createLcevcDec_(config, isDualTrack) {
    if (this.lcevcDec_ == null) {
      this.lcevcDec_ = new shaka.lcevc.Dec(
          /** @type {HTMLVideoElement} */ (this.video_),
          this.lcevcCanvas_,
          config,
          isDualTrack,
      );
      if (this.mediaSourceEngine_) {
        this.mediaSourceEngine_.updateLcevcDec(this.lcevcDec_);
      }
    }
  }
Create a shaka.lcevc.Dec object
@param {shaka.extern.LcevcConfiguration} config
@param {boolean} isDualTrack
@private