Struct SpectrumVisualizer 

pub struct SpectrumVisualizer<'a> { /* private fields */ }

Builder that renders a frequency spectrum as an image.

Input is a list of (frequency in Hz, magnitude) pairs; it does not need to be sorted. The x-axis is labeled with the frequencies, the y-axis ranges from zero to the largest magnitude unless Self::y_range fixes it.

This crate does not compute spectra itself; pair it with an FFT crate such as spectrum-analyzer. Individual frequencies can be highlighted in the resulting chart, which is handy to verify that an expected peak is where it should be. For real-time visualization see crate::live.

Example

use audio_visualizer::SpectrumVisualizer;

let spectrum: Vec<(f32, f32)> = vec![(55.0, 0.1), (60.0, 0.9), (65.0, 0.2)];
SpectrumVisualizer::new(&spectrum)
    .highlight(60.0)
    .write_png("spectrum.png")
    .unwrap();

Implementations

impl<'a> Spectrum<'a>

pub const fn new(data: &'a [(f32, f32)]) -> Self

Creates a spectrum visualization of (frequency in Hz, magnitude) pairs.

pub fn highlight(self, frequency_hz: f32) -> Self

Highlights the spectrum entry closest to the given frequency with a red marker. Can be called multiple times.

pub fn highlights(self, frequencies_hz: &[f32]) -> Self

Highlights the spectrum entry closest to the given frequencies with a red marker. Can be called multiple times.

pub const fn y_range(self, range: Range<f32>) -> Self

Fixes the y-axis to the given range instead of fitting it to the data. Magnitudes outside the range are clipped to its bounds.

This makes images of different spectra comparable.

pub const fn size(self, width: u32, height: u32) -> Self

Sets the image dimensions in pixels. Default: 1400x500.

pub fn title(self, title: impl Into<String>) -> Self

Sets a title displayed above the chart.

pub fn to_svg(&self) -> Result<String, Error>

Renders the spectrum to an SVG string.

pub fn write_png(&self, path: impl AsRef<Path>) -> Result<(), Error>

Renders the spectrum and writes it as PNG file, creating missing parent directories.

Trait Implementations

impl<'a> Clone for Spectrum<'a>

fn clone(&self) -> Spectrum<'a>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'a> Debug for Spectrum<'a>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.