Design and implementation of BeatME Server for Networked Musical Performance

摘要

Networked Musical Performance (NMP) occurs when a group of musicians, which are located in places that are physically separated, interacting via a network to play music together as if the musicians are located in the same room. NMP system is susceptible to latency. The limit of total latency acceptable in a music performance is 30 milliseconds. The research is conducted to find out how BeatME Server application can receive input from BeatME Client applications over the network and synthesize sound based on the input, with acceptable total latency in a musical performance. BeatME Server application is developed using MIDI command as input, and OSC as the method of client and server communication. Audio synthesis is performed using SoundFont standard. This application is tested on LAN. The work shows that the average latency obtained when the communication conducted via LAN is 3 milliseconds. The biggest factor of the latency is the difference between the time when the audio data was sent by BeatME Server and the time when the sound is generated by the soundcard. Therefore, it is important to select the right audio driver and audio buffer size.