Yu Wang's research while affiliated with Institute for Infocomm Research and other places

In wireless video transmission, the bursty packet losses of the channel will severely impair the reconstructed video quality. This paper presents an error-resilient packet reordering scheme to improve the error robustness of the transmitted video. Firstly, we propose a compressed domain transmission distortion model to efficiently estimate the importance of every video packet. Then based on this importance index, we create an intelligent transmission order for all packets in a transmission group to alleviate the impact of bursty losses on the video quality. Simulation results demonstrate that the proposed scheme can improve the reconstructed video quality by up to 1.8 dB compared with conventional methods. Moreover, the computational complexity of the proposed method is very low thus it is highly desirable for practical video streaming applications.

A compressed-domain distortion model is proposed for lossy transmission of compressed video. The model has low complexity and is suitable for real-time mobile applications, where resources are limited, to perform network resource allocation, performance control and system optimization. Simulation on various test sequences has demonstrated the robustness and accuracy of this model.

This paper addresses the quantization parameter (QP) selection problem in H.264 spatially scalable video coding (SVC). For frame level rate control in SVC, it is important to have an accurate QP selection scheme such that the target bit rate of each coding layer will be achieved. In this paper, we present an adaptive rate-quantization (R-Q) model to select the appropriate QP for each inter frame in spatial enhancement layers according to the target bit rate. The proposed algorithm introduces an efficient coding complexity estimation method by taking into consideration the inter-layer dependency between different spatial layers. Based on the coding complexity information, the R-Q model parameters can be adaptively updated. Experimental results demonstrate that compared to the traditional method, the proposed method provides better estimation accuracy for bit rate in terms of target bits mismatch error and thus it is very desirable for H.264/SVC rate control applications.

Video communication can be severely afflicted by burst packet loss over unreliable networks. In this paper, we present a novel error resilient slice interleaving strategy for improving the robustness of video transmission over bursty loss channels. The interleaving pattern is designed to distribute the burst packet loss intelligently in a scattered pattern to guarantee that each lost slice has, as many as possible, spatial and temporal neighbors that are correctly received. This scheme can greatly strengthen the error concealment performance compared with traditional methods. Experimental results on different video sequences demonstrate the effectiveness of the proposed approach.

Video communication is often afflicted by packet loss over u nreliable networks. To alleviate the quality degradation in the situation of packet loss, this paper proposes a novel error resilient slice interleaving method for compressed video packetization. Each packet is constructed by interleaving independently decodable slices of the coded video bit-stream in consecutive frames. The optimal interleaving pattern for minimizing the overall distortion of the decoded video, subject to a delay constraint, is determined based on the error concealment technique employed at the user end. Compared with traditional errorresilient methods, this scheme greatly improves the overall performance without requiring an increase in bit-rate. Experimental results on different video sequences demonstrate the effectiveness of the proposed approach.

Video transmission over wireless networks suffers from packet loss due to either temporary packet drop or fadinginduced bit errors. To ensure that the quality of the decoded video is not overly affected by the channel unreliability, the video applications have to provide sufficient robustness. In this paper, a novel slice interleaving algorithm is proposed for compressed video packetization. Each packet is constructed by interleaving independently decodable slices of the coded video bit-stream in a group of frames. We group slices into packets according to the maximum minimal distance of these slices. The scattered pattern guarantees that each lost slice has, as many as possible, spatial and temporal neighbors that belong to other correctly received packets. This scheme greatly strengthens the error concealment performance compared with traditional methods. Experimental results demonstrate the superiority of the proposed algorithm.