> > On 8 Mar 2014, at 4:12 pm, Trygve Inda <cocoa...@xericdesign.com> wrote: > >> I get the same times doing it this way, but maybe my color spaces are >> different. The CGImage returned from my AVAsset is: >> >> <CGColorSpace 0x100550490> (kCGColorSpaceICCBased; kCGColorSpaceModelRGB; >> Composite NTSC) >> >> I am not really sure what color space to pass into: >> >> [NSBitmapImageRep alloc] initWithBitmapDataPlanes:NULL..... > >> >> Currently I am using NSDeviceRGBColorSpace. >> >> Any thoughts? >> >> T. > > My guess is that this is a mismatch, because while both spaces are RGB, one is > NTSC derived and the other probably a simple linear RGB. > > > Unfortunately NSBitmapImageRep only accepts a colour space *name*. It might be > that the colorspace used by your images doesn't have a name - try using > CGColorSpaceCopyName on the CGColorSpaceRef you get from CGImageGetColorSpace. > > If it's NULL, you'll have to drop down to: > > CGBitmapContextCreate(...) which accepts the actual CGColorSpaceRef. This will > also accept the CGBitmapInfo obtained from your image to ensure that the > format matches. > > Once done compositing, use CGBitmapContextCreateImage to get the CGImage > (which shouldn't do an additional copy of the buffer as long as you treat the > image as read-only), then initialize an NSImage from it (again, should be only > a wrap operation). At this point you'll have an image using the original NTSC > colorspace. If that has to be drawn to the screen, likely it will need to do a > similar conversion. Could be that what you gain on the roundabouts you'll lose > on the swings.
This is slower by about 15%. :( _______________________________________________ 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
