remove fir_simd

Author: cm-ayf

src/vocoder/mlsa.rs

@@ -0,0 +1,100 @@
+use super::coefficients::Coefficients;
+
+/// N == pd + 1
+#[derive(Debug, Clone)]
+pub struct MelLogSpectrumApproximation<const N: usize> {
+    d11: [f64; N],
+    d12: [f64; N],
+    d21: [Vec<f64>; N],
+    d22: [f64; N],
+}
+
+pub trait Pade<const N: usize> {
+    const PPADE: [f64; N];
+}
+macro_rules! impl_pade {
+    ($($i:literal: $ppade:expr),* $(,)?) => {
+        $(
+            impl Pade<$i> for MelLogSpectrumApproximation<$i> {
+                const PPADE: [f64; $i] = $ppade;
+            }
+        )*
+    };
+}
+
+impl_pade!(
+    1: [1.00000000000f64],
+    2: [1.00000000000f64, 0.00000000000f64],
+    3: [1.00000000000f64, 0.00000000000f64, 0.00000000000f64],
+    4: [1.00000000000f64, 0.00000000000f64, 0.00000000000f64, 0.00000000000f64],
+    5: [1.00000000000f64, 0.49992730000f64, 0.10670050000f64, 0.01170221000f64, 0.00056562790f64],
+    6: [1.00000000000f64, 0.49993910000f64, 0.11070980000f64, 0.01369984000f64, 0.00095648530f64, 0.00003041721f64],
+);
+
+impl<const N: usize> MelLogSpectrumApproximation<N>
+where
+    Self: Pade<N>,
+{
+    pub fn new(nmcp: usize) -> Self {
+        Self {
+            d11: [0.0; N],
+            d12: [0.0; N],
+            d21: std::array::from_fn(|_| vec![0.0; nmcp]),
+            d22: [0.0; N],
+        }
+    }
+
+    #[inline(always)]
+    pub fn df(&mut self, x: &mut f64, alpha: f64, coefficients: &'_ Coefficients) {
+        self.df1(x, alpha, coefficients);
+        self.df2(x, alpha, coefficients);
+    }
+
+    #[inline(always)]
+    fn df1(&mut self, x: &mut f64, alpha: f64, coefficients: &'_ Coefficients) {
+        let aa = 1.0 - alpha * alpha;
+        let mut out = 0.0;
+        for i in (1..N).rev() {
+            self.d11[i] = aa * self.d12[i - 1] + alpha * self.d11[i];
+            self.d12[i] = self.d11[i] * coefficients[1];
+            let v = self.d12[i] * Self::PPADE[i];
+            *x += if i & 1 != 0 { v } else { -v };
+            out += v;
+        }
+        self.d12[0] = *x;
+        *x += out;
+    }
+
+    #[inline(always)]
+    fn df2(&mut self, x: &mut f64, alpha: f64, coefficients: &'_ Coefficients) {
+        let mut out = 0.0;
+        for i in (1..N).rev() {
+            self.d22[i] = fir(&mut self.d21[i - 1], self.d22[i - 1], alpha, coefficients);
+            let v = self.d22[i] * Self::PPADE[i];
+            *x += if i & 1 != 0 { v } else { -v };
+            out += v;
+        }
+        self.d22[0] = *x;
+        *x += out;
+    }
+}
+
+#[inline(always)]
+fn fir(d: &mut [f64], x: f64, alpha: f64, coefficients: &[f64]) -> f64 {
+    d[0] = x;
+
+    let a = alpha;
+    let iaa = 1.0 - a * a;
+    let mut rem = 0.0;
+
+    for di in &mut d[..] {
+        (*di, rem) = (a * *di + rem, iaa * *di - a * rem);
+    }
+
+    let mut y = 0.0;
+    let c = &coefficients[..d.len()];
+    for i in 2..d.len() {
+        y += d[i] * c[i];
+    }
+    y
+}