Apply formatting and update README

README.md

@@ -82,7 +82,7 @@ Follow the instructions above for your operating system to install a virtual aud
 
    - **TCP/UDP (WiFi)**:
      - Connect your phone and PC to the same network
-     - No additional setup required
+     - **Windows**: When the firewall prompt appears on first launch, click **Allow access**. Otherwise the PC can't receive connections from your phone. If you dismissed the prompt, allow AndroidMic in *Windows Security → Firewall & network protection → Allow an app through firewall*
 
    - **USB ADB**:
      - Install [Android Debug Bridge (ADB)](https://developer.android.com/tools/adb)
@@ -119,6 +119,7 @@ Follow the instructions above for your operating system to install a virtual aud
    - Grant required permissions:
      - **Microphone**: To access your phone's mic
      - **Notification**: To show recording status in background
+     - **Nearby devices**: Required on Android 17 and above to connect to your PC. Approve it when prompted, or enable it in *Settings → Apps → AndroidMic → Permissions*
    - Start recording
    - Connect to PC:
      - **TCP/UDP**: Enter PC IP address and port (shown in PC app log)
@@ -154,6 +155,15 @@ After setup, the virtual microphone will appear in your system's audio input dev
 - **USB Serial**: May need [Zadig](https://zadig.akeo.ie/) to change USB driver to WinUSB
 - **USB Serial (Linux)**: Configure udev rules for USB permissions
 
+### Phone can't connect to PC
+- **Android 37+**: Make sure the **Nearby devices** permission is granted to the app
+- **Windows**: Make sure AndroidMic is allowed through the firewall (see [Step 2](#step-2-pc-application-setup))
+- Confirm the phone and PC are on the same network
+
+### Audio is choppy, stuttering or glitchy
+- Increase the **jitter buffer** latency in the PC app settings. A larger buffer absorbs network delays at the cost of slightly higher latency. Raise it step by step until the audio is smooth
+- The PC app logs a warning (`playout: ... underruns ...`) when the buffer runs dry, which is a sign you should increase it
+
 ### Audio quality issues
 - Match audio settings between PC and Android app exactly
 - Try different sample rates (44.1kHz or 48kHz)

RustApp/benches/audio.rs

@@ -14,7 +14,6 @@ use android_mic::{
 };
 use criterion::{Criterion, criterion_group, criterion_main};
 
-
 fn make_random(size: usize) -> Vec<u8> {
     use rand::rngs::StdRng;
     use rand::{Rng, SeedableRng};

RustApp/src/audio/player.rs

@@ -57,21 +57,11 @@ pub fn create_audio_stream(
 
     // create stream config
     let stream: cpal::Stream = match audio_format {
-        AudioFormat::I16 => {
-            build_output_stream::<i16>(device, config, consumer, target_latency)
-        }
-        AudioFormat::I24 => {
-            build_output_stream::<f32>(device, config, consumer, target_latency)
-        }
-        AudioFormat::I32 => {
-            build_output_stream::<i32>(device, config, consumer, target_latency)
-        }
-        AudioFormat::U8 => {
-            build_output_stream::<u8>(device, config, consumer, target_latency)
-        }
-        AudioFormat::F32 => {
-            build_output_stream::<f32>(device, config, consumer, target_latency)
-        }
+        AudioFormat::I16 => build_output_stream::<i16>(device, config, consumer, target_latency),
+        AudioFormat::I24 => build_output_stream::<f32>(device, config, consumer, target_latency),
+        AudioFormat::I32 => build_output_stream::<i32>(device, config, consumer, target_latency),
+        AudioFormat::U8 => build_output_stream::<u8>(device, config, consumer, target_latency),
+        AudioFormat::F32 => build_output_stream::<f32>(device, config, consumer, target_latency),
     }?;
 
     // convert stream config to AudioPacketFormat
@@ -142,7 +132,11 @@ mod tests {
         // the filter delay passes first, then the signal comes through
         let mut output = [0_i16; 256];
         playout.fill(&mut output);
-        assert!(output[..filter_delay_frames() - 8].iter().all(|s| s.abs() < 1000));
+        assert!(
+            output[..filter_delay_frames() - 8]
+                .iter()
+                .all(|s| s.abs() < 1000)
+        );
         assert!(output[200..].iter().all(|s| (*s - 16383).abs() < 20));
     }
 }

RustApp/src/audio/playout.rs

@@ -300,7 +300,10 @@ impl Playout {
         let capacity = consumer.buffer().capacity() / channels;
         let mut target = to_frames(target_latency).max(1);
         if target > capacity / 2 {
-            warn!("playout: target latency is too big for the buffer, using {} frames", capacity / 2);
+            warn!(
+                "playout: target latency is too big for the buffer, using {} frames",
+                capacity / 2
+            );
             target = capacity / 2;
         }
 
@@ -841,7 +844,10 @@ mod tests {
         for drift in [-200.0, -30.0, 0.0, 50.0, 300.0] {
             // pseudo random jitter up to 15 ms, with a 30 ms spike every second
             let jitter = |n: usize| {
-                let r = ((n as u64).wrapping_mul(6364136223846793005).wrapping_add(1442695040888963407) >> 40) as f64
+                let r = ((n as u64)
+                    .wrapping_mul(6364136223846793005)
+                    .wrapping_add(1442695040888963407)
+                    >> 40) as f64
                     / (1u64 << 24) as f64;
                 r * 0.015 + if n % 200 == 0 { 0.03 } else { 0.0 }
             };
@@ -859,7 +865,10 @@ mod tests {
             );
             assert!(s < 0.2, "latency moved by {s} ms with {drift} ppm drift");
             // clicks 204.53 ms apart at the mic stay 204.53 ms apart, within a sample
-            assert!(interval < 0.02, "interval off by {interval} ms with {drift} ppm drift");
+            assert!(
+                interval < 0.02,
+                "interval off by {interval} ms with {drift} ppm drift"
+            );
         }
     }
 
@@ -879,7 +888,12 @@ mod tests {
         let latencies = click_latencies(&output, &clicks, 0.0);
 
         // the clicks inside the stall are lost, all the others are played on time
-        assert!(latencies.len() + 4 >= clicks.len(), "{} {}", latencies.len(), clicks.len());
+        assert!(
+            latencies.len() + 4 >= clicks.len(),
+            "{} {}",
+            latencies.len(),
+            clicks.len()
+        );
 
         let before = &latencies[250..390];
         let after = &latencies[latencies.len() - 250..latencies.len() - 50];

RustApp/src/audio/process.rs

@@ -197,7 +197,11 @@ impl AudioStream {
         let num_frames = std::cmp::min(self.buff.producer.slots() / num_channels, total_frames);
 
         if num_frames > 0 {
-            match self.buff.producer.write_chunk_uninit(num_frames * num_channels) {
+            match self
+                .buff
+                .producer
+                .write_chunk_uninit(num_frames * num_channels)
+            {
                 Ok(chunk) => {
                     let buffer_ref = &buffer;
 

RustApp/src/audio/resampler.rs

@@ -9,7 +9,7 @@ pub struct ResamplerCache {
     result: Vec<Vec<f32>>,
 }
 
-const CHUNK_SIZE: usize = 1024;
+const CHUNK_SIZE: usize = 256;
 
 pub fn resample_f32_stream_owned(
     data: &[Vec<f32>],
@@ -124,6 +124,15 @@ pub fn resample_f32_stream<'a>(
                 channel.clear();
             }
             input_offset = missing;
+        } else {
+            // not enough data to fill a chunk yet, keep accumulating
+            for (data, unprocessed_buffer) in data.iter().zip(unprocessed_buffer.iter_mut()) {
+                unprocessed_buffer.extend_from_slice(data);
+            }
+            for channel in &mut cache.result {
+                channel.clear();
+            }
+            return Ok(&mut cache.result);
         }
     };
 

RustApp/src/ui/tray.rs

@@ -18,7 +18,6 @@ pub struct SystemTrayStream {
 
 #[cfg(not(target_os = "linux"))]
 mod tray_icon_backend {
-    use futures::SinkExt;
     use std::sync::Arc;
     use tokio::sync::{Mutex, mpsc};
     use tray_icon::{
@@ -114,10 +113,10 @@ pub use tray_icon_backend::SystemTray;
 
 #[cfg(target_os = "linux")]
 mod ksni_backend {
-    use std::sync::Arc;
-    use tokio::sync::{Mutex, mpsc};
     use ksni::TrayMethods;
     use ksni::menu::{MenuItem as MenuEntry, StandardItem};
+    use std::sync::Arc;
+    use tokio::sync::{Mutex, mpsc};
 
     use crate::{fl, utils::APP_ID};
 
@@ -140,7 +139,10 @@ mod ksni_backend {
 
         fn apply(&mut self, cmd: TrayCommand) {
             match cmd {
-                TrayCommand::MenuState { disconnected, status } => {
+                TrayCommand::MenuState {
+                    disconnected,
+                    status,
+                } => {
                     self.disconnected = disconnected;
                     self.description = format!("AndroidMic - {status}");
                 }