Sub-millisecond Video Synchronization of Multiple Android Smartphones

TL;DR

This paper introduces a publicly-available Android app enabling synchronized video recording across multiple smartphones with sub-millisecond accuracy, suitable for high-dynamic environment applications in computer vision and robotics.

Contribution

It presents a generalized timestamping model validated on 47 devices and estimates low time drift, making smartphones comparable to professional multi-view systems.

Findings

Achieved sub-millisecond synchronization accuracy.

Validated timestamping model on diverse Android devices.

Demonstrated practical applications like panorama stitching.

Abstract

This paper addresses the problem of building an affordable easy-to-setup synchronized multi-view camera system, which is in demand for many Computer Vision and Robotics applications in high-dynamic environments. In our work, we propose a solution for this problem -- a publicly-available Android application for synchronized video recording on multiple smartphones with sub-millisecond accuracy. We present a generalized mathematical model of timestamping for Android smartphones and prove its applicability on 47 different physical devices. Also, we estimate the time drift parameter for those smartphones, which is less than 1.2 msec per minute for most of the considered devices, that makes smartphones' camera system a worthy analog for professional multi-view systems. Finally, we demonstrate Android-app performance on the camera system built from Android smartphones quantitatively on setup with lights and qualitatively -- on panorama stitching task.