Getting a saved video from document directory to v

Question

I'm Generating video and saving to CameraRoll,here i need to fetch the video to my next view which was generated and saved in Camera Roll.Hope someone helps.I'm not getting the correct one to follow.Actually I'm creating and saving video using this code

NSError *error = nil;
NSFileManager *fileMgr = [NSFileManager defaultManager];
NSString *documentsDirectory = [NSHomeDirectory()
stringByAppendingPathComponent:@"Documents"];
NSString *videoOutputPath = [documentsDirectory        stringByAppendingPathComponent:@"test_output.mp4"];
if ([fileMgr removeItemAtPath:videoOutputPath error:&error] != YES)
NSLog(@"Unable to delete file: %@", [error localizedDescription]);
CGSize imageSize = CGSizeMake(400, 200);
NSUInteger fps = 30;
NSArray* imagePaths = [[NSBundle mainBundle]   pathsForResourcesOfType:@"jpg" inDirectory:nil];
self.chosenImages = [[NSMutableArray alloc]   initWithCapacity:imagePaths.count];
NSLog(@"-->imageArray.count= %i", self.chosenImages.count);
for (NSString* path in imagePaths)
{
[self.chosenImages addObject:[UIImage imageWithContentsOfFile:path]];

}

NSLog(@"Start building video from defined frames.");

AVAssetWriter *videoWriter = [[AVAssetWriter alloc] initWithURL:
[NSURL fileURLWithPath:videoOutputPath]  fileType:AVFileTypeQuickTimeMovie
                                                      error:&error];
NSParameterAssert(videoWriter);

NSDictionary *videoSettings = [NSDictionary dictionaryWithObjectsAndKeys:
                           AVVideoCodecH264, AVVideoCodecKey,
[NSNumber numberWithInt:imageSize.width],   AVVideoWidthKey,
[NSNumber numberWithInt:imageSize.height], AVVideoHeightKey,
                           nil];

AVAssetWriterInput* videoWriterInput = [AVAssetWriterInput
assetWriterInputWithMediaType:AVMediaTypeVideo
                                    outputSettings:videoSettings];
AVAssetWriterInputPixelBufferAdaptor *adaptor =     [AVAssetWriterInputPixelBufferAdapto assetWriterInputPixelBufferAdaptorWithAssetWriterInput:videoWriterInput sourcePixelBufferAttributes:nil];
NSParameterAssert(videoWriterInput);
NSParameterAssert([videoWriter canAddInput:videoWriterInput]);
videoWriterInput.expectsMediaDataInRealTime = YES;
[videoWriter addInput:videoWriterInput];
[videoWriter startWriting];
[videoWriter startSessionAtSourceTime:kCMTimeZero];

CVPixelBufferRef buffer = NULL;
int frameCount = 0;
double numberOfSecondsPerFrame = 6;
double frameDuration = fps * numberOfSecondsPerFrame;
for(UIImage * img in self.chosenImages)
{
//UIImage * img = frm._imageFrame;
 buffer = [self pixelBufferFromCGImage:[img CGImage]];
 BOOL append_ok = NO;
 int j = 0;
 while (!append_ok && j < 30) {
    if (adaptor.assetWriterInput.readyForMoreMediaData)  {
        //print out status:
        NSLog(@"Processing video frame (%d,%lu)",frameCount,(unsigned long)   [self.chosenImages count]);

        CMTime frameTime = CMTimeMake(frameCount*frameDuration,(int32_t) fps);
        append_ok = [adaptor appendPixelBuffer:buffer withPresentationTime:frameTime];
        if(!append_ok){
            NSError *error = videoWriter.error;
            if(error!=nil) {
                NSLog(@"Unresolved error %@,%@.", error, [error userInfo]);
            }
        }
    }
    else {
        printf("adaptor not ready %d, %d\n", frameCount, j);
        [NSThread sleepForTimeInterval:0.1];
    }
    j++;
}
if (!append_ok) {
    printf("error appending image %d times %d\n, with error.", frameCount, j);
}
frameCount++;
}
 NSLog(@"**************************************************");

  //Finish the session:
 [videoWriterInput markAsFinished];
 [videoWriter finishWriting];
 NSLog(@"Write Ended");

AVMutableComposition* mixComposition = [AVMutableComposition composition];

NSString *bundleDirectory = [[NSBundle mainBundle] bundlePath];
// audio input file...
NSString *audio_inputFilePath = [bundleDirectory   stringByAppendingPathComponent:@"30secs.mp3"];
NSURL    *audio_inputFileUrl = [NSURL fileURLWithPath:audio_inputFilePath];
NSURL    *video_inputFileUrl = [NSURL fileURLWithPath:videoOutputPath];
NSString *outputFilePath = [documentsDirectory stringByAppendingPathComponent:@"final_video.mp4"];
NSURL    *outputFileUrl = [NSURL fileURLWithPath:outputFilePath];

if ([[NSFileManager defaultManager] fileExistsAtPath:outputFilePath])
[[NSFileManager defaultManager] removeItemAtPath:outputFilePath error:nil];

CMTime nextClipStartTime = kCMTimeZero;

AVURLAsset* videoAsset = [[AVURLAsset  alloc]initWithURL:video_inputFileUrl options:nil];
CMTimeRange video_timeRange =    CMTimeRangeMake(kCMTimeZero,videoAsset.duration);
AVMutableCompositionTrack *a_compositionVideoTrack = [mixComposition   addMutableTrackWithMediaType:AVMediaTypeVideo     preferredTrackID:kCMPersistentTrackID_Invalid];
[a_compositionVideoTrack insertTimeRange:video_timeRange ofTrack:      [[videoAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0]   atTime:nextClipStartTime error:nil];



AVURLAsset* audioAsset = [[AVURLAsset alloc]initWithURL:audio_inputFileUrl  options:nil];
CMTimeRange audio_timeRange = CMTimeRangeMake(kCMTimeZero, audioAsset.duration);
AVMutableCompositionTrack *b_compositionAudioTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
[b_compositionAudioTrack insertTimeRange:audio_timeRange ofTrack:[[audioAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0] atTime:nextClipStartTime error:nil];
AVAssetExportSession* _assetExport = [[AVAssetExportSession alloc] initWithAsset:mixComposition presetName:AVAssetExportPresetHighestQuality];
//_assetExport.outputFileType = @"com.apple.quicktime-movie";
_assetExport.outputFileType = @"public.mpeg-4";
//NSLog(@"support file types= %@", [_assetExport supportedFileTypes]);
_assetExport.outputURL = outputFileUrl;

[_assetExport exportAsynchronouslyWithCompletionHandler:
 ^(void ) {
   ALAssetsLibrary *assetLibrary = [[ALAssetsLibrary alloc] init];
     [assetLibrary writeVideoAtPathToSavedPhotosAlbum:outputFileUrl completionBlock:^(NSURL *assetURL, NSError *error){
         if(error == nil){
             NSLog(@"Saved Successfully");
         }

 }
 ];

  NSLog(@"DONE.....outputFilePath--->%@", outputFilePath);