opencv播放器和摄像头视频播放

在看《学习opencv》这本书，按着其中的例子和写了一个播放器和摄像头播放，代码如下

#include <opencv/cv.h>
#include <opencv/highgui.h>
#include <iostream>
#include <sstream>

using namespace std;
using namespace cv;

#define ESC 27

CvCapture* g_cvFileCap = 0;
CvCapture* g_cvCameraCap = 0;
int g_pos = 0;

int String2Int(const string& str_)
{
int _re = 0;
stringstream _ss;
_ss << str_;
_ss >> _re;
return _re;
}

void OnTrackbarSlide(int nPos_)
{
cvSetCaptureProperty(g_cvFileCap, CV_CAP_PROP_POS_FRAMES, nPos_);
}

int main(int argc, char* argv[])
{
if (argc < 3)
{
return -1;
}

int _re = String2Int(argv[1]);
if (_re == 0)
{
g_cvFileCap = cvCreateFileCapture(argv[2]);
if (g_cvFileCap != NULL)
{
cvNamedWindow("AVWidget");
cvMoveWindow("AVWidget", 100, 100);
int _nFrames = cvGetCaptureProperty(g_cvFileCap, CV_CAP_PROP_FRAME_COUNT);
cvCreateTrackbar("Pos", "AVWidget", &g_pos, _nFrames, OnTrackbarSlide);
while (1) {
IplImage* _frame = cvQueryFrame(g_cvFileCap);
if (_frame != NULL)
{
if (ESC == waitKey(1000 / 25))
{
break;
}
cvSmooth(_frame, _frame);
cvShowImage("AVWidget", _frame);
cvSetTrackbarPos("Pos", "AVWidget", g_pos++);

}

}

}
cvReleaseCapture(&g_cvFileCap);
} else {
int _index = String2Int(argv[2]);
g_cvCameraCap = cvCreateCameraCapture(_index);
if (g_cvCameraCap != NULL)
{
cvNamedWindow("CamWidget");
cvMoveWindow("CamWidget", 100, 100);
while (1) {
IplImage* _frame = cvQueryFrame(g_cvCameraCap);
if (_frame != NULL)
{
if (ESC == waitKey(1000 / 25))
{
break;
}
cvSmooth(_frame, _frame);
cvShowImage("CamWidget", _frame);
}

}
}
cvReleaseCapture(&g_cvCameraCap);
}

return 0;
}

通过传入参数实现打开那个视频和摄像头，当参数为 0 xxxx时，打开视频，参数为1 x打开第几个摄像头。



效果行。打开摄像头就算了。

其实使用opencv很方便。通过cvCreateFileCapture和cvQueryFrame就完成了视频文件的读取。操作摄像头唯一的不同是cvCreateCameraCapture，很方便。