OpenCV VideoCapture can't read from my webcam at all
I'm using OpenCV 2.4.6 on Ubuntu 13.04 (on an Acer C7 Chromebook), and I'm using a simple test program to see if my webcam will work with OpenCV. It works fine with Cheese and Skype, so I know that the webcam itself isn't the issue.
Here is my code (which compiles without any errors):
#include "opencv2/opencv.hpp"
#include <stdio.h>
#include <stdlib.h>
using namespace std;
using namespace cv;
int main(int argc, char *argv[])
{
cv::VideoCapture cap;
if(argc > 1)
{
cap.open(string(argv[1]));
}
else
{
cap.open(CV_CAP_ANY);
}
if(!cap.isOpened())
{
printf("Error: could not load a camera or video.n");
}
Mat frame;
namedWindow("video", 1);
for(;;)
{
waitKey(20);
cap >> frame;
if(!frame.data)
{
printf("Error: no frame data.n");
break;
}
imshow("video", frame);
}
}
If I run the program without any arguments (since I want it to use CV_CAP_ANY), I get
Error: could not load a camera or video.
init done
opengl support available
libpng warning: Application built with libpng-1.2.49 but running with 1.5.12
libpng warning: Application built with libpng-1.2.49 but running with 1.5.12
libpng warning: Application built with libpng-1.2.49 but running with 1.5.12
libpng warning: Application built with libpng-1.2.49 but running with 1.5.12
libpng warning: Application built with libpng-1.2.49 but running with 1.5.12
libpng warning: Application built with libpng-1.2.49 but running with 1.5.12
libpng warning: Application built with libpng-1.2.49 but running with 1.5.12
libpng warning: Application built with libpng-1.2.49 but running with 1.5.12
libpng warning: Application built with libpng-1.2.49 but running with 1.5.12
libpng warning: Application built with libpng-1.2.49 but running with 1.5.12
Error: no frame data.
If I specify /dev/video0 (my only camera) as the argument, I get
demux_wavpack: (open_wv_file:127) open_wv_file: non-seekable inputs aren't supported yet.
(ERROR)icvOpenAVI_XINE(): Unable to open source '/dev/video0'
init done
opengl support available
libpng warning: Application built with libpng-1.2.49 but running with 1.5.12
libpng warning: Application built with libpng-1.2.49 but running with 1.5.12
libpng warning: Application built with libpng-1.2.49 but running with 1.5.12
libpng warning: Application built with libpng-1.2.49 but running with 1.5.12
libpng warning: Application built with libpng-1.2.49 but running with 1.5.12
libpng warning: Application built with libpng-1.2.49 but running with 1.5.12
libpng warning: Application built with libpng-1.2.49 but running with 1.5.12
libpng warning: Application built with libpng-1.2.49 but running with 1.5.12
libpng warning: Application built with libpng-1.2.49 but running with 1.5.12
libpng warning: Application built with libpng-1.2.49 but running with 1.5.12
GStreamer Plugin: Embedded video playback halted; module source reported: Could not read from resource.
Error: no frame data.
If I specify the path to a video file as the argument, it plays the video just fine.
I'd appreciate any help. Thanks in advance!
There is a bug on Opencv 2.4.6 please take a look here
moreover try this: cv::VideoCapture cap = cv::VideoCapture(0);
Hope it helped !
您可以尝试将waitKey(20)值更改为20，直到80.某台计算机的值为20,30,40,50 ....