public IDanmakus getDanmakus() {
        if (mDanmakus != null)
            return mDanmakus;
        mContext.mDanmakuFactory.resetDurationsData();
        mDanmakus = parse();
        releaseDataSource();
        mContext.mDanmakuFactory.updateMaxDanmakuDuration();
        return mDanmakus;
    }
decide the speed of scroll-danmakus
@return
app/src/main/java/com/sunnyweather/android/flame/master/flame/danmaku/danmaku/parser/BaseDanmakuParser.java