Can anyone from apple provide the spline formulation that is used in the CIToneCurve filter?The documentation says that a spline is passed thru the points you give it, but thereare a lot of spline types in the world, and they all can yield different shapes thru the same set of points.

i pushed a couple of builds up to app store connect on dec5 and they just disappeared. not showing as in-process or anything. anyone else see this happening?

sometimes, for the very same video file, we get an error from this call on iOS example of fail case path: /var/mobile/Media/DCIM/102APPLE/IMG_2685.mp4 sometimes it works fine. what? [[NSFileManager defaultManager] attributesOfItemAtPath:filepath error:&error]; anyone see this before?

We are using AVAssetWriter to write a movie file. All works fine, but when the app goes into the background and pauses operations, we would expect the writer to come back to life when you bring the app back into the foreground. However, it does not, it fails with this error code. Any hints, workarounds? Error Domain=AVFoundationErrorDomain Code=-11847 "Operation Interrupted" UserInfo={NSLocalizedRecoverySuggestion=Stop other operations and try again., NSLocalizedDescription=Operation Interrupted, NSUnderlyingError=0x2820356b0 {Error Domain=NSOSStatusErrorDomain Code=-16121 "(null)"}}