> ## Documentation Index
> Fetch the complete documentation index at: https://docs.facebetter.net/llms.txt
> Use this file to discover all available pages before exploring further.

# FAQ

> iOS Beauty SDK Common Questions and Answers

## Integration Issues

### Q: What to do if engine creation fails?

A: Check the following points:

* Confirm that `appId` and `appKey` are correct
* Check if network connection is normal
* View log output for detailed error information
* Confirm if SDK version is latest
* Check if Framework is properly linked

### Q: Can't find header files or classes during compilation?

A: Possible reasons:

* Confirm that `Facebetter.framework` has been properly added to the project
* Check if Framework's "Embed & Sign" setting is correct
* Confirm import statement: `#import <Facebetter/FBBeautyEffectEngine.h>`
* Try Clean Build Folder and rebuild

### Q: Link errors at runtime?

A: Solutions:

* Confirm if device architecture is supported (arm64, armv7)
* Check if Framework file is complete
* Confirm Framework's deployment target setting is correct
* Check for other Framework conflicts

## Functionality Issues

### Q: Beauty effects are not obvious?

A: You can try:

* Increase beauty parameter values (range 0.0-1.0)
* Ensure corresponding beauty types are enabled
* Check if image quality is clear enough
* Confirm if face detection is working normally

### Q: Beauty effects are excessive or distorted?

A: Recommendations:

* Reduce beauty parameter values
* Check if parameter combinations are reasonable
* Avoid enabling too many beauty types simultaneously
* Adjust parameters based on image quality

### Q: Virtual background not working?

A: Check:

* Confirm `FBBeautyType_VirtualBackground` is enabled
* Check if background image path is correct
* Confirm if image format is supported (PNG, JPG)
* Check if image file exists and is readable

## Performance Issues

### Q: What to do if processing is slow?

A: Optimization suggestions:

* Use `FBFrameTypeVideo` for real-time processing
* Reduce image resolution
* Reduce number of simultaneously enabled beauty types
* Avoid image processing on main thread
* Use multi-threading for image processing

### Q: High memory usage?

A: Solutions:

* Release `FBImageFrame` and `FBImageBuffer` objects timely
* Avoid frequent creation and destruction of engine instances
* Reuse `FBImageFrame` objects
* Use object pool pattern to manage image buffers

### Q: App crashes or freezes?

A: Troubleshooting steps:

* Check if image processing is done on main thread
* Confirm resource release is complete
* View exception information in logs
* Check if parameter values are within valid range
* Use Instruments tool to analyze memory and performance

## Image Processing Issues

### Q: How to handle different image formats?

A: Use `FBImageFrame`'s format conversion methods:

* `toRGBA` - Convert to RGBA format
* `toI420` - Convert to I420 format
* `toNV12` - Convert to NV12 format
* `toBGRA` - Convert to BGRA format

### Q: Camera preview image processing?

A: Recommended process:

1. Get CVPixelBuffer from AVCaptureSession
2. Use `createWithData` to create FBImageFrame
3. Call `processImage` to process
4. Convert to target format for display

### Q: Image rotation issues?

A: Solutions:

* Use `FBImageFrame`'s `rotate` method to rotate images
* Supports 0°, 90°, 180°, 270° rotation
* Rotation operation modifies original image data

## Permission Issues

### Q: Camera permission issues?

A: Need to add permission description:

```xml theme={null}
<key>NSCameraUsageDescription</key>
<string>Camera permission required for beauty photography</string>
```

### Q: Photo library permission issues?

A: Need to add permission description:

```xml theme={null}
<key>NSPhotoLibraryUsageDescription</key>
<string>Photo library permission required to select photos for beauty</string>
```

## Debugging Issues

### Q: How to enable debug logging?

A: Configure before creating engine:

```objc theme={null}
FBLogConfig *logConfig = [[FBLogConfig alloc] init];
logConfig.consoleEnabled = YES;
logConfig.fileEnabled = YES;
logConfig.level = FBLogLevel_Debug;
[FBBeautyEffectEngine setLogConfig:logConfig];
```

### Q: How to get detailed error information?

A: Methods:

* Enable DEBUG level logging
* Check API return values (0 indicates success)
* View file log output
* Use Xcode's Console to view logs

## Version Compatibility

### Q: Which iOS versions are supported?

A: Supports iOS 10.0 and above

### Q: Which device architectures are supported?

A: Supports:

* arm64 (64-bit devices)
* armv7 (32-bit devices, iOS 10.0+)

### Q: How to upgrade SDK version?

A: Steps:

1. Download new version SDK
2. Replace old Framework file
3. Clean project cache
4. Rebuild project
5. Test if functionality works normally

## ARC Related Issues

### Q: How to handle memory management?

A: iOS uses ARC, but need to pay attention to:

* Set objects to nil timely
* Avoid circular references
* Use weak references to avoid strong reference cycles

### Q: How to handle CVPixelBuffer?

A: Recommendations:

* Use `CVPixelBufferRetain` and `CVPixelBufferRelease` for management
* Or use `__bridge_transfer` and `__bridge_retained` for conversion

## Multi-threading Issues

### Q: How to process images in background thread?

A: Recommendations:

* Use `dispatch_async` to process in background queue
* Avoid image processing on main thread
* Use `dispatch_async(dispatch_get_main_queue())` to update UI

### Q: How to handle concurrent access?

A: Solutions:

* Use `@synchronized` to protect shared resources
* Use serial queue for image processing
* Avoid multi-threaded access to engine instance

## Deployment Issues

### Q: App Store review rejected?

A: Possible reasons:

* Missing necessary permission descriptions
* Using private APIs
* Memory leak issues
* Crash issues

### Q: How to optimize app size?

A: Recommendations:

* Remove unused architectures (like armv7)
* Compress resource files
* Use App Thinning
* Remove unused Framework parts