vsp

Simple, fast and lightweight spectrum visualiser made in C. It is a successor of [vspectro][1] in terms of performance and features. It grabs audio from a input device, analyses it through a sliding [DFT][2] and renders a logarithmic frequency spectrum with linear magnitude which you can study or just vibe to.

Features

• Magnitude can be zoomed in with ↓ key and out with ↑ key.
• Logarithmic horizontal (frequency bins) and linear vertical scaling (magnitude).
• Arbitarary capture device selection.
• Changable background and foreground colors.

Installation

Prerequisites

• https://libsdl.org/ (>=2.0)
• http://www.fftw.org/
• https://mesonbuild.com/

  
  # on debian (or debian based distributions)
  $ apt install libsdl2-dev libfftw3-dev

on gentoo/funtoo

$ emerge media-libs/libsdl2 sci-libs/fftw

on msys2 (mingw-w64)

$ pacman -S mingw-w64-SDL2 mingw-w64-fftw

On Windows it is less painful to install [MSYS2](https://www.msys2.org/) then compile it.

### Compilation
Clone/download the repository and chdir into it ofcourse, then:

$ meson builddir -Doptimization=s -Dvsp:default_library=static $ ninja -C builddir

It will produce an executable in `builddir`, which is the program.

## Usage

$ ./builddir/vsp --help Usage:

-h, --help                show this help message and exit

Audio Options -d, --device= index of the capture device -r, --rate= desired samplerate of audio -s, --size= number of samples to analyse at once --list-devices list available devices --audio-bufsize= size of the SDL audio buffer --max-volume= initial maximum displayed volume

Display Options --fg-color= foreground color of the visualisation window --bg-color= background color of the visualisation window --width= initial width of the visualisation window --height= initial height of the visualisation window

`--fg-color` and `--bg-color` is in the hex-color format (optionally prefixed with `#`).

`--list-devices` shows what devices are for capturing with their indices.

list of capture devices: [index] [name] 0 Mic in at front panel (Pink) (Realtek High Definition Audio) 1 Stereo Mix (Realtek High Definition Audio)

If to choose a specific device than default, pass the any of the indices with `-d`.
If passed index is not in that list, it falls back to default.

## Technical details

- No windowing function is applied on the incoming samples, spectral leakage might occur.
- Frequency spectrum starts at 20hZ.

[1]: https://github.com/tripulse/vspectro
[2]: https://en.wikipedia.org/wiki/Discrete_Fourier_transform