MPEG-2视频反量化电路的VHDL描述与验证

设计了用于ＭＰＥＧ－２ＭＰ＠ＭＬ视频解码ＶＬＳＩ的ＩＱ电路结构,基于对ＩＱ的运算字长和精度关系的分析,有针对性地提出相应的硬件电路结构设计,减少了电路规模以适应ＭＰＥＧ－２ＭＰ＠ＭＬ视频较大的数据量,电路采用了ＶＨＤＬ进行描述并通过模拟和验证。结果表明该电路可以完成ＭＰＥＧ－２解码的功能。     

MPEG—2视频IDCT的VHDL描述与验证

反离散余弦变换是ＭＰＥＧ－２中恢复帧内编码系数或差分系数的重要手段。３设计了用于ＭＰＥＧ－２ＭＰ＠ＭＬ视频解码ＶＬＳＩ的ＩＤＣＴ电路结构,采用了ＶＨＤＬ进行描述并通过模拟和验证。这里采用了全硬件实现的方法,并针对性地提出相应的硬件电路结构设计,减少了电路规模以适应ＭＰＥＧ－２ＭＰ＠ＭＬ视频量大,处理复杂的特点,达到实进解码的目的。     

适用于MPEG2视频解码的VLD设计

提出了一种新的适用于ＭＰＥＧ２视频解码的变字长解码（ＶＬＤ）结构,根据ＭＰＥＧ２变字长码表的特点,通过合理的码字分割解决码字的存储问题,采用桶式移位器,使得每个时钟能处理一个码字。     

基于TMS320C80的MPEG—2视频解码器

文章提出了用ＴＩ（德州仪器公司）的ＴＭＳ３２０Ｃ８０多媒体视频处理器实现ＭＰＥＧ２解压缩的设计方法和基本结构框架，重点解决了数据流扫描、变长码解码和ＩＤＣＴ问题。鉴于ＴＭＳ３２０Ｃ８０是专门用于视频处理的多媒体视频处理器，通过分析，它可以以４０ＭＨｚ解码６Ｍｂｉｔ／ｓ的ＣＣＩＲ６０１４：２：０码流。     

实时MPEG－2解码器

实时ＭＰＥＧ－２解码器当阅读此文时，一种新的、称为Ｖｉｄｅｏｍａｘ（视频之最）（ＣＬ９１００）的单片（１６０脚ＱＦＰ）、实时ＭＰＥＧ－２视频解码器将在ＮＡＢ（美全国广播工作者协会）亮相。除ＭＰＥＧ－１和ＭＰＥＧ－Ｚ视频解码（非要求的主解码）外，它为用...     

基于CL9100／CL9110的MPEG—2解码系统的设计

利用ＭＰＥＧ－２标准压缩的动态图象具有高清晰度和高质量的视听效果，有着广泛的应用前景。本文描述了利用Ｃ－Ｃｕｂｅ的ＣＬ９１００／ＣＬ９１１０芯片组构成的ＭＰＥＧ－２解码系统，内容包括芯片功能介绍，解码系统结构及工作原理。     

MPEG2视频解码器VLSI结构研究

介绍了ＭＰＥＧ２视频解码器的ＶＬＳＩ实现方法，采用ＡＳＩＣ结构实现ＭＰＥＧ２标准的视频解码，用流水线哈佛结构ＲＩＳＣ型微控制器对视频数据流、变字长解码以及电路时序进行控制，提高了电路速度，减小了芯片面积。     

国外消息

国外消息▲单片ＬＳＩＭＰＥＧ┐２解码器日本东芝公司开发出一种单片视频解码器大规模集成电路（ＬＳＩ）。该新型视频解码器符合ＭＰＥＧ－２标准，能对高清晰度电视（ＨＤＴＶ）级图象清晰度的压缩数字信号进行解码，该解码器是数字式电视广播和多媒体系统的一项关键部...     

新型扩展LSI

新型扩展ＬＳＩ日本东芝公司推出的ＴＣ８１２００Ｆ型扩展ＬＳＩ，含有存储控制电路，能实时扩展按ＭＰＥＧ－２标准压缩的数字信号。此ＬＳＩ含有存储控制电路正是恢复用ＭＰＥＧ－２标准压缩的数字动态图象所必须的，只要用４块４ＭｂｉｔＤＲＡＭ。此外，它的全景扫描...     

MPEG-2视频编码器的实现

图象编码技术经过近４０多年的发展,某些技术已经成为成熟,特别是以离散余弦变换＋运动补偿为代表的一类算法得到广泛的应用和认可,并被许多国际标准所采纳,如ＪＰＥＧ,Ｈ２６１,ＭＰＥＧ－１,ＭＰＥＧ－２等。近年来随着ＶＬＳＩ技术及信息理论的进步,很多复杂算法的实现已成为可能,利用ＲＩＳＣ及ＦＰＧＡ芯片实现ＭＰＥＧ－２标准的ＭＰ＠ＭＬ级的硬件,质量较为理想,为目标码率为６－８Ｍｂｐｓ,可用于数字电视的广播     

保持编码效率的变长码分解方法

本文介绍了能用数学解杆式表示的变长码和它的三种编译码算法，提出了这种变长码的分解方法，分解后的多个变长码保持了原变长码的编码效率，但降低了编译码的复杂度。     

一种基于八叉树的Huffman解码方法及其在MPEG-4中的应用

传统的二值Huffman解码方法的解码效率较低。为了提高解码速度,该文提出了一种基于八叉树的Huffman解码方法。该方法将Huffman码表示为八叉树结构,并根据各个节点在树中的位置将码表重建为一维数组。解码时,每次从码流中读取3 bit码元,并使用数值计算代替判断和跳转操作,从而提高了解码效率。将本文方法应用于MPEG-4 VLC和RVLC解码的实验结果表明,该方法在内存增加不大的情况下能大幅度提高Huffman解码效率,其性能优于其它方法。     

运用VLC媒体播放器增加HDTV播出频道的实践

VLC是一个开放源代码的、跨平台的多媒体播放器,它可以播放多种音频和视频格式(MPEG-1、MPEG-2、MPEG-4、D ix、MP3、Ogg等以及DVD、VCD、CD音频以及各种流媒体协议),VLC同时也具有转码能力(UDP unicast和multicas、tHTTP等),主要为宽带网络设计的流媒体服务器使用。基于上述软件,结合拥有G igabitEthernet I/O板卡的统计复用网关DM6400、复用/加扰/调制器BN G6104和播发服务器、HDTV机顶盒,试验播出2个HDTV频道。     

A Cost-effective VLD Architecture for MPEG-2 and AVS

In this paper, we propose a cost-effective architecture of variable length decoder (VLD) for MPEG-2 and AVS. In order to save the buffer memory between VLD and IDCT and accelerate decoding speed, block-based pipeline buffers are adopted. Inverse scan (IScan) and inverse quantisation (IQ) are also merged into this architecture for cost-effective implementation and for easier system integration. A novel group-based architecture with the optimized look-up table is used for MPEG-2 and a new memory-efficient architecture with mixed memory organization is used for AVS. We use shared modules in both MPEG-2 and AVS as much as possible, such as the flush unit, the buffer controller and the buffers. Moreover, we propose merged IQ scheme and merged RAMs scheme. Based on 0.18 μm CMOS technology, the proposed design consumes about 11.5 K gates at a clock constrain of 125 MHz. The simulation results show that it can achieve real-time decoding, such as HD1080i (1,920 × 1,088 at 30 MHz) format video of AVS and MPEG-2. Furthermore, we propose an effective design of the buffers between VLD and IDCT according to the IDCT architecture, a cost-efficient IQ architecture with full flexibility and an efficient scheme for accelerating VLC decoding.

Data hiding in MPEG-2 bitstream by creating exceptions in code space

In this work, we have developed a file-size preserving algorithm to hide data directly in MPEG-2 bitstreams without violating the syntax. The approach is based on the realization that embedding of a bit directly in the bitstream can be achieved by creating an exception in the code space. An exception is created by inserting code words not occurring in the original content into the bitstream. Because the entropy-coded segment of MPEG-2 is fully used, every valid code word appears somewhere in the video. However, exceptions can still be created by recognizing that there are certain variable length codes (VLC) that never occur together in any video block. These are unused VLC pairs and although they vary from stream to stream, they always exist. It is then possible to embed one bit of data by forcing an unused pair in a block subject to a number of constraints, including transparency, file-size preservation and quality metric. The list of unused pairs constitutes a secure key that can be identified by pointer. This pointer can be efficiently encoded for sharing through a secure download. The content-dependence of the key allows a secure exchange of information because each key is valid only for the corresponding video. Because the cover video still uses standard VLCs, the marked bitstream is transparent to external observers. Application areas for the proposed approach are metadata binding and general data hiding when the size of the key is less important than the security and value of attaching data to content. Examples are surveillance video footage and medical applications.     

Robust source decoding of variable-length encoded video data taking into account source constraints

We first provide an analysis of available redundancy remaining in compressed video data. This residual redundancy has two origins: the variable-length code (VLC) syntax and the source constraints. We compute the two in terms of equivalent redundancy bits. Then, a VLC decoding algorithm able to exploit both VLC syntax and source constraints for improving the decoding performance is outlined. Finally, it is shown that by taking this redundancy into account, video decoding over additive white Gaussian noise channels is substantially improved.     

Soft-input soft-output decoding of variable length codes

We present a method for utilizing soft information in decoding of variable length codes (VLCs). When compared with traditional VLC decoding, which is performed using "hard" input bits and a state machine, the soft-input VLC decoding offers improved performance in terms of packet and symbol error rates. Soft-input VLC decoding is free from the risk, encountered in hard decision VLC decoders in noisy environments, of terminating the decoding in an unsynchronized state, and it offers the possibility to exploit a priori knowledge, if available, of the number of symbols contained in the packet     

An Efficient Variable-Length Code Construction for Iterative Source-Channel Decoding

We present a novel variable-length code (VLC) construction which exhibits an inherent error correcting capability due to the exclusive presence of codewords with even Hamming weight. Besides error robustness, the proposed code construction features a similar codeword length distribution as Golomb-Rice codes, and therefore, in particular for sources with exponentially distributed symbols, has good source compression properties at the same time. We show that in a source channel coding framework with outer source encoding, inner channel encoding with a recursive convolutional code, and iterative decoding the proposed VLC construction can lead to significant performance improvements compared to fixed-length source encoding with optimized mappings. In particular, simulation results for the AWGN channel verify that for Gauss-Markov sources a performance close to the theoretical limit can be achieved.     

MPEG-4运动补偿处理器的VLSI结构设计

针对MPEG-4编解码中运动补偿控制复杂、数据吞吐量大、实现较困难的特点,提出了一种适合MPEG-4的运动补偿硬件实现方案,解决了时序分配、输人输出控制等较难处理的问题。文中的方案已经在Xilinx ISE6．1i集成开发环境下,采用了VHDL进行描述,并使用了电子设计自动化（EDA）工具进行了模拟和验证。仿真和综合结果表明,该处理器逻辑功能完全正确,能满足MPEG-4Core Profiles＆ Level2实时编码要求,可用于MPEG-4的VLSI实现。     

MPEG-4运动补偿的VLSI结构设计

针对MPEG．4解码中运动补偿控制复杂、数据吞吐量大、实现较困难，提出了一种适合MPEG-4的运动补偿硬件实现方案，解决了时序分配、输入输出控制等较难处理的问题。此方案已经在Xilinx ISE6．li集成开发环境下，采用了VHDL进行描述，并使用了电子设计自动化（EDA）工具进行了模拟和验证。仿真和综合结果表明，设计的运动补偿处理器逻辑功能完全正确，而且可以满足MPEG-4 Core Profiles ＆ Level 2的实时编码要求，可用于MPEG-4的VLSI实现。