The Analysis and Research of IPTV Set-top Box System. Fangyan Bai 1, Qi Sun 2

Transcription

1 Applied Mechanics and Materials Online: ISSN: , Vols , pp doi: / Trans Tech Publications, Switzerland The Analysis and Research of IPTV Set-top Box System Fangyan Bai 1, Qi Sun 2 School of mechanical engineering, Anhui university of science and technology, Huainan city, China, austbfy@163.com, 2 sunqi@aust.edu.cn Keywords: IPTV, Protocol Standard, Set-top Box, ST7109 Abstract: IPTV has great value for media provider and consumer interaction, and it also can be configured in a number of functions to complete the user selection. This paper is mainly to introduce the key technology and protocol standards of IPTV related theory and IPTV set-top box. On the basis of this study high-definition IPTV system based on ST-7109 is designed. On the ST-7109 platform, the embedded terminal broadcast of the streaming media is realized by using embedded Linux software. The text also researches ST7109 module internal resources, as well as designs good source decoder hardware circuit on the base of peripheral interface circuit of the function; it also finishes the design and analysis surround set-top box software, function module, real-time operating system Linux. Introduction Information and communication technology development has brought national information strategy to vigorously push forward, and with the arrival of the new era, the development of the IP technology is very rapid, and our country internet broadband technology has been greatly developed, and the Internet in the development process begins to mix together with some traditional industry, thereby a lot of new development power are formed, for example the emergence of network television ( IPTV ) during this period. IPTV is an important milepost for media services and consumer interaction, it can conduct extensive selection of multimedia services, and adapt multimedia services according to the user's choice, so it can be said, this will greatly enhance the user's quality of life and the departments of work efficiency. For users and enterprises, it is a win-win situation. It has great significance both for the development and research. This text studies on the IPTV terminal set-top box. Key Technology of IPTV and Protocol Standards IPTV can use different physical network to send video program content and signal to a user effectively in the form of IP packet safety, it is an advanced system integration technology. Its basic forms are: content distribution and digital copyright technology, audio and video codec, broadband access technology, IP broadcast, multicast technology. Streaming media protocols standards: When IPTV technology platform is selected, the platform must satisfy two conditions: firstly it has a fit and high performance audio and video coding standards, and second it can process the impact caused by both of audio and video coding standards in the content delivery networks, streaming media and digital rights management. All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of Trans Tech Publications, (ID: , Pennsylvania State University, University Park, USA-06/03/16,06:58:05)

2 Applied Mechanics and Materials Vols IPTV Set-top Box Architecture IPTV set-top box basic system structure can be divided into front-end devices, networks, and the receiving end three parts, each part consists of a number of key equipment, while the completion of appropriate basic functionality, also to ensure the smooth operation of IPTV TV business. On one hand, The box receives IP network port data stream through Ethernet interface, after decode, descramble, demodulation, and then make the video and audio D/A convert, they will become the analog signal that can be recognized by the TV, and be transmitted to the TV. On the other hand, it receives control commands from the TV and send to the IP network server-side. The primary function of IP network server is to send the appropriate data to the client according to the TV instructions received by the box. To complete the function of the system, it needs the cooperation of IPTV set-top box, IP server and TV communication. Set-top box system architecture consists of three independent subsystems: TV Unit, PC unit and conditional access (encryption systems, CA) units. TV subsystem is composed of tuner and video decoders, which used to handle digital streaming information; CA subsystem service providers with control capabilities, users can achieve close monitoring and management, to know when the user watches what programmes; PC subsystem are largely modular designs, STB designers can increase or decrease depending on the needs of the components in the system, since IPTV STB's goal is to provide Internet services, its PC systems have agreed to provide TCP/IP stack, and has better stocks. At present many receiving end adopt motor plus STB mode, this mode requires the STB receiving data stream down from the Internet, and then transmits them to the TV playback after processing. Realization of IPTV Set-top Box Hardware In order to support the dissemination of video content within the home network, the ST-7109 built a high-speed Ethernet interface, make it the central component of family network center consist of home appliances such as digital cable, satellite, terrestrial and IP set-top boxes, digital video recorders, DVD recorders, home gateway and Media Server. In order to protect the important content and services, ST-7109 integrates ST's fourth-generation security technologies, as a series of reliable hardware platform, flexible security encryption systems can be achieved. This technique allows ST-7109 to support Windows Media DRM10 and safety video processor (SVP) standard, the two standard to allow consumer equipment and transmission of digital rights. ST-7109 is able to meet the current market for Blue-Ray (BR) DVD requirements, the product supports all the audio and video standard and emerging content copy protection technology. The ST-7109 also includes a continuous composite and processing from three different program transmission streams fusion device. Fig.1 is the ST7109 for IPTV the solution. Flash HDD DDR IR Tx/Rx SATA Audio Ethernet PHY ST7109 RS232 RGB/YPbPr HDMI Smart HDD card (expansion expansion) Fig1. ST7109 used for IPTV solutions

3 2900 Advances in Civil Engineering II Implementation of IPTV Set-top Box Software 1. Design and Development of BootLoader Because of the excellent features of Linux operating system, it becomes a leader in embedded system. Linux operating system is applied in the text. BootLoader is software before running the initial piece of code. It enables the system to reach best state from the device initialization to build map, creates the most suitable environment for operating system. In embedded systems, kernel and file system map run directly from the storage device, which is divided into stage1, stage2, etc, but generally it is stored in the stage1, and is used by the assembly language to complete objectives and tasks. Because it will affect the running speed, it is loaded into RAM to reduce the impact on the speed. The stage2 and stage1 functions are different. The former is the function of dealing with complex procedures, while the latter is the function of simple procedures. First of all, the stage1 task is to set hardware device to the primary stage, and interrupt mask, to set CPU speed and time frequency and RAM initialize. After initialization LED display that system status is true or false; CPU instructions or data records will be closed and records will be provided to the stage2; function pointers are set, and then go to the entry of the Stage2. Second, the stage2 's main function is download Linux kernel to the target Board by serial. Including the following steps: A. Initializing hardware device at this stage. Usually it includes initializing one serial port at least, so as to I/O output information output to end-users, initializing timers and so on. B. Detecting of the system's memory map. So-called memory map is the entire 4GB in which physical address space is allocated to addressing system RAM modules. C. Loading the kernel image and root file system from the Flash to RAM. Including two aspects: the first is memory range occupied by the kernel image; the second is the memory occupied by the root file system. When planning the memory layout, the major consideration is the base address and map size. D. Setting the kernel boot parameters. E. Calling the kernel. That bootloader calls the Linux kernel s method is to jump directly where the first instruction is. 2. Electronic Interface Menu As part of the user interface menu, a tree menu structure is designed. Diagram of the menu is shown in Fig.2. Fig2. Menu structure Fig3. DirectFB image display process

4 Applied Mechanics and Materials Vols In the design of specific procedures, each node in the tree menu is described by a structure variable. Menu establishment process is to operate the two structure variables which be used to describe menu node. 3. Graphical User Interface (GUI) The design adopted in the text is to show the decoded video and the playing technology is DirectFB. As a whole, in the design of embedded system, DirectFB provides hardware, input devices, and integrated window systems, and supports multiple display layers technology. The technique is used exclusively for completing hardware acceleration, improving the hardware to support image algorithm, while using minimal resource allocation to obtain the highest hardware acceleration performance. DirectFB technology is used in the design of menu display in this text use. It is shown in Fig.3. Conclusions This text is completed based on the design and development process of ST7109 IPTV set-top boxes. The design uses the mature systems of chip ST7109 as IPTV set-top box framework. The architecture is used to complete the whole IPTV set-top box design work (IPTV set-top box software and hardware). References: [1] Wang Xiang-hai, Cong Zhi-huan, Fang Ling-ling1: Advances in IPTV system architecture and streaming media technology[j]. Journal on Communications. Vol.33 No. 4 ( 2012).p1-9 [2] Wang Tianmiao: The design and example development of embedded systems [M]. Beijing: Tsinghua University Press(2010).p4-9 [3] Li Shanping, Liu Wenfeng, Wang Huanlong: Linux and embedded system [M]. Beijing: Tsinghua University Press, (2006).p52-67 [4] Shen Xin: IPTV set-top box design and implementation of software systems [D]. Beijing University. (2008) [5] Zhang Zhengqing, Hu Yuan:IPTV business features and related technologies [J]. a modern telecommunications technology.(2009.5) [6] Hu Bo, Wang Hongyuan: Flash Memory File System for Digital TV STB [J]. TV technology. (2007.9).p33-35 [7] Han Yun, Chen Zu Jue: H.264,VC-l and AVS video coding research [J]. TV technology. (2007.2).p6-9 [8] Li Zhiguo: Business model is the biggest bottleneck IPTV [J]. China Information World, (2007): p42-45

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