PitchTech

The PitchTech research project aims in providing high quality audio transformations implemented in Java.

Overview of the project
Software
Scientific publications
Audio and music examples
Links
Contact

The aim of the PitchTech project is to provide high quality audio effects implemented in Java. The research aspects are the following:

• High quality: How can the quality of existing audio transformations be further improved. Primarily targeted audio transformations are pitch shifting, time stretching and noise reduction.
• Low latency: How can the latency of existing audio effects be reduced.
• Parallel implementations: How can existing implementations be parallelized so that they can benefit from the future multi-core processors.
• New audio effects: Are the thousands of available audio effects the final word in audio processing theory, or is it still possible to make new ones?

• PitchTech: free exotic and experimental audio effects (as VST and LADSPA plugins)
• PitchBox: real-time voice and music transformations. Presented at the RoadShow.
• DRC-Meter (Dynamic Range Compression Meter): small tool to measure the consequences of the loudness war on your audio files

N. Juillerat, S. Schubiger-Banz, S. M. Arisona, Real-time, Low Latency Audio Processing in Java , International Computer Music Conference, ICMC 2007, pp. 99 - 102, 2007.

N. Juillerat, S. Schubiger-Banz, S. M. Arisona, Low Latency Audio Pitch Shifting in the Time Domain , IEEE International Conference on Audio, Language and Image Processing, ICALIP 2008, pp. 29 - 35, 2008. (Companion page)

N. Juillerat, S. Schubiger-Banz, S. M. Arisona, Enhancing the Quality of Audio Transformations Using the Multi-Scale Short-Time Fourier Transform , IASTED International Conference on Signal Processing, IASTED SIP 2008. (Companion page)

N. Juillerat, S. Schubiger-Banz, S. M. Arisona, A Hybrid Time and Frequency Domain Audio Pitch Shifting Algorithm , 125^th Audio Engineering Society Convention, AES 125^th, 2008. (Companion page)

N. Juillerat, B. Hirsbrunner, Low Latency Audio Pitch Shifting in the Frequency Domain , IEEE International Conference on Audio, Language and Image Processing, ICALIP 2010, 2010. (Companion page)

Comparison of pitch shifting and time-stretching techniques

Also look at the companion pages of the scientific publications above!

The DFT "à Pied": basics about the DFT and its use in audio transformations.
Pitch Shifting with the Fourier Transform: detailed explanation of the pitch shifting audio effect using the phase vocoder.
Java Sound Programmer Guide: documentation of the Java sound API.
Other related projects at Corebounce.

(English or French)