基于Android系统的可视电话中的图像采集与传输

发布时间：2018-08-07 16:21

【摘要】：可视电话以其直观有效的沟通方式,相对于传统电话而言,极大的丰富了人们的沟通。宽带互联网技术的广泛应用及嵌入式技术的飞速发展,更加提升了人们对于视频通信系统用户体验的要求。这些需求使得人们不得不更加专注于大力研发各类相关的技术,例如用于捕获更加高质量的高清视频的采集技术、用以提高视频数据压缩率的视频编解码技术。本论文以S5pv210开发板为开发硬件平台,研究在Android系统上实现视频通信等实际需求中所需要的视频图像采集技术、视频数据发送的相关协议以及它们代码实现。本论文将通过开发一个Android应用程序来实现以上功能,可以将本应用安装在任何带有摄像头的Android设备上,如平板电脑、智能手机、智能电视机顶盒等。本论文在对相关通信协议及编码标准进行研究后,依照协议流程实现了Android系统上RTSP视频流服务器的建立。如何在Android设备上实现RTSP服务器,建立RTSP会话,阻塞并等待用户发来的控制信息,然后由服务器端返回正确的响应报文及视频数据包是本次研究的重点。实现这些功能需要实现连接建立过程中所依赖的RTP协议。同时运用多线程处理的方式,实现了从摄像头获取数据并打包发送这一过程。通过相应的Android应用开发,完成了包括应用界面的设计和相关代码及方法的调用等方面的工作,最终完成了RTSP视频流服务器建立的整个过程。作为发送视频流数据之前的准备工作,还依照H.264编码标准及MP4文件的格式结构,完成了RTSP服务器所需发送的视频参数集的提取。本论文所研究的主要内容在可视电话的软件架构的层次中位于中间层,通过调用Android系统的API实现控制摄像头获取视频数据,并开启另一线程,通过检测NALU头的方式将数据分割,并经由RTP协议传送。本研究内容可为多种高级应用提供基础服务,不仅限于建立双线可视电话,还可用于家庭监护、视频会议等相关高级应用的搭建。
[Abstract]:Compared with traditional telephone, videophone enriches people's communication greatly because of its direct and effective communication. With the wide application of broadband Internet technology and the rapid development of embedded technology, the requirement of user experience in video communication system has been raised. These requirements force people to devote more attention to the research and development of various related technologies, such as the capture technology for capturing more high-quality high-definition video, and the video coding and decoding technology to improve the compression rate of video data. This paper takes the S5pv210 development board as the development hardware platform, studies the video image acquisition technology needed to realize the video communication and other practical requirements on the Android system, the related protocols of the video data transmission and their code implementation. This paper will develop a Android application to achieve the above functions, which can be installed on any Android device with camera, such as tablet computer, smart phone, smart TV set-top box and so on. In this paper, after researching the related communication protocols and coding standards, the establishment of RTSP video streaming server on Android system is realized according to the protocol flow. How to implement the RTSP server on the Android device, establish the RTSP session, block and wait for the control information from the user, and then return the correct response message and video packet from the server is the key point of this research. The implementation of these functions requires the implementation of the RTP protocol that is relied upon during the connection establishment process. At the same time, multithread processing is used to realize the process of acquiring data from the camera and packaging and sending it. Through the corresponding Android application development, including the design of the application interface and the related code and method call, the whole process of establishing the RTSP video stream server is completed. As the preparation work before sending video stream data, according to H.264 coding standard and format structure of MP4 file, the extraction of video parameter set required by RTSP server is completed. The main content of this paper lies in the middle layer of the software architecture of videophone. The video data is obtained by calling the API control camera of Android system, and another thread is opened, and the data is segmented by detecting the NALU header. And transmitted by RTP protocol. The content of this study can provide basic services for many advanced applications, not only for the establishment of dual-line videophone, but also for the construction of related advanced applications such as family monitoring, video conferencing and so on.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN949.28;TN919.81

【参考文献】