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Skew detection and compensation for Internet audio applications

Orion Hodson, Colin Perkins and Vicky Hardman

Proceedings of the IEEE International Conference on Multimedia and Expo, New York, NY, USA, July 2000.

DOI:10.1109/ICME.2000.871096

Long lived audio streams, such as music broadcasts, and small differences in clock rates lead to buffer underflow or overflow events in receiving applications that manifest themselves as audible interruptions. We present a low complexity algorithm for detecting clock skew in network audio applications that function with local clocks and in the absence of a synchronization mechanism. A companion algorithm to perform skew compensation is also presented. The compensation algorithm utilises the temporal redundancy inherent in audio streams to make inaudible playout adjustments. Both algorithms have been implemented in a simulator and in a network audio application. They perform effectively over the range of observed clock rate differences and beyond.

Download: icme2000.pdf

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