~ Spectrogram in Java with TarsosDSP

This is post presents a better version of the spectrogram implementation. Now it is included as an example in TarsosDSP, a small java audio processing library. The application show a live spectrogram, calculated using an FFT and the detected fundamental frequency (in red).

To test the application, download and execute the Spectrogram.jar file and start singing in a microphone.

There is also a command line interface, the following command shows the spectrum for in.wav:

java -jar Spectrogram.jar in.wav

The source code of the Java implementation can be found on the TarsosDSP github page.

Code, Java, Computational musicology, en TarsosDSP

Spectrogram.jar en spectrogram.png

~ Audio Time Stretching - Implementation in Pure Java Using WSOLA

The DSP library for Taros, aptly named TarsosDSP, now includes an implementation of a time stretching algorithm. The goal of time stretching is to change the duration of a piece of audio without affecting the pitch. The algorithm implemented is described in An Overlap-add Technique Based On Waveform Similarity (WSOLA) for High Quality Time-Scale Modification of Speech.

To test the application, download and execute the WSOLA jar file and load an audio file. For the moment only 44.1kHz mono wav is allowed. To get started you can try this piece of audio.

There is also a command line interface, the following command doubles the speed of in.wav:

java -jar TimeStretch.jar 2.0 in.wav out.wav

The source code of the Java implementation of WSOLA can be found on the TarsosDSP github page.

Java, TarsosDSP, Tarsos, en WSOLA

time_stretching_in_java.png, 08._Ladrang_Kandamanyura_10s-20s.wav, en TimeStretch.jar

~ TarsosDSP sample application: Utter Asterisk

The DSP library of Tarsos, aptly named TarsosDSP, contains an implementation of a game that bares some resemblance to SingStar. It is called UtterAsterisk. It is meant to be a technical demonstration showing real-time pitch detection in pure java using a YIN -implementation.

Download Utter Asterisk and try to sing (utter) as close to the melody as possible. The souce code for Utter Asterisk is available on github.

TarsosDSP

UtterAsterisk.jar

~ TarsosDSP used in jAM - Java Automatic Music Transcription

TarsosDSP, a small Java DSP library, has been used in a bachelor thesis: Entwicklung eines Systems zur automatischen Notentranskription von monophonischem Audiomaterial by Michael Wager.

The goal of the thesis was to develop an automatic transcription system for monophonic music. You can download the latest version of jAM – Java Automatic Music Transcription.

If you want to use TarsosDSP, please consult the TarsosDSP page on github or read more about TarsosDSP here.

Java en TarsosDSP

~ Dual-Tone Multi-Frequency (DTMF) Decoding with the Goertzel Algorithm in Java

The DSP library of Tarsos, aptly named TarsosDSP, now contains an implementation of the Goertzel Algorithm. It is implemented using pure Java.

The Goertzel algorithm can be used to detect if one or more predefined frequencies are present in a signal and it does this very efficiently. One of the classic applications of the Goertzel algorithm is decoding the tones generated on by touch tone telephones. These use DTMF-signaling.

To make the algorithm visually appealing a Java Swing interface has been created(visible right). You can try this application by running the Goertzel DTMF Jar-file. The souce code is included in the jar and is avaliable as a separate zip file. The TarsosDSP github page also contains the source for the Goertzel algorithm Java implementation.

DTMF detection of 9

DTMF detection of 2

Code, Java, en TarsosDSP

goertzel_DTMF_java_7.png, GoertzelDTMF.jar, en GoertzelDTMF_src.zip

~ TarsosDSP: a small JAVA audio processing library

TarsosDSP is a collection of classes to do simple audio processing. It features an implementation of a percussion onset detector and two pitch detection algorithms: Yin and the Mcleod Pitch method.

Its aim is to provide a simple interface to some audio (signal) processing algorithms implemented in JAVA.

To make some of the possibilities clear I coded some examples.

• TarsosDSP UtterAsterisk a game that shows real-time pitch detection with YIN.
• TarsosDSP Sound Detector is simply to show how to react when (loud) sound is available.
• TarsosDSP Percussion Detector is capable of detecting percussion onsets using the method described here. It plays a sound from freesound.org when percussion is detected.

The source code of TarsosDSP is available on github.

Presentation at Newline

Saturday the 25th of March TarsosDSP was presented at Newline, a small conference organized by whitespace. Here you can download the slides I used to present TarsosDSP, I also created an introductory text on sound and Java.

Percussion detection

UtterAsterisk

Sound Detector

Code, Java, featured, TarsosDSP, en Tarsos

PitchDetector.jar, PercussionDetector.jar, tarsosDSP_presentation.pdf, sound_and_java.pdf, UtterAsterisk.jar, en SoundDetector.jar