Implemetation of videos in video with blur effect in objective c - object

Question

I have to make a video editor with a blur effect on video .
Can someone please guide me some useful links or the way this task should be proceeded .I have tried doing overlapping of videos but it doesn't bring me videos in center exactly.
- (void) overlapVideos{
AVURLAsset* firstAsset = [AVURLAsset URLAssetWithURL:[NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:#"BearVideo" ofType:#"mp4"]] options:nil];
AVURLAsset * secondAsset = [AVURLAsset URLAssetWithURL:[NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:#"BearVideo" ofType:#"mp4"]] options:nil];
AVMutableComposition* mixComposition = [[AVMutableComposition alloc] init];
AVMutableCompositionTrack *firstTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
[firstTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, firstAsset.duration) ofTrack:[[firstAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] atTime:kCMTimeZero error:nil];
AVMutableCompositionTrack *secondTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
[secondTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, secondAsset.duration) ofTrack:[[secondAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] atTime:kCMTimeZero error:nil];
AVMutableVideoCompositionInstruction * instruction = [AVMutableVideoCompositionInstruction videoCompositionInstruction];
instruction.timeRange = CMTimeRangeMake(kCMTimeZero, firstAsset.duration);
AVMutableVideoCompositionLayerInstruction *FirstlayerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:firstTrack];
CGAffineTransform Scale = CGAffineTransformMakeScale(0.6f,0.6f);
CGAffineTransform Move = CGAffineTransformMakeTranslation(140,20);
[FirstlayerInstruction setTransform:CGAffineTransformConcat(Scale,Move) atTime:kCMTimeZero];
AVMutableVideoCompositionLayerInstruction *SecondlayerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:secondTrack];
CGAffineTransform SecondScale = CGAffineTransformMakeScale(0.9f,0.9f);
CGAffineTransform SecondMove = CGAffineTransformMakeTranslation(0,0);
[SecondlayerInstruction setTransform:CGAffineTransformConcat(SecondScale,SecondMove) atTime:kCMTimeZero];
instruction.layerInstructions = [NSArray arrayWithObjects:FirstlayerInstruction,SecondlayerInstruction,nil];;
AVMutableVideoComposition *videoComposition = [AVMutableVideoComposition videoComposition];
videoComposition.instructions = [NSArray arrayWithObject:instruction];
videoComposition.frameDuration = CMTimeMake(1, 30);
videoComposition.renderSize = CGSizeMake(1280, 720);
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *myPathDocs = [documentsDirectory stringByAppendingPathComponent:#"overlapVideo.mov"];
if([[NSFileManager defaultManager] fileExistsAtPath:myPathDocs])
{
[[NSFileManager defaultManager] removeItemAtPath:myPathDocs error:nil];
}
NSURL *url = [NSURL fileURLWithPath:myPathDocs];
AVAssetExportSession *exporter = [[AVAssetExportSession alloc] initWithAsset:mixComposition presetName:AVAssetExportPresetHighestQuality];
exporter.outputURL=url;
[exporter setVideoComposition:videoComposition];
exporter.outputFileType = AVFileTypeQuickTimeMovie;
[exporter exportAsynchronouslyWithCompletionHandler:^
{
dispatch_async(dispatch_get_main_queue(), ^{
[self exportDidFinish:exporter];
});
}];
}
- (void)exportDidFinish:(AVAssetExportSession*)session
{
NSURL *outputURL = session.outputURL;
if(self.videodelegateObj!=nil){
[_videodelegateObj videoOverlappingFinished:outputURL];
}
}
-(void)applyBlurOnAsset:(AVAsset *)asset Completion:(void(^)(BOOL success, NSError* error, NSURL* videoUrl))completion{
CIFilter *filter = [CIFilter filterWithName:#"CIGaussianBlur"];
AVVideoComposition *composition = [AVVideoComposition videoCompositionWithAsset: asset
applyingCIFiltersWithHandler:^(AVAsynchronousCIImageFilteringRequest *request){
// Clamp to avoid blurring transparent pixels at the image edges
CIImage *source = [request.sourceImage imageByClampingToExtent];
[filter setValue:source forKey:kCIInputImageKey];
[filter setValue:[NSNumber numberWithDouble:10.0] forKey:kCIInputRadiusKey];
CIImage *output = [filter.outputImage imageByCroppingToRect:request.sourceImage.extent];
[request finishWithImage:output context:nil];
}];
NSURL *outputUrl = [[NSURL alloc] initWithString:#"Your Output path"];
[[NSFileManager defaultManager] removeItemAtURL:outputUrl error:nil];
AVAssetExportSession *exporter = [[AVAssetExportSession alloc] initWithAsset:asset presetName:AVAssetExportPreset960x540] ;
exporter.videoComposition = composition;
exporter.outputFileType = AVFileTypeMPEG4;
if (outputUrl){
exporter.outputURL = outputUrl;
[exporter exportAsynchronouslyWithCompletionHandler:^{
switch ([exporter status]) {
case AVAssetExportSessionStatusFailed:
NSLog(#"crop Export failed: %#", [[exporter error] localizedDescription]);
if (completion){
dispatch_async(dispatch_get_main_queue(), ^{
completion(NO,[exporter error],nil);
});
return;
}
break;
case AVAssetExportSessionStatusCancelled:
NSLog(#"crop Export canceled");
if (completion){
dispatch_async(dispatch_get_main_queue(), ^{
completion(NO,nil,nil);
});
return;
}
break;
default:
break;
}
if (completion){
dispatch_async(dispatch_get_main_queue(), ^{
completion(YES,nil,outputUrl);
});
}
}];
}
}
Kindly give some guidance.Any help or guidance in this direction would be highly appreciated.Thanks in advance.