Performance controller for physical modelling FPGA sound synthesis of musical instruments
pp. 331-350
in: Rolf Bader (ed), Sound - perception - performance, Berlin, Springer, 2013Abstract
Performance controller for Physical Modeling algorithms need to change parameters of the model in real-time, e.g. bowing pressure or finger position in violin playing. As the FPGA implementation is the only real-time physical model for whole geometry musical instruments, changing these parameters during the performance needs a continuous data flow between the FPGA chip and a performance controller. This paper suggests an PCIe interface within a PCIe root complex to exchange parameter and data on a Windows platform. Therefore, several hardware devices need to cooperate. The solution suggested is an FPGA displaying itself as a memory device to the OS, where memory tables can be written or read. Using a Kernel as well as a User Mode Driver, a package protocol is implemented to submit the controller data to the VHDL architecture on the FPGA, where the physical parameters of the device are changed in real-time. With this implementation, also the results of the physical model data can be transferred to the User Mode level to access the displacement and velocity values of the model. Using an Audio device interface, again within the OS, the sound is then played back via an audio setup. Then, using appropriate sliders or the like, the performance parameter can be changed by a user and the resulting sound can be listened to instantaneously.