Question

I am trying to build a simple torch application for iOS 5 as described in http://developer.apple.com/library/mac/releasenotes/AudioVideo/RN-AVFoundation/_index.html#//apple_ref/doc/uid/TP40010717-CH1-DontLinkElementID_17 but i am getting “Apple Match-O Linker Error:

    Undefined symbols for architecture armv7:
  "_AVMediaTypeVideo", referenced from:
      -[FirstViewController viewDidLoad] in FirstViewController.o
  "_OBJC_CLASS_$_AVCaptureDevice", referenced from:
      objc-class-ref in FirstViewController.o
ld: symbol(s) not found for architecture armv7
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Any help appreciated

---

Anybody ?

Additionally: it only happens when running the project, no errors if i just clean & Build, and the code completion detects the library.

Thanks

Answer 1

You might need to link your project with the AVFoundation framework first.
If you’re already doing that, make sure you’re building for armv7 and not just armv6.
Check it in your project settings > Target > Build Settings > Architecture