avfoundation - AVAsserexportsession failed randomly

Question

I am creating the video from a set of images with AVAssetwriter and AVAssetExportSession and successfully getting the video and save it to the documents. But randomly the video exporting failed and it shows An Unknown error occured with error code -11800.

   ExportSessionError: -11800 adn userinfo{
   NSLocalizedDescription = "The operation could not be completed";
   NSLocalizedFailureReason = "An unknown error occurred (-12124)";
   NSUnderlyingError = "Error Domain=NSOSStatusErrorDomain Code=-12124 "The operation   couldnU2019t be completed. (OSStatus error -12124.)"";

Hi here is my code.. where strExport and strThumb is my path. It works fine but randomly shows errors..

     NSURL *soundFileURL = [NSURL fileURLWithPath:[[self pathToDocumentsDirectory] stringByAppendingPathComponent:_PATH_TMP_AUDIO_]];
   NSURL *videoFileURL = [NSURL fileURLWithPath:[[self pathToDocumentsDirectory] stringByAppendingPathComponent:@"screen.mov"]];

AVURLAsset* audioAsset = [[AVURLAsset alloc]initWithURL:soundFileURL options:nil];
AVURLAsset* videoAsset = [[AVURLAsset alloc]initWithURL:videoFileURL options:nil];

AVMutableComposition* mixComposition = [AVMutableComposition composition];
AVMutableCompositionTrack *compositionCommentaryTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeAudio
                                                                                    preferredTrackID:kCMPersistentTrackID_Invalid];
if ([[videoAsset tracksWithMediaType:AVMediaTypeVideo]count]>0) {
    [compositionCommentaryTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, audioAsset.duration)
                                        ofTrack:[[audioAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0]
                                         atTime:kCMTimeZero error:nil];    }


AVMutableCompositionTrack *compositionVideoTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo
                                                                               preferredTrackID:kCMPersistentTrackID_Invalid];
if ([[videoAsset tracksWithMediaType:AVMediaTypeVideo]count]>0) {
    [compositionVideoTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, videoAsset.duration)
                                   ofTrack:[[videoAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0]
                                    atTime:kCMTimeZero error:nil];
}


AVAssetExportSession* _assetExport = [[AVAssetExportSession alloc] initWithAsset:mixComposition  presetName:AVAssetExportPresetPassthrough];

UIImage *image = nil;

AVAssetImageGenerator *imageGenerator = [[AVAssetImageGenerator alloc] initWithAsset:videoAsset];
imageGenerator.appliesPreferredTrackTransform = YES;

// calc midpoint time of video
Float64 durationSeconds = CMTimeGetSeconds([videoAsset duration]);
CMTime midpoint = CMTimeMakeWithSeconds(durationSeconds/2.0, 600);

// get the image from
NSError *error = nil;
CMTime actualTime;
CGImageRef halfWayImage = [imageGenerator copyCGImageAtTime:midpoint actualTime:&actualTime error:&error];

if (halfWayImage != NULL)
{
    // cgimage to uiimage
    size_t width = CGImageGetWidth(halfWayImage);
    size_t height = CGImageGetHeight(halfWayImage);
    CGRect rect;
    CGSize size;
    if (width>height) {
        size=CGSizeMake(width/(height/thumb_size), thumb_size);
        rect=CGRectMake((size.width-thumb_size)/2.0, 0, thumb_size, thumb_size);
    }
    else{
        size=CGSizeMake(thumb_size,height/(width/thumb_size));
        rect=CGRectMake(0, (size.height-thumb_size)/2.0, thumb_size, thumb_size);
    }

    UIImage *scaleImage = [UIImage imageWithCGImage:halfWayImage];
    NSData *imgData = UIImageJPEGRepresentation(scaleImage, 1.0);
    [imgData writeToFile:self.strThumb atomically:YES];
    CGImageRelease(halfWayImage);
}
NSLog(@"exprt url %@ and thumb %@",self.strExport,self.strThumb);

NSURL    *exportUrl = [NSURL fileURLWithPath:self.strExport];
if ([[NSFileManager defaultManager] fileExistsAtPath:self.strExport])
    [[NSFileManager defaultManager] removeItemAtPath:self.strExport error:nil];

_assetExport.outputFileType = @"com.apple.quicktime-movie";

NSLog(@"file type %@", _assetExport.outputFileType);

_assetExport.outputURL = exportUrl;
NSLog(@"expoert urk %@",_assetExport.outputURL);
_assetExport.shouldOptimizeForNetworkUse = YES;

[_assetExport exportAsynchronouslyWithCompletionHandler: ^(void )
 {
     // your completion code here
     switch (_assetExport.status)
     {
         case AVAssetExportSessionStatusCompleted:
         {
             NSLog(@"Export Complete");
             [self performSelectorInBackground:@selector(loadText:) withObject:@"sucess"];

             break;
         }
         case AVAssetExportSessionStatusFailed:
             NSLog(@"Export Failed");
             NSLog(@"ExportSessionError: %d adn userinfo%@", [_assetExport.error code],[_assetExport.error userInfo]);
             [self performSelectorInBackground:@selector(loadText:) withObject:nil];
             break;
         case AVAssetExportSessionStatusCancelled:
             NSLog(@"Export canceled");
             NSLog(@"ExportSessionError: %@", [_assetExport.error localizedDescription]);
             break;
     }

 }];
[audioAsset release];
[videoAsset release];
[image release];

Can you check this... I struggled for 1 day i don't know where the error came. Thanks..

Answer 1

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