Search

This paper presents a new Scalable Video Codec (SVC)-based hybrid adaptive video streaming scheme, named HAVS, for mobile devices in wireless environments. The proposed approach takes two existing video streaming technologies, viz., progressive download and adaptive streaming, and switches them in a hybrid manner. To this end, HAVS employs the H.264/SVC encoding scheme, where each video chunk is encoded into one base layer and several enhancement layers. Since clients request the base layer every time a video is streamed, HAVS performs progressive download for the base layer and adaptive streaming for the enhancement layers. Through wireless test-bed experiments, it is demonstrated that the proposed scheme can be easily implemented on mobile devices without any server-side modification. This scheme effectively prevents video freeze thereby providing better quality video streaming than the existing non-hybrid streaming technologies. [ABSTRACT FROM PUBLISHER]

Designing a real-time video-streaming system involves the challenges of, network congestion and bandwidth fluctuations, lowering the video quality. In this paper, a realtime video-streaming system is designed and implemented for scalable video coding (SVC) with an adaptive control scheme, containing macro- and micro-control, to resolve the bandwidth fluctuation and network congestion. Under macro-control, the server allocates appropriated video-streaming of SVC for heterogeneous clients based on terminal capacity and network conditions. Under micro-control, the server changes the video frame rate based on video bit rates and network bandwidth. The streaming system with the adaptive control scheme is implemented to improve the peak signal noise ratio (PSNR) by 4.01 % to 10.89 % of the Foreman and Stefan videos. [ABSTRACT FROM AUTHOR]

The pace at which powerful portable wireless consumer devices such as smartphones and tablets have been adopted has not been matched by the ability of mobile networks to deliver high-quality video streams consistently to such nomadic users. In this work, we propose CMT-NEMO, a novel concurrent multipath transfer scheme for the delivery of scalable video content to users in multihomed mobile networks such as those expected to be found in public transport scenarios. Recent research in this context has shown that the single largest limiting factor for perceived video quality is the overhead introduced by path switching operations in multihomed mobile networks. CMT-NEMO eliminates the need for path switching and, by removing the associated path switching latency, provides a substantial performance improvement across a wide range of bandwidths and test sequences. An average Y-PSNR improvement of 5.9 dB is achieved when compared with previously proposed schemes. [ABSTRACT FROM AUTHOR]

H.264/SVC has been widely adopted to smart CE devices for network-adaptive video transmission. However, current H.264/SVC does not support sufficiently high subjective QoS (Quality of Service) because its scalability methods provide only coarse-grained network adaptivity. To address this problem, we propose a Scalable ROI (SROI) algorithm that applies the ROI (Region of Interests) concept to SVC (Scalable Video Codec). While existing methods use a fixed size of enhancement layers, our method utilizes only ROI area as an enhancement layer so that it can improve subjective QoS with low transmission overhead. Through some experiments, we show that our method can increase PSNR (Peak Signal-to-Noise Ratio) by 4~5 dB in ROI areas. [ABSTRACT FROM PUBLISHER]

Consumer demand for portable wireless devices such as smartphones or tablets capable of receiving high quality video content has risen sharply in recent years. This paper considers the real-time delivery of streamed H.264 Scalable Video Coding (SVC) content to users of such devices within mobile networks (e.g. situations where they are part of a group moving together on a bus or a train). We propose a novel scheme for the multipath delivery of H.264 SVC content to users in multihomed mobile networks .By implementing our scheme on a realistic testbed, we show that it offers a significant improvement in received video quality over previously proposed alternative schemes1. [ABSTRACT FROM AUTHOR]