OpenVideoWalls: an Open-Source System for Building Video Walls with Recycling Heterogeneous Displays

With the rapid development of the consumer electronics industry, how to efficiently recycle electronic waste such as display screens has become an important issue. Traditional display screen recycling methods are time-consuming and labor-intensive with a low recycling rate. Therefore, we propose an open-source and low-cost display screen recycling method, which enables everyone to assemble old displays into a larger display screen (i.e., video walls) and ensure premium quality even with distinct specifications among the multiple displays. In this paper, we focus on addressing the unique challenge of video walls that the video may be out of sync among multiple displays. Our proposed algorithm attaches a carefully designed timestamp to each frame on the server side and manages the frames based on the timestamps on the client side to achieve video synchronization. We deploy the synchronization algorithm in an end-to-end video wall system including a streaming server and a client (i.e., a video wall) consisting of multiple displays and their respective controlling Raspberry Pis. The evaluation results show that our algorithm effectively ensures video synchronization among different displays and can immediately resume synchronization after being affected by network fluctuations. Meanwhile, our algorithm does not introduce additional latency to the system or reduce video quality.