Download AM/FM DAFx In this work we explore audio effects based on the manipulation of estimated AM/FM decomposition of input signals, followed by resynthesis. The framework is based on an incoherent monocomponent based decomposition. Contrary to reports that discourage the usage of this simple scenario, our results have shown that the artefacts introduced in the audio produced are acceptable and not even noticeable in some cases. Useful and musically interesting effects were obtained in this study, illustrated with audio samples that accompany the text. We also make available Octave code for future experiments and new Csound opcodes for real-time implementations.
Download Approaches for constant audio latency on Android This paper discusses issues related to audio latency for realtime processing Android OS applications. We first introduce the problem, determining the difference between the concepts of low latency and constant latency. It is a well-known issue that programs written for this platform cannot implement low-latency audio. However, in some cases, while low latency is desirable, it is not crucial. In some of these cases, achieving a constant delay between control events and sound output is the necessary condition. The paper briefly outlines the audio architecture in the Android platform to tease out the difficulties. Following this, we proposed some approaches to deal with two basic situations, one where the audio callback system provided by the system software is isochronous, and one where it is not.
Download Interpretation and control in AM/FM-based audio effects This paper is a continuation of our first studies on AM/FM digital audio effects, where the AM/FM decomposition equations were reviewed and some exploratory examples of effects were introduced. In the current paper we present more insight on the signals obtained with the AM/FM decomposition, intending to illustrate manipulations in the AM/FM domain that can be applied as interesting audio effects. We provide high-quality AM/FM effects and their implementations, alongside a brief objective evaluation. Audio samples and codes for real-time operation are also supplied.
Download Towards High Sampling Rate Sound Synthesis on FPGA This “Late Breaking Results” paper presents an ongoing project aiming at providing an accessible and easy-to-use platform for high sampling rate real-time audio Digital Signal Processing (DSP). The current version can operate in the megahertz range and we aim to achieve sampling rates as high as 20 MHz in the near future. It relies on the Syfala compiler which can be used to program Field Programmable Gate Array (FPGA) platforms at a high level using the FAUST programming language. In our system, the audio DAC is directly implemented on the FPGA chip, providing exceptional performances in terms of audio latency as well. After giving an overview of the state of the art of this field, we describe the way this tool works and we present ongoing and future developments.