Eun-Seok Ryu

Home gateway for three-screen TV using H.264 SVC and raptor FEC

This paper describes the design and implementation of a multimedia home gateway for threescreen television (3STV) service. The proposed in-home wireless network uses scalable video coding (SVC) and unequal error protection with Raptor forward error correction (FEC) for maximizing the quality of experience (QoE) over the variable-bandwidth, error-prone wireless network. The gateway incorporates (a) dynamic SVC layerswitching, which enables the server to perform selecting appropriate layers from SVC bitstreams, (b) adaptive Raptor FEC, which controls the overhead of Raptor FEC according to packet loss rate (PLR), (c) an efficient combination of (a) and (b), and (d) slice group-based selective streaming in the overall gateway architecture. The paper explains the home gateway architecture as well as experiments for performance evaluation as compared to that of traditional SVC streaming. In the experiments conducted, gains in video quality vary from 2 to 5dB in peak signal-to-noise ratio (PSNR), with corresponding subjective improvements. Overall reductions of bit rate at the input to the home gateway vary from 28% to 36%1.

Power aware HEVC streaming for mobile

Mobile devices, increasingly equipped with high capability processors and connected with fast wireless networks, have become a major consumer of multi-media content. Limited battery life on mobile devices makes power saving a critical factor in delivering a good user experience. This paper proposes a power aware streaming system that combines the emerging High Efficiency Video Coding (HEVC) standard and the Dynamic Adaptive Streaming over HTTP (DASH) standard. The proposed system uses power aware HEVC encoding technologies and client side power adaptation logic to adaptively control power consumption on the client device. The proposed power aware HEVC streaming system can improve quality of experience by setting full-length video playback as clients objective. Demonstration of the proposed power aware HEVC system is available on the ASUS Transformer Xfinity (TF700T) tablet using an ARM processor.

Widget integration framework for context-aware middleware

Widget Integration Framework (WIF) is a framework that covers diverse widgets and their interactions with higher layers above. The framework offers several advantages of supporting a programming abstraction over widgets, supporting high reliability, run-time widget binding to the middleware and augmenting a service discoverer with available widget state information. This paper explains the processes of designing the WIF, including implementation, and applying WIF to the middleware. As an example, we explain a location-based service that uses a location positioning widget in a middleware employing WIF.

Telerobotic Haptic Exploration in Art Galleries and Museums for Individuals with Visual Impairments

This paper presents a haptic telepresence system that enables visually impaired users to explore locations with rich visual observation such as art galleries and museums by using a telepresence robot, a RGB-D sensor (color and depth camera), and a haptic interface. The recent improvement on RGB-D sensors has enabled real-time access to 3D spatial information in the form of point clouds. However, the real-time representation of this data in the form of tangible haptic experience has not been challenged enough, especially in the case of telepresence for individuals with visual impairments. Thus, the proposed system addresses the real-time haptic exploration of remote 3D information through video encoding and real-time 3D haptic rendering of the remote real-world environment. This paper investigates two scenarios in haptic telepresence, i.e., mobile navigation and object exploration in a remote environment. Participants with and without visual impairments participated in our experiments based on the two scenarios, and the system performance was validated. In conclusion, the proposed framework provides a new methodology of haptic telepresence for individuals with visual impairments by providing an enhanced interactive experience where they can remotely access public places (art galleries and museums) with the aid of haptic modality and robotic telepresence.

Channel-adaptive video transmission using H.264 SVC over mobile WiMAX network

The quality of video transmission over mobile worldwide interoperability for microwave access (WiMAX) network can be severely degraded due to the effect of fading and handoff. To cope with this problem, we propose a channel-adaptive video transmission method using H.264 scalable video coding (SVC) in this paper, which not only dynamically extracts the layer of bit stream based on the available channel bandwidth (ACBW), but also minimizes the error propagation during handoff. Firstly, the ACBW and the handoff in the mobile WiMAX are estimated by analyzing channel parameters including the carrier to interference and noise ratio (CINR). Secondly, the streaming server extracts the next transmission layer according to the estimated ACBW to support the better quality and controls the smart frame skipping adaptively based on the handoff detection. Experimental results indicate that the proposed method can improve the performance of the video streaming over mobile WiMAX network.

Quality Analysis of Massive High-Definition Video Streaming in Two-Tiered Embedded Camera-Sensing Systems

This paper presents the quality analysis results of high-definition video streaming in two-tiered camera sensor network applications. In the camera-sensing system, multiple cameras sense visual scenes in their target fields and transmit the video streams via IEEE 802.15.3c multigigabit wireless links. However, the wireless transmission introduces interferences to the other links. This paper analyzes the capacity degradation due to the interference impacts from the camera-sensing nodes to the main aggregation link (AL), that is, the link from AL transmitter to AL receiver. For the study, IEEE 802.15.3c specific path-loss and antenna models are used for more precise evaluation. Finally, the quality analysis results are presented in terms of the number of cameras in a cell, beamwidth, the transmit power at camera sensor nodes, and the transmit power at AL nodes. With the listed factors, the analysis quantifies the actual video quality degradation in the presented camera sensing system.

Prediction complexity-based HEVC parallel processing for asymmetric multicores

This paper proposes a novel Tile allocation method considering the computational ability of asymmetric multicores as well as the computational complexity of each Tile. This paper measures the computational ability of asymmetric multicores in advance, and measures the computational complexity of each Tile by using the amount of HEVC prediction unit (PU) partitioning. The implemented system counts and sorts the amount of PU partitions of each Tile, and also allocates Tiles to asymmetric big.LITTLE cores according to their expected computational complexity. When experiments were conducted, the amount of PU partitioning and the computational complexity (decoding time) showed a close correlation, and average performance gains of decoding time with the proposed adaptive allocation were around 36 % with 12 Tiles, 28 % with 18 Tiles, and 31 % with 24 Tiles, respectively.

Priority-based selective H.264 SVC video streaming over erroneous multiple networks

This paper provides new optimal H.264 SVC video transmission method over multiple networks which have different packet drop rates. The proposed method has two steps : First, the proposed method prioritizes SVC layers and slice groups by their importance using flexible macroblock ordering (FMO). Secondly, it allocates them to the prioritized networks by packet loss rate. The experimental result shows that proposed method can improve video quality by around 3 dB in PSNR, and has better error resilience features than conventional methods.

Towards robust UHD video streaming systems using scalable high efficiency video coding

With a new video coding standard high efficiency video coding (HEVC), the ultra high definition (UHD) TV service with robust video streaming technology is emerging in the TV industry. This paper addresses the system architecture for the UHD video streaming and proposes two main ideas: (i) picture prioritization method, (ii) error concealment mode signaling (ECMS). In the experiments using HEVC reference model conducted, the proposed picture prioritization method shows the gains in video quality from 2.2 to 7.5 dB in Y-PSNR, and the error concealment mode signaling gains from 0.2 to 2.5 dB in Y-PSNR, with corresponding subjective improvements.

Priority-based selective H.264 SVC streaming over erroneous converged networks

This paper provides a detailed description and discussion of new optimal H.264 scalable video coding (SVC) transmission method over multi-path networks that have variable packet loss rates (PLR). The proposed method has three steps: (1) using flexible macroblock ordering (FMO), it prioritizes SVC layers and slice groups (SG) according to their affect on video quality; (2) it measures current channel status and predicts future bandwidths (BW); and (3) it allocates SVC layers and SGs to the prioritized channels by PLR. Experiments show that the proposed selective streaming method can improve video quality as much as 3.4 dB in peak signal-to-noise ratio (PSNR), and has better error resilience than traditional streaming methods.