feat: full WSL2 audio support and Windows audio stability fix

pkg/audio/capture_linux.go

@@ -0,0 +1,112 @@
+//go:build linux
+
+package audio
+
+import (
+	"fmt"
+	"sync"
+
+	"github.com/gordonklaus/portaudio"
+)
+
+// Capturer handles audio capture using PortAudio
+type Capturer struct {
+	stream       *portaudio.Stream
+	running      bool
+	mu           sync.Mutex
+	onAudio      func(samples []int16)
+	currentLevel int
+	levelMu      sync.RWMutex
+}
+
+func NewCapturer() (*Capturer, error) {
+	if err := initPortAudio(); err != nil {
+		return nil, err
+	}
+
+	return &Capturer{}, nil
+}
+
+func (c *Capturer) SetCallback(fn func(samples []int16)) {
+	c.mu.Lock()
+	c.onAudio = fn
+	c.mu.Unlock()
+}
+
+func (c *Capturer) Start() error {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if c.running {
+		return nil
+	}
+
+	var err error
+	c.stream, err = portaudio.OpenDefaultStream(1, 0, 48000, frameSamples, c.processCapture)
+	if err != nil {
+		return fmt.Errorf("failed to open portaudio capture stream: %w", err)
+	}
+
+	if err := c.stream.Start(); err != nil {
+		c.stream.Close()
+		return fmt.Errorf("failed to start portaudio capture stream: %w", err)
+	}
+
+	c.running = true
+	return nil
+}
+
+func (c *Capturer) Stop() {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if !c.running {
+		return
+	}
+	c.running = false
+	if c.stream != nil {
+		c.stream.Abort()
+	}
+}
+
+func (c *Capturer) Close() {
+	c.Stop()
+	c.mu.Lock()
+	if c.stream != nil {
+		c.stream.Close()
+	}
+	c.mu.Unlock()
+	terminatePortAudio()
+}
+
+func (c *Capturer) processCapture(in []int16) {
+	c.mu.Lock()
+	callback := c.onAudio
+	running := c.running
+	c.mu.Unlock()
+
+	if !running || callback == nil {
+		return
+	}
+
+	// Calculate level
+	level := CalculateRMSLevel(in)
+	c.levelMu.Lock()
+	c.currentLevel = level
+	c.levelMu.Unlock()
+
+	// Clone buffer and send to callback
+	samples := make([]int16, len(in))
+	copy(samples, in)
+	callback(samples)
+}
+
+func (c *Capturer) GetLevel() int {
+	c.levelMu.RLock()
+	defer c.levelMu.RUnlock()
+	return c.currentLevel
+}
+
+func (c *Capturer) IsRunning() bool {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	return c.running
+}