How can i know the camera whose the id parameter of VideoCapture function are pointing out? I need to find a default on the id, because I need know if the webcam is the default installed at windows or anyone plugged there.
it works like this:
there is a list of devices, populated from your os, and invisible to you (sad as it is) , and your webcams appear there in the order you plugged them in.
so, if you're e.g on a laptop with a builtin camera, that will be id 0, if you plug in an additional one, that's id 1.
note, that in theory, you could also try -1 for id, which will fall back from default directshow code to arcane VFW(which is problematic on later win versions), and give you a box to choose from available devices.
I have try :
VideoCapture vid1(-1);
VideoCapture vid2(-1);
if (vid1.isOpened() && vid2.isOpened())
{
for (char c=0;c!=27;)
{
Mat frame1,frame2;
vid1 >> frame1;
vid2 >> frame2;
imshow("vid1", frame1);
imshow("vid2", frame2);
c=waitKey(1);
}
}
and it is working now with win vs2015 and opencv 3.1-dev
Asked: 2016-10-14 09:54:11 -0600
Seen: 2,548 times
Last updated: Oct 14 '16
