import com.google.android.exoplayer.chunk.ChunkOperationHolder; //导入依赖的package包/类
public void testSegmentIndexInitializationOnVod() {
  DashChunkSource chunkSource = new DashChunkSource(buildVodMpd(),
      DefaultDashTrackSelector.newVideoInstance(null, false, false), mock(DataSource.class),
      null);
  chunkSource.prepare();
  chunkSource.enable(0);

  List<MediaChunk> queue = new ArrayList<>();
  ChunkOperationHolder out = new ChunkOperationHolder();

  // request first chunk; should get back initialization chunk
  chunkSource.getChunkOperation(queue,  0, out);

  assertNotNull(out.chunk);
  assertNotNull(((InitializationChunk) out.chunk).dataSpec);
}
 

import com.google.android.exoplayer.chunk.ChunkOperationHolder; //导入依赖的package包/类
public HlsSampleSource(HlsChunkSource chunkSource, LoadControl loadControl,
    int bufferSizeContribution, Handler eventHandler, EventListener eventListener,
    int eventSourceId, int minLoadableRetryCount) {
  this.chunkSource = chunkSource;
  this.loadControl = loadControl;
  this.bufferSizeContribution = bufferSizeContribution;
  this.minLoadableRetryCount = minLoadableRetryCount;
  this.eventHandler = eventHandler;
  this.eventListener = eventListener;
  this.eventSourceId = eventSourceId;
  this.pendingResetPositionUs = NO_RESET_PENDING;
  extractors = new LinkedList<>();
  chunkOperationHolder = new ChunkOperationHolder();
}
 

import com.google.android.exoplayer.chunk.ChunkOperationHolder; //导入依赖的package包/类
private static void checkLiveEdgeConsistency(MediaPresentationDescription mpd,
    long liveEdgeLatencyMs, long seekPositionMs, long availableRangeStartMs,
    long availableRangeEndMs, long chunkStartTimeMs, long chunkEndTimeMs) {
  DashChunkSource chunkSource = buildDashChunkSource(mpd, true, liveEdgeLatencyMs);
  List<MediaChunk> queue = new ArrayList<>();
  ChunkOperationHolder out = new ChunkOperationHolder();
  checkLiveEdgeConsistency(chunkSource, queue, out, seekPositionMs, availableRangeStartMs,
      availableRangeEndMs, chunkStartTimeMs, chunkEndTimeMs);
}
 

import com.google.android.exoplayer.chunk.ChunkOperationHolder; //导入依赖的package包/类
@Override
public final void getChunkOperation(List<? extends MediaChunk> queue, long seekPositionUs,
    long playbackPositionUs, ChunkOperationHolder out) {
  evaluation.queueSize = queue.size();
  formatEvaluator.evaluate(queue, playbackPositionUs, formats, evaluation);
  SmoothStreamingFormat selectedFormat = (SmoothStreamingFormat) evaluation.format;
  out.queueSize = evaluation.queueSize;

  if (selectedFormat == null) {
    out.chunk = null;
    return;
  } else if (out.queueSize == queue.size() && out.chunk != null
      && out.chunk.format.id.equals(evaluation.format.id)) {
    // We already have a chunk, and the evaluation hasn't changed either the format or the size
    // of the queue. Do nothing.
    return;
  }

  int nextChunkIndex;
  if (queue.isEmpty()) {
    nextChunkIndex = streamElement.getChunkIndex(seekPositionUs);
  } else {
    nextChunkIndex = queue.get(out.queueSize - 1).nextChunkIndex;
  }

  if (nextChunkIndex == -1) {
    out.chunk = null;
    return;
  }

  boolean isLastChunk = nextChunkIndex == streamElement.chunkCount - 1;
  String requestUrl = streamElement.buildRequestUrl(selectedFormat.trackIndex,
      nextChunkIndex);
  Uri uri = Uri.parse(baseUrl + '/' + requestUrl);
  Chunk mediaChunk = newMediaChunk(selectedFormat, uri, null,
      extractors.get(Integer.parseInt(selectedFormat.id)), dataSource, nextChunkIndex,
      isLastChunk, streamElement.getStartTimeUs(nextChunkIndex),
      isLastChunk ? -1 : streamElement.getStartTimeUs(nextChunkIndex + 1), 0);
  out.chunk = mediaChunk;
}
 

import com.google.android.exoplayer.chunk.ChunkOperationHolder; //导入依赖的package包/类
private void checkLiveEdgeLatency(DashChunkSource chunkSource, List<MediaChunk> queue,
    ChunkOperationHolder out, long seekPositionMs, long seekRangeStartMs, long seekRangeEndMs,
    long chunkStartTimeMs, long chunkEndTimeMs) {
  chunkSource.getChunkOperation(queue, seekPositionMs * 1000, 0, out);
  TimeRange seekRange = chunkSource.getSeekRange();

  assertNotNull(out.chunk);
  checkSeekRange(seekRange, seekRangeStartMs * 1000, seekRangeEndMs * 1000);
  assertEquals(chunkStartTimeMs * 1000, ((MediaChunk) out.chunk).startTimeUs);
  assertEquals(chunkEndTimeMs * 1000, ((MediaChunk) out.chunk).endTimeUs);
}
 

import com.google.android.exoplayer.chunk.ChunkOperationHolder; //导入依赖的package包/类
@Override
public final void getChunkOperation(List<? extends MediaChunk> queue, long seekPositionUs,
    long playbackPositionUs, ChunkOperationHolder out) {
  evaluation.queueSize = queue.size();
  if (evaluation.format == null || !lastChunkWasInitialization) {
    evaluator.evaluate(queue, playbackPositionUs, formats, evaluation);
  }
  Format selectedFormat = evaluation.format;
  out.queueSize = evaluation.queueSize;

  if (selectedFormat == null) {
    out.chunk = null;
    return;
  } else if (out.queueSize == queue.size() && out.chunk != null
      && out.chunk.format.id.equals(selectedFormat.id)) {
    // We already have a chunk, and the evaluation hasn't changed either the format or the size
    // of the queue. Leave unchanged.
    return;
  }

  Representation selectedRepresentation = representations.get(selectedFormat.id);
  Extractor extractor = extractors.get(selectedRepresentation.format.id);

  RangedUri pendingInitializationUri = null;
  RangedUri pendingIndexUri = null;
  if (extractor.getFormat() == null) {
    pendingInitializationUri = selectedRepresentation.getInitializationUri();
  }
  if (!segmentIndexes.containsKey(selectedRepresentation.format.id)) {
    pendingIndexUri = selectedRepresentation.getIndexUri();
  }
  if (pendingInitializationUri != null || pendingIndexUri != null) {
    // We have initialization and/or index requests to make.
    Chunk initializationChunk = newInitializationChunk(pendingInitializationUri, pendingIndexUri,
        selectedRepresentation, extractor, dataSource, evaluation.trigger);
    lastChunkWasInitialization = true;
    out.chunk = initializationChunk;
    return;
  }

  int nextSegmentNum;
  DashSegmentIndex segmentIndex = segmentIndexes.get(selectedRepresentation.format.id);
  if (queue.isEmpty()) {
    nextSegmentNum = segmentIndex.getSegmentNum(seekPositionUs);
  } else {
    nextSegmentNum = queue.get(out.queueSize - 1).nextChunkIndex;
  }

  if (nextSegmentNum == -1) {
    out.chunk = null;
    return;
  }

  Chunk nextMediaChunk = newMediaChunk(selectedRepresentation, segmentIndex, extractor,
      dataSource, nextSegmentNum, evaluation.trigger);
  lastChunkWasInitialization = false;
  out.chunk = nextMediaChunk;
}