com.google.android.exoplayer2.source.dash.manifest.RangedUri Java Examples

protected Chunk newInitializationChunk(
    RepresentationHolder representationHolder,
    DataSource dataSource,
    Format trackFormat,
    int trackSelectionReason,
    Object trackSelectionData,
    RangedUri initializationUri,
    RangedUri indexUri) {
  RangedUri requestUri;
  String baseUrl = representationHolder.representation.baseUrl;
  if (initializationUri != null) {
    // It's common for initialization and index data to be stored adjacently. Attempt to merge
    // the two requests together to request both at once.
    requestUri = initializationUri.attemptMerge(indexUri, baseUrl);
    if (requestUri == null) {
      requestUri = initializationUri;
    }
  } else {
    requestUri = indexUri;
  }
  DataSpec dataSpec = new DataSpec(requestUri.resolveUri(baseUrl), requestUri.start,
      requestUri.length, representationHolder.representation.getCacheKey());
  return new InitializationChunk(dataSource, dataSpec, trackFormat,
      trackSelectionReason, trackSelectionData, representationHolder.extractorWrapper);
}
 

protected Chunk newInitializationChunk(
    RepresentationHolder representationHolder,
    DataSource dataSource,
    Format trackFormat,
    int trackSelectionReason,
    Object trackSelectionData,
    RangedUri initializationUri,
    RangedUri indexUri) {
  RangedUri requestUri;
  String baseUrl = representationHolder.representation.baseUrl;
  if (initializationUri != null) {
    // It's common for initialization and index data to be stored adjacently. Attempt to merge
    // the two requests together to request both at once.
    requestUri = initializationUri.attemptMerge(indexUri, baseUrl);
    if (requestUri == null) {
      requestUri = initializationUri;
    }
  } else {
    requestUri = indexUri;
  }
  DataSpec dataSpec = new DataSpec(requestUri.resolveUri(baseUrl), requestUri.start,
      requestUri.length, representationHolder.representation.getCacheKey());
  return new InitializationChunk(dataSource, dataSpec, trackFormat,
      trackSelectionReason, trackSelectionData, representationHolder.extractorWrapper);
}
 

private static Chunk newInitializationChunk(RepresentationHolder representationHolder,
    DataSource dataSource, Format trackFormat, int trackSelectionReason,
    Object trackSelectionData, RangedUri initializationUri, RangedUri indexUri) {
  RangedUri requestUri;
  String baseUrl = representationHolder.representation.baseUrl;
  if (initializationUri != null) {
    // It's common for initialization and index data to be stored adjacently. Attempt to merge
    // the two requests together to request both at once.
    requestUri = initializationUri.attemptMerge(indexUri, baseUrl);
    if (requestUri == null) {
      requestUri = initializationUri;
    }
  } else {
    requestUri = indexUri;
  }
  DataSpec dataSpec = new DataSpec(requestUri.resolveUri(baseUrl), requestUri.start,
      requestUri.length, representationHolder.representation.getCacheKey());
  return new InitializationChunk(dataSource, dataSpec, trackFormat,
      trackSelectionReason, trackSelectionData, representationHolder.extractorWrapper);
}
 

protected Chunk newInitializationChunk(
    RepresentationHolder representationHolder,
    DataSource dataSource,
    Format trackFormat,
    int trackSelectionReason,
    Object trackSelectionData,
    RangedUri initializationUri,
    RangedUri indexUri) {
  RangedUri requestUri;
  String baseUrl = representationHolder.representation.baseUrl;
  if (initializationUri != null) {
    // It's common for initialization and index data to be stored adjacently. Attempt to merge
    // the two requests together to request both at once.
    requestUri = initializationUri.attemptMerge(indexUri, baseUrl);
    if (requestUri == null) {
      requestUri = initializationUri;
    }
  } else {
    requestUri = indexUri;
  }
  DataSpec dataSpec = new DataSpec(requestUri.resolveUri(baseUrl), requestUri.start,
      requestUri.length, representationHolder.representation.getCacheKey());
  return new InitializationChunk(dataSource, dataSpec, trackFormat,
      trackSelectionReason, trackSelectionData, representationHolder.extractorWrapper);
}
 

protected Chunk newInitializationChunk(
    RepresentationHolder representationHolder,
    DataSource dataSource,
    Format trackFormat,
    int trackSelectionReason,
    Object trackSelectionData,
    RangedUri initializationUri,
    RangedUri indexUri) {
  RangedUri requestUri;
  String baseUrl = representationHolder.representation.baseUrl;
  if (initializationUri != null) {
    // It's common for initialization and index data to be stored adjacently. Attempt to merge
    // the two requests together to request both at once.
    requestUri = initializationUri.attemptMerge(indexUri, baseUrl);
    if (requestUri == null) {
      requestUri = initializationUri;
    }
  } else {
    requestUri = indexUri;
  }
  DataSpec dataSpec = new DataSpec(requestUri.resolveUri(baseUrl), requestUri.start,
      requestUri.length, representationHolder.representation.getCacheKey());
  return new InitializationChunk(dataSource, dataSpec, trackFormat,
      trackSelectionReason, trackSelectionData, representationHolder.extractorWrapper);
}
 

protected Chunk newInitializationChunk(
    RepresentationHolder representationHolder,
    DataSource dataSource,
    Format trackFormat,
    int trackSelectionReason,
    Object trackSelectionData,
    RangedUri initializationUri,
    RangedUri indexUri) {
  RangedUri requestUri;
  String baseUrl = representationHolder.representation.baseUrl;
  if (initializationUri != null) {
    // It's common for initialization and index data to be stored adjacently. Attempt to merge
    // the two requests together to request both at once.
    requestUri = initializationUri.attemptMerge(indexUri, baseUrl);
    if (requestUri == null) {
      requestUri = initializationUri;
    }
  } else {
    requestUri = indexUri;
  }
  DataSpec dataSpec = new DataSpec(requestUri.resolveUri(baseUrl), requestUri.start,
      requestUri.length, representationHolder.representation.getCacheKey());
  return new InitializationChunk(dataSource, dataSpec, trackFormat,
      trackSelectionReason, trackSelectionData, representationHolder.extractorWrapper);
}
 

private static void loadInitializationData(DataSource dataSource,
    Representation representation, ChunkExtractorWrapper extractorWrapper, RangedUri requestUri)
    throws IOException, InterruptedException {
  DataSpec dataSpec = new DataSpec(requestUri.resolveUri(representation.baseUrl),
      requestUri.start, requestUri.length, representation.getCacheKey());
  InitializationChunk initializationChunk = new InitializationChunk(dataSource, dataSpec,
      representation.format, C.SELECTION_REASON_UNKNOWN, null /* trackSelectionData */,
      extractorWrapper);
  initializationChunk.load();
}
 

/**
 * Loads initialization data for the {@code representation} and optionally index data then
 * returns a {@link ChunkExtractorWrapper} which contains the output.
 *
 * @param dataSource The source from which the data should be loaded.
 * @param representation The representation which initialization chunk belongs to.
 * @param loadIndex Whether to load index data too.
 * @return A {@link ChunkExtractorWrapper} for the {@code representation}, or null if no
 *     initialization or (if requested) index data exists.
 * @throws IOException Thrown when there is an error while loading.
 * @throws InterruptedException Thrown if the thread was interrupted.
 */
private static ChunkExtractorWrapper loadInitializationData(DataSource dataSource,
    Representation representation, boolean loadIndex)
    throws IOException, InterruptedException {
  RangedUri initializationUri = representation.getInitializationUri();
  if (initializationUri == null) {
    return null;
  }
  ChunkExtractorWrapper extractorWrapper = newWrappedExtractor(representation.format);
  RangedUri requestUri;
  if (loadIndex) {
    RangedUri indexUri = representation.getIndexUri();
    if (indexUri == null) {
      return null;
    }
    // It's common for initialization and index data to be stored adjacently. Attempt to merge
    // the two requests together to request both at once.
    requestUri = initializationUri.attemptMerge(indexUri, representation.baseUrl);
    if (requestUri == null) {
      loadInitializationData(dataSource, representation, extractorWrapper, initializationUri);
      requestUri = indexUri;
    }
  } else {
    requestUri = initializationUri;
  }
  loadInitializationData(dataSource, representation, extractorWrapper, requestUri);
  return extractorWrapper;
}
 

private static void loadInitializationData(DataSource dataSource,
    Representation representation, ChunkExtractorWrapper extractorWrapper, RangedUri requestUri)
    throws IOException, InterruptedException {
  DataSpec dataSpec = new DataSpec(requestUri.resolveUri(representation.baseUrl),
      requestUri.start, requestUri.length, representation.getCacheKey());
  InitializationChunk initializationChunk = new InitializationChunk(dataSource, dataSpec,
      representation.format, C.SELECTION_REASON_UNKNOWN, null /* trackSelectionData */,
      extractorWrapper);
  initializationChunk.load();
}
 

@Override
public DataSpec getDataSpec() {
  checkInBounds();
  Representation representation = representationHolder.representation;
  RangedUri segmentUri = representationHolder.getSegmentUrl(getCurrentIndex());
  Uri resolvedUri = segmentUri.resolveUri(representation.baseUrl);
  String cacheKey = representation.getCacheKey();
  return new DataSpec(resolvedUri, segmentUri.start, segmentUri.length, cacheKey);
}
 

private static void loadInitializationData(DataSource dataSource,
    Representation representation, ChunkExtractorWrapper extractorWrapper, RangedUri requestUri)
    throws IOException, InterruptedException {
  DataSpec dataSpec = new DataSpec(requestUri.resolveUri(representation.baseUrl),
      requestUri.start, requestUri.length, representation.getCacheKey());
  InitializationChunk initializationChunk = new InitializationChunk(dataSource, dataSpec,
      representation.format, C.SELECTION_REASON_UNKNOWN, null /* trackSelectionData */,
      extractorWrapper);
  initializationChunk.load();
}
 

/**
 * Loads initialization data for the {@code representation} and optionally index data then returns
 * a {@link ChunkExtractorWrapper} which contains the output.
 *
 * @param dataSource The source from which the data should be loaded.
 * @param trackType The type of the representation. Typically one of the {@link
 *     com.google.android.exoplayer2.C} {@code TRACK_TYPE_*} constants.
 * @param representation The representation which initialization chunk belongs to.
 * @param loadIndex Whether to load index data too.
 * @return A {@link ChunkExtractorWrapper} for the {@code representation}, or null if no
 *     initialization or (if requested) index data exists.
 * @throws IOException Thrown when there is an error while loading.
 * @throws InterruptedException Thrown if the thread was interrupted.
 */
private static @Nullable ChunkExtractorWrapper loadInitializationData(
    DataSource dataSource, int trackType, Representation representation, boolean loadIndex)
    throws IOException, InterruptedException {
  RangedUri initializationUri = representation.getInitializationUri();
  if (initializationUri == null) {
    return null;
  }
  ChunkExtractorWrapper extractorWrapper = newWrappedExtractor(trackType, representation.format);
  RangedUri requestUri;
  if (loadIndex) {
    RangedUri indexUri = representation.getIndexUri();
    if (indexUri == null) {
      return null;
    }
    // It's common for initialization and index data to be stored adjacently. Attempt to merge
    // the two requests together to request both at once.
    requestUri = initializationUri.attemptMerge(indexUri, representation.baseUrl);
    if (requestUri == null) {
      loadInitializationData(dataSource, representation, extractorWrapper, initializationUri);
      requestUri = indexUri;
    }
  } else {
    requestUri = initializationUri;
  }
  loadInitializationData(dataSource, representation, extractorWrapper, requestUri);
  return extractorWrapper;
}
 

/**
 * Loads initialization data for the {@code representation} and optionally index data then returns
 * a {@link ChunkExtractorWrapper} which contains the output.
 *
 * @param dataSource The source from which the data should be loaded.
 * @param trackType The type of the representation. Typically one of the {@link
 *     com.google.android.exoplayer2.C} {@code TRACK_TYPE_*} constants.
 * @param representation The representation which initialization chunk belongs to.
 * @param loadIndex Whether to load index data too.
 * @return A {@link ChunkExtractorWrapper} for the {@code representation}, or null if no
 *     initialization or (if requested) index data exists.
 * @throws IOException Thrown when there is an error while loading.
 * @throws InterruptedException Thrown if the thread was interrupted.
 */
private static @Nullable ChunkExtractorWrapper loadInitializationData(
    DataSource dataSource, int trackType, Representation representation, boolean loadIndex)
    throws IOException, InterruptedException {
  RangedUri initializationUri = representation.getInitializationUri();
  if (initializationUri == null) {
    return null;
  }
  ChunkExtractorWrapper extractorWrapper = newWrappedExtractor(trackType, representation.format);
  RangedUri requestUri;
  if (loadIndex) {
    RangedUri indexUri = representation.getIndexUri();
    if (indexUri == null) {
      return null;
    }
    // It's common for initialization and index data to be stored adjacently. Attempt to merge
    // the two requests together to request both at once.
    requestUri = initializationUri.attemptMerge(indexUri, representation.baseUrl);
    if (requestUri == null) {
      loadInitializationData(dataSource, representation, extractorWrapper, initializationUri);
      requestUri = indexUri;
    }
  } else {
    requestUri = initializationUri;
  }
  loadInitializationData(dataSource, representation, extractorWrapper, requestUri);
  return extractorWrapper;
}
 

private static void loadInitializationData(DataSource dataSource,
    Representation representation, ChunkExtractorWrapper extractorWrapper, RangedUri requestUri)
    throws IOException, InterruptedException {
  DataSpec dataSpec = new DataSpec(requestUri.resolveUri(representation.baseUrl),
      requestUri.start, requestUri.length, representation.getCacheKey());
  InitializationChunk initializationChunk = new InitializationChunk(dataSource, dataSpec,
      representation.format, C.SELECTION_REASON_UNKNOWN, null /* trackSelectionData */,
      extractorWrapper);
  initializationChunk.load();
}
 

@Override
public DataSpec getDataSpec() {
  checkInBounds();
  Representation representation = representationHolder.representation;
  RangedUri segmentUri = representationHolder.getSegmentUrl(getCurrentIndex());
  Uri resolvedUri = segmentUri.resolveUri(representation.baseUrl);
  String cacheKey = representation.getCacheKey();
  return new DataSpec(resolvedUri, segmentUri.start, segmentUri.length, cacheKey);
}
 

/**
 * Loads initialization data for the {@code representation} and optionally index data then returns
 * a {@link ChunkExtractorWrapper} which contains the output.
 *
 * @param dataSource The source from which the data should be loaded.
 * @param trackType The type of the representation. Typically one of the {@link
 *     com.google.android.exoplayer2.C} {@code TRACK_TYPE_*} constants.
 * @param representation The representation which initialization chunk belongs to.
 * @param loadIndex Whether to load index data too.
 * @return A {@link ChunkExtractorWrapper} for the {@code representation}, or null if no
 *     initialization or (if requested) index data exists.
 * @throws IOException Thrown when there is an error while loading.
 * @throws InterruptedException Thrown if the thread was interrupted.
 */
private static @Nullable ChunkExtractorWrapper loadInitializationData(
    DataSource dataSource, int trackType, Representation representation, boolean loadIndex)
    throws IOException, InterruptedException {
  RangedUri initializationUri = representation.getInitializationUri();
  if (initializationUri == null) {
    return null;
  }
  ChunkExtractorWrapper extractorWrapper = newWrappedExtractor(trackType, representation.format);
  RangedUri requestUri;
  if (loadIndex) {
    RangedUri indexUri = representation.getIndexUri();
    if (indexUri == null) {
      return null;
    }
    // It's common for initialization and index data to be stored adjacently. Attempt to merge
    // the two requests together to request both at once.
    requestUri = initializationUri.attemptMerge(indexUri, representation.baseUrl);
    if (requestUri == null) {
      loadInitializationData(dataSource, representation, extractorWrapper, initializationUri);
      requestUri = indexUri;
    }
  } else {
    requestUri = initializationUri;
  }
  loadInitializationData(dataSource, representation, extractorWrapper, requestUri);
  return extractorWrapper;
}
 

@Override
public DataSpec getDataSpec() {
  checkInBounds();
  Representation representation = representationHolder.representation;
  RangedUri segmentUri = representationHolder.getSegmentUrl(getCurrentIndex());
  Uri resolvedUri = segmentUri.resolveUri(representation.baseUrl);
  String cacheKey = representation.getCacheKey();
  return new DataSpec(resolvedUri, segmentUri.start, segmentUri.length, cacheKey);
}
 

@Override
public DataSpec getDataSpec() {
  checkInBounds();
  Representation representation = representationHolder.representation;
  RangedUri segmentUri = representationHolder.getSegmentUrl(getCurrentIndex());
  Uri resolvedUri = segmentUri.resolveUri(representation.baseUrl);
  String cacheKey = representation.getCacheKey();
  return new DataSpec(resolvedUri, segmentUri.start, segmentUri.length, cacheKey);
}
 

/**
 * Loads initialization data for the {@code representation} and optionally index data then returns
 * a {@link ChunkExtractorWrapper} which contains the output.
 *
 * @param dataSource The source from which the data should be loaded.
 * @param trackType The type of the representation. Typically one of the {@link
 *     com.google.android.exoplayer2.C} {@code TRACK_TYPE_*} constants.
 * @param representation The representation which initialization chunk belongs to.
 * @param loadIndex Whether to load index data too.
 * @return A {@link ChunkExtractorWrapper} for the {@code representation}, or null if no
 *     initialization or (if requested) index data exists.
 * @throws IOException Thrown when there is an error while loading.
 * @throws InterruptedException Thrown if the thread was interrupted.
 */
private static @Nullable ChunkExtractorWrapper loadInitializationData(
    DataSource dataSource, int trackType, Representation representation, boolean loadIndex)
    throws IOException, InterruptedException {
  RangedUri initializationUri = representation.getInitializationUri();
  if (initializationUri == null) {
    return null;
  }
  ChunkExtractorWrapper extractorWrapper = newWrappedExtractor(trackType, representation.format);
  RangedUri requestUri;
  if (loadIndex) {
    RangedUri indexUri = representation.getIndexUri();
    if (indexUri == null) {
      return null;
    }
    // It's common for initialization and index data to be stored adjacently. Attempt to merge
    // the two requests together to request both at once.
    requestUri = initializationUri.attemptMerge(indexUri, representation.baseUrl);
    if (requestUri == null) {
      loadInitializationData(dataSource, representation, extractorWrapper, initializationUri);
      requestUri = indexUri;
    }
  } else {
    requestUri = initializationUri;
  }
  loadInitializationData(dataSource, representation, extractorWrapper, requestUri);
  return extractorWrapper;
}
 

private static void loadInitializationData(DataSource dataSource,
    Representation representation, ChunkExtractorWrapper extractorWrapper, RangedUri requestUri)
    throws IOException, InterruptedException {
  DataSpec dataSpec = new DataSpec(requestUri.resolveUri(representation.baseUrl),
      requestUri.start, requestUri.length, representation.getCacheKey());
  InitializationChunk initializationChunk = new InitializationChunk(dataSource, dataSpec,
      representation.format, C.SELECTION_REASON_UNKNOWN, null /* trackSelectionData */,
      extractorWrapper);
  initializationChunk.load();
}
 

/**
 * Loads initialization data for the {@code representation} and optionally index data then returns
 * a {@link ChunkExtractorWrapper} which contains the output.
 *
 * @param dataSource The source from which the data should be loaded.
 * @param trackType The type of the representation. Typically one of the {@link
 *     com.google.android.exoplayer2.C} {@code TRACK_TYPE_*} constants.
 * @param representation The representation which initialization chunk belongs to.
 * @param loadIndex Whether to load index data too.
 * @return A {@link ChunkExtractorWrapper} for the {@code representation}, or null if no
 *     initialization or (if requested) index data exists.
 * @throws IOException Thrown when there is an error while loading.
 * @throws InterruptedException Thrown if the thread was interrupted.
 */
@Nullable
private static ChunkExtractorWrapper loadInitializationData(
    DataSource dataSource, int trackType, Representation representation, boolean loadIndex)
    throws IOException, InterruptedException {
  RangedUri initializationUri = representation.getInitializationUri();
  if (initializationUri == null) {
    return null;
  }
  ChunkExtractorWrapper extractorWrapper = newWrappedExtractor(trackType, representation.format);
  RangedUri requestUri;
  if (loadIndex) {
    RangedUri indexUri = representation.getIndexUri();
    if (indexUri == null) {
      return null;
    }
    // It's common for initialization and index data to be stored adjacently. Attempt to merge
    // the two requests together to request both at once.
    requestUri = initializationUri.attemptMerge(indexUri, representation.baseUrl);
    if (requestUri == null) {
      loadInitializationData(dataSource, representation, extractorWrapper, initializationUri);
      requestUri = indexUri;
    }
  } else {
    requestUri = initializationUri;
  }
  loadInitializationData(dataSource, representation, extractorWrapper, requestUri);
  return extractorWrapper;
}
 

private static void loadInitializationData(DataSource dataSource,
    Representation representation, ChunkExtractorWrapper extractorWrapper, RangedUri requestUri)
    throws IOException, InterruptedException {
  DataSpec dataSpec = new DataSpec(requestUri.resolveUri(representation.baseUrl),
      requestUri.start, requestUri.length, representation.getCacheKey());
  InitializationChunk initializationChunk = new InitializationChunk(dataSource, dataSpec,
      representation.format, C.SELECTION_REASON_UNKNOWN, null /* trackSelectionData */,
      extractorWrapper);
  initializationChunk.load();
}
 

@Override
public DataSpec getDataSpec() {
  checkInBounds();
  Representation representation = representationHolder.representation;
  RangedUri segmentUri = representationHolder.getSegmentUrl(getCurrentIndex());
  Uri resolvedUri = segmentUri.resolveUri(representation.baseUrl);
  String cacheKey = representation.getCacheKey();
  return new DataSpec(resolvedUri, segmentUri.start, segmentUri.length, cacheKey);
}
 

private static void addSegment(
    long startTimeUs, String baseUrl, RangedUri rangedUri, ArrayList<Segment> out) {
  DataSpec dataSpec =
      new DataSpec(rangedUri.resolveUri(baseUrl), rangedUri.start, rangedUri.length, null);
  out.add(new Segment(startTimeUs, dataSpec));
}
 

private static void addSegment(
    long startTimeUs, String baseUrl, RangedUri rangedUri, ArrayList<Segment> out) {
  DataSpec dataSpec =
      new DataSpec(rangedUri.resolveUri(baseUrl), rangedUri.start, rangedUri.length, null);
  out.add(new Segment(startTimeUs, dataSpec));
}
 

private static void addSegmentsForAdaptationSet(
    DataSource dataSource,
    AdaptationSet adaptationSet,
    long periodStartUs,
    long periodDurationUs,
    boolean allowIncompleteList,
    ArrayList<Segment> out)
    throws IOException, InterruptedException {
  for (int i = 0; i < adaptationSet.representations.size(); i++) {
    Representation representation = adaptationSet.representations.get(i);
    DashSegmentIndex index;
    try {
      index = getSegmentIndex(dataSource, adaptationSet.type, representation);
      if (index == null) {
        // Loading succeeded but there was no index.
        throw new DownloadException("Missing segment index");
      }
    } catch (IOException e) {
      if (!allowIncompleteList) {
        throw e;
      }
      // Generating an incomplete segment list is allowed. Advance to the next representation.
      continue;
    }

    int segmentCount = index.getSegmentCount(periodDurationUs);
    if (segmentCount == DashSegmentIndex.INDEX_UNBOUNDED) {
      throw new DownloadException("Unbounded segment index");
    }

    String baseUrl = representation.baseUrl;
    RangedUri initializationUri = representation.getInitializationUri();
    if (initializationUri != null) {
      addSegment(periodStartUs, baseUrl, initializationUri, out);
    }
    RangedUri indexUri = representation.getIndexUri();
    if (indexUri != null) {
      addSegment(periodStartUs, baseUrl, indexUri, out);
    }
    long firstSegmentNum = index.getFirstSegmentNum();
    long lastSegmentNum = firstSegmentNum + segmentCount - 1;
    for (long j = firstSegmentNum; j <= lastSegmentNum; j++) {
      addSegment(periodStartUs + index.getTimeUs(j), baseUrl, index.getSegmentUrl(j), out);
    }
  }
}
 

public RangedUri getSegmentUrl(long segmentNum) {
  return segmentIndex.getSegmentUrl(segmentNum - segmentNumShift);
}
 

@Override
public RangedUri getSegmentUrl(long segmentNum) {
  return new RangedUri(
      null, chunkIndex.offsets[(int) segmentNum], chunkIndex.sizes[(int) segmentNum]);
}
 

@Override
public RangedUri getSegmentUrl(long segmentNum) {
  return new RangedUri(
      null, chunkIndex.offsets[(int) segmentNum], chunkIndex.sizes[(int) segmentNum]);
}
 

public RangedUri getSegmentUrl(long segmentNum) {
  return segmentIndex.getSegmentUrl(segmentNum - segmentNumShift);
}