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#![allow(clippy::must_use_candidate)]
#![allow(clippy::return_self_not_must_use)]
/*use crate::window::{
BlackmanHarrisWindow, HammingWindow, HannWindow, RectangularWindow, WindowFunction,
};*/
use crate::window_function::{RectangularWindow, WindowFunction};
use num_complex::Complex;
use realfft::{ComplexToReal, RealFftPlanner, RealToComplex};
use std::{collections::VecDeque, sync::Arc};
pub struct WindowedRealFft {
fft_size: usize,
planner: RealFftPlanner<f32>,
forward: Arc<dyn RealToComplex<f32>>,
inverse: Arc<dyn ComplexToReal<f32>>,
window_function: Box<dyn WindowFunction>,
input: VecDeque<f32>,
output: VecDeque<f32>,
spectrum: Vec<Complex<f32>>,
scratch: Vec<Complex<f32>>,
}
impl WindowedRealFft {
pub fn new(mut fft_size: usize) -> Self {
if fft_size == 0 {
fft_size = 1;
}
let mut planner = RealFftPlanner::new();
let forward = planner.plan_fft_forward(fft_size);
let inverse = planner.plan_fft_inverse(fft_size);
let window_function = Box::new(RectangularWindow::new(fft_size));
let input = VecDeque::with_capacity(fft_size);
let output = VecDeque::with_capacity(fft_size);
let spectrum = vec![Complex::ZERO; (fft_size / 2) + 1];
let max_scratch_len = forward.get_scratch_len().max(inverse.get_scratch_len());
let scratch = vec![Complex::ZERO; max_scratch_len];
Self {
fft_size,
planner,
forward,
inverse,
window_function,
input,
output,
spectrum,
scratch,
}
}
pub fn fft_size(mut self, mut value: usize) -> Self {
if value == 0 {
value = 1;
}
self.fft_size = value;
self.forward = self.planner.plan_fft_forward(self.fft_size);
self.inverse = self.planner.plan_fft_inverse(self.fft_size);
self.input.reserve_exact(self.fft_size);
self.output.reserve_exact(self.fft_size);
self.input.clear();
self.output.clear();
self.spectrum.resize((self.fft_size / 2) + 1, Complex::ZERO);
let max_scratch_len = self
.forward
.get_scratch_len()
.max(self.inverse.get_scratch_len());
self.scratch.resize(max_scratch_len, Complex::ZERO);
self
}
pub fn clear_input(&mut self) {
self.input.clear();
}
pub fn push_front_input(&mut self, value: f32) -> bool {
self.input.push_front(value);
self.input.len() >= self.fft_size
}
pub fn pop_back_output(&mut self) -> f32 {
self.output.pop_back().unwrap_or(0.0)
}
pub fn get_spectrum(&mut self) -> &mut [Complex<f32>] {
&mut self.spectrum
}
pub fn forward(&mut self) {
self.window_function.apply(self.input.make_contiguous());
self.forward
.process_with_scratch(
self.input.make_contiguous(),
&mut self.spectrum,
&mut self.scratch,
);
}
pub fn inverse(&mut self) {
self.output.resize(self.fft_size, 0.0);
self.inverse
.process_with_scratch(
&mut self.spectrum,
self.output.make_contiguous(),
&mut self.scratch,
);
let fft_size_f32 = self.fft_size as f32;
for sample in &mut self.output {
*sample = *sample / fft_size_f32;
}
self.window_function.reverse(self.output.make_contiguous());
}
}
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