OK4418开发板qt opencv 如何调用USB摄像头

njxnet

开发板移植了opencv2.4.9。
QT代码如下：
widget.h

1. #ifndef WIDGET_H
   
2. #define WIDGET_H
   
3. 
   
4. #include <QWidget>
   
5. 
   
6. #include <QImage>
   
7. #include <QTimer>     // 设置采集数据的间隔时间
   
8. 
   
9. #include <opencv/highgui.h>  //包含opencv库头文件
   
10. #include <opencv/cv.h>
    
11. 
    
12. namespace Ui {
    
13. class Widget;
    
14. }
    
15. 
    
16. class Widget : public QWidget
    
17. {
    
18.     Q_OBJECT
    
19. 
    
20. public:
    
21.     explicit Widget(QWidget *parent = 0);
    
22.     ~Widget();
    
23. 
    
24. private slots:
    
25.     void openCamara();      // 打开摄像头
    
26.     void readFarme();       // 读取当前帧信息
    
27.     void closeCamara();     // 关闭摄像头。
    
28.     void takingPictures();  // 拍照
    
29. 
    
30. private:
    
31.     Ui::Widget *ui;
    
32.     QTimer    *timer;
    
33.     QImage    *imag;
    
34.     CvCapture *cam;// 视频获取结构， 用来作为视频获取函数的一个参数
    
35.     IplImage  *frame;//申请IplImage类型指针，就是申请内存空间来存放每一帧图像
    
36. };
    
37. 
    
38. #endif // WIDGET_H
    

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widget.cpp

1. #include "widget.h"
   
2. #include "ui_widget.h"
   
3. 
   
4. Widget::Widget(QWidget *parent) :
   
5.     QWidget(parent),
   
6.     ui(new Ui::Widget)
   
7. {
   
8.     ui->setupUi(this);
   
9. 
   
10.     cam = NULL ;
    
11.     timer = new QTimer(this);
    
12.     imag = new QImage();
    
13. 
    
14.     connect(timer,SIGNAL(timeout()),this,SLOT(readFarme()));   //时间到，读取当前摄像头信息
    
15.     connect(ui->OpenCameraPushButton,SIGNAL(clicked()),this,SLOT(openCamara()));
    
16.     connect(ui->TakePhotoPushButton,SIGNAL(clicked()),this,SLOT(takingPictures()));
    
17.     connect(ui->CloseCameraPushButton,SIGNAL(clicked()),this,SLOT(closeCamara()));
    
18. 
    
19. }
    
20. 
    
21. void Widget::openCamara()
    
22. {
    
23.     cam = cvCreateCameraCapture(-1);  //打开摄像头，从摄像头中获取视频
    
24.     timer->start(33);                // 开始计时，超时则发出timeout()信号
    
25. }
    
26. 
    
27. void Widget::readFarme()
    
28. {
    
29.     frame = cvQueryFrame(cam);
    
30. 
    
31.     QImage image((const uchar*)frame->imageData, frame->width,frame->height,QImage::Format_RGB888);
    
32. 
    
33.     ui->label->setPixmap(QPixmap::fromImage(image));
    
34. }
    
35. 
    
36. void Widget::takingPictures()
    
37. {
    
38.     frame = cvQueryFrame(cam);
    
39. 
    
40.     QImage image((const uchar*)frame->imageData, frame->width,frame->height,QImage::Format_RGB888);
    
41. 
    
42.     ui->label_2->setPixmap(QPixmap::fromImage(image));
    
43. }
    
44. 
    
45. void Widget::closeCamara()
    
46. {
    
47.     timer->stop();
    
48. 
    
49.     cvReleaseCapture(&cam);
    
50. }
    
51. 
    
52. Widget::~Widget()
    
53. {
    
54.     delete ui;
    
55.     delete timer;
    
56.     delete imag;
    
57.     delete frame;
    
58. }
    

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main.cpp

1. #include "widget.h"
   
2. #include <QApplication>
   
3. 
   
4. int main(int argc, char *argv[])
   
5. {
   
6.     QApplication a(argc, argv);
   
7.     Widget w;
   
8.     w.show();
   
9. 
   
10.     return a.exec();
    
11. }
    

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.pro

1. #-------------------------------------------------
   
2. #
   
3. # Project created by QtCreator 2019-03-21T20:20:55
   
4. #
   
5. #-------------------------------------------------
   
6. 
   
7. QT       += core gui
   
8. 
   
9. greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
   
10. 
    
11. TARGET = Opencv_pro1
    
12. TEMPLATE = app
    
13. 
    
14. 
    
15. SOURCES += main.cpp\
    
16.         widget.cpp
    
17. 
    
18. INCLUDEPATH += /usr/local/opencv/install_opencv/include/\
    
19.             /usr/local/opencv/install_opencv/include/opencv\
    
20.             /usr/local/opencv/install_opencv/include/opencv2
    
21. 
    
22. 
    
23. LIBS += /usr/local/opencv/install_opencv/lib/libopencv_calib3d.so\
    
24.         /usr/local/opencv/install_opencv/lib/libopencv_contrib.so\
    
25.         /usr/local/opencv/install_opencv/lib/libopencv_core.so\
    
26.         /usr/local/opencv/install_opencv/lib/libopencv_features2d.so\
    
27.         /usr/local/opencv/install_opencv/lib/libopencv_flann.so\
    
28.         /usr/local/opencv/install_opencv/lib/libopencv_gpu.so\
    
29.         /usr/local/opencv/install_opencv/lib/libopencv_highgui.so \
    
30.         /usr/local/opencv/install_opencv/lib/libopencv_imgproc.so\
    
31.         /usr/local/opencv/install_opencv/lib/libopencv_legacy.so\
    
32.         /usr/local/opencv/install_opencv/lib/libopencv_ml.so\
    
33.         /usr/local/opencv/install_opencv/lib/libopencv_nonfree.so\
    
34.         /usr/local/opencv/install_opencv/lib/libopencv_objdetect.so\
    
35.         /usr/local/opencv/install_opencv/lib/libopencv_ocl.so\
    
36.         /usr/local/opencv/install_opencv/lib/libopencv_photo.so\
    
37.         /usr/local/opencv/install_opencv/lib/libopencv_stitching.so\
    
38.         /usr/local/opencv/install_opencv/lib/libopencv_superres.so\
    
39.         /usr/local/opencv/install_opencv/lib/libopencv_video.so\
    
40.         /usr/local/opencv/install_opencv/lib/libopencv_videostab.so
    
41. 
    
42. 
    
43. HEADERS  += widget.h
    
44. 
    
45. FORMS    += widget.ui
    

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出现的问题：交叉编译移植ARM，点击PushButton打开摄像头，超级终端一直输出 VIDIOC_QUERYCTRL: Inappropriate ioctl for device

飞凌-chongzi

很抱歉，没有遇到过类似问题
是兼容性问题吗？uvc驱动里有VIDIOC_QUERYCTRL

七月

遇到同样的问题，贴主解决了么？