import com.google.android.exoplayer.upstream.FileDataSource; //导入依赖的package包/类
@Override
public void buildRenderers(ExoPlayerHelper player) {
    Allocator allocator = new DefaultAllocator(BUFFER_SEGMENT_SIZE);

    // Build the video and audio renderers.
    Extractor webmExtractor = new WebmExtractor();
    Extractor mp4Extractor = new Mp4Extractor();
    DataSource dataSource = new FileDataSource();
    ExtractorSampleSource sampleSource = new ExtractorSampleSource(uri, dataSource, allocator,
            BUFFER_SEGMENT_COUNT * BUFFER_SEGMENT_SIZE, webmExtractor, mp4Extractor);
    MediaCodecVideoTrackRenderer videoRenderer = new MediaCodecVideoTrackRenderer(context,
            sampleSource, MediaCodecSelector.DEFAULT, MediaCodec.VIDEO_SCALING_MODE_SCALE_TO_FIT, 5000, player.getMainHandler(),
            player, 50);
    MediaCodecAudioTrackRenderer audioRenderer = new MediaCodecAudioTrackRenderer(sampleSource, MediaCodecSelector.DEFAULT,
            null, true, player.getMainHandler(), player);
    TrackRenderer textRenderer = new TextTrackRenderer(sampleSource, player,
            player.getMainHandler().getLooper());

    // Invoke the callback.
    TrackRenderer[] renderers = new TrackRenderer[ExoPlayerHelper.RENDERER_COUNT];
    renderers[ExoPlayerHelper.TYPE_VIDEO] = videoRenderer;
    renderers[ExoPlayerHelper.TYPE_AUDIO] = audioRenderer;
    renderers[ExoPlayerHelper.TYPE_TEXT] = textRenderer;
    player.onRenderers(renderers, null);
}
 

import com.google.android.exoplayer.upstream.FileDataSource; //导入依赖的package包/类
private void loadDrmInitData(Representation representation) throws IOException {
    Uri initFile = representation.getInitializationUri().getUri();
    
    FileDataSource initChunkSource = new FileDataSource();
    DataSpec initDataSpec = new DataSpec(initFile);
    int trigger = 2;
    ChunkExtractorWrapper extractorWrapper = new ChunkExtractorWrapper(new FragmentedMp4Extractor());
    InitializationChunk chunk = new InitializationChunk(initChunkSource, initDataSpec, trigger, format, extractorWrapper);
    try {
        chunk.load();
    } catch (InterruptedException e) {
        Log.d(TAG, "Interrupted!", e);
    }
    if (!chunk.isLoadCanceled()) {
        drmInitData = chunk.getDrmInitData();
    }
    
    if (drmInitData != null) {
        DrmInitData.SchemeInitData schemeInitData = OfflineDrmManager.getWidevineInitData(drmInitData);
        if (schemeInitData != null) {
            widevineInitData = schemeInitData.data;
        }
    }
}
 

import com.google.android.exoplayer.upstream.FileDataSource; //导入依赖的package包/类
/**
 * Constructs an instance with default {@link DataSource} and {@link DataSink} instances for
 * reading and writing the cache. The sink is configured to fragment data such that no single
 * cache file is greater than maxCacheFileSize bytes.
 */
public CacheDataSource(Cache cache, DataSource upstream, boolean blockOnCache,
    boolean ignoreCacheOnError, long maxCacheFileSize) {
  this(cache, upstream, new FileDataSource(), new CacheDataSink(cache, maxCacheFileSize),
      blockOnCache, ignoreCacheOnError, null);
}