getCodecsForVariantTag_(tag) {
    let codecsString = tag.getAttributeValue('CODECS') || '';

    this.codecInfoInManifest_ = codecsString.length > 0;

    if (!this.codecInfoInManifest_ && !this.config_.hls.disableCodecGuessing) {
      // These are the default codecs to assume if none are specified.
      const defaultCodecsArray = [];

      if (!this.config_.disableVideo) {
        defaultCodecsArray.push(this.config_.hls.defaultVideoCodec);
      }
      if (!this.config_.disableAudio) {
        defaultCodecsArray.push(this.config_.hls.defaultAudioCodec);
      }

      codecsString = defaultCodecsArray.join(',');
    }

    // Strip out internal whitespace while splitting on commas:
    /** @type {!Array<string>} */
    const codecs = codecsString.split(/\s*,\s*/);

    return shaka.media.SegmentUtils.codecsFiltering(codecs);
  }
Get the codecs from the 'EXT-X-STREAM-INF' tag.

@param {!shaka.hls.Tag} tag
@return {!Array<string>} codecs
@private