<p>The current Internet is not reliable; packet loss rates are frequently high, and varying over time. Transmitting high-quality interactive video over the Internet is challenging because the quality of compressed video is very susceptible to packet losses. Loss of packets belonging to a video frame manifests itself not only in the reduced quality of that frame but also in the propagation of that distortion to successive frames. This error propagationproblem is inherent in many motion-based video codecs due to the interdependence of encoded video frames. Recently a new approach to improving error resilience of compressed video, called Recovery from Error Spread using Continuous Updates(RESCU), has been proposed. In RESCU, picture coding patterns can be adjusted to enable the use of transport level recovery schemes in recoveringlost packets without having to introduce any playout delay at the receiving end. In this thesis, we propose dynamic loss recovery schemes which when combined with RESCU, effectively alleviate error propagation in the transmission of interactive video. In these schemes, picture coding patterns are dynamically adapted to current network conditions in order to maximize the effectiveness of hybrid transport level recovery (employing both forward error correction and retransmission) in reducing error propagation. Through an experimental study based on actual Internet transmission traces representing various network conditions, we study the effectiveness and limitations of our proposed techniques and compare their performance with that of existing video error recovery techniques such as Intra-H.261 and H.263+(NEWPRED). Our study indicates that the proposed techniques exhibit better error resilience and incur much less bit overhead than existing video error recovery techniques. This document also describes the implementation of a prototype interactive video transmission system employing a proposed loss recovery scheme.<P>
| Identifer | oai:union.ndltd.org:NCSU/oai:NCSU:etd-20000215-204201 |
| Date | 16 February 2000 |
| Creators | Joshi, Srinath R |
| Contributors | Dr. Injong Rhee, Dr. Douglas Reeves, Dr. George Rouskas |
| Publisher | NCSU |
| Source Sets | North Carolina State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://www.lib.ncsu.edu/theses/available/etd-20000215-204201 |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to NC State University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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