ALAssetsGroupLibrary contains no video items - objective-c

Question

I'm using the ALAssetLibrary to enumerate the videos on the device, and it works just fine for videos created on the device itself. But for groups that were created as a result of a synced album/event from iTunes I get no videos, although there are videos in the correspondence directory of the "Videos" app.
Code that search for videos and log the number of assets and videos in every group:
//using dispatch_async just to make sure it is called on the main thread
dispatch_async(dispatch_get_main_queue(),^{
ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
[library enumerateGroupsWithTypes:ALAssetsGroupEvent|ALAssetsGroupLibrary usingBlock:^(ALAssetsGroup *group, BOOL *stop) {
if (group!=nil) {
NSLog(#"Number of assets in %# :%d",[group valueForProperty:ALAssetsGroupPropertyName],[group numberOfAssets]);
[group setAssetsFilter:[ALAssetsFilter allVideos]];
NSLog(#"Number of videos in %# :%d",[group valueForProperty:ALAssetsGroupPropertyName],[group numberOfAssets]);
}
} failureBlock: ^(NSError *error) {
NSLog(#"ERROR: %#",[error localizedDescription]);
}];
});
Any idea what's wrong? or how to get those videos that were synced from iTunes?
(iOS5 with iPhone4)

Answer 1

The AssetsLibrary only enumerates the Photo-Library. Therefore you only get photos/videos that are managed by the "Photos"-App (e.g. videos recorded with the device's camera). The videos managed by the "Videos" app are in a different Library. There is no way to access these by an official developer API.
Cheers,
Hendrik