Android平台下流媒体播放器的设计与应用

发布时间：2018-10-14 12:14

【摘要】：随着流媒体技术、移动通信技术和嵌入式技术的迅速发展,已经客观上改变了人们的生活和工作方式。传统的基于PC的流媒体交互方式已不能满足人们多元化的需求方式；基于IP流媒体技术的嵌入式流媒体智能终端因其实时性、可靠性和便携性而受到用户青睐,成为研究的热点,拥有巨大的市场前景。然而,当前市场上嵌入式流媒体播放器普遍存在以下三方面的问题：第一,由于流媒体播放时对带宽的高占有特性,使得传统的C/S方式很容易导致服务器负载过重,成为系统瓶颈,限制了系统的服务能力；第二,采用专用的编解码芯片虽然能保证流媒体播放时的实时性和流畅性,但系统整体灵活性较差,不利于算法升级,且价格昂贵、性价比不高；第三,采用纯软件方法虽然易于系统升级和移植,但系统实时性较差。本文在介绍了流媒体技术、基于PC的流媒体播放器发展过程和优缺点、当前嵌入式流媒体播放器国内外研究现状以及课题平台的选择后,概述了Android系统结构、Android应用程序框架和FFMPEG编解码库。概述了实时传输协议RTP、实时传输控制协议RTCP、实时流协议RTSP、P2P技术、MPEG-4编码原理和过程。接着针对当前嵌入式流媒体播放器中存在的性能、成本和算法易升级性等问题,本文提出了一种层次化、模块化的硬件加软件的设计方案,该方案以具有较强多媒体处理能力的S3C6410为微处理器,以基于Linux的、目前较为流行的Android系统为依托,根据Android OS系统特点对FFMPEG进行裁剪、优化并移植到Android平台下。同时,本文针对嵌入式硬件终端特性,将P2P思想引入到嵌入式流媒体终端中,对终端缓存空间重新设计,实现终端设备节点之间流媒体数据的直接传输,并详细阐述了缓存空间的管理机制及估算方法。最后,本文对系统进行了功能测试,测试结果表明该设计简单高效,并对下一步工作提出了建议。
[Abstract]:With the rapid development of streaming media technology, mobile communication technology and embedded technology, people's life and working style have been changed objectively. The traditional interactive mode of streaming media based on PC can not meet the diverse needs of people, and the intelligent terminal of embedded streaming media based on IP streaming media technology is favored by users because of its real-time, reliability and portability. Become the research hot spot, has the huge market prospect. However, there are generally three problems in the embedded streaming media player in the market. Firstly, due to the high bandwidth of streaming media player, the traditional C / S mode can easily lead to the overloading of the server. It becomes the bottleneck of the system, which limits the service ability of the system. Secondly, the use of a dedicated codec chip can ensure the real-time and fluency of streaming media playback, but the overall flexibility of the system is poor, which is not conducive to algorithm upgrading, and expensive. Third, the pure software method is easy to upgrade and transplant, but the real-time system is poor. This paper introduces the streaming media technology, the development process, advantages and disadvantages of streaming media player based on PC, the current domestic and foreign research status of embedded streaming media player and the choice of the subject platform. The Android system structure, Android application framework and FFMPEG codec library are summarized. This paper introduces the real time transmission protocol (RTP,), the real time transmission control protocol (RTCP,), the real time stream protocol (RTSP,P2P), the principle and process of MPEG-4 coding. Then, aiming at the problems of performance, cost and algorithm easy to upgrade in the current embedded streaming media player, this paper proposes a hierarchical, modular design of hardware and software. This scheme is based on S3C6410, which has strong multimedia processing ability, and is based on the popular Android system based on Linux. According to the characteristics of Android OS system, the FFMPEG is clipped, optimized and transplanted to Android platform. At the same time, aiming at the characteristic of embedded hardware terminal, this paper introduces P2P idea into embedded streaming media terminal, redesigns the buffer space of terminal, and realizes the direct transmission of streaming media data between terminal device nodes. The management mechanism and estimation method of cache space are described in detail. Finally, the function of the system is tested. The test results show that the design is simple and efficient, and some suggestions for the next work are put forward.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TP368.1;TN919.8

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