[WIP] Change playback latency spikes on Audio Output Quality changes

audio_handlers.go

@@ -284,6 +284,13 @@ func handleSetAudioQuality(c *gin.Context) {
 		return
 	}
 
+	// Check if audio output is active before attempting quality change
+	// This prevents race conditions where quality changes are attempted before initialization
+	if !IsAudioOutputActive() {
+		c.JSON(503, gin.H{"error": "audio output not active - please wait for initialization to complete"})
+		return
+	}
+
 	// Convert int to AudioQuality type
 	quality := audio.AudioQuality(req.Quality)
 

internal/audio/cgo_audio.go

@@ -87,8 +87,10 @@ static volatile int playback_initialized = 0;
 // Function to dynamically update Opus encoder parameters
 int update_opus_encoder_params(int bitrate, int complexity, int vbr, int vbr_constraint,
                               int signal_type, int bandwidth, int dtx) {
-    if (!encoder || !capture_initialized) {
+    // This function is specifically for audio OUTPUT encoder parameters
-        return -1; // Encoder not initialized
+    // Only require playback initialization for audio output quality changes
+    if (!encoder || !playback_initialized) {
+        return -1; // Audio output encoder not initialized
     }
 
     // Update the static variables

internal/audio/quality_presets.go

@@ -204,10 +204,9 @@ func SetAudioQuality(quality AudioQuality) {
 			dtx = Config.AudioQualityMediumOpusDTX
 		}
 
-		// Restart audio output subprocess with new OPUS configuration
+		// Update audio output subprocess configuration dynamically without restart
-		if supervisor := GetAudioOutputSupervisor(); supervisor != nil {
 		logger := logging.GetDefaultLogger().With().Str("component", "audio").Logger()
-			logger.Info().Int("quality", int(quality)).Msg("restarting audio output subprocess with new quality settings")
+		logger.Info().Int("quality", int(quality)).Msg("updating audio output quality settings dynamically")
 
 		// Immediately boost adaptive buffer sizes to handle quality change frame burst
 		// This prevents "Message channel full, dropping frame" warnings during transitions
@@ -218,56 +217,37 @@ func SetAudioQuality(quality AudioQuality) {
 			logger.Debug().Msg("boosted adaptive buffers for quality change")
 		}
 
-			// Set new OPUS configuration
+		// Set new OPUS configuration for future restarts
+		if supervisor := GetAudioOutputSupervisor(); supervisor != nil {
 			supervisor.SetOpusConfig(config.Bitrate*1000, complexity, vbr, signalType, bandwidth, dtx)
+		}
 
-			// Stop current subprocess
+		// Send dynamic configuration update to running audio output
+		vbrConstraint := Config.CGOOpusVBRConstraint
+		if err := updateOpusEncoderParams(config.Bitrate*1000, complexity, vbr, vbrConstraint, signalType, bandwidth, dtx); err != nil {
+			logger.Warn().Err(err).Msg("failed to update OPUS encoder parameters dynamically")
+			// Fallback to subprocess restart if dynamic update fails
+			if supervisor := GetAudioOutputSupervisor(); supervisor != nil {
+				logger.Info().Msg("falling back to subprocess restart")
 				supervisor.Stop()
-
-			// Wait for supervisor to fully stop before starting again with timeout
-			// This prevents race conditions and audio breakage
-			stopTimeout := time.After(Config.QualityChangeSupervisorTimeout)
-			ticker := time.NewTicker(Config.QualityChangeTickerInterval)
-			defer ticker.Stop()
-
-			for {
-				select {
-				case <-stopTimeout:
-					logger.Warn().Msg("supervisor did not stop within 5s timeout, proceeding anyway")
-					goto startSupervisor
-				case <-ticker.C:
-					if !supervisor.IsRunning() {
-						goto startSupervisor
-					}
-				}
-			}
-
-		startSupervisor:
-
-			// Start subprocess with new configuration
 				if err := supervisor.Start(); err != nil {
-				logger.Error().Err(err).Msg("failed to restart audio output subprocess")
+					logger.Error().Err(err).Msg("failed to restart audio output subprocess after dynamic update failure")
+				}
+			}
 		} else {
-				logger.Info().Int("quality", int(quality)).Msg("audio output subprocess restarted successfully with new quality")
+			logger.Info().Msg("audio output quality updated dynamically")
 
-				// Reset audio input server stats after quality change
+			// Reset audio output stats after config update
 			// Allow adaptive buffer manager to naturally adjust buffer sizes
 			go func() {
 				time.Sleep(Config.QualityChangeSettleDelay) // Wait for quality change to settle
 				// Reset audio input server stats to clear persistent warnings
 				ResetGlobalAudioInputServerStats()
-					// Attempt recovery if microphone is still having issues
+				// Attempt recovery if there are still issues
 				time.Sleep(1 * time.Second)
 				RecoverGlobalAudioInputServer()
 			}()
 		}
-		} else {
-			// Fallback to dynamic update if supervisor is not available
-			vbrConstraint := Config.CGOOpusVBRConstraint
-			if err := updateOpusEncoderParams(config.Bitrate*1000, complexity, vbr, vbrConstraint, signalType, bandwidth, dtx); err != nil {
-				logging.GetDefaultLogger().Error().Err(err).Msg("Failed to update OPUS encoder parameters")
-			}
-		}
 	}
 }
 

ui/src/routes/devices.$id.tsx

@@ -54,6 +54,7 @@ import { useDeviceUiNavigation } from "@/hooks/useAppNavigation";
 import { FeatureFlagProvider } from "@/providers/FeatureFlagProvider";
 import { DeviceStatus } from "@routes/welcome-local";
 import { SystemVersionInfo } from "@routes/devices.$id.settings.general.update";
+import audioQualityService from "@/services/audioQualityService";
 
 interface LocalLoaderResp {
   authMode: "password" | "noPassword" | null;
@@ -533,6 +534,11 @@ export default function KvmIdRoute() {
     };
   }, [clearCandidatePairStats, clearInboundRtpStats, setPeerConnection, setSidebarView]);
 
+  // Register callback with audioQualityService
+  useEffect(() => {
+    audioQualityService.setReconnectionCallback(setupPeerConnection);
+  }, [setupPeerConnection]);
+
   // TURN server usage detection
   useEffect(() => {
     if (peerConnectionState !== "connected") return;

ui/src/services/audioQualityService.ts

@@ -24,6 +24,7 @@ class AudioQualityService {
     2: 'High',
     3: 'Ultra'
   };
+  private reconnectionCallback: (() => Promise<void>) | null = null;
 
   /**
    * Fetch audio quality presets from the backend
@@ -96,12 +97,34 @@ class AudioQualityService {
   }
 
   /**
-   * Set audio quality
+   * Set reconnection callback for WebRTC reset
+   */
+  setReconnectionCallback(callback: () => Promise<void>): void {
+    this.reconnectionCallback = callback;
+  }
+
+  /**
+   * Trigger audio track replacement using backend's track replacement mechanism
+   */
+  private async replaceAudioTrack(): Promise<void> {
+    if (this.reconnectionCallback) {
+      await this.reconnectionCallback();
+    }
+  }
+
+  /**
+   * Set audio quality with track replacement
    */
   async setAudioQuality(quality: number): Promise<boolean> {
     try {
       const response = await api.POST('/audio/quality', { quality });
-      return response.ok;
+      
+      if (!response.ok) {
+        return false;
+      }
+      
+      await this.replaceAudioTrack();
+      return true;
     } catch (error) {
       console.error('Failed to set audio quality:', error);
       return false;