Hardward and algorithm architectures for real-time additive synthesis

Additive synthesis is a fundamental computer music synthesis paradigm tracing its origins to the work of Fourier and Helmholtz. Rudimentary implementation linearly combines harmonic sinusoids (or partials) to generate tones whose perceived timbral characteristics are a strong function of the partial amplitude spectrum. Having evolved over time, additive synthesis describes a collection of algorithms each characterised by the time-varying linear combination of basis components to generate temporal evolution of timbre. Basis components include exactly harmonic partials, inharmonic partials with time-varying frequency or non-sinusoidal waveforms each with distinct spectral characteristics. Additive synthesis of polyphonic musical instrument tones requires a large number of independently controlled partials incurring a large computational overhead whose investigation and reduction is a key motivator for this work. The thesis begins with a review of prevalent synthesis techniques setting additive synthesis in context and introducing the spectrum modelling paradigm which provides baseline spectral data to the additive synthesis process obtained from the analysis of natural sounds. We proceed to investigate recursive and phase accumulating digital sinusoidal oscillator algorithms, defining specific metrics to quantify relative performance. The concepts of phase accumulation, table lookup phase-amplitude mapping and interpolated fractional addressing are introduced and developed and shown to underpin an additive synthesis subclass - wavetable lookup synthesis (WLS). WLS performance is simulated against specific metrics and parameter conditions peculiar to computer music requirements. We conclude by presenting processing architectures which accelerate computational throughput of specific WLS operations and the sinusoidal additive synthesis model. In particular, we introduce and investigate the concept of phase domain processing and present several “pipeline friendly” arithmetic architectures using this technique which implement the additive synthesis of sinusoidal partials

Implementación de un sintetizador granular en FPGA

En el presente trabajo se detallan los pasos seguidos para la implementación de un sintetizador granular en la tecnología FPGA (Field Programmable Gate Array). Dicha técnica de síntesis consiste en generar texturas o tonalidades únicas mediante la manipulación de pequeños fragmentos de sonido llamados granos. Su implementación en FPGA consistirá en desarrollar un manejo de memoria para obtener dichas unidades de sonido, aplicar una envolvente a cada una de ellas, y generar así un flujo de datos que será modificado mediante un bloque de filtrado y una envolvente ASR (Attack Sustain Release). Finalmente, se extraerá el flujo a través del protocolo I2S (Integrated Interchip Sound), y se permitirá al usuario modificar los parámetros internos del bloque mediante los elementos Hardware de la placa.In the present work, the steps followed to implement a granular synthesizer on a FPGA board will be presented. This synthesis technic consists in taking small audio fragments called Grains and manipulate them in such a way that unique textures and timbres are obtained. The FPGA implementation will consist in developing a memory management block to obtain the grains, then applying an envelope to each of them, creating a data stream that will be processed by a filter and an ASR envelope (Attack Sustain Release). After that, the sound will be externalised with the I2S protocol, and the internal parameters of the synthesis will be modifiable by the user via the board Hardware.Grado en Ingeniería de Tecnologías de Telecomunicació

Sound Synthesis Using Programmable System-On-Chip Devices

The last 20 years has witnessed a resurgence of interest in analogue synthesisers 1 . Manufacturers, such as Moog and Sequential Circuits, that had disappeared from the commercial marketplace by the end of the 1980’s, have reappeared with an impressive line of products. Other established companies such as Korg and Roland, as well as entrants that had made their name with digital technology, such as Novation and Arturia, have released analogue instruments. Although the feature set of digital synthesisers is extensive and with a falling comparative cost, the analogue market has continued to grow with more and more devices coming available. They are perceived to be of superior sound quality by users, but their primary drawback is price, as numerous discrete components or specialist integrated circuits are required. This thesis introduces two novel low-cost approaches to building analogue-type synthesisers. Such a low-cost instrument could have applications in an educational laboratory environment for synthesisers. The first approach is to exploit a new mixed-signal technology called the Programmable System-on-Chip (PSoC), which includes a CPU core and mixed-signal arrays of configurable integrated analogue and digital peripherals. The second exploits a System on Chip (SoC) comprising an ARM-based (Acorn RISC Machine) processor and a Field-Programmable Gate Array (FPGA). Two synthesisers were built and were evaluated for difficulty of implementation and assessed for their sound quality. The design and testing process was recorded and documented in detail. The mixed-signal approach was found to be cheaper than the FPGA-approach both in terms of component costs and development time compared to the FPGA-based approach. Actually, the FPGA-approach was determined to be prohibitively expensive in terms of the development time incurred. The sound quality analysis demonstrated that both instruments were perceived by users to be of high quality, achieving a noticeable analogue sound. Future work would be to repackage the PSoC system and modules into rack-mounted form for use in an educational synthesiser laboratory environment

Sound Synthesis Using Programmable System-On-Chip Devices

The last 20 years has witnessed a resurgence of interest in analogue synthesisers 1 . Manufacturers, such as Moog and Sequential Circuits, that had disappeared from the commercial marketplace by the end of the 1980’s, have reappeared with an impressive line of products. Other established companies such as Korg and Roland, as well as entrants that had made their name with digital technology, such as Novation and Arturia, have released analogue instruments. Although the feature set of digital synthesisers is extensive and with a falling comparative cost, the analogue market has continued to grow with more and more devices coming available. They are perceived to be of superior sound quality by users, but their primary drawback is price, as numerous discrete components or specialist integrated circuits are required. This thesis introduces two novel low-cost approaches to building analogue-type synthesisers. Such a low-cost instrument could have applications in an educational laboratory environment for synthesisers. The first approach is to exploit a new mixed-signal technology called the Programmable System-on-Chip (PSoC), which includes a CPU core and mixed-signal arrays of configurable integrated analogue and digital peripherals. The second exploits a System on Chip (SoC) comprising an ARM-based (Acorn RISC Machine) processor and a Field-Programmable Gate Array (FPGA). Two synthesisers were built and were evaluated for difficulty of implementation and assessed for their sound quality. The design and testing process was recorded and documented in detail. The mixed-signal approach was found to be cheaper than the FPGA-approach both in terms of component costs and development time compared to the FPGA-based approach. Actually, the FPGA-approach was determined to be prohibitively expensive in terms of the development time incurred. The sound quality analysis demonstrated that both instruments were perceived by users to be of high quality, achieving a noticeable analogue sound. Future work would be to repackage the PSoC system and modules into rack-mounted form for use in an educational synthesiser laboratory environment

Design of Pattern Matching Systems: Pattern, Algorithm, and Scanner

Pattern matching is at the core of many computational problems, e.g., search engine, data mining, network security and information retrieval. In this dissertation, we target at the more complex patterns of regular expression and time series, and proposed a general modular structure, named character class with constraint repetition (CCR), as the building block for the pattern matching algorithm. An exact matching algorithm named MIN-MAX is developed to support overlapped matching of CCR based regexps, and an approximate matching algorithm named Elastic Matching Algorithm is designed to support overlapped matching of CCR based time series, i.e., music melody. Both algorithms are parallelized to run on FPGA to achieve high performance, and the FPGA-based scanners are designed as a modular architecture which is parameterizable and can be reconfigured by simple memory writes, achieving a perfect balance between performance and deployment time

Digitial Readout for Microwave Kinetic Inductance Detectors and Applications in High Time Resolution Astronomy

This dissertation spans two topics relating to optical tonear-infrared astronomical cameras built around Microwave KineticInductance Detectors (MKIDs). The first topic is the development of adigital readout system for 10- to 30-kilopixel arrays of MKIDs. MKIDs aresuperconducting detectors that can detect individual photons with a widerange of wavelengths with high time resolution (\SI{2}{\micro s}) and low energyresolution. The advantage of MKIDs over other low temperature detectors with similar capabilities is that it is relatively straightforward to multiplex MKIDs into largearrays. All the complexity of readout is in room temperature electronics.This work discusses the implementation and programming of theseelectronics.The second part of this work demonstrates the capabilities of the prototypeoptical and near-infrared MKID instrument with observations ofpulsars. Detecting optical pulsations in these objects require high timeresolution and low noise. The discovery of a correlation between thebrightness of optical pulses from the Crab pulsar and the time of arrivalof coincident giant radio pulses is presented. The search for opticalpulses from a millisecond pulsar J0337+1715 is discussed along with a newupper limit on the brightness of its optical pulses

Proceedings of the 19th Sound and Music Computing Conference

Proceedings of the 19th Sound and Music Computing Conference - June 5-12, 2022 - Saint-Étienne (France). https://smc22.grame.f