Whenever I upload video the page getting hang - ios

Question

I am doing a chatting app with JSQmessagecontroller library every thing is working fine but whenever I upload video the page get hang.
I am doing a chatting app with JSQmessagecontroller library every thing is working fine but whenever I upload video the page get hang.
- (id<JSQMessageData>)collectionView:(JSQMessagesCollectionView *)collectionView messageDataForItemAtIndexPath:(NSIndexPath *)indexPath
{
NSString * chat = [[DataArray objectAtIndex:indexPath.row] objectForKey:#"Message"];
NSString * imageurl = [[DataArray objectAtIndex:indexPath.row] objectForKey:#"media"];
if (chat == nil)
{
// NSString *responseString = [[NSString alloc]initWithData:webdata encoding:NSUTF8StringEncoding];
if ([imageurl rangeOfString:#".jpg"].location == NSNotFound) {
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0), ^{
dispatch_async(dispatch_get_main_queue(), ^{
NSLog(#"Video is Loading....");
image1 =[[UIImageView alloc]init];
MPMoviePlayerController *player1 = [[MPMoviePlayerController alloc] initWithContentURL:[NSURL URLWithString:imageurl]];
[player1 stop];
[self thumbnailImageFromURL:[NSURL URLWithString:imageurl]];
JSQPhotoMediaItem *vitem;
vitem = [[JSQPhotoMediaItem alloc] initWithImage:thumbnailImage];
// NSString * date12=[[DataArray objectAtIndex:indexPath.row] objectForKey:#"date"];
NSString *dateString = [[DataArray objectAtIndex:indexPath.row] objectForKey:#"date"];
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:#"dd-MM-YY HH:mm a"];
dateFromString = [[NSDate alloc] init];
dateFromString=[dateFormatter dateFromString:dateString];
messageForRow = [[JSQMessage alloc] initWithSenderId:[[DataArray objectAtIndex:indexPath.row] objectForKey:#"UserId"] senderDisplayName:[[DataArray objectAtIndex:indexPath.row] objectForKey:#"Name"]date:[[DataArray objectAtIndex:indexPath.row] objectForKey:#"date"] media:vitem] ;
// JSQPhotoMediaItem *vitem = [[JSQPhotoMediaItem alloc] initWithImage:thumbnailImage];
});
});
}
else
{
image1 =[[UIImageView alloc]init];
UIImage *im=[[UIImage alloc]init];
[image1 sd_setImageWithURL:[NSURL URLWithString:imageurl]
placeholderImage:nil];
im=image1.image;
JSQPhotoMediaItem *item = [[JSQPhotoMediaItem alloc] initWithImage:im];
NSString *dateString = [[DataArray objectAtIndex:indexPath.row] objectForKey:#"date"];
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:#"dd-MM-YY HH:mm a"];
//dateFromString = [[NSDate alloc] init];
dateFromString=[dateFormatter dateFromString:dateString];
messageForRow = [[JSQMessage alloc] initWithSenderId:[[DataArray objectAtIndex:indexPath.row] objectForKey:#"UserId"] senderDisplayName:[[DataArray objectAtIndex:indexPath.row] objectForKey:#"Name"] date:[[DataArray objectAtIndex:indexPath.row] objectForKey:#"date"] media:item] ;
}
}
else
{
messageForRow = [[JSQMessage alloc] initWithSenderId:[[DataArray objectAtIndex:indexPath.row] objectForKey:#"UserId"] senderDisplayName:[[DataArray objectAtIndex:indexPath.row] objectForKey:#"Name"] date:[[DataArray objectAtIndex:indexPath.row] objectForKey:#"date"] text: [[DataArray objectAtIndex:indexPath.row] objectForKey:#"Message"]] ;
}
return messageForRow;
}