Guarantee camera pictureSize is negotiated before countdown starts to prevent fallback to massive memory-crashing resolutions

src/screens/CameraScreen.tsx

@@ -94,6 +94,7 @@ export default function CameraScreen({
   const usbCameraRef = useRef<UsbCameraRef>(null);
   const expoCameraRef = useRef<any>(null);
   const burstTimerRef = useRef<any>(null);
+  const countdownTimerRef = useRef<any>(null);
   const isCancelledRef = useRef<boolean>(false);
 
   // Reanimated countdown pulse animation
@@ -159,11 +160,12 @@ export default function CameraScreen({
   useEffect(() => {
     return () => {
       if (burstTimerRef.current) clearTimeout(burstTimerRef.current);
+      if (countdownTimerRef.current) clearTimeout(countdownTimerRef.current);
     };
   }, []);
 
   // Set safe picture size to avoid OOM
-  const handleCameraReady = async () => {
+  const handleCameraReady = useCallback(async () => {
     if (expoCameraRef.current) {
       try {
         const sizes = await expoCameraRef.current.getAvailablePictureSizes();
@@ -188,18 +190,24 @@ export default function CameraScreen({
             setPictureSize(optimal.size);
           } else if (parsedSizes.length > 0) {
             setPictureSize(parsedSizes[parsedSizes.length - 1].size);
+          } else {
+            setPictureSize('fallback');
           }
+        } else {
+          setPictureSize('fallback');
         }
       } catch (e) {
         console.warn('Failed to fetch picture sizes:', e);
+        setPictureSize('fallback');
       }
     }
-  };
+  }, []);
 
   // Cancel capture process
   const handleLocalCancel = async () => {
     isCancelledRef.current = true;
     if (burstTimerRef.current) clearTimeout(burstTimerRef.current);
+    if (countdownTimerRef.current) clearTimeout(countdownTimerRef.current);
     
     // Clean up any temp files from a partially completed burst
     for (const uri of burstUris) {
@@ -229,14 +237,20 @@ export default function CameraScreen({
       return;
     }
 
+    // Delay start until safe picture size is negotiated (or fallback is set)
+    // Only applies to built-in camera, USB camera ignores pictureSize
+    if (pictureSize === undefined && !isUsbConnected) {
+      console.log('Waiting for pictureSize negotiation...');
+      return;
+    }
+
     startCountdown();
 
     return () => {};
-  }, [countdownDuration, isIdle]);
+  }, [countdownDuration, isIdle, pictureSize, isUsbConnected]);
 
   const startCountdown = () => {
     isCancelledRef.current = false;
-    let timer: any;
     let count = countdownDuration;
 
     setCountdown(count);
@@ -248,20 +262,17 @@ export default function CameraScreen({
       if (count > 1) {
         count -= 1;
         setCountdown(count);
-        timer = setTimeout(runTimer, 1000);
+        countdownTimerRef.current = setTimeout(runTimer, 1000);
       } else if (count === 1) {
         setCountdown('smile');
         setIsCapturing(true);
-        timer = setTimeout(() => {
+        countdownTimerRef.current = setTimeout(() => {
           capture();
         }, 800);
       }
     };
 
-    timer = setTimeout(runTimer, 1000);
-
-    // Store timer for cleanup
-    burstTimerRef.current = timer;
+    countdownTimerRef.current = setTimeout(runTimer, 1000);
   };
 
   // 4. Capture photo function
@@ -552,7 +563,7 @@ export default function CameraScreen({
               ref={expoCameraRef}
               style={styles.cameraPreview}
               facing="front"
-              pictureSize={pictureSize}
+              pictureSize={pictureSize === 'fallback' ? undefined : pictureSize}
               onCameraReady={handleCameraReady}
             />
           )}