The first part of this Master’s Thesis deals with the theory of digital signal processing and describes the JUCE library. In this part some basic operations are explained with digital audio signals, such as polarity inversion, delay and linear interpolation of signal samples. The creation of new audio applications using the JUCE library in the C++ programming language is explained too. The next parts of this thesis describe the implemented audio application that allows the user to provide the described basic operations with digital audio signals in real time. For multiple channel audio signals the channels can be processed independently.

This diploma thesis deals with the creation of sound from images. Before looking into the actual conversion of data, it takes into consideration the correlation between sound and images. Colour models of pictures used for the extraction of image data suitable for conversion into sound are examined here. Subsequently the work introduces methods for creating sound and changing its basic parameters. In order to present a suitable representation of sound, the work also explains the basics of music theory and methods of sound synthesis. The first part of the thesis offers two fully-fledged solutions using independent applications created in the MATLAB environment, where the basic principle is the division of the image into lines and the use of granular synthesis. The second part of the thesis describes the solution of the third application created in C++ language, where the emphasis is on adhering to the principles of music composition.

Purpose – Examine if there is any difference in performance between the C++ framework JUCE and the domain-specific programming language FAUST to create a decision basis to facilitate choices between them when developing plugins. Method – An experimental study where two delay-plugins with identical functionality were developed and compared in latency, CPU load and memory usage. The experiment consisted of three test cases and were performed on three different computers. Findings – FAUST performed better than JUCE regarding latency and CPU load during the experiment. JUCE on the other hand performed better than FAUST regarding memory usage. Implications – This study has made it easier to make a decision based on performance when choosing between JUCE and FAUST regarding development of plugins. Limitations – Time restrictions has led to only comparing JUCE and FAUST, leaving other relevant alternatives aside. It has also led to only developing one type of plugin. The results of the study cannot be generalized or applied to other frameworks and programming languages whose purpose is to ease processing of digital signals. / Syfte – Undersöka om det är någon skillnad i prestanda mellan C++-ramverket JUCE och det domänspecifika programmeringsspråket FAUST för att skapa ett beslutsunderlag för att underlätta val mellan dem vid utveckling av plugins. Metod – En experimentell studie där två delay-plugins med identisk funktionalitet utvecklades och jämfördes i latency, CPU-belastning och minnesanvändning. Experimentet bestod av tre testfall och utfördes på tre olika datorer. Resultat – FAUST presterade bättre än JUCE gällande latency och CPU-belastning under experimentet. JUCE presterade däremot bättre gällande minnesanvändning. Implikationer – Denna studie har gjort det lättare att fatta ett beslut baserat på prestanda vid val mellan JUCE och FAUST beträffande utveckling av plugins. Begränsningar – Tidsbegränsningar har lett till att endast en jämförelse mellan JUCE och FAUST har genomförts. Andra relevanta alternativ har uteslutits på grund av detta. Det har också medfört att endast en typ av plugin har utvecklats. Studiens resultat kan inte tillämpas eller generaliseras till andra ramverk och domänspecifika programmeringsspråk vars syfte är att bearbeta digitala ljudsignaler.

This thesis describes the design and implementation of a software for digital mixing console built on the Windows platform. This software is designed to offer real-time multi-channel audio processing using multiple input and output units, signal routing between these units and insertion and management of VST plug-in modules. The software uses an audio interface connected with ASIO technology. The thesis is divided into several applications. Main application which computes audio samples and allows insertion and management of plug-ins is programmed in C++ using JUCE technology. This application can be controlled with its own local graphical interface or with web control interface, which is programmed in TypeScript with the use of React technology. Web interface allows user to control VST plug-in modules with its own custom implementation of plug-in control.