import com.google.android.exoplayer2.extractor.mp3.Mp3Extractor; //导入依赖的package包/类
@Override
public synchronized Extractor[] createExtractors() {
  Extractor[] extractors = new Extractor[FLAC_EXTRACTOR_CONSTRUCTOR == null ? 11 : 12];
  extractors[0] = new MatroskaExtractor(matroskaFlags);
  extractors[1] = new FragmentedMp4Extractor(fragmentedMp4Flags);
  extractors[2] = new Mp4Extractor();
  extractors[3] = new Mp3Extractor(mp3Flags);
  extractors[4] = new AdtsExtractor();
  extractors[5] = new Ac3Extractor();
  extractors[6] = new TsExtractor(tsMode, tsFlags);
  extractors[7] = new FlvExtractor();
  extractors[8] = new OggExtractor();
  extractors[9] = new PsExtractor();
  extractors[10] = new WavExtractor();
  if (FLAC_EXTRACTOR_CONSTRUCTOR != null) {
    try {
      extractors[11] = FLAC_EXTRACTOR_CONSTRUCTOR.newInstance();
    } catch (Exception e) {
      // Should never happen.
      throw new IllegalStateException("Unexpected error creating FLAC extractor", e);
    }
  }
  return extractors;
}
 

import com.google.android.exoplayer2.extractor.mp3.Mp3Extractor; //导入依赖的package包/类
@Override
public synchronized Extractor[] createExtractors() {
  Extractor[] extractors = new Extractor[FLAC_EXTRACTOR_CONSTRUCTOR == null ? 11 : 12];
  extractors[0] = new MatroskaExtractor(matroskaFlags);
  extractors[1] = new FragmentedMp4Extractor(fragmentedMp4Flags);
  extractors[2] = new Mp4Extractor(mp4Flags);
  extractors[3] = new Mp3Extractor(mp3Flags);
  extractors[4] = new AdtsExtractor();
  extractors[5] = new Ac3Extractor();
  extractors[6] = new TsExtractor(tsMode, tsFlags);
  extractors[7] = new FlvExtractor();
  extractors[8] = new OggExtractor();
  extractors[9] = new PsExtractor();
  extractors[10] = new WavExtractor();
  if (FLAC_EXTRACTOR_CONSTRUCTOR != null) {
    try {
      extractors[11] = FLAC_EXTRACTOR_CONSTRUCTOR.newInstance();
    } catch (Exception e) {
      // Should never happen.
      throw new IllegalStateException("Unexpected error creating FLAC extractor", e);
    }
  }
  return extractors;
}
 

import com.google.android.exoplayer2.extractor.mp3.Mp3Extractor; //导入依赖的package包/类
private void prepareAudioFile(File file, long startPositionMs) {
    Uri fileUri = Uri.fromFile(file);

    DataSource.Factory dataSourceFactory = new FileDataSourceFactory();
    DefaultExtractorsFactory extractorsFactory = new DefaultExtractorsFactory();
    extractorsFactory.setMp3ExtractorFlags(Mp3Extractor.FLAG_ENABLE_CONSTANT_BITRATE_SEEKING);
    MediaSource source = new ExtractorMediaSource(
            fileUri, dataSourceFactory, extractorsFactory, null, null);

    exoPlayer.seekTo(startPositionMs);
    exoPlayer.prepare(source, false, true);
}
 

import com.google.android.exoplayer2.extractor.mp3.Mp3Extractor; //导入依赖的package包/类
/**
 * Sets flags for {@link Mp3Extractor} instances created by the factory.
 *
 * @see Mp3Extractor#Mp3Extractor(int)
 * @param flags The flags to use.
 * @return The factory, for convenience.
 */
public synchronized DefaultExtractorsFactory setMp3ExtractorFlags(@Mp3Extractor.Flags int flags) {
  mp3Flags = flags;
  return this;
}