Useful code snippets and interesting coding ideas.
Audacity includes an excellent “Change Tempo” effect which can stretch the length of the selected audio without altering the pitch. The effect includes the ability to specify the required new length, but this option is not available when using the effect in a Macro, or with Scripting. Setting the target length in a Macro Audacity … Continue reading Stretching audio to length
The most basic way to copy a list or an array is simply to assign a new variable with SETQ or SETF, but this may behave in unexpected ways. Let us look at an example: Try running the above in Audacity’s Nyquist Prompt effect (use the Debug button to see the output), and you may … Continue reading Copying lists and arrays
A simple “tuning fork” plug-in for Audacity, specifically for tuning a ukulele. This plug-in just generates a tone of the specified note, which is basically what a tuning fork does, except that a real (mechanical) tuning fork is restricted to just one frequency, whereas this plug-in allows you to select the required note. Ukuleles are … Continue reading Ukulele Tuning Tones
Sometimes we may want to fade-in or fade-out an effect rather than have it start and end suddenly. This article looks at how we can do this automatically within an effect. The way that we would do this manually is by duplicating the track, applying the effect to the duplicate, then crossfading the two tracks … Continue reading Fading an effect in and out
Audacity has the ability to export label tracks as a text file, and/or import labels from a text file. More information about this is available in the Audacity manual. A limitation of this feature is that it is not available to use in batch processing. There is a macro command ImportLabels: but it only opens … Continue reading Import Labels
This plug-in can be helpful in situations where you have a project that has a lot (possibly hundreds) of labels, and you want to locate one specific label quickly by searching for the label text. While it is perfectly possible to scroll through the Label Editor window and look for the label text, the Label … Continue reading Find Label (plug-in)
Introduction “Assertions” (or simply “Asserts” are commonly used in many programming languages to help developers read and understand code, and to help to detect possible defects (bugs). An assert is usually a predicate that tests a variable in the program and returns a boolean (true / false) value. In common English, it is like saying: … Continue reading Assertions
What are crossover filters? Due to mechanical / physical constraints it is near impossible for a single speaker cone to accurately reproduce the full audio range. Carefully designed small speakers may work adequately for low power use such as portable radios, but for larger, higher power and higher sound quality speakers, multiple “driver” units are … Continue reading Three band crossover filter (part 1)
*Scratch* is a very useful Nyquist variable (in Audacity). It has the unique property that it survives from one call of Nyquist to the next. This allows, for example, a plug-in to perform sequential operations on a series of tracks, or for one plug-in to analyse a track and then another plug-in to process the … Continue reading *SCRATCH* – the variable that lasts
This is a short tutorial about generating sounds and shaping the sound with an envelope. Nyquist includes a number of oscillators and other simple sound generators that may be used as building blocks. In this tutorial we will be using the triangle waveform oscillator as the basis of a simple piano-like “ding” sound.We’ll start with … Continue reading Synthesizing musical notes