Android多媒体框架下Stagefright的功能扩展

Function extension for Stagefright of Android media framework

鉴于现有Android系统多媒体框架的局限性,对其进行扩展,使之支持所有常见的多媒体文件格式和编码标准,以满足智能电视等应用需求。采用桥接设计模式,基于FFmpeg创建并添加了适配于Android Stagefright框架的解包装和解码插件,新插件支持的文件格式和编码标准齐全且支持本地文件、http网络多媒体和实时流传输协议(RTSP)多媒体实时流3个信道。相对于传统扩展方案,基于插件的扩展方法使得新多媒体框架移植性好,Java应用程序与原Android完全兼容。

Due to the capacity limitation of Android media framework,it is extended to support all normal containers and codecs of multimedia, aiming to satisfy the demands of Smart TV. Based on bridge pattern and FFmpeg libraries,a container extractor component and a decoder component are created and plugged in,respectively. Every plug-in adapts to the architectures of both Stagefright and Android media framework. The experimental results show that the extended Android can support all normal containers and audio/video codecs; moreover, it can parse multimedia streaming from local file system, http and Real Time Streaming Protocol（RTSP）. Compared to traditional methods, this plug-in based design pattern promises the extended Android with portability and the compatibility with its Java applications.