlsMediaSource.Builder.setUseSessionKeys, and is
+      // necessary to get data for different CDNs (e.g. Widevine and PlayReady) into a single
+      // drmInitData.
+      int j = i + 1;
+      while (j < mutableSessionKeyDrmInitData.size()) {
+        DrmInitData nextDrmInitData = mutableSessionKeyDrmInitData.get(j);
+        if (TextUtils.equals(nextDrmInitData.schemeType, scheme)) {
+          drmInitData = drmInitData.merge(nextDrmInitData);
+          mutableSessionKeyDrmInitData.remove(j);
+        } else {
+          j++;
+        }
+      }
+      drmInitDataBySchemeType.put(scheme, drmInitData);
+    }
+    return drmInitDataBySchemeType;
+  }
+
+  private static Format deriveVideoFormat(Format variantFormat) {
+    String codecs = Util.getCodecsOfType(variantFormat.codecs, C.TRACK_TYPE_VIDEO);
+    String sampleMimeType = MimeTypes.getMediaMimeType(codecs);
+    return Format.createVideoContainerFormat(
+        variantFormat.id,
+        variantFormat.label,
+        variantFormat.containerMimeType,
+        sampleMimeType,
+        codecs,
+        variantFormat.metadata,
+        variantFormat.bitrate,
+        variantFormat.width,
+        variantFormat.height,
+        variantFormat.frameRate,
+        /* initializationData= */ null,
+        variantFormat.selectionFlags,
+        variantFormat.roleFlags);
+  }
+
+  private static Format deriveAudioFormat(
+      Format variantFormat, @Nullable Format mediaTagFormat, boolean isPrimaryTrackInVariant) {
+    String codecs;
+    Metadata metadata;
+    int channelCount = Format.NO_VALUE;
+    int selectionFlags = 0;
+    int roleFlags = 0;
+    String language = null;
+    String label = null;
+    if (mediaTagFormat != null) {
+      codecs = mediaTagFormat.codecs;
+      metadata = mediaTagFormat.metadata;
+      channelCount = mediaTagFormat.channelCount;
+      selectionFlags = mediaTagFormat.selectionFlags;
+      roleFlags = mediaTagFormat.roleFlags;
+      language = mediaTagFormat.language;
+      label = mediaTagFormat.label;
+    } else {
+      codecs = Util.getCodecsOfType(variantFormat.codecs, C.TRACK_TYPE_AUDIO);
+      metadata = variantFormat.metadata;
+      if (isPrimaryTrackInVariant) {
+        channelCount = variantFormat.channelCount;
+        selectionFlags = variantFormat.selectionFlags;
+        roleFlags = variantFormat.roleFlags;
+        language = variantFormat.language;
+        label = variantFormat.label;
+      }
+    }
+    String sampleMimeType = MimeTypes.getMediaMimeType(codecs);
+    int bitrate = isPrimaryTrackInVariant ? variantFormat.bitrate : Format.NO_VALUE;
+    return Format.createAudioContainerFormat(
+        variantFormat.id,
+        label,
+        variantFormat.containerMimeType,
+        sampleMimeType,
+        codecs,
+        metadata,
+        bitrate,
+        channelCount,
+        /* sampleRate= */ Format.NO_VALUE,
+        /* initializationData= */ null,
+        selectionFlags,
+        roleFlags,
+        language);
+  }
+
+}