trouble loading a CiFilter

Question

This question is probably relevant to other first time CIFilter writers, also. I need advice on updating a video player QTKit application for Mac OS X (based on QTKitPlayer) to use CIFilters. I've already read the Image Unit and Core Image guides. And I've successfully gotten the app to load and run the builtin CIFilters, using [CIPlugIn loadAllPlugIns].

I've also successfully written my first CIFilter, wrapped it as an Image Unit, and placed it into /Library/Graphics/Image Units And I've tested it successfully with Quartz Composer, which loads it and runs sucessfully. I've also loaded it successfully in Core Image Fun House.

However,the altered QTKitPlayer app won't LOAD my CIFilter. Breakpoints reveal that all the builtin CIFilters loaded, but my filter did not.

Since I'm a newbie to writing and using CIFilters, I'm worried that I must've missed some Core Image initialization code, or a QTMovieView nib flag, or compiler flag, or something. Do I need to do any set-up stuff before invoking loadAllPlugins? Here's the code:

[CIPlugIn loadAllPlugIns]; CIFilter *ciFilter = [CIFilter filterWithName:@"MyDistortionWarp"];

I check to see if it loads with:

NSArray *filterList = [CIFilter filterNamesInCategories:[NSArray arrayWithObject:kCICategoryDistortionEffect]];

During debugging, my CIFilter does not appear in the filterList inside my QTKitPlayer derivative. But, inserting the same code into the Core Image Fun House src, shows that filterList does contain my filter. FunHouse also sets ciFilter to the filter, but my app only get set to a Nil.

What is my QTKit app missing, that it needs to load a CIPlugin?

Brian Brian · Accepted Answer · 2011-07-23T07:09:23

Thanks for your response. I have since resolved this problem. It turned out to be a 32 bit vs 64 bit build issue in XCode.

My projects were set up for the Release build to be both 32 and 64 bit plugin binaries. But, often the Debug build had been set up to build only "native" binaries. Since the projects were either old or were altered sample code projects, it took me a while to realize the problem was in the old build settings, not the newly altered code.

[CIPlugIn loadAllPlugIns] only loads plugins that are binary compatible with the app. So, a 32 bit app would not see CIFilters built only for 64 bit. And, a 64 bit app would not see plugins built only for 32 bit systems. Etc, etc. In my case, FunHouse could load my image units, while the altered QTKitPlayer could not. I just needed to alter the project's build settings.

A word to the wise -- after upgrading to a new Mac, with a new OSX & new XCode, if you get twilight zone issues -- check your build settings.

trouble loading a CiFilter

2 Answers