Simplify audio configuration and error handling

- Replace helper function in getAudioConfig with explicit validation
- Consolidate audio default application in LoadConfig
- Streamline relay retry logic with inline conditions
- Extract closeFile and openHidFile helpers in USB gadget
- Simplify setPendingInputTrack pointer handling
- Improve error handling clarity in startAudio and updateUsbRelatedConfig
- Clean up processInputPacket mutex usage

.devcontainer/install_audio_deps.sh

@@ -4,14 +4,11 @@
 set -e
 
 # Sudo wrapper function
-SUDO_PATH=$(which sudo 2>/dev/null || echo "")
 function use_sudo() {
-  if [ "$UID" -eq 0 ]; then
+  if [ "$UID" -eq 0 ] || [ -z "$(which sudo 2>/dev/null)" ]; then
     "$@"
-  elif [ -n "$SUDO_PATH" ]; then
-    ${SUDO_PATH} -E "$@"
   else
-    "$@"
+    sudo -E "$@"
   fi
 }
 

audio.go

@@ -49,49 +49,47 @@ func initAudio() {
 func getAudioConfig() audio.AudioConfig {
 	cfg := audio.DefaultAudioConfig()
 
-	// Helper to validate numeric ranges and return sanitized values
-	// Returns (value, true) if valid, (0, false) if invalid
-	validateAndApply := func(value int, min int, max int, paramName string) (int, bool) {
-		if value >= min && value <= max {
-			return value, true
-		}
-		if value != 0 {
-			audioLogger.Warn().Int(paramName, value).Msgf("Invalid %s, using default", paramName)
-		}
-		return 0, false
+	// Apply bitrate (64-256 kbps)
+	if config.AudioBitrate >= 64 && config.AudioBitrate <= 256 {
+		cfg.Bitrate = uint16(config.AudioBitrate)
+	} else if config.AudioBitrate != 0 {
+		audioLogger.Warn().Int("bitrate", config.AudioBitrate).Msg("Invalid audio bitrate, using default")
 	}
 
-	// Validate and apply bitrate
-	if bitrate, valid := validateAndApply(config.AudioBitrate, 64, 256, "audio bitrate"); valid {
-		cfg.Bitrate = uint16(bitrate)
+	// Apply complexity (0-10)
+	if config.AudioComplexity >= 0 && config.AudioComplexity <= 10 {
+		cfg.Complexity = uint8(config.AudioComplexity)
+	} else if config.AudioComplexity != 0 {
+		audioLogger.Warn().Int("complexity", config.AudioComplexity).Msg("Invalid audio complexity, using default")
 	}
 
-	// Validate and apply complexity
-	if complexity, valid := validateAndApply(config.AudioComplexity, 0, 10, "audio complexity"); valid {
-		cfg.Complexity = uint8(complexity)
+	// Apply buffer periods (2-24)
+	if config.AudioBufferPeriods >= 2 && config.AudioBufferPeriods <= 24 {
+		cfg.BufferPeriods = uint8(config.AudioBufferPeriods)
+	} else if config.AudioBufferPeriods != 0 {
+		audioLogger.Warn().Int("buffer_periods", config.AudioBufferPeriods).Msg("Invalid buffer periods, using default")
+	}
+
+	// Apply sample rate (Opus supports: 8k, 12k, 16k, 24k, 48k)
+	switch config.AudioSampleRate {
+	case 8000, 12000, 16000, 24000, 48000:
+		cfg.SampleRate = uint32(config.AudioSampleRate)
+	default:
+		if config.AudioSampleRate != 0 {
+			audioLogger.Warn().Int("sample_rate", config.AudioSampleRate).Msg("Invalid sample rate, using default")
+		}
+	}
+
+	// Apply packet loss percentage (0-100)
+	if config.AudioPacketLossPerc >= 0 && config.AudioPacketLossPerc <= 100 {
+		cfg.PacketLossPerc = uint8(config.AudioPacketLossPerc)
+	} else if config.AudioPacketLossPerc != 0 {
+		audioLogger.Warn().Int("packet_loss_perc", config.AudioPacketLossPerc).Msg("Invalid packet loss percentage, using default")
 	}
 
 	cfg.DTXEnabled = config.AudioDTXEnabled
 	cfg.FECEnabled = config.AudioFECEnabled
 
-	// Validate and apply buffer periods
-	if periods, valid := validateAndApply(config.AudioBufferPeriods, 2, 24, "buffer periods"); valid {
-		cfg.BufferPeriods = uint8(periods)
-	}
-
-	// Opus-compatible rates only: 8k, 12k, 16k, 24k, 48k
-	validRates := map[int]bool{8000: true, 12000: true, 16000: true, 24000: true, 48000: true}
-	if validRates[config.AudioSampleRate] {
-		cfg.SampleRate = uint32(config.AudioSampleRate)
-	} else if config.AudioSampleRate != 0 {
-		audioLogger.Warn().Int("sample_rate", config.AudioSampleRate).Uint32("default", cfg.SampleRate).Msg("Invalid sample rate, using default")
-	}
-
-	// Validate and apply packet loss percentage
-	if pktLoss, valid := validateAndApply(config.AudioPacketLossPerc, 0, 100, "packet loss percentage"); valid {
-		cfg.PacketLossPerc = uint8(pktLoss)
-	}
-
 	return cfg
 }
 
@@ -120,13 +118,17 @@ func startAudio() error {
 		inputErr = startInputAudioUnderMutex(getAlsaDevice("usb"))
 	}
 
-	if outputErr != nil && inputErr != nil {
-		return fmt.Errorf("audio start failed - output: %w, input: %v", outputErr, inputErr)
+	// Simplified error handling - both errors are worth reporting
+	if outputErr != nil || inputErr != nil {
+		if outputErr != nil && inputErr != nil {
+			return fmt.Errorf("audio start failed - output: %w, input: %v", outputErr, inputErr)
+		}
+		if outputErr != nil {
+			return outputErr
+		}
+		return inputErr
 	}
-	if outputErr != nil {
-		return outputErr
-	}
-	return inputErr
+	return nil
 }
 
 func startOutputAudioUnderMutex(alsaOutputDevice string) error {
@@ -250,9 +252,8 @@ func setAudioTrack(audioTrack *webrtc.TrackLocalStaticSample) {
 }
 
 func setPendingInputTrack(track *webrtc.TrackRemote) {
-	trackID := new(string)
-	*trackID = track.ID()
-	currentInputTrack.Store(trackID)
+	trackID := track.ID()
+	currentInputTrack.Store(&trackID)
 	go handleInputTrackForSession(track)
 }
 
@@ -397,22 +398,11 @@ func handleInputTrackForSession(track *webrtc.TrackRemote) {
 
 // processInputPacket handles writing audio data to the input source
 func processInputPacket(opusData []byte) error {
-	// Early check to avoid mutex acquisition if source is nil
-	if inputSource.Load() == nil {
-		return nil
-	}
-
 	inputSourceMutex.Lock()
 	defer inputSourceMutex.Unlock()
 
-	// Reload source inside mutex to ensure we have the currently active source
 	source := inputSource.Load()
-	if source == nil {
-		return nil
-	}
-
-	// Defensive null check - ensure dereferenced pointer is valid
-	if *source == nil {
+	if source == nil || *source == nil {
 		return nil
 	}
 

config.go

@@ -290,6 +290,7 @@ func LoadConfig() {
 		loadedConfig.JigglerConfig = getDefaultConfig().JigglerConfig
 	}
 
+	// Apply audio defaults for new configs
 	if loadedConfig.AudioBitrate == 0 {
 		defaults := getDefaultConfig()
 		loadedConfig.AudioBitrate = defaults.AudioBitrate
@@ -297,13 +298,8 @@ func LoadConfig() {
 		loadedConfig.AudioDTXEnabled = defaults.AudioDTXEnabled
 		loadedConfig.AudioFECEnabled = defaults.AudioFECEnabled
 		loadedConfig.AudioBufferPeriods = defaults.AudioBufferPeriods
-	}
-
-	if loadedConfig.AudioSampleRate == 0 {
-		loadedConfig.AudioSampleRate = getDefaultConfig().AudioSampleRate
-	}
-	if loadedConfig.AudioPacketLossPerc == 0 {
-		loadedConfig.AudioPacketLossPerc = getDefaultConfig().AudioPacketLossPerc
+		loadedConfig.AudioSampleRate = defaults.AudioSampleRate
+		loadedConfig.AudioPacketLossPerc = defaults.AudioPacketLossPerc
 	}
 
 	// fixup old keyboard layout value

internal/audio/relay.go

@@ -70,54 +70,54 @@ func (r *OutputRelay) Stop() {
 func (r *OutputRelay) relayLoop() {
 	defer close(r.stopped)
 
-	const initialDelay = 1 * time.Second
-	const maxDelay = 30 * time.Second
 	const maxRetries = 10
-
-	retryDelay := initialDelay
+	retryDelay := 1 * time.Second
 	consecutiveFailures := 0
 
 	for r.running.Load() {
+		// Connect if not connected
 		if !(*r.source).IsConnected() {
 			if err := (*r.source).Connect(); err != nil {
-				consecutiveFailures++
-				if consecutiveFailures >= maxRetries {
-					r.logger.Error().Int("failures", consecutiveFailures).Msg("Max connection retries exceeded, stopping relay")
+				if consecutiveFailures++; consecutiveFailures >= maxRetries {
+					r.logger.Error().Int("failures", consecutiveFailures).Msg("Max retries exceeded, stopping relay")
 					return
 				}
-				r.logger.Debug().Err(err).Int("failures", consecutiveFailures).Dur("retry_delay", retryDelay).Msg("failed to connect, will retry")
+				r.logger.Debug().Err(err).Int("failures", consecutiveFailures).Msg("Connection failed, retrying")
 				time.Sleep(retryDelay)
-				retryDelay = min(retryDelay*2, maxDelay)
+				retryDelay = min(retryDelay*2, 30*time.Second)
 				continue
 			}
 			consecutiveFailures = 0
-			retryDelay = initialDelay
+			retryDelay = 1 * time.Second
 		}
 
+		// Read message from source
 		msgType, payload, err := (*r.source).ReadMessage()
 		if err != nil {
-			if r.running.Load() {
-				consecutiveFailures++
-				if consecutiveFailures >= maxRetries {
-					r.logger.Error().Int("failures", consecutiveFailures).Msg("Max read retries exceeded, stopping relay")
-					return
-				}
-				r.logger.Warn().Err(err).Int("failures", consecutiveFailures).Msg("read error, reconnecting")
-				(*r.source).Disconnect()
-				time.Sleep(retryDelay)
-				retryDelay = min(retryDelay*2, maxDelay)
+			if !r.running.Load() {
+				break
 			}
+			if consecutiveFailures++; consecutiveFailures >= maxRetries {
+				r.logger.Error().Int("failures", consecutiveFailures).Msg("Max read retries exceeded, stopping relay")
+				return
+			}
+			r.logger.Warn().Err(err).Int("failures", consecutiveFailures).Msg("Read error, reconnecting")
+			(*r.source).Disconnect()
+			time.Sleep(retryDelay)
+			retryDelay = min(retryDelay*2, 30*time.Second)
 			continue
 		}
 
+		// Reset retry state on success
 		consecutiveFailures = 0
-		retryDelay = initialDelay
+		retryDelay = 1 * time.Second
 
+		// Write audio sample to WebRTC
 		if msgType == ipcMsgTypeOpus && len(payload) > 0 {
 			r.sample.Data = payload
 			if err := r.audioTrack.WriteSample(r.sample); err != nil {
 				r.framesDropped.Add(1)
-				r.logger.Warn().Err(err).Msg("failed to write sample to WebRTC")
+				r.logger.Warn().Err(err).Msg("Failed to write sample to WebRTC")
 			} else {
 				r.framesRelayed.Add(1)
 			}

internal/usbgadget/usbgadget.go

@@ -204,58 +204,47 @@ func (u *UsbGadget) Close() error {
 func (u *UsbGadget) CloseHidFiles() {
 	u.log.Debug().Msg("closing HID files")
 
-	// Close keyboard HID file
-	if u.keyboardHidFile != nil {
-		if err := u.keyboardHidFile.Close(); err != nil {
-			u.log.Debug().Err(err).Msg("failed to close keyboard HID file")
+	closeFile := func(file **os.File, name string) {
+		if *file != nil {
+			if err := (*file).Close(); err != nil {
+				u.log.Debug().Err(err).Msgf("failed to close %s HID file", name)
+			}
+			*file = nil
 		}
-		u.keyboardHidFile = nil
 	}
 
-	// Close absolute mouse HID file
-	if u.absMouseHidFile != nil {
-		if err := u.absMouseHidFile.Close(); err != nil {
-			u.log.Debug().Err(err).Msg("failed to close absolute mouse HID file")
-		}
-		u.absMouseHidFile = nil
-	}
-
-	// Close relative mouse HID file
-	if u.relMouseHidFile != nil {
-		if err := u.relMouseHidFile.Close(); err != nil {
-			u.log.Debug().Err(err).Msg("failed to close relative mouse HID file")
-		}
-		u.relMouseHidFile = nil
-	}
+	closeFile(&u.keyboardHidFile, "keyboard")
+	closeFile(&u.absMouseHidFile, "absolute mouse")
+	closeFile(&u.relMouseHidFile, "relative mouse")
 }
 
 // PreOpenHidFiles opens all HID files to reduce input latency
 func (u *UsbGadget) PreOpenHidFiles() {
-	// Add a small delay to allow USB gadget reconfiguration to complete
-	// This prevents "no such device or address" errors when trying to open HID files
+	// Small delay for USB gadget reconfiguration to complete
 	time.Sleep(100 * time.Millisecond)
 
+	openHidFile := func(file **os.File, path string, name string) {
+		if *file == nil {
+			f, err := os.OpenFile(path, os.O_RDWR, 0666)
+			if err != nil {
+				u.log.Debug().Err(err).Msgf("failed to pre-open %s HID file", name)
+			} else {
+				*file = f
+			}
+		}
+	}
+
 	if u.enabledDevices.Keyboard {
 		if err := u.openKeyboardHidFile(); err != nil {
 			u.log.Debug().Err(err).Msg("failed to pre-open keyboard HID file")
 		}
 	}
+
 	if u.enabledDevices.AbsoluteMouse {
-		if u.absMouseHidFile == nil {
-			var err error
-			u.absMouseHidFile, err = os.OpenFile("/dev/hidg1", os.O_RDWR, 0666)
-			if err != nil {
-				u.log.Debug().Err(err).Msg("failed to pre-open absolute mouse HID file")
-			}
-		}
+		openHidFile(&u.absMouseHidFile, "/dev/hidg1", "absolute mouse")
 	}
+
 	if u.enabledDevices.RelativeMouse {
-		if u.relMouseHidFile == nil {
-			var err error
-			u.relMouseHidFile, err = os.OpenFile("/dev/hidg2", os.O_RDWR, 0666)
-			if err != nil {
-				u.log.Debug().Err(err).Msg("failed to pre-open relative mouse HID file")
-			}
-		}
+		openHidFile(&u.relMouseHidFile, "/dev/hidg2", "relative mouse")
 	}
 }

jsonrpc.go

@@ -866,30 +866,30 @@ func rpcGetUsbDevices() (usbgadget.Devices, error) {
 func updateUsbRelatedConfig(wasUsbAudioEnabled bool) error {
 	ensureConfigLoaded()
 	nowHasUsbAudio := config.UsbDevices != nil && config.UsbDevices.Audio
-	outputSourceIsUsb := config.AudioOutputSource == "usb"
 
-	// must stop input audio before reconfiguring
+	// Stop audio before reconfiguring USB gadget
 	stopInputAudio()
-
-	// if we're currently sourcing audio from USB, stop the output audio before reconfiguring
-	if outputSourceIsUsb {
+	if config.AudioOutputSource == "usb" {
 		stopOutputAudio()
 	}
 
-	// Auto-switch to HDMI audio output when USB audio was selected and is now disabled
+	// Auto-switch to HDMI when USB audio disabled
 	if wasUsbAudioEnabled && !nowHasUsbAudio && config.AudioOutputSource == "usb" {
-		logger.Info().Msg("USB audio just disabled, automatic switch audio output source to HDMI")
+		logger.Info().Msg("USB audio disabled, switching output to HDMI")
 		config.AudioOutputSource = "hdmi"
 	}
 
+	// Update USB gadget configuration
 	if err := gadget.UpdateGadgetConfig(); err != nil {
-		return fmt.Errorf("failed to write gadget config: %w", err)
+		return fmt.Errorf("failed to update gadget config: %w", err)
 	}
 
+	// Save configuration
 	if err := SaveConfig(); err != nil {
 		return fmt.Errorf("failed to save config: %w", err)
 	}
 
+	// Restart audio if needed
 	if err := startAudio(); err != nil {
 		logger.Warn().Err(err).Msg("Failed to restart audio after USB reconfiguration")
 	}