Split video in iOS - iphone

Question

i have to split the video into two parts.i am using with this trim function twicely is that good approach i have read the AVFoundation frame work but didn't found any direct solution to split the video.but there are some iPhone Apps which are splitting the video very smoothly.are they using the trim function ? need suggestion
-(void)splitSecondVideo{
NSString *deleteVideo = [_videoPath path];
AVURLAsset *asset = [AVURLAsset URLAssetWithURL:_videoPath options:nil];
AVAssetExportSession *exportSession = [[AVAssetExportSession alloc]initWithAsset:asset presetName:AVAssetExportPresetLowQuality];
NSString *outputURL = nil;
NSString *videoFileName = nil;
videoFileName = [SPUtility getDefaultVideoName];
outputURL = [NSString stringWithFormat:#"%#/%#.mov", _clipFolderPath, videoFileName];
NSFileManager *manager = [NSFileManager defaultManager];
[manager createDirectoryAtPath:outputURL withIntermediateDirectories:YES attributes:nil error:nil];
[manager removeItemAtPath:outputURL error:nil] ;
exportSession.outputURL = [NSURL fileURLWithPath:outputURL];
exportSession.shouldOptimizeForNetworkUse = YES;
exportSession.outputFileType = AVFileTypeQuickTimeMovie;
// Trim to half duration
double halfDuration = CMTimeGetSeconds([asset duration])/2.0;
double fullDuration = CMTimeGetSeconds([asset duration]);
CMTime firsthalfDuration = CMTimeMakeWithSeconds(halfDuration, 1);
CMTime secondhalfDuration = CMTimeMakeWithSeconds(fullDuration, 1);
CMTimeRange secondrange = CMTimeRangeMake(firsthalfDuration, secondhalfDuration);
exportSession.timeRange = secondrange;
[exportSession exportAsynchronouslyWithCompletionHandler:^(void)
{
switch (exportSession.status) {
case AVAssetExportSessionStatusCompleted:
[manager removeItemAtPath:deleteVideo error:nil];
NSLog(#"Export Complete %d %#", exportSession.status, exportSession.error);
break;
case AVAssetExportSessionStatusFailed:
NSLog(#"Failed:%#",exportSession.error);
break;
case AVAssetExportSessionStatusCancelled:
NSLog(#"Canceled:%#",exportSession.error);
break;
default:
break;
}
}];
}