Trabalho de Conclusão de Curso de Graduação
Desenvolvimento em HDL de uma alternativa de hardware dedicado para síntese de áudio utilizando o protocolo MIDI
Fecha
2015-12-17Autor
Felzmann, Isaías Bittencourt
Institución
Resumen
An audio synthesizer is a system able to play musical notes according to a determined
pattern, mimicking real instruments. In musical theory, a note pitch is directly related to the
fundamental harmonic frequency, as is an instrument characteristics (timbre) to the harmonics
distribution, given that all harmonics are multiples in frequency of the first one. The Loris
analyser models musical sounds decomposing them into harmonics, represented as frequencyand
amplitude-variable in time sine waves. Based on this modelling, we propose a
synthesizer, implemented in dedicated hardware, that recreates the sounds by modelling them
from the multiple sine waves, based on communication using the MIDI protocol. The main
challenge is the time aspect, because creating each one of the waves uses resource-consuming
multiplication operations, and thousands of those should be generated in a few microseconds,
because synthesizers are commonly evaluated according to the number of simultaneous notes
they can play. The proposed system, limited by the programmable logic device in which it
was tested, can generate up to 2048 simultaneous sine waves, enough for playing singleinstrument
music correctly, with good performance and realistic enough sound quality,
although some noise issues are perceptible. This result is a proof of the proposed concept and
may base future work on adding new features and improving the already developed ones.