fix: Improve microphone device selection to avoid alias deviceIds

- Add isAlias() helper to identify 'default' and 'communications' aliases
- Prefer actual device IDs (long strings) over alias IDs
- For alias deviceIds, use {audio: true} to let system choose
- For real deviceIds, try exact first, then ideal as fallback
- Add debug logging for isSecureContext and alias detection

This fixes the "Could not start audio source" error when Electron tries
to open a microphone using exact: 'communications' constraint.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

client/src/main.js

@@ -288,9 +288,12 @@ function createWindow() {
 }
 
 function startSidecar() {
+  console.log("=== startSidecar() called ===");
   const sidecarDir = app.isPackaged
     ? path.join(process.resourcesPath, "sidecar")
     : path.join(__dirname, "..", "..", "sidecar");
+  console.log("Sidecar directory:", sidecarDir);
+  console.log("App is packaged:", app.isPackaged);
 
   // Determine the sidecar executable path based on packaging and platform
   let sidecarExecutable;
@@ -327,11 +330,13 @@ function startSidecar() {
     sidecarArgs = [sidecarScript];
   }
 
+  console.log("Checking sidecar executable at:", sidecarExecutable);
   if (!fs.existsSync(sidecarExecutable)) {
-    console.log("Sidecar executable not found at:", sidecarExecutable);
+    console.log("ERROR: Sidecar executable not found at:", sidecarExecutable);
     console.log("Transcription will not be available.");
     return;
   }
+  console.log("Sidecar executable found:", sidecarExecutable);
 
   try {
     // Get Whisper configuration from config.json or environment variables
@@ -434,10 +439,16 @@ function startSidecar() {
             mainWindow.webContents.send("model-download-progress", msg);
           }
 
-          // Forward model error status
-          if (msg.status === "model_error" && mainWindow) {
+          // Forward model error status and mark sidecar as not ready
+          if (msg.status === "model_error") {
+            sidecarReady = false;
+            if (activeWhisperConfig) {
+              activeWhisperConfig.error = msg.error || "Model load failed";
+            }
+            if (mainWindow) {
               mainWindow.webContents.send("model-download-progress", msg);
             }
+          }
         } catch (e) {
           console.log("Sidecar output:", line);
         }

client/src/pages/meeting-detail.html

@@ -289,10 +289,17 @@
       try {
         const status = await window.electronAPI.getSidecarStatus();
         if (status.whisper) {
+          // Check if there was an error loading the model
+          if (status.whisper.error) {
+            whisperStatusEl.textContent = `❌ Model error: ${status.whisper.error}`;
+            whisperStatusEl.style.color = '#dc3545';
+            whisperStatusEl.title = 'Model failed to load';
+          } else {
             const readyIcon = status.ready ? '✅' : '⏳';
             whisperStatusEl.textContent = `${readyIcon} Model: ${status.whisper.model} | Device: ${status.whisper.device} | Compute: ${status.whisper.compute}`;
             whisperStatusEl.title = `Config source: ${status.whisper.configSource || 'unknown'}`;
             whisperStatusEl.style.color = status.ready ? '#28a745' : '#ffc107';
+          }
         } else {
           whisperStatusEl.textContent = status.ready ? '✅ Ready' : '⏳ Loading...';
           whisperStatusEl.style.color = status.ready ? '#28a745' : '#ffc107';
@@ -414,6 +421,9 @@
           return;
         }
 
+        // Debug: Check if we're in a secure context
+        console.log('isSecureContext:', window.isSecureContext);
+
         // Check for available audio devices first
         const devices = await navigator.mediaDevices.enumerateDevices();
         const audioInputs = devices.filter(d => d.kind === 'audioinput');
@@ -424,41 +434,57 @@
           return;
         }
 
+        // Helper to identify alias deviceIds (not real device IDs)
+        const isAlias = (id) => id === 'default' || id === 'communications';
+
         // Filter out Stereo Mix (立體聲混音) - it's not a real microphone
         const realMicrophones = audioInputs.filter(d =>
           !d.label.includes('立體聲混音') &&
-          !d.label.toLowerCase().includes('stereo mix') &&
-          d.deviceId !== 'default'  // Skip default which might be Stereo Mix
+          !d.label.toLowerCase().includes('stereo mix')
         );
 
-        // Prefer communications device or actual microphone
+        // Prefer actual device IDs (long strings), not aliases like 'default' or 'communications'
+        // First try to find a real microphone with actual deviceId
         let selectedMic = realMicrophones.find(d =>
-          d.deviceId === 'communications' ||
+          !isAlias(d.deviceId) && (
             d.label.includes('麥克風') ||
             d.label.toLowerCase().includes('microphone')
-        ) || realMicrophones[0];
+          )
+        ) || realMicrophones.find(d => !isAlias(d.deviceId)) || realMicrophones[0];
 
         console.log('Real microphones found:', realMicrophones.length);
         console.log('Selected microphone:', selectedMic);
+        console.log('Selected deviceId is alias:', selectedMic ? isAlias(selectedMic.deviceId) : 'N/A');
 
         if (!selectedMic) {
           alert('No real microphone found. Only Stereo Mix detected. Please connect a microphone.');
           return;
         }
 
-        // Try with the selected microphone
+        // Get microphone stream with proper constraints handling
+        try {
+          if (isAlias(selectedMic.deviceId)) {
+            // For alias deviceIds (default/communications), let the system choose
+            console.log('Using system default (alias detected)');
+            mediaStream = await navigator.mediaDevices.getUserMedia({ audio: true });
+          } else {
+            // For real deviceIds, try exact first, then ideal as fallback
             try {
               mediaStream = await navigator.mediaDevices.getUserMedia({
                 audio: { deviceId: { exact: selectedMic.deviceId } }
               });
-          console.log('Successfully connected to:', selectedMic.label);
             } catch (exactErr) {
-          console.warn('Exact device ID failed, trying preferred:', exactErr);
-          // Fallback: try with preferred instead of exact
+              console.warn('Exact device ID failed, trying ideal:', exactErr);
               mediaStream = await navigator.mediaDevices.getUserMedia({
-            audio: { deviceId: selectedMic.deviceId }
+                audio: { deviceId: { ideal: selectedMic.deviceId } }
               });
             }
+          }
+          console.log('Successfully connected to:', selectedMic.label);
+        } catch (err) {
+          console.error('getUserMedia failed:', err.name, err.message);
+          throw err; // Let outer catch handle the error message
+        }
 
         isRecording = true;
         recordBtn.textContent = 'Stop Recording';