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#![allow(clippy::must_use_candidate)]
#![allow(clippy::return_self_not_must_use)]
#![allow(unused)]
#![allow(dead_code)]
use crate::{
window_function::{
BlackmanHarrisWindow, HammingWindow, HannWindow, RectangularWindow, Sine4Window,
WindowFunction,
},
window_size::WindowSize,
window_type::WindowType,
};
use num_complex::Complex;
use realfft::{ComplexToReal, RealFftPlanner, RealToComplex};
use std::{collections::VecDeque, sync::Arc};
pub struct WindowedRealFft {
window_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(window_size: WindowSize) -> Self {
let window_function = Box::new(HannWindow::new(&window_size));
let window_size = window_size.inner();
let mut planner = RealFftPlanner::new();
let forward = planner.plan_fft_forward(window_size);
let inverse = planner.plan_fft_inverse(window_size);
let input = VecDeque::with_capacity(window_size);
let output = VecDeque::with_capacity(window_size);
let spectrum = vec![Complex::ZERO; (window_size / 2) + 1];
// scratches should be the same length for both left and right channels
let scratch = forward.make_scratch_vec();
Self {
window_size,
planner,
forward,
inverse,
window_function,
input,
output,
spectrum,
scratch,
}
}
pub fn window_function(&mut self, window_type: &WindowType) {
self.input.clear();
self.output.clear();
let window_function = window_type.new_function(&WindowSize::from(self.window_size));
self.window_function = window_function;
}
pub fn window_size(&mut self, window_size: WindowSize) {
if window_size == self.window_size.into() {
return;
}
self.window_function.resize(&window_size);
self.window_size = window_size.inner();
self.forward = self.planner.plan_fft_forward(self.window_size);
self.inverse = self.planner.plan_fft_inverse(self.window_size);
self.input.reserve_exact(self.window_size);
self.output.reserve_exact(self.window_size);
self.input.clear();
self.output.clear();
self.spectrum
.resize((self.window_size / 2) + 1, Complex::ZERO);
self.scratch
.resize(self.forward.get_scratch_len(), Complex::ZERO);
}
pub fn clear_input(&mut self) {
self.input.clear();
}
pub fn push_back_input(&mut self, value: f32) -> bool {
self.input.push_back(value);
self.input.len() >= self.window_function.needed()
}
pub fn pop_front_output(&mut self) -> f32 {
self.output.pop_front().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(&mut self.input);
let _ = self.forward.process_with_scratch(
self.input.make_contiguous(),
&mut self.spectrum,
&mut self.scratch,
);
}
pub fn inverse(&mut self) {
self.output.resize(self.window_size, 0.0);
let _ = self.inverse.process_with_scratch(
&mut self.spectrum,
self.output.make_contiguous(),
&mut self.scratch,
);
let window_size_f32 = self.window_size as f32;
for sample in &mut self.output {
*sample /= window_size_f32;
}
self.window_function.reverse(self.output.make_contiguous());
}
}
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