基于视频转换编码的数字电视台标机设计

介绍了一种基于视频转换编码技术的数字电视台标机的软件设计,对其采用的图标插入视频转换编码算法进行了深入讨论。该台标机经码流分析仪检测功能正确,且与同类产品相比性价比较高。     

MPEG-4标准中的视频编码

MPEG－4是一个全新的多媒体标准,采用了基于对象和模型的编码方法,本文简要总结了MPEG－4视频编码的各种特点,并对其中的纹理编码、形状编码、静止纹理编码、脸部对象编码、网格对象编码、Sprite对象编码以及可分级编码作了简要的介绍。     

MPEG—4视频编码分析

本对MPEG-4视频编码的功能与特点进行了描述。对基于VOP的视频编码器的原理与结构进行了分析,并将MPEG-4与其他视频编码标准做了对比。     

转换编码模拟实验平台

给出了转换编码模拟实验平台的简要构成，它包括视频编码、音频编码、复用／解复用、码流转换、分析、输出／播放及工具模块；着重剖析了作为搭建实验环境纽带的MPEG4IP软件包，包括MPEG-4视频、音频编码，码流复用、播放。实验表明，基于该平台可有效地进行转换编码研究。     

区域基视频编码的基本方法及关键技术

介绍了一种区域基频编码的基本方法以及关键技术，这种编码方法适合于极低比特率的视频编码应用，包括时间递归形态分割，基于区域的运动估计以及采用运动补偿预测的轮廓－纹理编码。该编码方法是输入的图像序列内容没有任何限制，而且其算法结构可按不同的图像质量等级和比特率要求实现可分级的编码过程。     

运动补偿视频编码中DCT编码效率的研究

在视频序列图像编码中，运动补偿帧差图像的统计特性与静止自然图像有明显差别，对静止自然图像可以称为准最佳变换的离散余弦变换对帧差图像的编码效率有所下降。本文对这一问题进行了理论分析和实验验证，从而指出进一步提高视频序列图像编码效率的潜力所在。     

一种可变长码在视频编码中的应用

本文所讨论的一种可逆的可变长码，其码长分布与Golomb-Rice和exp-Golomb编码相同。其编码数据格式能够很好地应用于图像和视频的统计编码中，在保持编码效率的同时，很大程度地提高编码在信道传输中的纠错能力。     

MPEG—2视频编码的自适应量化器设计

本文在研究ＭＰＥＧ－２ＴＭ５建议的自适应量化策略的基础上，设计了一种新的逢适应量化器。以块为基础分析宏块的局部视觉活动特性。并通过综合评介宏块中各块的视觉活动特性来最终决定自适应视觉量化因子。     

MPEG—2视频码流的拼接

1 前言 运动图像及其伴音的压缩编码技术是多媒体计算机、多媒体数据库、多媒体通信、标准清晰度电视(SDTV)、高清晰度电视(HDTV)及交互式电视(Interactive TV)等系统中的关键技术。国际标准化组织(ISO)1986年成立了制定运动图像及其伴音压缩编码标准的运动图像专家组MPEG(Moving Picture Expert Group)。1993年MPEG正式推出用于数字存储媒体、码率直到1.5Mbps的MPEG-1标准(ISO/IEC     

视频转换编码及其实现技术的研究

转换编码技术是近年来出现的新课题,广泛应用于数字视频通信和多媒体网络中.它是指对已经压缩编码的码流进行再处理,使经过处理后的数据符合传输和接收的要求.本文对转换编码技术的分类和当前的研究进展进行了系统研讨,并进一步指出了它的发展前景.     

Prediction of bit rate sequences of encoded video signals [forISDN]

A new approach for video traffic characterization (VTC) is proposed. In this approach, it is assumed that every video sequence is characterized by a set of fundamental indexes or parameters and that the bit rate process can be generated by a parametric model of the corresponding indices. Among the implications of this approach are: the encoding process is no longer necessary to simulate the bit rate process for a particular video sequence: a video sequence needs to be processed only once to obtain its fundamental parameters: and, in general, the computation of the index processes requires much less processing than the actual encoding. If parametric models are identified for all encoding algorithms of interest, then the problem of developing models for various combinations of encoders and classes of video sequences reduces to the problem of developing a single model for the index processes of various classes of video sequences     

MPEG视频编码中的码率控制原理及算法

对视频码流的特点、码率控制的目的、码率控制的关键因素、CBR虚拟缓冲器限制等问题进行了详细分析，同时介绍了MPEG-4校验模型所推荐的码率控制算法。     

An extended discrete autoregressive model for variable bit rate video traffic encoded by scalable video codec

Designing an effective and high performance network requires accurate characterization and modeling of network traffic. This paper provides a study of the transmission, modeling, and analysis of variable bit rate (VBR) video, which is fundamental for designing protocols and for effective utilization of networks in video transmission. To meet the specified requirements of future networks, the scalable video codec (SVC) was chosen as the video compression standard. The main objective of this work was to propose a statistical model that will allow better coordination between generated SVC video traffic and original video traffic. The performance of the proposed model was evaluated by comparing the model with three existing low‐complex statistical models using graphical and statistical measurements as well as cross‐validation. For all evaluation techniques, the accuracy of the proposed model was evaluated, and the frame size distribution of the modeled traffic was found to match that of the original video traffic better than other existing models. Copyright © 2015 John Wiley & Sons, Ltd.     

高清晰度电视视频解码器码流分配电路实时实现技术

我国自行研制的第一代高清晰度电视功能样机视频编、解码器中,采用十字划分方案,以便使用标准清晰度电视视频编、解码芯片实现高清晰度电视视频编、解码器。文中在介绍高清晰度电视视频码流结构的基础上,提出了高清晰度电视视频解码器中码流分配电路的实现方法,并给出了实现结果。实验表明,使用该方法可以实现码流中头信息的修改、码字划分及不定长视频包的有序传输及控制。     

H.263甚低码率视频编码标准的码率控制方法

主要提出ＩＴＵ组织的Ｈ．２６３甚低码率视频压缩编码标准输出码率的控制方案。着重分析了一种通过调整宏观量化器的量化参数来控制Ｈ．２６３编码器输出码率的方法,它能满足在ＰＳＴＮ网上低时延中的码率输出要求。     

低比特率视频编码新标准H．263＋

介绍了低比特率视频编码新标准Ｈ．２６３＋。Ｈ．２６３＋是Ｈ．２６３的升级版本,增加了１２个新的编码可选模式。     

Multiplexing gains in bit stream multiplexors

We are concerned with characterizing the variation of multiplexing gains with source type and burstiness in integrated service systems such as ATM. We model a fixed capacity high speed bit pipe that multiplexes a moderate number of bit streams with minimal buffer under a low loss constraint. Each service type is defined by its instantaneous bitrate distribution, but the bitrate distribution of multiplexed streams is approximated as Gaussian. The Gaussian approximation is not as accurate as Chernoff bounds, but it allows for stronger characterization of multiplexing gains. We consider three schemes for allocating bandwidth to services: by individual user, by path and service type, and by path only. We find explicit formulae for sensitivities of required capacity to source rate mean and variance and to loss rate. We characterize multiplexing gains and costs to identify the benefits of each allocation policy. We find that the capacity savings resulting from sharing resources is proportional to the square root of the ratio of source rate variance to source rate mean. This suggests that although bursty sources require more bandwidth, multiplexing gains are increasing with burstiness. We also find that the extra capacity required to multiplex dissimilar source types is increasing with the difference between their burstinesses. This suggests that when bit streams are partially grouped, it is most important first, to group similar source types     

Optimal bit rate conversion of MPEG-2 video bit streams

An optimal bit rate conversion scheme for MPEG-2 video bit streams, based on a drift free video transcoder, is proposed. It is shown that optimally transcoded bit streams produce better picture quality than both a cascade of decoder-encoder and than a standard encoder using the original pictures, at the same reduced bit rates     

HDTV码流输出系统的研制

提出了将ＨＤＴＶ软件编码数据流转换成串行码流的方案并研制了相应的转换,输出系统。系统基于通用微机,将非实时软件编码的ＨＤＴＶ视频或舆流数据转换成串行码流,并提供时钟同步或包同步信号,其码流类别,编码系数,码率,工作方式等可选,它的研制成功在目前尚无ＨＤＴＶ编码芯片的情况下,得以为ＨＤＴＶ制式研究,设备或系统的研制或测试等,灵活,方便地提供信号。     

Unequal error protection of SPIHT encoded image bit streams

A derivative of the set partitioning into hierarchical trees (SPIHT) image coding method, which generates substreams with different error-resilience properties, is proposed. By dividing the image bit stream into three classes, substreams with different immunity properties are obtained. The unequal protection of these substreams with different channel coding rates improves the overall performance of the method against channel errors. Simulation results show the superiority of the proposed method over some of the state-of-the-art methods