A neural network-based video bit-rate control algorithm for variable bit-rate applications of versatile video coding standard

Versatile video coding is a new video coding standard that has more capabilities and higher coding efficiency compared with its predecessor. Practical video storage and transmission applications face constrained buffer size and available bandwidth. It is necessary to design the appropriate rate control algorithm to overcome such challenges. In this paper, the non-linear relationship between consumed bits, buffer size, and quantization parameter is estimated by taking the advantages of artificial neural networks, and a rate control algorithm is developed for real-time variable bit rate applications of the versatile video coding standard. The proposed rate control algorithm performs the control action in only one step that results in faster control action. The experimental results show that the proposed algorithm controls the bit-rate as well as the buffer state. Also, the rate–distortion analysis shows that the well-known $\lambda$-domain algorithm has only 2.7% bit-rate reduction in comparison with the proposed method.     

Online traffic smoothing for delivery of variable bit rate media streams

Traffic smoothing for delivery of online variable bit rate (VBR) media streams is one of the most important problems in designingmultimedia systems. Given an available client buffer, a window size, and a window-sliding size, previous window-based online smoothing methods have tried to reduce the peak bandwidth allocated in each window. However, as bandwidths allocated in different windows are minimized independently, these methods require a large peak bandwidth for transmitting an entire stream. In this paper, a new window-based method is proposed. It introduces two new ideas, the dynamic windowsliding size and the aggressive workahead, for delivery of online VBR media streams. Our aggressive and dynamic window sliding (ADWS) method can automatically decide on the suitable window-sliding sizes for different windows. Thus, the allocated peak bandwidth can be further reduced. By examining various media streams, ADWS is shown to be effective and efficient. Considering the online transmission of the movieStar Wars with a 90-kB client buffer, ADWS yields 13% less in peak bandwidth, compared with the bestknown window-based online smoothing algorthm SLWIN(1). Its computation cost (the window-sliding number) is 75% of that required by SLWIN(1).This work was partially supported by NSC, Taiwan, under grants. NSC88-2213-E-001-011, NSC88-2213-E-001-012, and NSC88-2213-E-001-025. A primitive version of this work appeared in IEEE INFOCOM'99 [7].     

Adaptive block tree structure for video coding

The Joint Video Exploration Team (JVET) has studied future video coding (FVC) technologies with a potential compression capacity that significantly exceeds that of the high-efficiency video coding (HEVC) standard. The joint exploration test model (JEM), a common platform for the exploration of FVC technologies in the JVET, employs quadtree plus binary tree block partitioning, which enhances the flexibility of coding unit partitioning. Despite significant improvement in coding efficiency for chrominance achieved by separating luminance and chrominance tree structures in I slices, this approach has intrinsic drawbacks that result in the redundancy of block partitioning data. In this paper, an adaptive tree structure correlating luminance and chrominance of single and dual trees is presented. Our proposed method resulted in an average reduction of −0.24% in the Y Bjontegaard Delta rate relative to the intracoding of JEM 6.0 common test conditions.     

基于DSP的MPEG-4网络视频编码器实现

给出基于TMS320DM642实验平台的MPEG-4网络实时编码实现方法，阐述了系统实现结构框图，在分析DM642特点的基础上，讨论了网络视频编码器的实现和优化策略，并给出了较好的实验结果。     

Adaptive rate control algorithm for low power video coding systems

With the recent development of third-generation communication technologies, low power video coding system (such as PDA, Handphone or system on chip) has found wide applications such as live video using a PDA and sharing it among friends, etc. However, video coding in a low power system has two major hurdles to overcome: (1) In a low power system, video coding needs to meet the rigorous constraints of the available memory and computational capacity; (2) In a low power system, the computational power allocated to video coding may vary drastically (in bursts). In this paper, a new adaptive rate control algorithm is proposed for low power video coding system. This adaptive rate control scheme takes into account the time constraint of a low power system, and its bit allocation depends not only on the available data bits, but more importantly, on the available coding time. Experimental results show that, compared to the existing rate control scheme, the new algorithm can always achieve the maximum frame rate, maximize the utilization of the available bandwidth and computing power, increase the average PSNR, and improve the subjective perceptual quality of the reconstructed video.     

Real-time moving object segmentation in H.264 compressed domain based on approximate reasoning

This paper presents a real-time segmentation algorithm to obtain moving objects from the H.264 compressed domain. The proposed segmentation works with very little information and is based on two features of the H.264 compressed video: motion vectors associated to the macroblocks and decision modes. The algorithm uses fuzzy logic and allows to describe position, velocity and size of the detected regions in a comprehensive way, so the proposed approach works with low level information but manages highly comprehensive linguistic concepts. The performance of the algorithm is improved using dynamic design of fuzzy sets that avoids merge and split problems. Experimental results for several traffic scenes demonstrate the real-time performance and the encouraging results in diverse situations.     

基于数学形态学视频压缩方法研究

将采集到的视频图像进行分割，在传统运动补偿预测编码的基础上运用了数学形态学的理论方法，通过形态变换对宏块中的不规则小块进行提取，达到滤出不规则小块的目的，再对不规则小块的大小、位置、运动矢量进行编码，该方法可以有效地减少帧间误差DFD，其效果与压缩标准MPEG-1相比，图像的压缩比和信噪比得到较好地改善。     

基于H.264的远程网络视频监控系统

提出了一种基于H.264的远程网络视频监控系统.介绍了突发情况警报的简易实现方案及视频数据网络传输与处理等主要技术.同时从网络带宽节省和实时编码的角度出发,根据视频监控图像序列的特点,提出了一种帧间模式选择的改进方案.测试结果表明,该方案可在视频质量几乎没有损耗的前提下,大幅度提高编码速度,并且压缩率也得到了提高.     

嵌入式MPEG-4视频流媒体服务器设计

利用GPI(通用公共授权)的开源Linux代码,介绍了嵌入式MPEG-4视频服务器的设计和研制,阐述了在嵌入式Linux平台上设计、优化设备驱动程序和视频流媒体服务器的策略。本设计采用GO7007SB作为硬件压缩芯片,使用AT91RM9200芯片作为主要控制芯片,实现了带100 MHz以太网接口的高性能网络摄像机。在约1 Mbit/s的传输率下,可以达到CCIR-601格式的视频信号的实时压缩和传输能力。