fix resampling

.vscode/launch.json

@@ -0,0 +1,16 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "type": "lldb",
+            "request": "launch",
+            "name": "Debug",
+            "program": "${workspaceFolder}/<executable file>",
+            "args": [],
+            "cwd": "${workspaceFolder}"
+        }
+    ]
+}

src/audio/resampling.rs

@@ -1,4 +1,4 @@
-use rubato::{Resampler, SincFixedIn, SincInterpolationParameters, SincInterpolationType, WindowFunction};
+use rubato::{FastFixedIn, FastFixedOut, PolynomialDegree, Resampler, SincFixedIn, SincInterpolationParameters, SincInterpolationType, WindowFunction};
 
 const MAX_CHUNK_SIZE: usize = 1024;
 
@@ -65,3 +65,18 @@ pub fn resampling(
 
     Ok(output)
 }
+
+pub fn get_resampler<T>(from: f64, to: f64, channels: usize, chunk_size: usize) -> FastFixedIn<T>
+where
+    T: rubato::Sample
+{
+    let resample_ratio = to / from;
+
+    FastFixedIn::<T>::new(
+        resample_ratio,
+        2.0,
+        PolynomialDegree::Cubic,
+        chunk_size,
+        channels
+    ).unwrap()
+}

src/commands/run.rs

@@ -1,13 +1,12 @@
 use std::{
-    cmp::min,
+    cmp::min, io::Read, mem::MaybeUninit, sync::{Arc, Mutex}
-    io::Read,
-    sync::{Arc, Mutex},
 };
 
 use cpal::{
     traits::{DeviceTrait, HostTrait, StreamTrait},
     Device, Stream, StreamConfig, SupportedStreamConfig,
 };
+use rubato::FastFixedIn;
 
 use crate::{args::Run, device::virtual_device::VirtualDevice};
 
@@ -351,7 +350,7 @@ fn input_callback<T>(data: &[T], channels: usize, virtual_device: Arc<Mutex<Virt
 where
     T: Clone + num::cast::ToPrimitive,
 {
-    let data: Vec<f32> = data.iter().map(|d| d.to_f32().unwrap()).collect();
+    let data: Vec<f64> = data.iter().map(|d| d.to_f64().unwrap()).collect();
     let audio_data = reshape_audio_data(&data, channels);
     virtual_device
         .lock()
@@ -377,7 +376,7 @@ fn output_callback<T>(
         data.len() / channels,
     );
     let mut count = 0;
-    while audio_data.is_none() && count < 1 {
+    while audio_data.is_none() && count < 1000 {
         audio_data = virtual_device.take_output(
             index,
             min(channels as u8, vd_channels),
@@ -401,7 +400,7 @@ fn output_callback<T>(
 
     let audio_data: Vec<T> = audio_data
         .iter()
-        .map(|d| T::from_f32(*d).unwrap())
+        .map(|d| T::from_f64(*d).unwrap())
         .collect();
 
     data.clone_from_slice(&audio_data);

src/device/virtual_device.rs

@@ -1,6 +1,8 @@
-use std::collections::HashMap;
+use std::{collections::HashMap, mem::MaybeUninit, sync::{Arc, Mutex}};
 
-use crate::audio::resampling::resampling;
+use rubato::{FastFixedIn, Resampler};
+
+use crate::audio::resampling::{get_resampler, resampling};
 
 pub struct VirtualDevice {
     pub name: String,
@@ -8,7 +10,7 @@ pub struct VirtualDevice {
     pub sample_rate: u32,
 
     output_index: HashMap<u32, Vec<usize>>,
-    output_buffer: HashMap<u32, Vec<Vec<f32>>>,
+    output_buffer: HashMap<u32, (Vec<Vec<f64>>, Arc<Mutex<Option<FastFixedIn<f64>>>>)>,
 }
 
 impl VirtualDevice {
@@ -31,7 +33,7 @@ impl VirtualDevice {
         if let std::collections::hash_map::Entry::Vacant(e) = self.output_index.entry(sample_rate) {
             e.insert(Vec::new());
             self.output_buffer
-                .insert(sample_rate, vec![vec![]; self.channels as usize]);
+                .insert(sample_rate, (vec![vec![]; self.channels as usize], Arc::new(Mutex::new(None))));
         }
         let min_index = self.get_min_index(sample_rate);
         self.output_index
@@ -47,17 +49,17 @@ impl VirtualDevice {
         channels: u8,
         sample_rate: u32,
         take_size: usize,
-    ) -> Option<Vec<Vec<f32>>> {
+    ) -> Option<Vec<Vec<f64>>> {
         let mut buffer = vec![Vec::with_capacity(take_size); channels as usize];
         let start = self.output_index[&sample_rate][index];
         let end = start + take_size;
 
         for channel in 0..channels {
-            if end >= self.output_buffer[&sample_rate][channel as usize].len() {
+            if end >= self.output_buffer[&sample_rate].0[channel as usize].len() {
                 println!(
                     "End of buffer: {}, {}[{}]",
                     end,
-                    self.output_buffer[&sample_rate][channel as usize].len(),
+                    self.output_buffer[&sample_rate].0[channel as usize].len(),
                     channel as usize
                 );
                 return None;
@@ -67,7 +69,7 @@ impl VirtualDevice {
         for i in start..end {
             for channel in 0..channels {
                 buffer[channel as usize]
-                    .push(self.output_buffer[&sample_rate][channel as usize][i]);
+                    .push(self.output_buffer[&sample_rate].0[channel as usize][i]);
             }
         }
         self.output_index.get_mut(&sample_rate).unwrap()[index] = end;
@@ -75,8 +77,8 @@ impl VirtualDevice {
         let min = self.get_min_index(sample_rate);
         if min != 0 {
             for i in 0..self.channels as usize {
-                let len = self.output_buffer[&sample_rate][i].len();
+                let len = self.output_buffer[&sample_rate].0[i].len();
-                self.output_buffer.get_mut(&sample_rate).unwrap()[i]
+                self.output_buffer.get_mut(&sample_rate).unwrap().0[i]
                     .drain(0..(if len < min { len } else { min }));
             }
             for i in 0..self.output_index.len() {
@@ -87,17 +89,23 @@ impl VirtualDevice {
         Some(buffer)
     }
 
-    pub fn write_input_multiple_channels(&mut self, input_buffer: &[Vec<f32>]) {
+    pub fn write_input_multiple_channels(&mut self, input_buffer: &[Vec<f64>]) {
         for (sample_rate, buffer) in self.output_buffer.iter_mut() {
+            let mut guard = buffer.1.lock().unwrap();
+            let resampler = {
+                if guard.is_none() {
+                    *guard = Some(get_resampler::<f64>(self.sample_rate as f64, *sample_rate as f64, self.channels as usize, input_buffer[0].len()));
+                }
+                guard.as_mut().unwrap()
+            };
+
             let buffer_resample =  if self.sample_rate == *sample_rate {
                 input_buffer.to_vec()
             } else {
-                resampling(self.sample_rate, *sample_rate, input_buffer.to_vec()).unwrap()
+                resampler.process(input_buffer, None).unwrap()
             };
 
-            println!("Resampling: {} -> {}", input_buffer[0].len(), buffer_resample[0].len());
+            (0..self.channels as usize).for_each(|i| buffer.0[i].extend(buffer_resample[i].iter()));
-
-            (0..self.channels as usize).for_each(|i| buffer[i].extend(buffer_resample[i].iter()));
         }
     }
 }