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gbenna

macrumors member
Original poster
Jul 27, 2011
62
0
When I take a video using UIImagePickerController and save it to SavedPhotosAlbum using

Code:
ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
       [library writeVideoAtPathToSavedPhotosAlbum:(NSURL *)movieURL
        completionBlock:^(NSURL *assetURL, NSError *error){
        if (error) {
        NSLog(@"Save video fail:%@",error);
        } else {
        NSLog(@"Save video succeed.");
         [self getsavedvideo];
         }}];

the saved file contains a name and creation date but not the GPS info. I am surprised by this since I am using the built in camera and the imagePicker. Why wouldn't Apple just include the GPS coordinates (even if I had to ask users permission to use location services).

anyway I digress

I have not found anyway to add the GPS coordinates to the video as it is being saved and I haven't been able to find anyway to add the this information in the completionBlock.

If someone knows how please let me know.

So I wrote a bit of code that is called after the video is saved [self getsavedvideo]; above which gets the saved video and I can get the movie name and creation date and it shows there is no location info.

Code:
-(void) getsavedvideo;{
       ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
      // Enumerate just the photos and videos group by using ALAssetsGroupSavedPhotos.
       [library enumerateGroupsWithTypes:ALAssetsGroupSavedPhotos usingBlock:^(ALAssetsGroup *group,     BOOL *stop) {
       // Within the group enumeration block, filter to enumerate just photos.
      [group setAssetsFilter:[ALAssetsFilter allVideos]];
        // Chooses the photo at the last index
        [group enumerateAssetsWithOptions:NSEnumerationReverse usingBlock:^(ALAsset *alAsset,   NSUInteger index, BOOL *innerStop) {
         // The end of the enumeration is signaled by asset == nil.
          if (alAsset) {
         ALAssetRepresentation *representation = [alAsset defaultRepresentation];
         // Stop the enumerations
         *stop = YES; *innerStop = YES;
          // Do something interesting with the AV asset.
          NSString *fileName = [representation filename];
           NSDate *myDate = [alAsset valueForProperty:ALAssetPropertyDate];
           CLLocation *location = [alAsset valueForProperty:ALAssetPropertyLocation];
           NSLog(@"fileName!!!!,%@",fileName);
           NSDateFormatter * dateFormatter = [[NSDateFormatter alloc] init];
          [dateFormatter setDateFormat:mad:"dd-MM-yyyy 'at' HH:mm"];
           NSLog( @"date for this file is %@ %@", [[[alAsset defaultRepresentation] url] absoluteString],   [dateFormatter stringFromDate: myDate] );
            NSLog (@"locate!!!!%@",location);
             } }];
            } failureBlock: ^(NSError *error) {
             NSLog(@"No groups");}];}

so does anyone know how to append this with the GPS information and save it back to the video's metadata.
I have been wracking my brains out on this for a few days and haven't really found anything helpful.

Plz help
 
Last edited:
So I figured this out for a device running ios8 or newer anyway.

add this code in the

Code:
-(void) getsavedvideo that was in the completionBlock above.

Make sure you have 
#import <Photos/Photos.h>

    if ([PHAsset class]) { // If this class is available, we're running iOS 8
           
            PHFetchOptions *fetchOptions = [PHFetchOptions new];
            fetchOptions.sortDescriptors = @[[NSSortDescriptor sortDescriptorWithKey:@"creationDate" ascending:NO]];
            fetchOptions.fetchLimit = 1;
            PHFetchResult *fetchResult = [PHAsset fetchAssetsWithMediaType:PHAssetMediaTypeVideo options:fetchOptions];
            PHAsset *lastImageAsset = [fetchResult lastObject];
           
            [[PHImageManager defaultManager]requestImageForAsset:lastImageAsset targetSize:PHImageManagerMaximumSize contentMode:PHImageContentModeDefault options:nil resultHandler:^(UIImage *result, NSDictionary *info){
                if ([info objectForKey:PHImageErrorKey] == nil && ![[info objectForKey:PHImageResultIsDegradedKey] boolValue]) {
                   
                    NSArray *resources = [PHAssetResource assetResourcesForAsset:lastImageAsset];
                    NSString *orgFilename = ((PHAssetResource*)resources[0]).originalFilename;
                   
                   
                   
                    [lastImageAsset requestContentEditingInputWithOptions:nil
                                               completionHandler:^(PHContentEditingInput *contentEditingInput, NSDictionary *info) {
                                                   NSURL *imageURL = contentEditingInput.fullSizeImageURL;
                                                   NSString *urlstring = [imageURL absoluteString];
                                                   NSLog(@"urlstring%@",urlstring);
                                               }];
               
               
                   
                    CLLocationCoordinate2D    locationNew = CLLocationCoordinate2DMake( currentLocation.coordinate.latitude, currentLocation.coordinate.longitude) ;
                    NSDate *nowDate = [NSDate date];
                   
                    CLLocation *myLocation = [[CLLocation alloc ]initWithCoordinate:locationNew altitude:0.0 horizontalAccuracy:1.0 verticalAccuracy:1.0 timestamp:nowDate];
                   
                 
                    [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
                        // Create a change request from the asset to be modified.
                        PHAssetChangeRequest *request = [PHAssetChangeRequest changeRequestForAsset:lastImageAsset];
                        // Set a property of the request to change the asset itself.
                        request.location = myLocation;
                       
                    } completionHandler:^(BOOL success, NSError *error) {
                        NSLog(@"Finished updating asset. %@", (success ? @"Success." : error));
                    }];
                }
           }];
        }
   

        else {
              //if you aren't running ios8 or newer I haven't found a way to add/change metadata but I will keep looking.So if you leave this blank no new metadata is added.
    }

You can add other metadata just create the data in the form needed and then use request.(what you want to change) = new data.

you can check to see if the data already exist and if there is a metadata for it by putting in something like

lastImageAsset (which was the PHAsset fetch result above) and then the property like

NSDate *originalFileDate = [lastImageAsset creationDate]; etc.
there is a list at
https://developer.apple.com/reference/photos/phasset
 
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