【作者】 赵付轩；

【导师】 杨斌；

【作者基本信息】 西南交通大学 ， 信号与信息处理， 2013， 硕士

【摘要】 随着嵌入式技术的不断发展以及无线快速数据通信需求的逐步增长,音视频等多媒体应用的发展也越来越受到人们的重视。人们迫切需要一种费用低廉且高质量的音视频实时通信产品,因此,音视频多媒体的开发具有广阔的发展空间。嵌入式处理器结构的不断发展和改进也为多媒体应用的开发提供了硬件基础。其中比较典型的有TI公司基于ARM+DSP异构双核架构的DM3730处理器,它是专门针对嵌入式系统设计的开放多媒体应用处理器,足以满足现阶段的多媒体通信的需要。而在操作系统方面,采用微内核架构的QNX实时操作系统在嵌入式系统终端领域逐步发展,以其实时性、安全性和可靠性等特点在通信领域占据一席之地。VoIP技术由于其经济、灵活、功能丰富等优点越来越广泛地应用,而其与无线技术结合产生的无线VoIP通信技术是其最重要的发展趋势之一。经过对现有的无线VoIP通信领域相关技术的研究,本文针对实际情况开展了基于ARM+DSP异构双核平台下的音视频实时通信系统的研究与设计。在本系统设计中,采用了模块化的设计思想,完成了达芬奇子系统软件模块、SIP信令控制模块和无线网络传输模块等主要部分组成。该系统可以极大地提高消费者对于嵌入式音视频实时通信的体验。本论文通过深入分析ARM+DSP异构双核处理器架构及其软件开发模式,并结合VoIP音视频多媒体通信技术进行系统设计。系统首先完成了整个系统的方案论证,确定各个部分的技术要点,然后根据ARM+DSP异构双核处理器的硬件特点,选定达芬奇软件框架进行异构双核系统应用程序的开发。依据达芬奇软件框架设计的原则和规范,实现了从底层语音和视频算法库的xDM标准封装到上层音视频实时通信应用程序的开发。将采用微内核架构的QNX嵌入式实时操作系统作为ARM核上的操作系统,通过跨平台的QT界面设计软件完成嵌入式终端操作界面的设计,实现了系统通信的控制和音视频播放,人机交互界面简洁友好。最后,搭建了OpenSIPS服务器并完成了终端上的SIP和RTP协议功能。通过对各个模块的功能和性能进行测试,结果显示整个系统运行良好,达到了当初论文设计的初衷,最终可以通过本系统进行音视频通信。更多还原

【Abstract】 With the development of embedded technology and the gradual growth of the wireless fast data communication need, the multimedia applications of voice and video attract more and more attention. There is an urgent need for a product that can meet the demand for high-quality voice and video communication and can greatly reduce consumer’s cost. Therefore, the development of voice and video multimedia applications has a broad space for development. The continuous development and improvement of the embedded processor architecture lays the hardware foundation for the development of multimedia applications, DM3730processor based on ARM+DSP heterogeneous dual-core architecture is specifically designed for the embedded open multimedia communication. With regard to operating system, the microkernel-based QNX real-time operating system has been gradually developed in the field of embedded terminals and has occupied a place in the field of commnunication because of its characteristics of real-time, security and reliability.VoIP technology is more and more widely applied because of its economic, flexible and feature-rich advantages, combined with wireless technology, wireless VoIP communication technology becomes one of the most important trends in th field. Based on the research of existing wireless VoIP communication technology, this thesis carries out the reaserch on the voice and video communication system based on the heterogeneous dual-core platform for the actual situation. The system adopts the modular design method, including several main parts of the DaVinci software module, the SIP signaling control module and network transmission module and so on. This system can greatly improve the consumer’s experience of embedded voice and video realtime communication.The thesis profoundly analyzes the heterogeneous dual-core processor architecture and its software development model, combined with the VoIP communication technology of the voice and video multimedia, and finally accomplishes the system design. The system completes the entire system demonstration program and determines the main technical points of various parts, and then selects DaVinci software framework for the system development based on the characteristics of heterogeneous dual-core processor hardware, brings about the design from the underlying voice and video algorithm libraries wrapped by the xDM standard to the upper visible VoIP communication application development based on the the DaVinci software design principles and norms. The system adopts the microkernel-based QNX embedded real-time operating system as the operating system on the ARM core, and carries through operating interface development of the terminal development board throught the cross-platform QT interface-designing software to measure up the control of the communication system and voice and video features which is man-machine interface-friendly. Eventually, builds the OpenSIPS server in PC and completes the implementation of SIP protocol module in the terminal development board. Through the system functions and performance tested, the results show that the entire system can be running well, which achieve the original intention of the thesis design. Ultimately, the system can be carried out voice and video communication.更多还原