Relatively poor BitmapData.encode JPEG performance (iOS)

Question

Hi,
Our app currently uses a native extension to access the inbulit JPEG encoder in iOS (UIImageJPEGRepresentation(...)). With a quality setting of 0.6 (not sure if that relates to standard JPEG quality settings) and a image size of 640x360, a typical encode operation takes 18ms on an iPhone 4S.
I just tested the new BitmapData.encode functionality with the hope of migrating from using a native extension, but even at a quality of zero i'm seeing encode times around 49ms. At a quality of 60 it's not much slower (52-53ms) although it does return a file less than half the size of the native encoder.
Have you considered wrapping the iOS SDK encoder, or if you are, should it be taking so much longer?
My native encoding extension implementation: http://pastebin.com/VS1jhKB8
By the way, really enjoying the momentum behind the Air releases!
Cheers,
Dave

Answer 1

Well, in general I operate on the princiapal that removing code is a good thing
I can see what you're saying about Native Extensions, however in this case since they've just added a JPEG encoder to the API it might make sense to use the fastest one available. However I can also see that they might prefer consistent behaviour over execution speed - no doubt the iOS native JPEG encoder will produce a different result than the Android one (http://pastebin.com/vu6BeE5p)