Audio Signal Visualisation and Measurement

The authors offer an introductory walk-through of professional audio signal measurement and visualisation using free software. Many users of audio software at some time face problems that requires reliable measurement. The presentation focuses on the SiSco.lv2 (Simple Audio Signal Oscilloscope) and the Meters.lv2 (Audio Level Meters) LV2 plugins, which have been developed open-source since August 2013. The plugin bundle is a super-set, built upon existing tools adding novel GUIs (e.g ebur128, jmeters,..), and features new meter-types and visualisations unprecedented on GNU/Linux (e.g. true-peak, phase-wheel,..). Various meter-types are demonstrated and the motivation for using them explained. The accompanying documentation provides an overview of instrumentation tools and measurement standards in general, emphasising the requirement to provide a reliable and standardised way to measure signals. The talk is aimed at developers who validate DSP during development, as well as sound-engineers who mix and master according to commercial constraints.