Screencast dissected

Abstract

Dynamic and adaptive binding between computing devices and displays is increasingly more popular, and screencast technologies enable such binding over wireless networks. In this paper, we design and conduct the first detailed measurement study on the performance of the state-of-the-art screencast technologies. Several commercial and one open-source screencast technologies are considered in our detailed analysis, which leads to several insights: (i) there is no single winning screencast technology, indicating rooms to further enhance the screencast technologies, (ii) hardware video encoders significantly reduce the CPU usage at the expense of slightly higher GPU usage and end-to-end delay, and should be adopted in future screencast technologies, (iii) comprehensive error resilience tools are needed as wireless communication is vulnerable to packet loss, (iv) emerging video codecs designed for screen contents lead to better Quality of Experience (QoE) of screencast, and (v) rate adaptation mechanisms are critical to avoiding degraded QoE due to network dynamics. Furthermore, our measurement methodology and open-source screencast platform allow researchers and developers to quantitatively evaluate other design considerations, which will lead to optimized screencast technologies.