Customer feedback

Where KFR Is Used

  • Audio and music technology: instruments, effects, amp modeling, mixing, mastering, and real-time plugins.
  • Medical diagnostics: EEG, polysomnography, sleep testing, and physiological-signal analysis.
  • Test, measurement, and communications: oscilloscopes, RF instruments, automotive diagnostics, software-defined radios, spectrum analysis, and direction finding.
  • Scientific, industrial, and embedded systems: numerical analysis, instrumentation, robotics, sensor processing, quality assurance, environmental monitoring, and ML preprocessing.
  • Creative technology: interactive sequencing, experimental music, audio recognition, pitch detection, and multimedia research.

Case stories

Here is a selection of user stories and customer feedback.

reFX, Nexus

We use kfrlib with great success. It has ready to use convolution, FFT and other goodies. Builds for x64, arm, etc. with full optimizations and native SIMD usage. We’re using it in Nexus for FFT and convolution.

LIGO, Virgo and KAGRA, Gravitational-wave research

The integration of KFR library, a modern C++ library actively maintained for around a decade, enables ROOT data analysis framework with two agnostic key features: rapid FFT calculations and advanced signal processing. KFR allows efficient handling of large signals through high-performance Fast Fourier Transform (FFT) computations in n-dimensions and also robust signal processing techniques, including windowing functions, Finite Impulse Response (FIR), and Infinite Impulse Response (IIR) filtering.

Read the research paper

Jean-Michaël Celerier, Ossia

Jean-Michaël Celerier (SCRIME, Université de Bordeaux) used KFR’s FFT as a benchmark in his paper “A Cross-Platform Development Toolchain for JIT-Compilation in Multimedia Software”, presented at the 17th Linux Audio Conference (LAC-19, CCRMA, Stanford, 2019).

For this benchmark, we compare the run time of a Fast Fourier Transform algorithm implemented in the KFR library mentioned earlier.

This library provides hand-optimized versions for many different instructions sets, ranging from SSE2 to AVX2. The results are presented in Table 1. The test is done on a large array: 16384 double-precision floatingpoint values.

Table 1: Performance increases yielded by using the proper instruction set.
Machine Generic JIT Time saved
Broadwell 214 µs 144 µs 32.7%
Coffeelake 172 µs 107 µs 37.8%

Read the research paper

Marco Meyer-Conde, Assistant Professor at Tokyo City University

To achieve this enhancement, we employ the KFR modern C++ library, specifically designed for advanced signal processing and digital complex filtering. This integration is seamlessly performed in use of ROOT software.

Read the ACAT2024 abstract

Trusted by

Here is a selection of companies using KFR.

reFX

What the company does: Virtual instrument and audio software developer

Industry: Music software

KFR is used in: Nexus

Sound theory

What the company does: Audio software company known for developing real-time audio processing plugins based on a computational model of human auditory perception

Industry: Audio software

KFR is used in: Gullfoss

AIVA.AI

What the company does: Develops AI-based music composition software specializing in classical and symphonic music, including the Music Engine platform

Industry: Music technology

W.M. Associates, Inc

What the company does: Develops industrial test and quality systems

Industry: Industrial testing and quality assurance

Acustica Audio

What the company does: Develops analog-modeled audio plugins for mixing, mastering, and sound design

Industry: Audio software

KrakenRF

What the company does: Develops low-cost coherent software-defined radios for direction finding and passive radar.

Industry: Radio frequency electronics

KFR is used in: Heimdall DAQ Firmware

Keilwerth Audio

What the company does: Develops professional audio software, synthesizers, instruments, effects, and mastering tools

Industry: Audio software

Neural DSP

What the company does: Develops guitar and bass amp modelers, effects plugins, and audio hardware

Industry: Music technology

Neurovirtual

What the company does: Manufactures EEG, polysomnography, and home sleep testing systems

Industry: Medical diagnostics

Pico Technology

What the company does: Develops PC-based oscilloscopes, data loggers, RF instruments, and automotive diagnostics

Industry: Test and measurement

FlexRadio

What the company does: Develops software-defined radios and SmartSDR software for amateur, commercial, and government communications

Industry: Radio communications technology

What the company does: Develops the Easy Dynamic plug-in with Dynamic EQ, Multiband Compressor, and Transient Shaper

Industry: Audio software

KFR is used in: Easy Dynamic

Visit PlugLet

Willey Piano, PianoMeter

Anthony Willey develops PianoMeter, an Android app for professional-quality piano tuning

Industry: Music software

KFR is used in: PianoMeter

View PianoMeter on Google Play

Ossia

What the company does: Develops an interactive sequencer for the intermedia arts

Industry: Creative technology

KFR is used in: FFT, convolution, and pitch detection.

Visit Ossia

What developers say

I can’t recommend KFR enough. Very fast (similar to IPP in our use). Multiplatform (x86 / arm). Built in vectorisation for array operations.

We pay for it and use it commercially, but I believe it is available under GPL v2+ licence.

Read the discussion on Reddit

KFRLib seems excellent for audio DSP: https://www.kfrlib.com/

Read the discussion on Reddit

KFR seems to be one of the best C++ DSP library.

Read the comment on GitHub

Geoff

Fantastic library BTW - great work.

Read the comment on GitHub

Menrva

Special Thanks

KFR - For providing an awesome Fast Fourier Transform & DSP Library.

All trademarks, service marks, trade names, and logos referenced herein are the property of their respective owners.

Information about which products use KFR is accurate as of the date of each testimonial.