Problème avec le groupe filtre GPUImage

Question

Je suis en train d'appliquer un filtre à une image, donc j'utiliser GPUImageFilterGroup pour mélanger les filtres, mais mes plantages d'applications, voici mon code:

- (IBAction)effectApply:(id)sender { 

    GPUImageFilterGroup *groupFilter = [[GPUImageFilterGroup alloc]init]; 
    GPUImagePicture *stillImage= [[GPUImagePicture alloc]initWithImage:_img.image]; 

    GPUImageBrightnessFilter *brightnessFilter = [[GPUImageBrightnessFilter alloc]init]; 
    [brightnessFilter setBrightness:.4]; 

    GPUImageContrastFilter *contrastFilter = [[GPUImageContrastFilter alloc]init]; 
    [contrastFilter setContrast:2.0]; 

    GPUImageExposureFilter *exposureFilter =[[GPUImageExposureFilter alloc]init]; 
    [exposureFilter setExposure:.2]; 


    [groupFilter addFilter:brightnessFilter]; 
    [groupFilter addFilter:contrastFilter]; 
    [groupFilter addFilter:exposureFilter]; 


    [(GPUImageFilterGroup *) groupFilter setInitialFilters:[NSArray arrayWithObject: brightnessFilter]]; 
    [(GPUImageFilterGroup *) groupFilter setTerminalFilter:exposureFilter]; 


    [stillImage addTarget:filter]; 

    [filter useNextFrameForImageCapture]; 
    [stillImage processImage]; 

    UIImage *currentFilteredVideoFrame = [filter imageFromCurrentFramebuffer]; 

    _img.image = currentFilteredVideoFrame; 

} 

journaux Crash:

2014-07-10 15:27:03.955 Effect Test[65595:60b] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[__NSArrayM insertObject:atIndex:]: object cannot be nil' 
*** First throw call stack: 
(
    0 CoreFoundation      0x00000001021b9495 __exceptionPreprocess + 165 
    1 libobjc.A.dylib      0x0000000101f1899e objc_exception_throw + 43 
    2 CoreFoundation      0x0000000102170374 -[__NSArrayM insertObject:atIndex:] + 820 
    3 Effect Test       0x0000000100012077 __46-[GPUImageOutput addTarget:atTextureLocation:]_block_invoke + 103 
    4 libdispatch.dylib     0x000000010370e72d _dispatch_client_callout + 8 
    5 libdispatch.dylib     0x00000001036fd5d0 _dispatch_barrier_sync_f_invoke + 57 
    6 Effect Test       0x000000010001147c runSynchronouslyOnVideoProcessingQueue + 108 
    7 Effect Test       0x0000000100011fb0 -[GPUImageOutput addTarget:atTextureLocation:] + 272 
    8 Effect Test       0x000000010001637c -[GPUImagePicture addTarget:atTextureLocation:] + 108 
    9 Effect Test       0x0000000100011e56 -[GPUImageOutput addTarget:] + 86 
    10 Effect Test       0x000000010000167b -[ViewController effectApply:] + 667 
    11 UIKit        0x0000000100ac6f06 -[UIApplication sendAction:to:from:forEvent:] + 80 
    12 UIKit        0x0000000100ac6eb4 -[UIApplication sendAction:toTarget:fromSender:forEvent:] + 17 
    13 UIKit        0x0000000100ba3880 -[UIControl _sendActionsForEvents:withEvent:] + 203 
    14 UIKit        0x0000000100ba2dc0 -[UIControl touchesEnded:withEvent:] + 530 
    15 UIKit        0x0000000100afdd05 -[UIWindow _sendTouchesForEvent:] + 701 
    16 UIKit        0x0000000100afe6e4 -[UIWindow sendEvent:] + 925 
    17 UIKit        0x0000000100ad629a -[UIApplication sendEvent:] + 211 
    18 UIKit        0x0000000100ac3aed _UIApplicationHandleEventQueue + 9579 
    19 CoreFoundation      0x0000000102148d21 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17 
    20 CoreFoundation      0x00000001021485f2 __CFRunLoopDoSources0 + 242 
    21 CoreFoundation      0x000000010216446f __CFRunLoopRun + 767 
    22 CoreFoundation      0x0000000102163d83 CFRunLoopRunSpecific + 467 
    23 GraphicsServices     0x0000000104f93f04 GSEventRunModal + 161 
    24 UIKit        0x0000000100ac5e33 UIApplicationMain + 1010 
    25 Effect Test       0x0000000100001bc3 main + 115 
    26 libdyld.dylib      0x000000010395f5fd start + 1 
) 
libc++abi.dylib: terminating with uncaught exception of type NSException 

Answer 1

GPUImageFilterGroup *groupFilter = [[GPUImageFilterGroup alloc]init]; 

    [groupFilter addTarget:brightnessFilter]; 
    [brightnessFilter addTarget: contrastFilter]; 
    [contrastFilter addTarget: exposureFilter]; 

    [(GPUImageFilterGroup *) groupFilter setInitialFilters:[NSArray arrayWithObject: brightnessFilter]]; 
    [(GPUImageFilterGroup *) groupFilter setTerminalFilter:exposureFilter]; 

[stillImage addTarget:groupFilter]; 

Hope it helps