本文研究的主要内容,是设计一种廉价的、方便部署的、高扩展性的音视频监控系统。该系统基于 Android 嵌入式设备,以 IP 网络作为传输媒介,支持当前主流国际规范和通信协议。本文的任务是对该监控系统做出详细的需求分析,确定系统架构,给出详细设计方案,对核心技术进行分析,并列举系统实现的关键代码,最后对系统实现进行验证。
6. DESIGN AND IMPLEMENTATION OF AUDIO AND VIDEO
REAL-TIME MONITORING SYSTEM BASED ON
ANDROID DEVICES
ABSTRACT
Due to security issues, there are many monitoring systems in our life. They are
widely used in many fields, such as triffic, power, communication, banking, factory,
mine, venues, forest fire prevention, long distance command, and even family security.
Generally, special transport equipments and network must be deployed for traditional
monitoring systems. It costs much and is hard to transport to a long distance.
On the other hand, since 3G becomes overall popular in China, data-carrying
capacity of the communication network has made significant progress. As a result, a
variety of smart phones, tablet computers and other equipments quickly get the
popularization. Android devices are the most typical case. They quickly occupied the
market in every corner. Android is much suitable for being civil intelligent terminal
device's operating system as it is low-priced, open, compatible and efficient.
This paper studies on a monitoring system which captures media by
Android-device and transports them over internet and 3G communication network.
This system features as inexpensive, remote control, simple installation and
independent from exclusive network devices. If the image quality is not the most
important factor, traditional civil monitoring system can absolutely be replaced with
this system.
In this paper, the application scenarios of the system is analyzed, technical
objectives and norms are given and the system is planned to develop with a
hierarchical model. It is developed bottom-up after technical model is chosen and
interfaces between layers are defined. International standards are used and
well-known codecs and transport protocols are implemented overall to make the
system compatible and flexible. This system is composed of both Android-based
monitoring terminal and streaming server. To monitor, one can simply use a streaming
player which support RTSP, e.g. Real Player. As well, a customized client can be
developed for this. This system uses many technologies, such as FFmpeg transplant,
audio and video capture on Android, H.263 codec, G.723 codec, RTP/RTCP
(Real-time Transport Protocol/Real Time Control Protocol), RTSP/SDP (Real-Time
Streaming Protocol/Session Description Protocol), UPnP (Universal Plug and Play),
etc.
KEY WORDS:Android, Codec, Real-time monitoring, Streaming server