高清晰度电视信源解码器的设计与实现

本文介绍作为中国国家ＨＤＴＶ功能样机项目一部分的信源解码器,该解码器能以６０Ｍｂｐｓ的比特率对ＭＰＥＧ－２传输流进行实时解码。     

TMS320C80 DSP在HDTV信源解码器中的应用

本文讨论了采用ＴＭＳ３２０Ｃ８０民高清晰度电视信源解码器的解复用器和视频显示缓存器的原理、性能及实现与信源解码器的调试和部分测试功能的原理与实现。该单元电路符合ＭＰＥＧ－２系统标准（ＩＳＯ／ＩＥＣ １３８１８－１）和视频标准（ＩＳＯ／ＩＥＣ １３８１８－２）。     

基于ST20TP4的HDTV信源解码器的软硬件实现

介绍了以ST20TP4为主控制芯片控制Sti4600和Sti7000进行音、视频解码的HDTV信源解码器，ST20TP4还负责对前端或LVDS板输入的TS流进行解复用，重点阐明基于32bit微控制器的HDTV信源解码器的硬件设计和软件编程。     

基于DSP的数字电视信源解码器的设计

本文提出了一种基于TMS320TMS320C6415的数字电视信源解码器硬件系统.该硬件系统解决了传送流输入、视频显示和音频播放的硬件实现,还通过硬件手段较好地解决了系统高数据吞吐率的问题.     

基于DSP芯片的HDTV信源解码系统软件设计

基于DSP芯片的HDTV信源解码器是目前研究的一个热点,由于目前的DSP芯片大都具有强大的功能,为我们解决问题带来了新的方法。重点讨论类似系统的软件设计部分,包括系统调度和视频解码两个主要方向。     

数字HDTV信源解码器的硬件实现

本文提出了一种主要基于FPGA的数字HDTV信源解码器的总体设计方案和硬件实现方法.同时还介绍了整机的测试系统和测试结果.目前,该信源解码器已研制完成,并参加了于1998年9月8日至11日在北京成功进行了我国HDTV功能样机系统的公开演示.     

DVB-C机顶盒信源解码器的设计与实现

本文实现了以SC2005为主芯片的机顶盒信源解码器,并将该解码器配接L64768前端,组成了符合DVB-C标准的完整机顶盒方案;可对符合MPEG-2标准的音视频流进行解码并兼容PAL/NTSC/SECAM制式的模拟电视接收。     

一种新型数字SDTV信源解码器的实现

本文实现了以专用芯片STi5518为核心器件的SDTV信源解码器.该解码器可配接不同制式的前端,组成完整的机顶盒方案;可对符合MPEG-2的视频流进行解码;可对AC-3或MPEG两种音频解码;另外,本系统还实现了硬盘录像和条件接收两个有特色的功能.本文重点叙述该信源解码器的硬件设计和实现原理.     

联合信源信道编码的原理及其在无线通信中的应用

根据香农信源和信道分离编码理论进行的分离信源和信道编码在时变信道时不能充分利用系统资源。正是在这种情况下 ,提出了信源信道联合编码 ,可以跟随信道的变化充分利用通信系统的资源 ,达到最好的端对端的通信效果。本文首先阐述了联合信源信道编码的原理 ,然后介绍了常用的实现方法 ,最后 ,提出了在设计联合信源信道编码系统时的改进方法。     

基于开源IP核的视频解码SoC平台研究

文章设计了一款基于开源IP核的SoC视频解码平台,该平台中使用的IP均经过了CQIP系统的严格评测,并在Xilinx公司的FPGA上进行了验证,实验结果证明该系统具有良好的实时性和较低的功耗,非常适合于便携式设备。     

全数字PAL解码器的原理与应用

分析了全数字ＡＰＬ解码器的一般原理，并结合具体应用讨论了解码器与后面的数字处理部分之间的缓冲控制。     

On source coding with side information at the decoder

Let{(X_k, Y_k, V_k)}_{k=1}^{infty}be a sequence of independent copies of the triple(X,Y,V)of discrete random variables. We consider the following source coding problem with a side information network. This network has three encoders numbered 0, 1, and 2, the inputs of which are the sequences{ V_k}, {X_k}, and{Y_k}, respectively. The output of encoder i is a binary sequence of rateR_i, i = 0,1,2. There are two decoders, numbered 1 and 2, whose task is to deliver essentially perfect reproductions of the sequences{X_k}and{Y_k}, respectively, to two distinct destinations. Decoder 1 observes the output of encoders 0 and 1, and decoder 2 observes the output of encoders 0 and 2. The sequence{V_k}and its binary encoding (by encoder 0) play the role of side information, which is available to the decoders only. We study the characterization of the family of rate triples(R_0,R_1,R_2)for which this system can deliver essentially perfect reproductions (in the usual Shannon sense) of{X_k}and{Y_k}. The principal result is a characterization of this family via an information-theoretic minimization. Two special cases are of interest. In the first,V = (X, Y)so that the encoding of{V_k }contains common information. In the second,Y equiv 0so that our problem becomes a generalization of the source coding problem with side information studied by Slepian and Wo1f [3].     

球解码算法及其改进

首先对现有的2种球解码算法进行了研究,并对它们在性能和复杂度上进行了比较。然后,考虑性能较好的算法,在中高信噪比下适当减少搜索每一解码分量候选符号集内元素的个数,根据信号的强弱对解码信号的各维分量按从强到弱进行排序,加快了解码的速度,也在一定程度上弥补了由于减少搜索损失的性能。仿真结果表明了这种改进算法的有效性。     

Novel Viterbi decoder VLSI implementation and its performance

An advanced, high-speed, and universal-coding-rate Viterbi decoder VLSI implementation is presented. Two novel circuit design schemes have been proposed: scarce state transition (SST) decoding and direct high-coding-rate convolutional code generation and variable-rate decoding. SST makes it possible to omit the final decision circuit and to reduce the required path memory length without degrading error probability performance. Moreover, the power consumption of the SST Viterbi decoder is significantly reduced when implemented as a CMOS device. These features overcome the speed limits of high-speed and high-coding-gain Viterbi decoder VLSIs in the rate one-half mode imposed by the thermal limitation. The other Viterbi decoding scheme makes it possible to realize a simple and variable coding-rate forward-error-correction circuit by changing only the branch metric calculation ROM tables. By employing these schemes, high-speed (25-Mb/s) and universal-coding-rate Viterbi decoder VLSIs have been developed     

A general combinatorial sphere decoder and its application

The conventional problem of searching the shortest vector z of a N-dimensional lattice L(H) with generating matrix HisinR^NtimesM is considered in a more general setting. There are P generating matrices H_iisinR^NtimesM(i=1,2,...,P) of the P lattices L(H_i). For a (bounded) integer vector bisinZ^M , we obtain P lattice points H_ib. Let d_i be the Euclidean norm of H_ib. The problem of interest is how to search for a vector b so that the maximum of d_i is minimized. We propose a new sphere decoder called combinatorial sphere decoder (CSD) to solve this problem. One of the applications of the new CSD is presented in detail to show its effectiveness     

视频解码自适应亮色分离及其LabVIEW实现

亮色分离是视频解码中的一个关键技术。文中对此提出了四种适应于不同情况下NTSC制数字复合视频信号解码的亮色分离滤波器,并由此设计了一种基于此四种滤波器的自适应Y-C分离算法。最后通过LabVIEW来实现该算法,论证了算法的可行性。     

Fast JPEG 2000 decoder and its use in medical imaging

Over the last decade, a picture archiving and communications system (PACS) has been accepted by an increasing number of clinical organizations. Today, PACS is considered as an essential image management and productivity enhancement tool. Image compression could further increase the attractiveness of PACS by reducing the time and cost in image transmission and storage as long as 1) image quality is not degraded and 2) compression and decompression can be done fast and inexpensively. Compared to JPEG, JPEG 2000 is a new image compression standard that has been designed to provide improved image quality at the expense of increased computation. Typically, the decompression time has a direct impact on the overall response time taken to display images after they are requested by the radiologist or referring clinician. We present a fast JPEG 2000 decoder running on a low-cost programmable processor. It can decode a losslessly compressed 2048/spl times/2048 CR image in 1.51 s. Using this kind of a decoder, performing JPEG 2000 decompression at the PACS display workstation right before images are displayed becomes viable. A response time of 2 s can be met with an effective transmission throughput between the central short-term archive and the workstation of 4.48 Mb/s in case of CT studies and 20.2 Mb/s for CR studies. We have found that JPEG 2000 decompression at the workstation is advantageous in that the desired response time can be obtained with slower communication channels compared to transmission of uncompressed images.