An Analysis of Time Drift in Hand-Held Recording Devices.

Automatic synchronization of audio and video recordings from events like music concerts, sports, or speeches, gathered from heterogeneous sources like smartphones and digital cameras, is an interesting topic with lots of promising use-cases. There are already many published methods, unfortunately none of them takes time drift into account. Time drift is inherent in every recording device, resulting from random and systematic errors in oscillators. This effect leads to audio and video sampling rates deviating from their nominal rates, effectively leading to different playback speeds of parallel recordings, with deltas measured up to 60 ms/min. In this paper, we present experiments and measurements showing that time drift is an existing problem that cannot be ignored when good quality results are demanded. Therefore, it needs to be taken care of in future synchronization methods and algorithms.