fix bugs on linux (mix two channels down to 1, build with vulkan)

src-tauri/Cargo.toml

@@ -42,6 +42,12 @@ tauri-plugin-store = "2"
 [target.'cfg(target_os = "macos")'.dependencies]
 whisper-rs = { version = "0.13.2", features = ["metal"] }
 
+[target.'cfg(target_os = "windows")'.dependencies]
+whisper-rs = { version = "0.13.2", features = ["vulkan"] }
+
+[target.'cfg(target_os = "linux")'.dependencies]
+whisper-rs = { version = "0.13.2", features = ["openblas", "vulkan"] }
+
 [target.'cfg(not(any(target_os = "android", target_os = "ios")))'.dependencies]
 tauri-plugin-autostart = "2"
 tauri-plugin-global-shortcut = "2"

src-tauri/src/managers/audio.rs

@@ -12,6 +12,7 @@ pub enum RecordingState {
     Recording { binding_id: String },
 }
 
+#[derive(Clone)]
 pub struct AudioRecordingManager {
     state: Arc<Mutex<RecordingState>>,
     buffer: Arc<Mutex<Vec<f32>>>,
@@ -84,6 +85,7 @@ impl AudioRecordingManager {
         // Generic function to process audio data
         fn process_audio<T: SampleToF32 + Send + 'static>(
             data: &[T],
+            channels: usize,
             state_clone: Arc<Mutex<RecordingState>>,
             temp_buffer_clone: Arc<Mutex<Vec<f32>>>,
             resampler_clone: Arc<Mutex<FftFixedIn<f32>>>,
@@ -95,9 +97,20 @@ impl AudioRecordingManager {
             if let RecordingState::Recording { .. } = *state_guard {
                 let mut temp_buffer = temp_buffer_clone.lock().unwrap();
 
-                // Convert incoming data to f32
-                let f32_data: Vec<f32> = data.iter().map(|sample| sample.to_f32()).collect();
-                temp_buffer.extend_from_slice(&f32_data);
+                // Handle multichannel audio by mixing down to mono
+                if channels > 1 {
+                    // Process chunks of `channels` samples at a time (each chunk is one audio frame)
+                    for chunk in data.chunks(channels) {
+                        // Average the channels to create a mono sample
+                        let mono_sample: f32 =
+                            chunk.iter().map(|s| s.to_f32()).sum::<f32>() / channels as f32;
+                        temp_buffer.push(mono_sample);
+                    }
+                } else {
+                    // Single channel processing
+                    let f32_data: Vec<f32> = data.iter().map(|sample| sample.to_f32()).collect();
+                    temp_buffer.extend_from_slice(&f32_data);
+                }
 
                 // Process when we have enough samples
                 while temp_buffer.len() >= 1024 {
@@ -142,12 +155,17 @@ impl AudioRecordingManager {
             let err_fn = |err| eprintln!("Error in stream: {}", err);
 
             // Build the appropriate stream based on the sample format
+            // Store the number of channels for use in the closure
+            let channels = config.channels() as usize;
+            println!("Using {} channel(s) for recording", channels);
+
             let stream = match config.sample_format() {
                 SampleFormat::I8 => device.build_input_stream(
                     &config.into(),
                     move |data: &[i8], _| {
                         process_audio(
                             data,
+                            channels,
                             Arc::clone(&state_clone),
                             Arc::clone(&temp_buffer_clone),
                             Arc::clone(&resampler_clone),
@@ -164,6 +182,7 @@ impl AudioRecordingManager {
                     move |data: &[i16], _| {
                         process_audio(
                             data,
+                            channels,
                             Arc::clone(&state_clone),
                             Arc::clone(&temp_buffer_clone),
                             Arc::clone(&resampler_clone),
@@ -180,6 +199,7 @@ impl AudioRecordingManager {
                     move |data: &[i32], _| {
                         process_audio(
                             data,
+                            channels,
                             Arc::clone(&state_clone),
                             Arc::clone(&temp_buffer_clone),
                             Arc::clone(&resampler_clone),
@@ -196,6 +216,7 @@ impl AudioRecordingManager {
                     move |data: &[f32], _| {
                         process_audio(
                             data,
+                            channels,
                             Arc::clone(&state_clone),
                             Arc::clone(&temp_buffer_clone),
                             Arc::clone(&resampler_clone),
@@ -268,7 +289,7 @@ impl AudioRecordingManager {
                 } else {
                     // Pad to minimum 1000ms if needed
                     if duration_ms < 1000.0 {
-                        let target_samples = (16400.0 * (1000.0 / 1000.0)) as usize; // 16000 samples for 1 second
+                        let target_samples = (16000.0 * (1000.0 / 1000.0)) as usize; // 16000 samples for 1 second
                         let mut padded_audio = audio_data;
                         padded_audio.resize(target_samples, 0.0); // Pad with silence (zeros)
                         Some(padded_audio)

src-tauri/src/managers/transcription.rs

@@ -1,5 +1,6 @@
 use anyhow::Result;
 use std::sync::Mutex;
+use std::thread;
 use tauri::{App, Manager};
 use whisper_rs::install_whisper_log_trampoline;
 use whisper_rs::{
@@ -7,7 +8,6 @@ use whisper_rs::{
 };
 
 pub struct TranscriptionManager {
-    context: WhisperContext,
     state: Mutex<WhisperState>,
 }
 
@@ -30,7 +30,6 @@ impl TranscriptionManager {
         let state = context.create_state().expect("failed to create state");
 
         Ok(Self {
-            context,
             state: Mutex::new(state),
         })
     }
@@ -47,6 +46,10 @@ impl TranscriptionManager {
             return Ok(result);
         }
 
+        let num_threads = thread::available_parallelism()
+            .map(|count| count.get() as i32)
+            .unwrap_or(1);
+
         let mut state = self.state.lock().unwrap();
         // Initialize parameters
         let mut params = FullParams::new(SamplingStrategy::default());