> On Jun 23, 2017, at 10:22 AM, Carl Hoefs <newsli...@autonomy.caltech.edu> > wrote: > > At this high frame rate, I'm expecting that callbacks would not be able to > keep up in real time without an unacceptably high rate of dropped frames. > Having the encryption integrated within the capture / movie file chain would > be ideal (perhaps implemented by utilizing the iPhone's GPU to keep up pace), > but it doesn't sound like iOS supports it at this point.
I don’t think there’d be any noticeable difference in performance. Why do you think an app-defined callback would be that much slower than an OS-provided one? Either way, 99.9% of the time would be spent in the AES codec, which is hardware-optimized on Apple’s CPUs. (Not by the GPU; there’s are some special CPU instructions that do it.) The codec should definitely be able to keep up, since all file I/O in apps already goes through AES encryption at the filesystem level. I could argue that adding a second level of encryption is pointless, but I know that HIPAA has some strict regulations, even if they’re not always sensical. (When you encrypt the file you're generating a random IV, then writing the IV at the start of the file, or something like that, right? And the key is stored someplace at least as safe as the Keychain? Sorry if I’m being nosy, but I’ve done enough crypto stuff to be very paranoid.) —Jens _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
