NMP - a new networked music performance system

Although IT has penetrated into nearly every aspect of the work and life of human beings, music professionals still stick to the traditional way of carrying out rehearsals and concerts. Music performance in this way requires physical presence of the participants and has a number of inherent limitations. We introduce in this paper a prototype of a novel networked music performance system that enables the music professionals and enthusiasts to play with each other through cyberspace. An application like this is bandwidth demanding, highly delay-sensitive and requires the synchronization of the audio streams. Hence, the support from underlying end-systems and networks is critical. However, the current source coding mechanisms and the best-effort nature of the Internet poses many challenges to achieve the desired quality of service. We have implemented the prototype in a local area network environment on Linux PCs. The system contains four major interactive components and enables two different application scenarios of real-time rehearsal and rehearsal on-demand multi-channel audio transport and different audio compression schemes are supported. Our evaluation results based on both subjective and objective measurements show that the system suffices the audio quality level for the target application. In the future, we extend our system to larger scale and consider more realistic network conditions in the Internet. Moreover, the support for MPEG-4 AAC codec for even better quality of multi-channel audio streaming and enhanced audio quality under the same bandwidth constrains are added.