c++ - QTKit 没有找到任何附加的视频输入设备

Question

每当我尝试运行 simple application to grab frames from the camera 时都会出现以下错误Macbook Pro 13"(内置 iSight):

QTKit didn't find any attached Video Input Devices!
Warning, camera failed to properly initialize!
Cleaned up camera.

我试过将 -1、0 和作为参数传递给 cvCreateCameraCapture() 和 cv::VideoCapture 对象，但没有成功。重要的是要说我在这台机器上使用 OpenCV 2.3.1 很长一段时间，它在传递 -1 作为参数时运行良好。

这个问题似乎发生在 Mac OS X 10.7.5 上的 OpenCV v2.4.2 和 v2.4.3 上。

有什么想法吗？

编辑:

经过一些研究，我发现 QTKit is the QuickTime Kit与Qt无关.因此，下一个合乎逻辑的做法是从 OpenCV 构建中禁用 QTKit，方法是通过标记 -DWITH_QUICKTIME=YES，这会强制 OpenCV使用 QuickTime for Video I/O 而不是 QTKit 构建。

不幸的是，这个解决方案也没有用，因为它导致了几个我不想处理的编译错误:

[ 32%] Building CXX object modules/highgui/CMakeFiles/opencv_highgui.dir/src/cap_qt.cpp.o
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:75: error: ‘Movie’ does not name a type
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp: In function ‘CvCapture_QT_Movie* icvCaptureFromFile_QT(const char*)’:
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:100: warning: declaration of ‘did_enter_movies’ shadows a global declaration [-Wshadow]
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:67: warning: shadowed declaration is here [-Wshadow]
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:103: error: ‘EnterMovies’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp: In function ‘int icvOpenFile_QT_Movie(CvCapture_QT_Movie*, const char*)’:
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:142: error: ‘ClearMoviesStickyError’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:145: error: ‘struct CvCapture_QT_Movie’ has no member named ‘myMovie’
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:161: error: ‘kQTPOSIXPathStyle’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:161: error: ‘QTNewDataReferenceFromFullPathCFString’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:169: error: ‘struct CvCapture_QT_Movie’ has no member named ‘myMovie’
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:169: error: ‘newMovieActive’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:169: error: ‘newMovieAsyncOK’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:170: error: ‘NewMovieFromDataRef’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:190: error: ‘struct CvCapture_QT_Movie’ has no member named ‘myMovie’
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:190: error: ‘nextTimeMediaSample’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:190: error: ‘nextTimeEdgeOK’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:191: error: ‘GetMovieNextInterestingTime’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:205: error: ‘struct CvCapture_QT_Movie’ has no member named ‘myMovie’
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:212: error: ‘GetMoviesError’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:213: error: ‘struct CvCapture_QT_Movie’ has no member named ‘myMovie’
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:213: error: ‘GetMovieBox’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:218: error: ‘QTNewGWorld’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:220: error: ‘struct CvCapture_QT_Movie’ has no member named ‘myMovie’
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:220: error: ‘SetMovieGWorld’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp: In function ‘int icvClose_QT_Movie(CvCapture_QT_Movie*)’:
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:243: error: ‘struct CvCapture_QT_Movie’ has no member named ‘myMovie’
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:247: error: ‘DisposeGWorld’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:248: error: ‘struct CvCapture_QT_Movie’ has no member named ‘myMovie’
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:248: error: ‘DisposeMovie’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp: In function ‘double icvGetProperty_QT_Movie(CvCapture_QT_Movie*, int)’:
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:264: error: ‘struct CvCapture_QT_Movie’ has no member named ‘myMovie’
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:281: error: ‘struct CvCapture_QT_Movie’ has no member named ‘myMovie’
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:281: error: ‘GetMovieTimeScale’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:286: error: ‘struct CvCapture_QT_Movie’ has no member named ‘myMovie’
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:286: error: ‘GetMovieDuration’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:300: error: ‘struct CvCapture_QT_Movie’ has no member named ‘myMovie’
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:300: error: ‘GetMovieDuration’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:301: error: ‘struct CvCapture_QT_Movie’ has no member named ‘myMovie’
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:301: error: ‘GetMovieTimeScale’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp: In function ‘int icvSetProperty_QT_Movie(CvCapture_QT_Movie*, int, double)’:
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:331: error: ‘struct CvCapture_QT_Movie’ has no member named ‘myMovie’
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:351: error: ‘struct CvCapture_QT_Movie’ has no member named ‘myMovie’
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:351: error: ‘GetMovieTimeScale’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:356: error: ‘struct CvCapture_QT_Movie’ has no member named ‘myMovie’
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:356: error: ‘GetMovieDuration’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:370: error: ‘struct CvCapture_QT_Movie’ has no member named ‘myMovie’
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:370: error: ‘nextTimeStep’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:371: error: ‘GetMovieNextInterestingTime’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:372: error: ‘GetMoviesError’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:385: error: ‘struct CvCapture_QT_Movie’ has no member named ‘myMovie’
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:385: error: ‘nextTimeStep’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:386: error: ‘GetMovieNextInterestingTime’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:387: error: ‘GetMoviesError’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:408: error: ‘struct CvCapture_QT_Movie’ has no member named ‘myMovie’
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:408: error: ‘nextTimeStep’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:409: error: ‘GetMovieNextInterestingTime’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:410: error: ‘GetMoviesError’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp: In function ‘int icvGrabFrame_QT_Movie(CvCapture_QT_Movie*)’:
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:441: error: ‘struct CvCapture_QT_Movie’ has no member named ‘myMovie’
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:449: error: ‘struct CvCapture_QT_Movie’ has no member named ‘myMovie’
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:449: error: ‘SetMovieTimeValue’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:450: error: ‘GetMoviesError’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:458: error: ‘struct CvCapture_QT_Movie’ has no member named ‘myMovie’
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:458: error: ‘GetMovieTime’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:462: error: ‘struct CvCapture_QT_Movie’ has no member named ‘myMovie’
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:462: error: ‘nextTimeStep’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:462: error: ‘GetMovieNextInterestingTime’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp: In function ‘const void* icvRetrieveFrame_QT_Movie(CvCapture_QT_Movie*, int)’:
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:484: error: ‘struct CvCapture_QT_Movie’ has no member named ‘myMovie’
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:494: error: ‘struct CvCapture_QT_Movie’ has no member named ‘myMovie’
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:494: error: ‘UpdateMovie’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:495: error: ‘GetMoviesError’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:503: error: ‘struct CvCapture_QT_Movie’ has no member named ‘myMovie’
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:503: error: ‘MoviesTask’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:515: error: ‘GetGWorldPixMap’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:516: error: ‘LockPixels’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:517: error: ‘GetPixBaseAddr’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:517: error: ‘GetPixRowBytes’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:523: error: ‘UnlockPixels’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp: At global scope:
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:556: error: ‘SeqGrabComponent’ does not name a type
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:557: error: ‘SGChannel’ does not name a type
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:560: error: ‘ImageSequence’ does not name a type
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp: In function ‘CvCapture_QT_Cam* icvCaptureFromCam_QT(int)’:
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:590: error: ‘EnterMovies’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp: At global scope:
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:609: warning: unused parameter ‘capture’ [-Wunused-parameter]
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:609: warning: unused parameter ‘property_id’ [-Wunused-parameter]
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:616: warning: unused parameter ‘capture’ [-Wunused-parameter]
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:616: warning: unused parameter ‘property_id’ [-Wunused-parameter]
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:616: warning: unused parameter ‘value’ [-Wunused-parameter]
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:853: error: ‘SGChannel’ was not declared in this scope
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:853: error: expected primary-expression before ‘raw_data’
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:853: error: expected primary-expression before ‘long’
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:853: error: expected primary-expression before ‘long’
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:853: error: expected primary-expression before ‘long’
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:853: error: expected primary-expression before ‘,’ token
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:853: error: expected primary-expression before ‘short’
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:853: error: expected primary-expression before ‘long’
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:853: error: initializer expression list treated as compound expression
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:854: error: expected ‘,’ or ‘;’ before ‘{’ token
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:238: warning: ‘int icvClose_QT_Movie(CvCapture_QT_Movie*)’ defined but not used
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:261: warning: ‘double icvGetProperty_QT_Movie(CvCapture_QT_Movie*, int)’ defined but not used
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:328: warning: ‘int icvSetProperty_QT_Movie(CvCapture_QT_Movie*, int, double)’ defined but not used
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:438: warning: ‘int icvGrabFrame_QT_Movie(CvCapture_QT_Movie*)’ defined but not used
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:481: warning: ‘const void* icvRetrieveFrame_QT_Movie(CvCapture_QT_Movie*, int)’ defined but not used
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:98: warning: ‘CvCapture_QT_Movie* icvCaptureFromFile_QT(const char*)’ defined but not used
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:572: warning: ‘int icvOpenCamera_QT(CvCapture_QT_Cam*, int)’ declared ‘static’ but never defined
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:573: warning: ‘int icvClose_QT_Cam(CvCapture_QT_Cam*)’ declared ‘static’ but never defined
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:609: warning: ‘double icvGetProperty_QT_Cam(CvCapture_QT_Cam*, int)’ defined but not used
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:616: warning: ‘int icvSetProperty_QT_Cam(CvCapture_QT_Cam*, int, double)’ defined but not used
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:576: warning: ‘int icvGrabFrame_QT_Cam(CvCapture_QT_Cam*)’ declared ‘static’ but never defined
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:577: warning: ‘const void* icvRetrieveFrame_QT_Cam(CvCapture_QT_Cam*, int)’ declared ‘static’ but never defined
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:586: warning: ‘CvCapture_QT_Cam* icvCaptureFromCam_QT(int)’ defined but not used
/OpenCV-2.4.3/modules/highgui/src/cap_qt.cpp:853: warning: ‘icvDataProc_QT_Cam’ defined but not used
make[2]: *** [modules/highgui/CMakeFiles/opencv_highgui.dir/src/cap_qt.cpp.o] Error 1
make[1]: *** [modules/highgui/CMakeFiles/opencv_highgui.dir/all] Error 2
make: *** [all] Error 2

Answer 1

I reported this problem但现在我认为它可能特定于我的系统，我将尝试执行更多测试以清除它。

无论如何，这是我必须解决的问题:

编辑modules/highgui/src/cap_qtkit.mm并跳转到第313行查看实现:

int CvCaptureCAM::startCaptureDevice(int cameraNum) {

我们将对此方法进行更改，因此找到以下 block :

if (cameraNum >= 0) { 
    int nCameras = [devices count];
    if( cameraNum < 0 || cameraNum >= nCameras )   
        return 0;
    device = [devices objectAtIndex:cameraNum] ;
} else {
    device = [QTCaptureDevice defaultInputDeviceWithMediaType:QTMediaTypeVideo]  ;
} 

并替换为:

if (cameraNum >= 0) { 
    int nCameras = [devices count];
    if( cameraNum > nCameras )
        return 0;
    cameraNum--;
    device = [devices objectAtIndex:cameraNum] ;
} else {
    device = [QTCaptureDevice defaultInputDeviceWithMediaType:QTMediaTypeVideo]  ;
} 

重新编译 OpenCV，不要忘记在您的系统上再次安装它。