Storage technique for real-time streaming of layered video |
| |
Authors: | Sooyong Kang Sungwoo Hong Youjip Won |
| |
Affiliation: | (1) Division of Information and Communications, Hanyang University, Seoul, South Korea;(2) Department of Electronics and Computer Engineering, Hanyang University, Seoul, South Korea |
| |
Abstract: | Scalable streaming technology has been proposed to effectively support heterogeneous devices with dynamically varying bandwidth.
From the file system’s point of view, scalable streaming introduces another dimension of complexity in disk scheduling. Most
of the existing efforts on multimedia file systems are dedicated to I/O scheduling algorithm and data placement scheme that
efficiently guarantee I/O bandwidth. The important underlying assumption in these efforts is that most of the multimedia file
accesses are simple playback operations and therefore are sequential. However, this workload characteristic is not valid in
scalable streaming environment. In a scalable streaming environment, i.e., when only a subset of imagery is retrieved, the
playback does not necessarily coincide with the sequential access on the file. The current file structure and the file system
organization leaves much to be desired for supporting scalable streaming service. In this work, we propose a file system scheme,
Harmonic Placement to efficiently support scalable streaming. The basic idea of Harmonic placement is to cluster the frequently accessed layers
together to avoid unnecessary disk seeks. The data blocks are partitioned into two sets with respect to the layers: lower layers and upper layers. In Harmonic placement, the data blocks in the lower layers are placed with respect to their frame sequence and the
data blocks in the upper layers are clustered according to the layers they belong to. We develop elaborate performance models
for three different file system schemes: Progressive placement, Interleaved Placement and Harmonic Placement. We investigate the performance of the file server with different file system schemes. It was found that file system performance
is very sensitive to the file organization scheme. When most of the service requests are for low-quality video (e.g., 128
Kbits/s ISDN), Progressive placement scheme supports twice as many sessions as the Interleaved placement scheme. When most
of the service requests are for high-quality video (e.g., 1.5 Mbits/s MPEG-2 DVD quality), Interleaved placement can support
twice as many requests as Progressive placement. In both cases, Harmonic placement scheme yields the most promising performance.
Primitive version of this work has appeared on Proceedings of NOSSDAV ’06, Providence, Rhode Island, USA.
This work is in part funded by KOSEF throught National Research Lab (ROA-2007-000-200114-0) and by HY-SDR center at Hanyang
University. |
| |
Keywords: | Scalable streaming File system Storage Multimedia Layered encoding |
本文献已被 SpringerLink 等数据库收录! |
|