录象机定时集成电路的分析与设计

简要地介绍了松下ＮＶ－ＨＤ１００／ＨＤ８２／ＳＤ５０录象机控制系统的构成，通过对松下录象机的定时器电路输入输出信号时序关系的测试和分析，提出了录象机控制 定地器电路的功能和定时器集成电路设计过程中应当考虑和注意的问题。     

FLC and VLC coding for professional digital HDTV recording — Application to D1-like recorders

Digital recording is a key issue for HDTV studio applications. However, digital baseband recording of HDTV has some drawbacks, for example, high tape consumption and the fact that 1.2 Gbit/s recorders are close to technology limits. Bit-rate reduction techniques allow these difficulties to be overcome. This paper deals with two different approaches for picture coding suitable for professional HDTV recording, with special attention paid to compatibility with existing D1 VCRs (video cassettes recorder). The first approach considers that the behavior of a recorder requires FLC (fixed length code) data as opposed to VLC (variable length code) data, and the second approach supposes that the problems generated by use of VLC data can be overcome with preanalysis and extra error protection strategies. Comparisons of efficiency are presented including multiple copying.     

VHS家用录象机走带系统的数学分析

本文用数学的方法详细推导了家用录象机走带系统各参数之间的关系,并依次编制了计算机程序。     

一种嵌入式流媒体播放器VCR控制的设计与实现

提出一种嵌入式流媒体播放器VCR控制的设计和实现方案，主要对控制文件的生成方法、系统工作原理、网络传输机制、QoS控制机制进行介绍。     

传统磁记录摄像机实施“磁改非”的技术价值分析

本世纪初,新一代使用数字芯片作为记录介质的摄像机欣然问世,就象本世纪初以来数字照相机以其绝对优势和惊人的速度在及短的时间内就淘汰了传统的胶片式照相机一样,这种全数字化记录模式的摄像机大有取代以磁带为记录介质的传统摄像机的趋势。然而,全国总数量超百万台、总价值愈数千亿元的磁记录摄像机目前仍在使用高峰期,短时间内淘汰是不现实的。那么研究、推广使用一种有效的方法、以很小的投入使传统磁记录摄像机得以技术提升并达到延续使用,完成新老设备更新期的过渡,即是本文之分析目的。     

Channel coding scheme for in HDTV digital VCR

The authors have developed an experimental in HDTV digital videocassette recorder (VCR). The VCR can record HDTV digital base-band signals for more than 64 min on a in metal particle (MP) tape. An eight-to-eight modulation ( ) scheme has been developed for this VCR to realize high-density recording. In order to suppress sufficiently the low-frequency components and reduce the occurrence probability of long-run-lengths for the recording data sequence, a new conversion table and bit-rearrangement method have been introduced in this modulation scheme. This conversion table has been particularly structured to reduce run-length using the bit-rearrangement process. Three kinds of typical HDTV images were used to evaluate the performance compared with the scrambled-NRZ method. The run-length distribution and the frequency spectrum were calculated for each image. The results showed that the occurrence probability of long-run-lengths were well reduced and the low-frequency components along with the DC component were sufficiently suppressed. Cross-talk interferences and overwriting noises were also found to be much less than those for the scrambled-NRZ method.     

基于GOP取帧与变帧率的VCR实现方法

 MPEG编码视频帧间存在解码依赖性,导致VCR操作尤其是快进快退,需要服务端传送大量解码依赖帧.目前的VCR实现方法在解决这种依赖传输现象时,系统资源消耗与机顶盒解码复杂度非常高.本文提出一种基于GOP取帧与变帧率的VCR实现方法,基于GOP取帧消除依赖传输从而降低快进快退码率,可降到正常播的22%.变帧率实现码率可定制的效果,满足不同链路需求.该方法无需预处理视频,可作为在线算法应用于实时视频系统.     

一种支持VCR功能的视频流共享方案

真视频点播(TVoD)服务要求提供对“任何时候、任意节目”的请求支持和诸如暂停/恢复、任意定位、快进/快退、慢放等VCR功能。已有的多种共享视频流方案有效节约了系统存储开销和网络开销，但同时增加了用户服务延迟和支持VCR操作的难度。文章提出的可重组Patching方案可同时支持零延迟的用户到达服务和零延迟的VCR服务。经过仿真实验验证，可重组Patching方法利用较少的客户端存储资源有效提高了系统服务能力，并用易于实现的方法提供对多种VCR请求的支持。     

基于VCR模型的空间相关信道下V-BLAST系统性能分析

本文研究了空间相关信道下V-BLAST系统的最大似然检测性能.本文的分析基于VCR信道模型,它可以描述本地相关和非本地相关同时存在的情形.通过推导成对错误概率的精确表达式,得出系统误比特率的联合界,并利用成对错误概率在高信噪比下的近似表达式,研究了系统的分集性能,最后用计算机仿真对理论分析进行了验证.     

基于ATmega8的多功能定时器设计

目前钟表和定时器的输入多采用五个按键,显示采用字段方式,操作繁琐,人机界面不友好.本文提出一种采用4×4键盘输入,128×64点阵液晶显示的多功能定时器,具有人机界面友好、使用方便灵活、便于功能拓展的优点.文中给出了系统设计方案和主要设计思路,经验证,这种设计确实可行.     

一种嵌入式流媒体播放器VCR控制的设计与实现

提出一种嵌入式流媒体播放器VCR控制的设计和实现方案 ,主要对控制文件的生成方法、系统工作原理、网络传输机制、QoS控制机制进行介绍