fix: prevent audio processing when no audio source is loaded

src/components/AudioArea.vue

@@ -27,19 +27,16 @@ export default defineComponent({
     console.debug(`[AUDIOAREA] Initializing ${props.definition.src}...`);
     console.debug(props.definition);
 
-    // Silent 1ms audio as placeholder (data URI of a minimal silent MP3)
-    // This prevents browser from attempting to load any audio until we're ready
-    const SILENT_AUDIO = 'data:audio/mp3;base64,SUQzAwAAAAAAJlRJVDIAAAAHAAAAU2lsZW50/+MYxAAEaAIAAgAAAAkBngQAAABMQVJHAAAABQAA/+MYxA8EaAIAAgAAABAAAP/7kMQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAD/4xjEMgAAAAACAAAAAAAAAP/jGMRFAAAAAAAAAAAAAAAAAAAA';
-    
     // Preload the audio file completely to avoid keeping connections open
     // Use the global audio loading queue to throttle concurrent loads
     const preloadAudio = (src: string) => {
       console.debug(`[AUDIOAREA] Queueing audio for preload: ${src}`);
 
-      // Set placeholder silent audio to avoid errors without triggering real load
-      audioSrc.value = SILENT_AUDIO;
+      // Set audioSrc to empty initially
+      audioSrc.value = "";
 
       // Queue the audio for loading through our global service
+      // Our improved AudioLoader will cache and deduplicate requests
       queueAudioForLoading(src)
         .then((blobUrl) => {
           // Use blob URL to avoid keeping connections open
@@ -63,6 +60,8 @@ export default defineComponent({
     const vol_b = 1 - vol_x;
 
     const onBBoxChange = () => {
+      if (!audioSrc.value) return;
+
       const x = props.bbox.x + props.bbox.w / 2;
       const y = props.bbox.y + props.bbox.h / 2;
       const distance = Math.sqrt(

src/services/AudioLoader.ts

@@ -13,6 +13,12 @@ const audioQueue: Array<{
   onError: (error: Error) => void;
 }> = [];
 
+// Cache of loaded audio files (src -> blobUrl)
+const loadedAudioCache: Record<string, string> = {};
+
+// Keep track of pending loads to avoid duplicates
+const pendingLoads: Set<string> = new Set();
+
 /**
  * Queue an audio file for loading, respecting the global concurrent loading limit
  * Returns a promise that resolves with the blob URL when loading is complete
@@ -22,6 +28,35 @@ export function queueAudioForLoading(
   onComplete?: (blobUrl: string) => void,
   onError?: (error: Error) => void
 ): Promise<string> {
+  // Return cached result immediately if available
+  if (loadedAudioCache[src]) {
+    console.debug(`[AudioLoader] Using cached audio for ${src}`);
+    const blobUrl = loadedAudioCache[src];
+    if (onComplete) setTimeout(() => onComplete(blobUrl), 0);
+    return Promise.resolve(blobUrl);
+  }
+  
+  // If this source is already being loaded, add to existing promises
+  if (pendingLoads.has(src)) {
+    console.debug(`[AudioLoader] Already loading ${src}, adding to pending requests`);
+    return new Promise((resolve, reject) => {
+      audioQueue.push({
+        src,
+        onComplete: (blobUrl) => {
+          if (onComplete) onComplete(blobUrl);
+          resolve(blobUrl);
+        },
+        onError: (error) => {
+          if (onError) onError(error);
+          reject(error);
+        }
+      });
+    });
+  }
+  
+  // Mark as pending
+  pendingLoads.add(src);
+  
   return new Promise((resolve, reject) => {
     // Add to queue
     audioQueue.push({
@@ -45,28 +80,56 @@ export function queueAudioForLoading(
  * Process the next items in the queue if we have capacity
  */
 function processQueue() {
-  // Load more audio files if we have capacity and items in the queue
+  // Group queue items by src to avoid duplicate loads
+  const nextBatch: Record<string, Array<{
+    onComplete: (blobUrl: string) => void;
+    onError: (error: Error) => void;
+  }>> = {};
+
+  // Find next items to process while respecting MAX_CONCURRENT_LOADS
   while (activeLoads < MAX_CONCURRENT_LOADS && audioQueue.length > 0) {
     const next = audioQueue.shift();
-    if (next) {
-      loadAudio(next.src, next.onComplete, next.onError);
+    if (!next) continue;
+    
+    // If already cached, complete immediately without consuming a slot
+    if (loadedAudioCache[next.src]) {
+      next.onComplete(loadedAudioCache[next.src]);
+      continue;
     }
+    
+    // Group by src
+    if (!nextBatch[next.src]) {
+      nextBatch[next.src] = [];
+      // Each unique src counts as one active load
+      activeLoads++;
     }
+    
+    nextBatch[next.src].push({
+      onComplete: next.onComplete,
+      onError: next.onError
+    });
+  }
+  
+  // Start loading each unique audio file
+  Object.entries(nextBatch).forEach(([src, handlers]) => {
+    loadAudio(src, handlers);
+  });
 }
 
 /**
  * Internal function to handle the actual audio loading using fetch API
  * This ensures the entire audio file is downloaded
+ * @param src The source URL to load
+ * @param handlers Array of handlers to call when loading completes or fails
  */
 async function loadAudio(
   src: string,
-  onComplete: (blobUrl: string) => void,
-  onError: (error: Error) => void
+  handlers: Array<{
+    onComplete: (blobUrl: string) => void;
+    onError: (error: Error) => void;
+  }>
 ) {
-  // Increment active loads counter
-  activeLoads++;
-
-  console.debug(`[AudioLoader] Loading ${src}`);
+  console.debug(`[AudioLoader] Loading ${src} (${handlers.length} listeners)`);
   
   try {
     // Fetch the entire audio file
@@ -82,16 +145,22 @@ async function loadAudio(
     // Create a blob URL to use as the audio source
     const blobUrl = URL.createObjectURL(blob);
     
+    // Store in cache
+    loadedAudioCache[src] = blobUrl;
+    
     console.debug(`[AudioLoader] Successfully loaded ${src}`);
     
-    // Call completion handler
-    onComplete(blobUrl);
+    // Call all completion handlers
+    handlers.forEach(handler => handler.onComplete(blobUrl));
   } catch (error) {
     console.error(`[AudioLoader] Error loading audio: ${error}`);
     
-    // Call error handler
-    onError(error as Error);
+    // Call all error handlers
+    handlers.forEach(handler => handler.onError(error as Error));
   } finally {
+    // Remove from pending loads
+    pendingLoads.delete(src);
+    
     // Decrement counter when audio is loaded (or failed)
     activeLoads--;