#TITLE_ALTERNATIVE#

• Main Author: Seandy Sunjoko NIM : 13502038, Yohanes
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/9676
• Institution: Institut Teknologi Bandung

Abstract: <br /> <br /> <br /> <br /> <br /> <br /> In this final project has been implemented a real-time beat tracking system for musical audio signals <br /> <br /> <br /> <br /> <br /> <br /> named Rebana. While the song is being played, the system makes predictions about temporal position, <br /> <br /> <br /> <br /> <br /> <br /> tempo, and beat type of the next beat. <br /> <br /> <br /> <br /> <br /> <br /> There are several problems on real-time beat tracking. First, beats are not explicitly expressed in <br /> <br /> <br /> <br /> <br /> <br /> musical audio signals, but may be tracked by inferring various musical elements extracted from the <br /> <br /> <br /> <br /> <br /> <br /> signals, e.g onset times and chord changes. Second, real-time beat tracking faces a problem, i.e gardenpath <br /> <br /> <br /> <br /> <br /> <br /> error, thus multiple predictions are necessary. In order to make multiple predictions, in this final <br /> <br /> <br /> <br /> <br /> <br /> project a multiagent system is used. <br /> <br /> <br /> <br /> <br /> <br /> As information about onset times and chord changes is extracted from the received signals, agents keep <br /> <br /> <br /> <br /> <br /> <br /> making and evaluating predictions according to their own strategy. The predictions are then grouped <br /> <br /> <br /> <br /> <br /> <br /> and are selected by an entity called the manager based on some criteria. <br /> <br /> <br /> <br /> <br /> <br /> This system has been successfully implemented on Mandrake Linux 9.2 in a PC with single processor. <br /> <br /> <br /> <br /> <br /> <br /> It makes use several programming tools, i.e GCC, PortAudio, FFTW, and GTK+. Multithreading is <br /> <br /> <br /> <br /> <br /> <br /> applied in the implementation because the system is urged to perform several tasks together at a time. <br /> <br /> <br /> <br /> <br /> <br /> Its performance is tested by considering three sides, i.e the technicals, the correctness of selected <br /> <br /> <br /> <br /> <br /> <br /> predictions, and the response time. <br /> <br /> <br /> <br /> <br /> <br /> From the technical side, the tests reveal some cases that require special treatments related to the agents <br /> <br /> <br /> <br /> <br /> <br /> work. <br /> <br /> <br /> <br /> <br /> <br /> From the side of correctness of selected predictions, the test result of the system is quite good. It is <br /> <br /> <br /> <br /> <br /> <br /> shown by the high average of correctness value among 17 times of tracking, i.e 62.65%. The most <br /> <br /> <br /> <br /> <br /> <br /> common failures which often occur are that the temporal position of the predictions lies between two <br /> <br /> <br /> <br /> <br /> <br /> successive correct beats and the presence of unstable beats yielded by the manager. <br /> <br /> <br /> <br /> <br /> <br /> From the side of response time, the tests show that response time generally exceeds inter-beat interval <br /> <br /> <br /> <br /> <br /> <br /> as the upper limit of acceptable response time. It is obviously shown as there are only three of 17 times <br /> <br /> <br /> <br /> <br /> <br /> of tracking giving tolerable response time. The factors causing it are the time that must be repeatedly <br /> <br /> <br /> <br /> <br /> <br /> spent by the manager to wait as predictions from the agents are gathered, the time spent in checking <br /> <br /> <br /> <br /> <br /> <br /> chord changes, and the scheduling mechanism of threads performed by the operating system. <br /> <br /> <br /> <br /> <br /> <br /> Therefore, this beat tracking system is unfortunately too slow to be acknowledged as a real-time <br /> <br /> <br /> <br /> <br /> <br /> application. <br />