AVExportSession with a streaming AVAsset -11800 Error - ios

Question

I have been using AVPlayer to play video where the underlying asset that is backed by a Streaming URL.
I am trying to create a snip of the video (just a 9 second clip), in order to save the clip locally.
I tried AVAssetExportSession with the following code, but the session returns AVAssetExportSessionStatusFailed every time. The specific error is Error Domain=AVFoundationErrorDomain Code=-11800, which means unknown error.
AVURLAsset *otherAsset = [[AVURLAsset alloc] initWithURL:streamURL options:options];
NSArray *exportPresets = [AVAssetExportSession exportPresetsCompatibleWithAsset:otherAsset];
NSLog(exportPresets.description);
AVAssetExportSession *session = [AVAssetExportSession exportSessionWithAsset:otherAsset presetName:AVAssetExportPresetMediumQuality];
NSArray *supportedFileTypes = session.supportedFileTypes;
NSLog(supportedFileTypes.description);
NSString *documentsDirectory = [NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex: 0];
NSString *dstPath = [documentsDirectory stringByAppendingString:#"/sample.mov"];
NSURL *savetUrl = [NSURL fileURLWithPath:dstPath];
session.outputFileType = #"com.apple.quicktime-movie";
session.outputURL = savetUrl;
session.shouldOptimizeForNetworkUse = YES;
[session exportAsynchronouslyWithCompletionHandler:
^(void ) {
switch ([session status]) {
case AVAssetExportSessionStatusFailed:
NSLog([session error].description);
NSLog(#"Export failed: %#",[[session error]localizedDescription]);
break;
case AVAssetExportSessionStatusCancelled:
NSLog(#"Export canceled");
break;
default:
NSLog(#"Export Success, File Saved.");
break;
}
}
];
I've checked to make sure that I am not overwriting a file, and checked other causes of AVAssetExportSessionStatusFailed.
I am guessing that AVAssetExportSession is not meant to be used with streaming assets. (I could be wrong).
Is my guess right, or is there something else I need to do. Is there an easier way to snip and cache a streaming URL?
Thanks for your time!

Answer 1

For as far as I know, there is no way to export other than local files under iOS7.
It seems to work fine under iOS8 though.
I suggest you just use NSData.writeToFile(filePath, atomically: bool) if you don't have to set an exportInterval.
Hope this'll help!