chore: Release spectrust version 0.2.5

Move PCM decoding into a producer thread that feeds an mpsc channel,
letting the render loop drain samples non-blockingly each frame. Add a
frame-aligned sleep via event::poll to replace the implicit CPU yield
that the old blocking read provided. Also replace powf(0.5) with sqrt().

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Cargo.lock

@@ -429,7 +429,7 @@ checksum = "8ed6a63f02c8539c91a8685a86f4099661ba3da017932f6ebbea6de3f0fa7c90"
 
 [[package]]
 name = "spectrust"
-version = "0.2.4"
+version = "0.2.5"
 dependencies = [
  "byteorder",
  "clap",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "spectrust"
-version = "0.2.4"
+version = "0.2.5"
 edition = "2021"
 
 [profile.release]

aur/PKGBUILD

@@ -1,6 +1,6 @@
 # Maintainer: Bendik Aagaard Lynghaug <bendik.lynghaug@gmail.com>
 pkgname=spectrust
-pkgver=0.2.4
+pkgver=0.2.5
 pkgrel=1
 pkgdesc="Terminal audio spectrum analyzer"
 arch=('x86_64' 'aarch64')

src/main.rs

@@ -13,6 +13,8 @@ use rustfft::{algorithm::Radix4, num_complex::Complex, Fft, FftDirection};
 use std::collections::VecDeque;
 use std::io::{stdout, Read, Write};
 use std::fs::File;
+use std::sync::mpsc;
+use std::thread;
 use std::time::{Duration, Instant};
 use byteorder::{LittleEndian, ReadBytesExt};
 use std::process::{Command, Stdio};
@@ -159,22 +161,15 @@ fn main() {
 
     let fft = Radix4::new(fft_size, FftDirection::Forward);
 
-    let mut input_buffer = vec![0u8; samples_per_frame * num_channels * (bit_depth / 8)];
     let mut complex_buffer = vec![Complex { re: 0.0f32, im: 0.0f32 }; fft_size];
 
     let hann_window: Vec<f32> = (0..fft_size)
         .map(|i| 0.5 * (1.0 - (2.0 * std::f32::consts::PI * i as f32 / fft_size as f32).cos()))
         .collect();
 
-    enum AudioSource {
-        StdIn(std::io::StdinLock<'static>),
-        File(File),
-        PipeWire(std::process::ChildStdout),
-    }
-
     let _ = out.flush();
 
-    let mut audio_source = if cli.pipewire {
+    let reader: Box<dyn Read + Send + 'static> = if cli.pipewire {
         let process = Command::new("pw-record")
             .args(["--format=s16", "--rate=48000", "--channels=2", "--raw", "-"])
             .stdout(Stdio::piped())
@@ -182,14 +177,51 @@ fn main() {
             .expect("failed to start pw-record");
         let pipe = process.stdout.expect("failed to capture pw-record stdout");
         let _ = out.flush();
-        AudioSource::PipeWire(pipe)
+        Box::new(pipe)
     } else if let Some(filename) = &cli.input {
-        let file = File::open(filename).expect("failed to open input file");
+        Box::new(File::open(filename).expect("failed to open input file"))
-        AudioSource::File(file)
     } else {
-        AudioSource::StdIn(std::io::stdin().lock())
+        Box::new(std::io::stdin())
     };
 
+    let (tx, rx) = mpsc::channel::<Vec<f32>>();
+    let _audio_thread = thread::spawn(move || {
+        let mut reader = reader;
+        let mut input_buffer = vec![0u8; samples_per_frame * num_channels * (bit_depth / 8)];
+        loop {
+            match reader.read(&mut input_buffer) {
+                Ok(0) => break,
+                Ok(n) => {
+                    let mut samples = Vec::with_capacity(n / (num_channels * (bit_depth / 8)));
+                    let mut cursor = std::io::Cursor::new(&input_buffer[..n]);
+                    while cursor.position() < (n as u64 - (num_channels * (bit_depth / 8)) as u64 + 1) {
+                        let mut frame_sum = 0.0f32;
+                        let mut valid_channels = 0u32;
+                        for _ in 0..num_channels {
+                            match cursor.read_i16::<LittleEndian>() {
+                                Ok(sample) => {
+                                    frame_sum += sample as f32;
+                                    valid_channels += 1;
+                                }
+                                Err(_) => break,
+                            }
+                        }
+                        if valid_channels > 0 {
+                            samples.push((frame_sum / valid_channels as f32) / 32768.0);
+                        }
+                    }
+                    if !samples.is_empty() && tx.send(samples).is_err() {
+                        break;
+                    }
+                }
+                Err(e) if e.kind() == std::io::ErrorKind::WouldBlock => {
+                    thread::sleep(Duration::from_millis(1));
+                }
+                Err(_) => break,
+            }
+        }
+    });
+
     let max_width: u16 = 1000;
     let max_height: u16 = 1000;
 
@@ -226,7 +258,8 @@ fn main() {
     let mut max_magnitude: f32 = 1.0;
 
     loop {
-        if event::poll(Duration::ZERO).unwrap_or(false) {
+        let time_to_next_frame = interval.saturating_sub(last_frame_time.elapsed());
+        if event::poll(time_to_next_frame).unwrap_or(false) {
             match event::read() {
                 Ok(Event::Key(KeyEvent { code: KeyCode::Char('q'), .. })) => break,
                 Ok(Event::Key(KeyEvent {
@@ -272,69 +305,17 @@ fn main() {
             }
 
             all_samples.clear();
-            let mut buffer_is_empty = false;
-
             loop {
-                let read_result = match &mut audio_source {
+                match rx.try_recv() {
-                    AudioSource::StdIn(input) => input.read(&mut input_buffer),
+                    Ok(batch) => all_samples.extend_from_slice(&batch),
-                    AudioSource::File(file) => file.read(&mut input_buffer),
+                    Err(_) => break,
-                    AudioSource::PipeWire(pipe) => pipe.read(&mut input_buffer),
-                };
-
-                match read_result {
-                    Ok(0) => {
-                        buffer_is_empty = true;
-                        break;
-                    }
-                    Ok(n) => {
-                        let mut cursor = std::io::Cursor::new(&input_buffer[..n]);
-                        while cursor.position() < (n as u64 - (num_channels * (bit_depth / 8)) as u64 + 1) {
-                            let mut frame_sum = 0.0f32;
-                            let mut valid_channels = 0u32;
-                            for _ in 0..num_channels {
-                                match cursor.read_i16::<LittleEndian>() {
-                                    Ok(sample) => {
-                                        frame_sum += sample as f32;
-                                        valid_channels += 1;
-                                    }
-                                    Err(_) => break,
-                                }
-                            }
-                            if valid_channels > 0 {
-                                all_samples.push((frame_sum / valid_channels as f32) / 32768.0);
-                            }
-                        }
-                        if all_samples.len() >= fft_size * 2 {
-                            break;
-                        }
-                    }
-                    Err(e) if e.kind() == std::io::ErrorKind::UnexpectedEof => break,
-                    Err(e) if e.kind() == std::io::ErrorKind::WouldBlock => {
-                        buffer_is_empty = true;
-                        break;
-                    }
-                    Err(e) => {
-                        let error_msg = format!("Error: {}", e);
-                        for (i, c) in error_msg.chars().enumerate() {
-                            if i < sc {
-                                next_buffer[0][i] = Cell { character: c, filled: true };
-                            }
-                        }
-                        view_diff.clear();
-                        for y in 0..sr {
-                            for x in 0..sc {
-                                if current_buffer[y][x] != next_buffer[y][x] {
-                                    view_diff.add_change(y, x, next_buffer[y][x].character);
-                                }
-                            }
-                        }
-                        view_diff.apply();
-                        std::mem::swap(&mut current_buffer, &mut next_buffer);
-                        let _ = out.flush();
-                        break;
-                    }
                 }
             }
+            // Latency guard: if the audio thread got ahead, drop old samples
+            if all_samples.len() > fft_size * 2 {
+                let excess = all_samples.len() - fft_size * 2;
+                all_samples.drain(..excess);
+            }
 
             if !all_samples.is_empty() {
                 if all_samples.len() > fft_size {
@@ -364,7 +345,7 @@ fn main() {
                     if mapping_idx < fft_size / 2 {
                         let magnitude = complex_buffer[mapping_idx].norm();
                         let freq_boost = 1.0 + (mapping_idx as f32 / (fft_size / 2) as f32) * 4.0;
-                        let scaled = (magnitude * 80.0 * freq_boost).powf(0.5);
+                        let scaled = (magnitude * 80.0 * freq_boost).sqrt();
                         freq_bands[i] = if scaled > last_bars[i] { scaled } else { last_bars[i] * drop_factor };
                     }
                 }
@@ -397,7 +378,7 @@ fn main() {
                 std::mem::swap(&mut current_buffer, &mut next_buffer);
                 last_frame_time = Instant::now();
                 let _ = out.flush();
-            } else if buffer_is_empty {
+            } else {
                 for i in 0..sc {
                     last_bars[i] *= drop_factor;
                     render_bar(&mut next_buffer, i, sr, (last_bars[i] / max_magnitude) * sr as f32);