Improvement: automatically resume audio when the audio usb gadget is re-enabled from settings

internal/audio/relay.go

@@ -3,6 +3,7 @@ package audio
 import (
 	"context"
 	"fmt"
+	"reflect"
 	"sync"
 	"time"
 
@@ -168,15 +169,22 @@ func (r *AudioRelay) relayLoop() {
 // forwardToWebRTC forwards a frame to the WebRTC audio track
 func (r *AudioRelay) forwardToWebRTC(frame []byte) error {
 	r.mutex.RLock()
+	defer r.mutex.RUnlock()
+	
 	audioTrack := r.audioTrack
 	config := r.config
 	muted := r.muted
-	r.mutex.RUnlock()
 
+	// Comprehensive nil check for audioTrack to prevent panic
 	if audioTrack == nil {
 		return nil // No audio track available
 	}
 
+	// Check if interface contains nil pointer using reflection
+	if reflect.ValueOf(audioTrack).IsNil() {
+		return nil // Audio track interface contains nil pointer
+	}
+
 	// Prepare sample data
 	var sampleData []byte
 	if muted {
@@ -186,7 +194,7 @@ func (r *AudioRelay) forwardToWebRTC(frame []byte) error {
 		sampleData = frame
 	}
 
-	// Write sample to WebRTC track
+	// Write sample to WebRTC track while holding the read lock
 	return audioTrack.WriteSample(media.Sample{
 		Data:     sampleData,
 		Duration: config.FrameSize,

main.go

@@ -11,6 +11,7 @@ import (
 
 	"github.com/gwatts/rootcerts"
 	"github.com/jetkvm/kvm/internal/audio"
+	"github.com/pion/webrtc/v4"
 )
 
 var (
@@ -46,9 +47,17 @@ func startAudioSubprocess() error {
 		func(pid int) {
 			logger.Info().Int("pid", pid).Msg("audio server process started")
 
-			// Start audio relay system for main process without a track initially
-			// The track will be updated when a WebRTC session is created
-			if err := audio.StartAudioRelay(nil); err != nil {
+			// Start audio relay system for main process
+			// If there's an active WebRTC session, use its audio track
+			var audioTrack *webrtc.TrackLocalStaticSample
+			if currentSession != nil && currentSession.AudioTrack != nil {
+				audioTrack = currentSession.AudioTrack
+				logger.Info().Msg("restarting audio relay with existing WebRTC audio track")
+			} else {
+				logger.Info().Msg("starting audio relay without WebRTC track (will be updated when session is created)")
+			}
+
+			if err := audio.StartAudioRelay(audioTrack); err != nil {
 				logger.Error().Err(err).Msg("failed to start audio relay")
 			}
 		},