说明：  android camera的框架分析，android下面比较框架基本上都是客户端服务器的架构，客户端提供接口给上层使用，服务器端实现具体的方法，包括与底层的接口。
(android camera' s frame analysis, android following comparative framework basically client-server architecture, the client provides an interface to the upper use server-side implementation of specific methods, including the underlying interface.)