Performance Analysis of a Godot Game-Agnostic Streaming Tool

Abstract: Background. Streaming games is traditionally done with video and audio both for watching on websites like Twitch and YouTube or playing via cloud gaming services. Streaming with video and audio requires good internet speeds to be of satisfactory quality therefore compression algorithms are used. Compression algorithms decrease bandwidth usage but it also lowers the quality of the stream. An alternative would be to stream game states and user inputs to recreate the game state for the viewer, this would lower the bandwidth usage while not compromising the quality. Objectives. This thesis aims to explore and compare a generalized streaming tool for the Godot engine. Where game states and user inputs are sent between two game instances to synchronize the host game with the client game. The tool will then be compared to a video and audio streaming setup in terms of image quality, bandwidth, and processing power. Methods. A combination of state replication and client simulation has been implemented for a streaming tool for games. Bandwidth, image quality, and processing power metrics are gathered for seven games for streaming with state replication and client simulation. The performance metrics have also been gathered when streaming video and audio data. To validate the streaming tool, the seven games were visually compared between images from the host and client of the streaming tool. Results. Compared to streaming video and audio data there was shown to be an overhead for streaming game states and user inputs. This overhead causes multiple games to have significant performance issues in terms of processing power for the CPU. In terms of image quality and bandwidth, the generalized streaming tool performed better.  Conclusions. The results showed that there is a possibility for a generalized streaming tool for the Godot engine to be successfully implemented. The implementation of the Godot streaming tool didn't work perfectly for each tested game, but most games use less bandwidth and there's no quality loss regarding the image quality. However, the streaming tool requires better hardware than traditional video and audio streaming.