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Clock synchronization for distributed media applications
Author(s) -
Distler Thomas James,
Ouyang Jinsong
Publication year - 2007
Publication title -
software: practice and experience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 70
eISSN - 1097-024X
pISSN - 0038-0644
DOI - 10.1002/spe.815
Subject(s) - software portability , computer science , synchronization (alternating current) , interoperability , software , embedded system , key (lock) , computer hardware , operating system , host (biology) , block (permutation group theory) , computer network , ecology , channel (broadcasting) , biology , geometry , mathematics
Current video wall technology relies on custom processing hardware to drive the individual display channels. This hardware is both expensive to design and to maintain. Given that modern off‐the‐shelf computers have a significant amount of computing power, future video displays can be driven with this hardware at a lower cost. By using mass‐produced computers and a standard commercial operating system, the benefits of economies of scale can be brought to the custom video wall market. This paper describes a Windows library that provides the synchronized timing support necessary to drive a video wall with consumer hardware. The goal is to provide a key building block for the media software that will process the incoming video stream. This library exports several interfaces to the host software and provides support for synchronized timers, a synchronized clock, and reliable multicast messaging. The library uses common Windows APIs and protocols for maximum interoperability and portability. Through empirical testing, we are able to show that synchronization between any two machines in the system can be maintained to within 12 ms when run on Windows XP SP2. This synchronization is also shown to be consistent even when there is a heavy load on the processor. As a result, this library will successfully allow a commercial video wall to be driven from media software running on consumer hardware and software. Copyright © 2007 John Wiley & Sons, Ltd.