基于频域特征的H.264/AVC帧内编码模式快速预测

为降低H．264／AVC帧内预测计算复杂度，提出了基于频域特征的快速帧内编码模式预测算法．首先，对要编码的4×4块进行DCT变换，得到少数的几个DCT系数．然后，通过这几个系数计算块的特征方向和方差．最后，根据特征方向和方差计算最可能的几种预测模式．实验验证了该算法在不牺牲图像质量和压缩效率的基础上将帧内预测的计算复杂度平均降低了67．5％．     

H.264在高速公路图像监控系统中的运用

根据沪宁高速图像监控系统使用的现状,对比分析了MPEG-2与H.264两种视频压缩标准的在技术上的特点。分析表明H.264标准以其不可比拟的压缩率和低带宽占用率,必将取代高速公路视频监控系统现采用的标准。而被广泛应用。     

H.264视频技术在山西省高速公路监控系统中的应用

山西省在2003年已实现视频监控的模拟和MPEG-2混合的视频联网,随着路网的扩大,图像的增加,目前这种视频组网方式存在片区中心和省中心扩容较难,通信资源占用过大的问题,由于H.264技术已完善成熟,为了解决当前所面临的问题,决定对现有系统进行H.264图像传输改造,主要对片区输出图像在输出端视频分配后进行H.264编...     

An improved frame-layer bit allocation scheme for H.264/AVC rate control

In this paper, we aim at improving the video quality degradation due to high motions or scene changes. An improved frame-layer bit allocation scheme for H.264/AVC rate control is proposed. First, current frame is pre-encoded in 16×16 modes with a fixed quantization parameter (QP). The frame coding complexity is then measured based on the resulting bits and peak signal-to-ratio (PSNR) in the pre-coding stage. Finally, a bit budgetis calculated for current frame according to its coding complexity and inter-frame PSNR fluctuation, combined with the buffer status. Simulation results show that, in comparison with the H.264 adopted rate control scheme, our method is more efficient to suppress the sharp PSNR drops caused by high motions and scene changes. The visual quality variations in a sequence are also relieved.     

Fast Mode Decision Method Based on Historical Information for H. 264/AVC

Mode decision based on rate-distortion optimization algorithm brings high compression efficiency to H.264/AVC. However, heavy computation load is also added to the encoder at the same time. In order to reduce the computation burden of mode decision, this paper presented a fast mode decision method based on mode information of the previously coded frame. Moreover, all coding modes were activated when scene change occurs and a scheme to detect scene change was proposed. The simulation results show that compared to the original encoder, the proposed method achieves a reduction of over 38% encoding time and keeps almost the same PSNR and bitrate for a wide range of quantization parameter.     

Error Robust H.264 Video Transmission Schemes Based on Multi-frame

Multi-frame coding is supported by the emerging H. 264. It is important for the enhancement of both coding efficiency and error robustness. In this paper, error resilient schemes for H. 264 based on multi frame were investigated. Error robust H. 264 video transmission schemes were introduced for the applications with and without a feedback channel. The experimental results demonstrate the effectiveness of the proposed schemes.     

浅谈高速公路数字视频监控发布系统设计

根据视频监控的发展趋势,重点描述辽中环线高速公路数字视频监控发布系统的建设与应用。     

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介绍了路况视频监控系统的现状和视频转码概况,提出了一种基于H.264的异构视频转码服务器设计方案,阐述了异构视频转码的机理,给出了转码服务器的构成,包括任务调度、转码等模块具体实现,就视频数据进程间通信和网络传输中的数据处理等关键技术进行了分析。采用级联象素域转码结构,使用多线程调度管理、共享内存、环形缓冲等技术实现了该转码系统,并已成功应用于江苏省高速公路的数字视频监控系统中。     

基于DM6467的视频处理软件设计与优化

针对视频处理系统的实时性要求及视频压缩编码算法的现状,本文给出了基于TIDM6467的嵌入式视频处理软件及关键算法的优化实现.TMS320DM6467 ARM＋DSP的ARM核进行实时采集与传输视频数据,DSP内核进行视频处理;软件基于嵌入式Linux操作系统,采用达芬奇软件框架实现视频采集和编码服务器的设计.为了提高压缩效率,本文提出一种快速半像素运动估计算法,在最佳整像素点周围通过计算直接推导出最佳半像素点的位置,避免全搜索的大运算处理,快速半像素运动估计算法所用时间为标准全搜索算法所用时间的41％～57％.本文所设计的视频处理软件能达到实时进行高清视频的采集与压缩处理,并将处理的结果存入U盘,同时能通过扩展实现多路视频的处理.实现系统控制与存储等功能.     

Parallel-pipelined architecture of H.264 deblocking filter with adaptive dynamic power

In H.264,the computational complexity and memory access of deblocking filter are variable and depend on the video contents. In this paper,a pipelined VLSI architecture of deblocking filter with adaptive dynamic power is proposed. It avoids redundant computations and memory access by precluding the blocks which can be skipped. And the vertical and horizontal edges are simultaneously processed in an advanced scan order to speed up the decoder. As a result,the dynamic power of the proposed architecture can be ...     

H.26L视频正向差错跟踪技术

H.26L解码器端引入的差错掩盖技术在视频序列变化较为剧烈的情况下，效果并不十分理想，为更好地遏制差错的进一步传播，介绍了一种正向视频差错跟踪技术，这种技术只对当前帧中受到差错“污染”的宏块进行帧内编码，不会带来数据量的急剧增加，在此基础上提出了多帧分级更新策略，使得差错跟踪恢复后的数据量得以平滑地过渡，实验表明，该技术对于运动较为剧烈的图像的差错恢复效果较好。