25 research outputs found
Streaming Spectral Processing with Consumer-level Graphics Processing Units
This paper describes the implementation of a streaming spectral
processing system for realtime audio in a consumer-level onboard
GPU (Graphics Processing Unit) attached to an off-the-shelf
laptop computer. It explores the implementation of four processes:
standard phase vocoder analysis and synthesis, additive synthesis
and the sliding phase vocoder. These were developed under the
CUDA development environment as plugins for the Csound 6 audio
programming language. Following a detailed exposition of
the GPU code, results of performance tests are discussed for each
algorithm. They demonstrate that such a system is capable of realtime
audio, even under the restrictions imposed by a limited GPU
capability
Streaming Spectral Processing with Consumer-level Graphics Processing Units
This paper describes the implementation of a streaming spectral
processing system for realtime audio in a consumer-level onboard
GPU (Graphics Processing Unit) attached to an off-the-shelf
laptop computer. It explores the implementation of four processes:
standard phase vocoder analysis and synthesis, additive synthesis
and the sliding phase vocoder. These were developed under the
CUDA development environment as plugins for the Csound 6 audio
programming language. Following a detailed exposition of
the GPU code, results of performance tests are discussed for each
algorithm. They demonstrate that such a system is capable of realtime
audio, even under the restrictions imposed by a limited GPU
capability
An Energy Conserving Finite Difference Scheme for the Simulation of Collisions in Snare Drums
In this paper, a physics-based model for a snare drum will be dis-cussed, along with its finite difference simulation. The interac-tions between a mallet and the membrane and between the snares and the membrane will be described as perfectly elastic collisions. A novel numerical scheme for the implementation of collisions will be presented, which allows a complete energy analysis for the whole system. Viscothermal losses will be added to the equation for the 3D wave propagation. Results from simulations and sound examples will be presented. 1
Differentiable Grey-box Modelling of Phaser Effects using Frame-based Spectral Processing
Machine learning approaches to modelling analog audio effects have seen
intensive investigation in recent years, particularly in the context of
non-linear time-invariant effects such as guitar amplifiers. For modulation
effects such as phasers, however, new challenges emerge due to the presence of
the low-frequency oscillator which controls the slowly time-varying nature of
the effect. Existing approaches have either required foreknowledge of this
control signal, or have been non-causal in implementation. This work presents a
differentiable digital signal processing approach to modelling phaser effects
in which the underlying control signal and time-varying spectral response of
the effect are jointly learned. The proposed model processes audio in short
frames to implement a time-varying filter in the frequency domain, with a
transfer function based on typical analog phaser circuit topology. We show that
the model can be trained to emulate an analog reference device, while retaining
interpretable and adjustable parameters. The frame duration is an important
hyper-parameter of the proposed model, so an investigation was carried out into
its effect on model accuracy. The optimal frame length depends on both the rate
and transient decay-time of the target effect, but the frame length can be
altered at inference time without a significant change in accuracy.Comment: Accepted for publication in Proc. DAFx23, Copenhagen, Denmark,
September 202