feat: full WSL2 audio support and Windows audio stability fix

pkg/audio/playback.go

@@ -1,8 +1,11 @@
+//go:build windows
+
 package audio
 
 import (
 	"encoding/binary"
 	"fmt"
+	"log"
 	"sync"
 	"time"
 	"unsafe"
@@ -32,19 +35,11 @@ type Player struct {
 	bufferMu     sync.Mutex
 }
 
-type UserSettings struct {
-	Volume float32 // 0.0 - 1.0 (or higher for boost)
-	Muted  bool
-}
-
-const (
-	frameSamples = 960 // 20ms at 48kHz
-)
-
 // NewPlayer creates a new WASAPI audio player
 func NewPlayer() (*Player, error) {
 	// Initialize COM
 	ole.CoInitializeEx(0, ole.COINIT_APARTMENTTHREADED)
+	log.Printf("[Audio] Windows/WASAPI initializing...")
 
 	var deviceEnumerator *wca.IMMDeviceEnumerator
 	if err := wca.CoCreateInstance(
@@ -255,7 +250,7 @@ func (p *Player) GetUserSettings(clientID uint16) (float32, bool) {
 }
 
 func (p *Player) playbackLoop() {
-	ticker := time.NewTicker(20 * time.Millisecond)
+	ticker := time.NewTicker(10 * time.Millisecond)
 	defer ticker.Stop()
 
 	for {
@@ -269,79 +264,88 @@ func (p *Player) playbackLoop() {
 }
 
 func (p *Player) writeFrame() {
-	var padding uint32
-	if err := p.client.GetCurrentPadding(&padding); err != nil {
-		return
-	}
+	for {
+		var padding uint32
+		if err := p.client.GetCurrentPadding(&padding); err != nil {
+			return
+		}
 
-	available := p.bufferSize - padding
-	if available < frameSamples {
-		return
-	}
+		available := p.bufferSize - padding
+		if available < frameSamples {
+			return
+		}
 
-	p.bufferMu.Lock()
+		p.bufferMu.Lock()
 
-	// Mix audio from all active user buffers
-	mixed := make([]int32, frameSamples)
-	activeUsers := 0
+		// Mix audio from all active user buffers
+		mixed := make([]int32, frameSamples)
+		activeUsers := 0
+		hasAnyAudio := false
 
-	for id, buf := range p.userBuffers {
-		if len(buf) > 0 {
-			activeUsers++
-			// Take up to frameSamples from this user
-			toTake := frameSamples
-			if len(buf) < frameSamples {
-				toTake = len(buf)
-			}
-
-			for i := 0; i < toTake; i++ {
-				sample := int32(buf[i])
-
-				// Apply user volume if set
-				if settings, ok := p.userSettings[id]; ok {
-					sample = int32(float32(sample) * settings.Volume)
+		for id, buf := range p.userBuffers {
+			if len(buf) > 0 {
+				hasAnyAudio = true
+				activeUsers++
+				// Take up to frameSamples from this user
+				toTake := frameSamples
+				if len(buf) < frameSamples {
+					toTake = len(buf)
 				}
 
-				mixed[i] += sample
-			}
+				for i := 0; i < toTake; i++ {
+					sample := int32(buf[i])
 
-			// Advance buffer
-			if len(buf) <= frameSamples {
-				delete(p.userBuffers, id)
-			} else {
-				p.userBuffers[id] = buf[frameSamples:]
+					// Apply user volume if set
+					if settings, ok := p.userSettings[id]; ok {
+						sample = int32(float32(sample) * settings.Volume)
+					}
+
+					mixed[i] += sample
+				}
+
+				// Advance buffer
+				if len(buf) <= frameSamples {
+					delete(p.userBuffers, id)
+				} else {
+					p.userBuffers[id] = buf[frameSamples:]
+				}
 			}
 		}
-	}
 
-	p.bufferMu.Unlock()
+		p.bufferMu.Unlock()
 
-	// Get WASAPI buffer
-	var buffer *byte
-	if err := p.renderClient.GetBuffer(uint32(frameSamples), &buffer); err != nil {
-		return
-	}
-
-	p.mu.Lock()
-	vol := p.volume
-	p.mu.Unlock()
-
-	// Write mixed samples with clipping protection and volume application
-	bufSlice := unsafe.Slice(buffer, int(frameSamples)*2)
-	for i := 0; i < int(frameSamples); i++ {
-		val := mixed[i]
-
-		// Apply volume
-		val = int32(float32(val) * vol)
-
-		// Hard clipping
-		if val > 32767 {
-			val = 32767
-		} else if val < -32768 {
-			val = -32768
+		// If no audio is playing, don't write anything (keep buffer empty for lower latency when audio starts)
+		if !hasAnyAudio {
+			return
 		}
-		binary.LittleEndian.PutUint16(bufSlice[i*2:], uint16(val))
-	}
 
-	p.renderClient.ReleaseBuffer(uint32(frameSamples), 0)
+		// Get WASAPI buffer
+		var buffer *byte
+		if err := p.renderClient.GetBuffer(uint32(frameSamples), &buffer); err != nil {
+			return
+		}
+
+		p.mu.Lock()
+		vol := p.volume
+		p.mu.Unlock()
+
+		// Write mixed samples with clipping protection and volume application
+		bufSlice := unsafe.Slice(buffer, int(frameSamples)*2)
+		for i := 0; i < int(frameSamples); i++ {
+			val := mixed[i]
+
+			// Apply master volume
+			val = int32(float32(val) * vol)
+
+			// Hard clipping
+			if val > 32767 {
+				val = 32767
+			} else if val < -32768 {
+				val = -32768
+			}
+			binary.LittleEndian.PutUint16(bufSlice[i*2:], uint16(val))
+		}
+
+		p.renderClient.ReleaseBuffer(uint32(frameSamples), 0)
+	}
 }