H.263视频编码算法原理及DSP实现

介绍ITU-T H.263视频编码器在德州仪器（Texas Instruments)公司新一代数字信号处理芯片IMS320C6000上的实时实现技术。编程实现了H.263标准的主要内容及H.263 中提出的新的编码技术，重点讨论了H.263编码在TMS320C6711 DSP上的优化和实现。     

基于DSP的视频编码的优化和实现

介绍了低码率视频编码国际标准H.263建议的主要内容及H.263 中提出的新的编码技术，重点讨论了H.263编码在TMS320C6711 DSP上的优化和实现。     

H.263码流的RTP封装的研究与实现

在对RTP/RTCP特点与功能的研究、H.263视频数据的RTP封装格式研究和H.263码流结构分析的基础上,提出了一种将H.263码流封装成RTP数据包的实现方法.     

低比特率通信的H.263视频编解码

本文介绍了国际电联组织ITU-T 于1995年2月起草并通过的 H.263建议草案中低比特率视频编解码的原理、实现流程和图像的数据结构,并对H.263建议的4个增强编解码模式以及 H.263建议与H.261建议编解码的不同之处进行了探讨。     

基于USB2.0集成芯片的H.264解码器芯片设计

H.264/AVC标准具有一系列优于MPEG4和H.263的新特性,在相同的重建图像质量下,H.264比H.263节约50%左右的码率.     

基于TMS320C80 DSP的H.263编解码系统

本文提出了使用单片TMS320C80通用DSP实现H.263实时视频编解码器的硬件方案.本方案实现了低码率H.263编解码系统,实验证明,它能够在20kbps下完成8fps全双工实时H263编解码.     

H263+的数学模型及性能研究

根据ITU-T H263 的标准和测试模型（TMN8）,对H263 的编码过程和其中部分选项作了数学描述,最后对H263 的编解码结果与H263的编解码结果在主观和客观效果上作了比较,H263 明显优于H263。而且增加的复杂度和计算量很小,并分析了对编码效率改善显著的几个选项。     

H.263实时编码器的优化

编码器的优化是实时高效实现信源编码的关键。文章针对H.263建议的实现提出H.263编码器的几种优化方法,并对结果进行了分析。     

H.26L视频压缩编码协议及其性能分析

在与H.263协议进行比较的基础上简要介绍了H.26L视频压缩编码协议，并结合H.26L和h.263对Forman序列、silent序列进行的编码，以及得到的比特率和信噪比分析了两者的性能，给出了分析结果。     

基于H．263编码标准的H．264实时编码器的优化设计

从实时应用角度出发,参考H.263编码标准,对H.264视频编码器进行精简,并对耗时较大的算法进行改进.仿真结果表明,简化后的H.264编码器编码速度达到20f/s(帧/秒),达到实时编码要求,且编码性能优于H.263编码标准的编码器.     

MPEG-4 and H.263 video traces for network performance evaluation

MPEG-4 and H.263 encoded video is expected to account for a large portion of the traffic in future wireline and wireless networks. However, due to a lack of sufficiently long frame size traces of MPEG-4 and H.263 encoded videos, most network performance evaluations currently use MPEG-1 encodings. We present and study a publicly available library of frame size traces of long MPEG-4 and H.263 encoded videos, which we have generated at the Technical University Berlin. The frame size traces have been generated from MPEG-4 and H.263 encodings of over 10 video sequences each 60 minutes long. We conduct a thorough statistical analysis of the traces     

甚低速视频编码中PB帧技术的研究

本文首先对甚低速视频编码H.263的PB帧技术和H.263+所采用IPB帧技术进行性能分析,在此基础上,提出一种简单有效的B帧选取方法(称之为B帧熵最大选取法),其基本思路是根据信息论熵值理论定义B帧的熵,并根据熵值来选择信息量最大、对暴露区补偿最有意义的B帧,实验结果表明该方法在保留了H.263+的IPB帧的优点的同时,可获得更优的补偿效果。     

General Architecture for MPEG-2/H.263/H.264/AVC to H.264/AVC Intra Frame Transcoding

The latest international video-coding standard H.264/AVC significantly achieves better coding performance compared to prior video coding standards such as MPEG-2 and H.263, which have been widely used in today’s digital video applications. To provide the interoperability between different coding standards, this paper proposes an efficient architecture for MPEG-2/H.263/H.264/AVC to H.264/AVC intra frame transcoding, using the original information such as discrete cosine transform (DCT) coefficients and coded mode type. Low-frequency components of DCT coefficients and a novel rate distortion cost function are used to select a set of candidate modes for rate distortion optimization (RDO) decision. For H.263 and H.264/AVC, a mode refinement scheme is utilized to eliminate unlikely modes before RDO mode decision, based on coded mode information. The experimental results, conducted on JM12.2 with fast C8MB mode decision, reveal that average 58%, 59% and 60% of computation (re-encoding) time can be saved for MPEG-2, H.263, H.264/AVC to H.264/AVC intra frame transcodings respectively, while preserving good coding performance when compared with complex cascaded pixel domain transcoding (CCPDT); or average 88% (a speed up factor of 8) when compared with CCPDT without considering fast C8MB. The proposed algorithm for H.264/AVC homogeneous transcoding is also compared to the simple cascaded pixel domain transcoding (with original mode reuse). The results of this comparison indicate that the proposed algorithm significantly outperforms the mode reuse algorithm in coding performance, with only slightly higher computation.     

Multiframe video coding for improved performance over wirelesschannels

We propose and evaluate a multi-frame extension to block motion compensation (BMC) coding of videoconferencing-type video signals for wireless channels. The multi-frame BMC (MF-BMC) coder makes use of the redundancy that exists across multiple frames in typical videoconferencing sequences to achieve additional compression over that obtained by using the single frame BMC (SF-BMC) approach, such as in the base-level H.263 codec. The MF-BMC approach also has an inherent ability of overcoming some transmission errors and is thus more robust when compared to the SF-BMC approach. We model the error propagation process in MF-BMC coding as a multiple Markov chain and use Markov chain analysis to infer that the use of multiple frames in motion compensation increases robustness. The Markov chain analysis is also used to devise a simple scheme which randomizes the selection of the frame (amongst the multiple previous frames) used in BMC to achieve additional robustness. The MF-BMC coders proposed are a multi-frame extension of the base level H.263 coder and are found to be more robust than the base level H.263 coder when subjected to simulated errors commonly encountered on wireless channels.     

An error detection and recovery algorithm for compressed videosignal using source level redundancy

The motion compensation-discrete cosine transform (MC-DCT) coding is an efficient compression technique for a digital video sequence. However, the compressed video signal is vulnerable to transmission errors over noisy channels. In this paper, we propose a robust video transmission algorithm, which protects the compressed video signal by inserting redundant information at the source level. The proposed algorithm encodes every lth frame in the semi-intra frame (S-frame) mode, in which the redundant parity-check DC coefficients (PDCs) are systematically inserted into the compressed bitstream. Then, the decoder is capable of recovering very severe transmission errors, such as loss of an entire frame, in addition to detecting the errors effectively without requesting any information from external devices. The proposed algorithm is implemented based on the H.263 coder, and tested intensively in realistic error prone environment. It is shown that the proposed algorithm provides much better objective and subjective performances than the conventional H.263 coder in the error prone environment.     

视频编码标准H.263+的新特征研究

介绍了视频编码标准H.263 可协商的编码选项，尤其对于其中的改进PB帆帧模式、片结构模式和前向纠错模式进行了较深入研究。     

A Novel Rate Control Method for Low Delay Applications

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H.263建议的原理及其特点

本文讨论了ＩＴＵ－Ｈ．２６３建议的原理和它的一些主要特点，如ＰＢ帧模式，运动补偿、算术编码等，把它们与Ｈ．２６１建议和ＭＰＥＧ标准作了比较，并通过计算机模拟检验其效果。     

Best packetisation scheme for H.263 Internet video communication

The H.263 codec is an efficient way to stream variable bit-rate video sequences. It is proposed that, for equivalent bandwidth and frame rate, a two-slice packetisation scheme results in superior peak signal-to-noise ratio, rather than the conventional one-slice scheme, and that constant inter-packet gap rather than 'bursty' delivery is preferable.