中国电视台视频记录存储设备的发展历史和前瞻

追述中国电视台60年来视频记录存储设备发展的历史,从只是依靠电影胶片记录存储电视信号,发展到当今的标清和高清录像机、蓝光盘、高清记录存储卡、数据流磁带机、以多通道和网络化的硬盘阵列为主的视频服务器系统等等,存储媒介也从胶片和磁带,向多媒体记录方式的文件化、高清化、网络化转变.从现代科技的视角阐述了对电视台未来视频记录存储设备发展策略的思考.     

An error-correction scheme for a helical-scan magnetic data storagesystem

An error-correction scheme for a helical-scan magnetic recording system is presented. The system consists of a commercial VHS video cassette recorder with the front-end electronics adapted for high-speed digital recording. Error statistics have been collected and show a bursty error recording channel both within each track and from track-to-track. The proposed error-correction scheme uses interleaved Reed-Solomon codes. The interleaving function consists of a two-level interleaver performing track interleaving and byte interleaving. An efficient interleaving implementation is presented     

用于视频监控的便携式数字录像机设计

针对各类视频监控和记录的应用特点和要求,设计并研制了一个基于嵌入式微处理器、专用视频压缩芯片及大容量IDE硬盘或电子盘的便携式数字录像机.讨论了系统结构设计及各功能模块的电路选择,介绍了关键接口电路设计和系统软件设计.系统采用单一直流电源供电,为了方便视频压缩数据的存取,设计了专用的文件系统.测试结果表明,系统性能良好、功能灵活,功耗低、集成度高、独立、便携,非常适合各类视频监控和记录应用.     

Embedding Data Into Pictures by Modulo Masking

Three systems are proposed for embedding data into industrial quality monochrome analog pictures. The video signal on each scan line is sampled, and a data bit is inserted into a block of three or five pels by modulo masking scrambling the luminance level of only one pel in the block. Prior to transmission, the combined data and video sequence is converted into a continuous signal with a bandwidth that is no greater than that of the original video signal. Using six images each containing 65 536 pels, Systems 1 and 2 embedded an average of 17 430 and 8713 bits per image, while System 3 accommodated data at a constant rate of 21 760 bits/image. The data embedding procedures of Systems 1, 2, and 3 operated with average picture SNR's of 41, 44, and 30 dB, respectively, when the transmission channel was ideal. When the transmission was over a channel composed of a second-order Butterworth filter plus additive noise that yield a channel SNR of 40 dB, no bit errors occurred but System 3 offered the greater safety margin to bit errors than Systems 1 and 2.     

机载多路数字视频记录仪的设计与实现

视频的压缩记录是现代航空技术中很重要的一个研究内容，通过它可以实时记录飞机的多种直观信息，对飞行指挥和作战训练起到积极的指导作用，本文介绍了一种现代数学图像处理技术实现机载多路数字视频记录的方法，与传统的模拟记录方法相比，该方法具有记录容量大，记录时间长，图像质量高等特点。     

Digital video recording

Through mutual technology transfer between consumer and professional video recorders, the last 20 years has witnessed a rapid evolution from analog to digital recording. Each new digital videotape recorder (VTR) uses different channel coding. This implies that improving the recording density involves the development of new channel-coding schemes together with evolutionary magnetic tapes and heads. As a result, professional digital VTR's offer the best features for video recording. This paper reviews state-of-the-art magnetic recording devices, signal processing techniques for digital recording. It also describes the specifications for home-use digital recorders for current television systems, and discusses disk recording technology in the future     

基于TMS320DM365视频压缩传输系统的设计

针对原始视频数据量大,不利于存储与传输的问题,设计了基于TMS320DM365的视频压缩传输系统。实现将多路输入的模拟视频转换为数字视频,在TMS320DM365中压缩编码并打包成TS码流。提供帧率、分辨率、P/I比等参数的设置功能,能适应于多种应用场景。实验结果表明,系统可实现25帧/s、D1分辨率标清视频的压缩传输,满足视频监控的需求     

Nucleation-film/Electron-beam recorder: Near-real-time display system

A direct electron-beam recorder (EBR) for nucleation film has been built and tested. This recorder overcomes many of the disadvantages of CRT-on-film recorders by providing a high-resolution black-on-white image that is available for viewing 1 s after recording. Immediate viewing of the film record eliminates the need for a CRT display with storage for viewing images from line-scan reconnaissance sensors. Nucleation film is developed by the selective condensation of zinc vapor on nucleation sites produced by electron exposure. It is developed in vacuum, adjacent to the recording electron beam. The image has a contrast of 8:1 for an exposure of 2 × 10¹¹electrons/cm². This EBR display uses 70-mm film at speeds of 0.08 to 8.3 cm/s to record a video image from a line-scan reconnaissance sensor. This contrasts with a previously described nucleation film/EBR that recorded high-resolution television images at 60 fields/s on 35-mm-wide film transported at 43 cm/s. The present recorder/display has an image viewing area 6 cm wide by 22 cm high where the 70-mm-wide film moves from top to bottom. The video bandwidth is 5 MHz and the horizontal resolution is 2400 lines. A major accomplishment of the work reported here was the design of a zinc vapor source with uniform flux for development of the 70-mm-wide nucleation film in a 0.5-cm space adjacent to the recording electron beam.     

Integrated-Circuit Analog Multiplexer

An analog multiplexer which allows several data channels to share the available bandwidth of one channel of an analog tape recorder is described. The method involves demodulation by correlating with a separately recorded carrier. Inexpensive integrated circuits are the only active elements.     

移动视频监控系统中的关键技术研究

针对移动设备有限的运算存储能力以及目前无线信道窄带高误码等问题,设计并实现了在移动环境下的实时视频监控系统。该系统融合了改进的高级Foveation滤波技术、自适应帧率调节、鲁棒的视频编码等技术。通过采用这些技术,以使有限的编码比特流合理分配,从而极大地提高监控系统的图像质量。同时,为了防止视频监控数据遭到恶意的攻击和篡改,系统集成了水印安全认证模块,保证了监控系统的安全性。     

一种全谱段多光谱遥感器的星上信息处理系统

全谱段多光谱星上信息处理系统应用于某型号多光谱遥感器,由可见光信息处理电路及红外信息处理电路构成。该系统基于推扫成像的遥感器设计方案,通过外同步控制方式,完成了可见光、短中波红外、长波红外探测器的时序控制与驱动、模拟信号采集与处理、数字信号整合与格式编排等功能,具有多焦面同步工作、采集模拟通道多、信噪比高的特点。最终系统共采集32路模拟图像信号,输出量化位数为14 bit,五路串行LVDS输出,单路数据率为30 Mbps。在给定的测试条件下,实验室环境实测可见光通道、短波红外通道信噪比分别达到307和422,中波红外通道、长波红外通道NETD分别达到0.14 K和0.16 K。并使用可见光通道进行了外景成像,得到了良好的图像数据。通过实验室测试及外景成像验证了本系统能够满足遥感器使用需求。     

Multitrack Recording of Reduced Bandwidth TV Signals

The system described here was developed in order to record the pseudorandom scan television signal developed by Deutsch. The objective was to investigate the possibility of recording a 200 kHz video signal on a 1/4 in tape running at 15 in/s. The difficulties which arise in such a task are two-fold: 1) bandwidth limitations of the recorder; and 2) flutter and skew of the recorder. Since a tape recorder at this speed has a bandwidth of about 45 kHz, time-division multiplexing was used to reduce the signal into low-frequency signals. The problem is to reassemble the signals at playback. This is a difficult task since these signals are shifted in time randomly by flutter and skew. Experiments disclose that the skew is linearly distributed across the tape; therefore, by knowing this time shift between two tracks at any instant, the position of the appropriate sample at any other track can be predicted. For skew and flutter compensation purposes two reference signals are recorded on the two outer tracks of the tape. The phaseshift of the reference signals at playback is used as a measure for the skew prediction system for each track. Thus the video signals are sampled at the correct value. In order to reassemble the samples in the correct time sequence, they are stored in analog memory cells. The memory cells are read out with the aid of an oscillator which is in turn synchronized with flutter. The deflection waveforms are also generated synchronous with this oscillator.     

基于FPGA与NAND闪存的固态存储系统设计

设计了一款可以测量记录6通道直流脉冲信号、分辨率8bit、每通道10MHz采样率的固态存储系统,该系统以FPGA作为核心控制器,主要完成多通道选择控制、AD采样频率及转换控制、数据缓冲FIFO以及控制NAND闪存进行数据存储的功能。系统采用模块化设计,内部采用VHDL语言设计,在ISE9.1软件环境下通过程序控制硬件实...     

1/2-inch cassette VTR for baseband HDTV signal recording

Technical details are reported for a 1/2-inch cassette videotape recorder (VTR) developed for recording the baseband high-definition TV (HDTV) signal. A recording time of 63 min was achieved by using metal-particle tape and laminated amorphous video heads. The frequency bandwidths used for luminance and chrominance signals were 20 and 7 MHz, respectively. A novel two-channel, three-segment recording method was developed for the purpose. Four-channel digital audio recording with a sampling frequency of 48 kHz and 16-b linear quantization was used. The digital audio signal was recorded on the overlapped area succeeding to the video track by using the same heads used for video recording     

3G网络中的视频通信优化设计

3G网络CDMA2000信道带宽低、抖动大。为了在3G网络中进行实时视频通信,提出一种基于H.264硬件编解码的系统优化设计。该设计包括图像预处理器、H.264硬件编解码器Codec、ARM9主控CPU、网络传输模块。图像经预处理器AD转换,并进行抽样,压缩为CIF分辨率,CPU对H.264编码进行综合优化设置,调整QP参数和GOP结构,由硬件编码器Codec压缩,压缩后的数据由CPU封装打包进行网络RTP传输。解码时从网络接收数据,排序恢复数据后直接交由硬件解码器进行解码显示。实验表明,优化后的系统可以有效降低图像数据码率,减少传输带宽需求,达到3G网络实时通信的设计目的。     

A digital video system for the CATV industry

A ditigal pulse code modulator (PCM) system is proposed to implement long-haul video system for the CATV industry. A comparison is made between PCM system and wide-band FM system in terms of repeaterability versus additional occupied signal bandwidth. This is followed by a noise analysis of coaxial cable to determine the correct PCM format and bit information rate. An 80- megabit system is selected, which uses an 8-bit code in a four-level, eight-level, eight-level pulse sequence per video sample. The selected PCM system is then evaluated for its performance on both a long-haul cable system and a long-haul microwave system. Performance calculations are made on a 500-mile cable system in terms of error rate and its related video signal-to-noise ratio. Repeater spacings are computad for various configurations, including the replacement of the digital regenerators with analog amplifiers. Additional performance calculations are then made on a 3000-mile microwave system, including the effect of simultaneous Rayleigh fading.     

高密度光存储实现途径分析

随着光存储技术的发展,如何提高光盘存储密度备受关注.应用信道分析的方法,讨论了影响存储密度的因素和参量,提出光学系统分辨本领及光存储机理是其中最重要的因素.分别从缩短波长、增大数值孔径、超分辨以及缩小记录点、复用记录点及增加存储维度等角度总结了提高系统分辨能力、改变存储机理以提高光盘存储密度的途径.     

Achievements in rotary head magnetic recording

The principal achievements since 1980 in rotary head recording on magnetic tape are outlined. These developments are related to fundamental improvements in recording media, heads, the design of tape transports, and signal processing. The D-1 and D-2 video tape recorders (VTRs), the Hi-Band 8-mm video cassette recorder (VCR), and the rotary digital audio tape (R-DAT) recorders are discussed. The future of rotary head recorders for consumer digital VCRs, professional high-definition TV (HDTV) VTRs, and consumer HDTV VCRs is assessed     

基于3G技术的无线视频传输系统研究

设计并实现了一个基于RFC通用标准的H.264视频流实时传输系统。为了克服无线信道高误码、低带宽等不利因素,本文提出了通过cdma2000 EV-DO下的UDP/RTP虚拟链路保证实时传输,同时为了弥补AIMD算法的不足,采用Gilbert信道模型估算有效带宽,并通过预测带宽调整发送速率。结果显示,本系统由于引入了RTCP反馈机制,在网络出现堵塞后会自动降低视频发送的帧率,从而保证视频的实时传输。     

Robust adaptive transmission of images and video over multiple channels

Reliable transmission of images and video over wireless networks must address both potentially limited bandwidths and the possibilities of loss. When bandwidth sufficient to transmit the bit stream is unavailable on a single channel, the data can be partitioned over multiple channels with possibly unequal bandwidths and error characteristics at the expense of more complex channel coding (i.e., error correction). This paper addresses the problem of efficiently channel coding and partitioning pre-encoded image and video bit streams into substreams for transmission over multiple channels with unequal and time-varying characteristics. Within channels, error protection is unequally applied based on both data decoding priority and channel packet loss rates, while cross-channel coding addresses channel failures. In comparison with conventional product codes, the resulting product code does not restrict the total encoded data to a rectangular structure; rather, the data in each channel is adaptively coded according to the channel's varying conditions. The coding and partitioning are optimized to achieve two performance criteria: maximum bandwidth efficiency and minimum delay. Simulation results demonstrate that this approach is effective under a variety of channel conditions and for a broad range of source material.