MediaStore

对API类，字段讲解含义比较好的blog : http://www.cnblogs.com/nanshihui/p/3619856.html

seekTo方法精确定位到指定帧： http://blog.csdn.net/u010607906/article/details/50496595 http://www.jianshu.com/p/f51b2febcfd2