AVAsset has no tracks or duration when created from an ALAsset URL

Question

I'm pulling all of the video assets from ALAssetsLibrary (Basically everything that's being recorded from the native camera app). I am then running an enumeration on each video asset that does this to each video:

 // The end of the enumeration is signaled by asset == nil.
           if (alAsset) {

                 //Get the URL location of the video
               ALAssetRepresentation *representation = [alAsset defaultRepresentation];
               NSURL *url = [representation url];

                 //Create an AVAsset from the given URL
               NSDictionary *asset_options = [NSDictionary dictionaryWithObject:[NSNumber numberWithBool:YES] forKey:AVURLAssetPreferPreciseDurationAndTimingKey];
               AVAsset *avAsset = [[AVURLAsset alloc] initWithURL:url options:asset_options];//[AVURLAsset URLAssetWithURL:url options:asset_options];

               //Here is the problem
               NSLog([NSString stringWithFormat:@"%i", [avAsset.tracks count]]);
               NSLog([NSString stringWithFormat:@"%f", CMTimeGetSeconds(avAsset.duration)]);
           }

NSLog is reporting that the AVAsset that I've gotten from my ALAsset has 0 tracks, and has a duration of 0.0 seconds. I checked the url, and it's "assets-library://asset/asset.MOV?id=9F482CF8-B4F6-40C2-A687-0D05F5F25529&ext=MOV" which seems correct. I know alAsset is actually a video, and the correct video, because I've displayed alAsset.thumbnail, and it's shown the correct thumbnail for the video.

All this leads me to believe there's something going wrong in the initialization for avAsset, but for the life of me, I can't figure out what's going wrong. Can anyone help me?

Update:

I think i've confirmed that the url being given to me by ALAssetRepresentation is faulty, which is weird because it gives me the correct thumbnail. I added this code in:

NSLog([NSString stringWithFormat:@"%i", [url checkResourceIsReachableAndReturnError:&error]]);
NSLog([NSString stringWithFormat:@"%@", error]);

It gives me this:

0
Error Domain=NSCocoaErrorDomain Code=4 "The operation couldn’t be completed. (Cocoa error 4.)" UserInfo=0x19df60 {}

I'm still not sure what would cause that. The only thing I'm noticing is the url, which is "assets-library://asset/asset.MOV?id=9F482CF8-B4F6-40C2-A687-0D05F5F25529&ext=MOV" is different from what I've seen as I've been searching around for this. The one i've seen elsewhere looks more like "assets-library://asset/asset.MOV?id=1000000394&ext=MOV", with a number instead of an alphanumeric, dash separated name.

If it helps, I'm using XCode 4.2 Beta, and iOS5. Please let me know if you can think of anything. Thanks.

Answer 1

Okay, looks like it was a bug in the iOS5 beta v1. I upgraded to the newest and it worked. Thanks to those who took a look at my question.