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我正在按照http://developer.apple.com/iphone/library/qa/qa2010/qa1702.html上的参考从 iPhone 相机捕获视频。除了该页面的代码之外，这是一个新项目。我也将 AVFoundation 框架添加到项目中。这是我得到的链接器错误：

Build my project of project my project with configuration Debug

CompileC "build/my project.build/Debug-iphoneos/my project.build/Objects-normal/armv6/MainViewController.o" /Users/mwilliamson/Projects/my_project/iphone/Classes/MainViewController.m normal armv6 objective-c com.apple.compilers.gcc.4_2
cd /Users/mwilliamson/Projects/my_project/iphone
setenv LANG en_US.US-ASCII
setenv PATH "/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin:/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/X11/bin:/opt/local/bin:/usr/local/git/bin"
/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/gcc-4.2 -x objective-c -arch armv6 -fmessage-length=0 -pipe -std=c99 -Wno-trigraphs -fpascal-strings -O0 -Wreturn-type -Wunused-variable -isysroot /Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS4.0.sdk -fvisibility=hidden -gdwarf-2 -mthumb -miphoneos-version-min=4.0 -iquote "/Users/mwilliamson/Projects/my_project/iphone/build/my project.build/Debug-iphoneos/my project.build/my project-generated-files.hmap" "-I/Users/mwilliamson/Projects/my_project/iphone/build/my project.build/Debug-iphoneos/my project.build/my project-own-target-headers.hmap" "-I/Users/mwilliamson/Projects/my_project/iphone/build/my project.build/Debug-iphoneos/my project.build/my project-all-target-headers.hmap" -iquote "/Users/mwilliamson/Projects/my_project/iphone/build/my project.build/Debug-iphoneos/my project.build/my project-project-headers.hmap" -F/Users/mwilliamson/Projects/my_project/iphone/build/Debug-iphoneos -I/Users/mwilliamson/Projects/my_project/iphone/build/Debug-iphoneos/include -I/Users/mwilliamson/Projects/my_project/iphone/opencv_device/include "-I/Users/mwilliamson/Projects/my_project/iphone/build/my project.build/Debug-iphoneos/my project.build/DerivedSources/armv6" "-I/Users/mwilliamson/Projects/my_project/iphone/build/my project.build/Debug-iphoneos/my project.build/DerivedSources" -include /var/folders/kW/kW6u6B7SGyGYu+nNumtIa++++TI/-Caches-/com.apple.Xcode.501/SharedPrecompiledHeaders/my_project_Prefix-alujyqxskcuyuogdsynmjyrkxbhh/my_project_Prefix.pch -c /Users/mwilliamson/Projects/my_project/iphone/Classes/MainViewController.m -o "/Users/mwilliamson/Projects/my_project/iphone/build/my project.build/Debug-iphoneos/my project.build/Objects-normal/armv6/MainViewController.o"

/Users/mwilliamson/Projects/my_project/iphone/Classes/MainViewController.m: In function '-[MainViewController captureOutput:didOutputSampleBuffer:fromConnection:]':
/Users/mwilliamson/Projects/my_project/iphone/Classes/MainViewController.m:126: warning: 'MainViewController' may not respond to '-imageFromSampleBuffer:'
/Users/mwilliamson/Projects/my_project/iphone/Classes/MainViewController.m:126: warning: (Messages without a matching method signature
/Users/mwilliamson/Projects/my_project/iphone/Classes/MainViewController.m:126: warning: will be assumed to return 'id' and accept
/Users/mwilliamson/Projects/my_project/iphone/Classes/MainViewController.m:126: warning: '...' as arguments.)

Ld "build/my project.build/Debug-iphoneos/my project.build/Objects-normal/armv6/my project" normal armv6
cd /Users/mwilliamson/Projects/my_project/iphone
setenv IPHONEOS_DEPLOYMENT_TARGET 4.0
setenv PATH "/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin:/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/X11/bin:/opt/local/bin:/usr/local/git/bin"
/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/gcc-4.2 -arch armv6 -isysroot /Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS4.0.sdk -L/Users/mwilliamson/Projects/my_project/iphone/build/Debug-iphoneos -F/Users/mwilliamson/Projects/my_project/iphone/build/Debug-iphoneos -filelist "/Users/mwilliamson/Projects/my_project/iphone/build/my project.build/Debug-iphoneos/my project.build/Objects-normal/armv6/my project.LinkFileList" -dead_strip -lz -lstdc++ /Users/mwilliamson/Projects/my_project/iphone/opencv_device/lib/libcxcore.a /Users/mwilliamson/Projects/my_project/iphone/opencv_device/lib/libcv.a -miphoneos-version-min=4.0 -framework Foundation -framework UIKit -framework CoreGraphics -framework AVFoundation -o "/Users/mwilliamson/Projects/my_project/iphone/build/my project.build/Debug-iphoneos/my project.build/Objects-normal/armv6/my project"

Undefined symbols:
  "_CVPixelBufferGetBaseAddress", referenced from:
      -[MainViewController imageFromSampleBuffer:] in MainViewController.o
  "_CVPixelBufferUnlockBaseAddress", referenced from:
      -[MainViewController imageFromSampleBuffer:] in MainViewController.o
  "_CVPixelBufferLockBaseAddress", referenced from:
      -[MainViewController imageFromSampleBuffer:] in MainViewController.o
  "_CMSampleBufferGetImageBuffer", referenced from:
      -[MainViewController imageFromSampleBuffer:] in MainViewController.o
  "_CVPixelBufferGetHeight", referenced from:
      -[MainViewController imageFromSampleBuffer:] in MainViewController.o
  "_kCVPixelBufferPixelFormatTypeKey", referenced from:
      _kCVPixelBufferPixelFormatTypeKey$non_lazy_ptr in MainViewController.o
     (maybe you meant: _kCVPixelBufferPixelFormatTypeKey$non_lazy_ptr)
  "_CVPixelBufferGetWidth", referenced from:
      -[MainViewController imageFromSampleBuffer:] in MainViewController.o
  "_CVPixelBufferGetBytesPerRow", referenced from:
      -[MainViewController imageFromSampleBuffer:] in MainViewController.o
  "_CMTimeMake", referenced from:
      -[MainViewController setupCaptureSession] in MainViewController.o
  "_CVPixelBufferGetDataSize", referenced from:
      -[MainViewController imageFromSampleBuffer:] in MainViewController.o
ld: symbol(s) not found
collect2: ld returned 1 exit status

CompileC "build/my project.build/Debug-iphoneos/my project.build/Objects-normal/armv7/MainViewController.o" /Users/mwilliamson/Projects/my_project/iphone/Classes/MainViewController.m normal armv7 objective-c com.apple.compilers.gcc.4_2
cd /Users/mwilliamson/Projects/my_project/iphone
setenv LANG en_US.US-ASCII
setenv PATH "/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin:/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/X11/bin:/opt/local/bin:/usr/local/git/bin"
/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/gcc-4.2 -x objective-c -arch armv7 -fmessage-length=0 -pipe -std=c99 -Wno-trigraphs -fpascal-strings -O0 -Wreturn-type -Wunused-variable -isysroot /Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS4.0.sdk -fvisibility=hidden -gdwarf-2 -mthumb -miphoneos-version-min=4.0 -iquote "/Users/mwilliamson/Projects/my_project/iphone/build/my project.build/Debug-iphoneos/my project.build/my project-generated-files.hmap" "-I/Users/mwilliamson/Projects/my_project/iphone/build/my project.build/Debug-iphoneos/my project.build/my project-own-target-headers.hmap" "-I/Users/mwilliamson/Projects/my_project/iphone/build/my project.build/Debug-iphoneos/my project.build/my project-all-target-headers.hmap" -iquote "/Users/mwilliamson/Projects/my_project/iphone/build/my project.build/Debug-iphoneos/my project.build/my project-project-headers.hmap" -F/Users/mwilliamson/Projects/my_project/iphone/build/Debug-iphoneos -I/Users/mwilliamson/Projects/my_project/iphone/build/Debug-iphoneos/include -I/Users/mwilliamson/Projects/my_project/iphone/opencv_device/include "-I/Users/mwilliamson/Projects/my_project/iphone/build/my project.build/Debug-iphoneos/my project.build/DerivedSources/armv7" "-I/Users/mwilliamson/Projects/my_project/iphone/build/my project.build/Debug-iphoneos/my project.build/DerivedSources" -include /var/folders/kW/kW6u6B7SGyGYu+nNumtIa++++TI/-Caches-/com.apple.Xcode.501/SharedPrecompiledHeaders/my_project_Prefix-gtrotaxhqdjhgqbqbsnyeqjkaxdt/my_project_Prefix.pch -c /Users/mwilliamson/Projects/my_project/iphone/Classes/MainViewController.m -o "/Users/mwilliamson/Projects/my_project/iphone/build/my project.build/Debug-iphoneos/my project.build/Objects-normal/armv7/MainViewController.o"

/Users/mwilliamson/Projects/my_project/iphone/Classes/MainViewController.m: In function '-[MainViewController captureOutput:didOutputSampleBuffer:fromConnection:]':
/Users/mwilliamson/Projects/my_project/iphone/Classes/MainViewController.m:126: warning: 'MainViewController' may not respond to '-imageFromSampleBuffer:'
/Users/mwilliamson/Projects/my_project/iphone/Classes/MainViewController.m:126: warning: (Messages without a matching method signature
/Users/mwilliamson/Projects/my_project/iphone/Classes/MainViewController.m:126: warning: will be assumed to return 'id' and accept
/Users/mwilliamson/Projects/my_project/iphone/Classes/MainViewController.m:126: warning: '...' as arguments.)

Ld "build/my project.build/Debug-iphoneos/my project.build/Objects-normal/armv7/my project" normal armv7
cd /Users/mwilliamson/Projects/my_project/iphone
setenv IPHONEOS_DEPLOYMENT_TARGET 4.0
setenv PATH "/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin:/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/X11/bin:/opt/local/bin:/usr/local/git/bin"
/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/gcc-4.2 -arch armv7 -isysroot /Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS4.0.sdk -L/Users/mwilliamson/Projects/my_project/iphone/build/Debug-iphoneos -F/Users/mwilliamson/Projects/my_project/iphone/build/Debug-iphoneos -filelist "/Users/mwilliamson/Projects/my_project/iphone/build/my project.build/Debug-iphoneos/my project.build/Objects-normal/armv7/my project.LinkFileList" -dead_strip -lz -lstdc++ /Users/mwilliamson/Projects/my_project/iphone/opencv_device/lib/libcxcore.a /Users/mwilliamson/Projects/my_project/iphone/opencv_device/lib/libcv.a -miphoneos-version-min=4.0 -framework Foundation -framework UIKit -framework CoreGraphics -framework AVFoundation -o "/Users/mwilliamson/Projects/my_project/iphone/build/my project.build/Debug-iphoneos/my project.build/Objects-normal/armv7/my project"

Undefined symbols:
  "_CVPixelBufferGetBaseAddress", referenced from:
      -[MainViewController imageFromSampleBuffer:] in MainViewController.o
  "_CVPixelBufferUnlockBaseAddress", referenced from:
      -[MainViewController imageFromSampleBuffer:] in MainViewController.o
  "_CVPixelBufferLockBaseAddress", referenced from:
      -[MainViewController imageFromSampleBuffer:] in MainViewController.o
  "_CMSampleBufferGetImageBuffer", referenced from:
      -[MainViewController imageFromSampleBuffer:] in MainViewController.o
  "_CVPixelBufferGetHeight", referenced from:
      -[MainViewController imageFromSampleBuffer:] in MainViewController.o
  "_kCVPixelBufferPixelFormatTypeKey", referenced from:
      _kCVPixelBufferPixelFormatTypeKey$non_lazy_ptr in MainViewController.o
     (maybe you meant: _kCVPixelBufferPixelFormatTypeKey$non_lazy_ptr)
  "_CVPixelBufferGetWidth", referenced from:
      -[MainViewController imageFromSampleBuffer:] in MainViewController.o
  "_CVPixelBufferGetBytesPerRow", referenced from:
      -[MainViewController imageFromSampleBuffer:] in MainViewController.o
  "_CMTimeMake", referenced from:
      -[MainViewController setupCaptureSession] in MainViewController.o
  "_CVPixelBufferGetDataSize", referenced from:
      -[MainViewController imageFromSampleBuffer:] in MainViewController.o
ld: symbol(s) not found
collect2: ld returned 1 exit status
4

2 回答 2

76

再一次，我回答了我自己的问题……我还需要添加 CoreVideo 和 CoreMedia 框架。

于 2010-08-03T02:45:32.153 回答
2

我花了几个小时来解决这个问题的一个变体。我发布此内容是为了帮助可能处于相同情况的其他人。我已经将 CoreVideo 和 CoreMedia 链接到我的项目。但是，我仍然遇到这个问题。经过大量搜索和尝试不同的事情后，我发现了这篇文章。这是我的修复：

1）删除有问题的库（在我的例子中是CoreVideo和CoreMedia）。通过在项目导航中删除它们并选择“删除引用”并在“构建阶段”中从链接框架中删除它们来执行此操作

2）再次添加框架，清理并重新编译。

于 2013-06-04T18:54:17.693 回答