How to launch two csi cameras in one pipeline gstremer and synchronize their settings?

C++
,
1

I have changed the default example opencvcap, but it still only displayed one camera? How can I make output of two cameras right and left in one window cv cap?

" gst-launch-1.0 max-buffers=1 drop=true sync=false" 
" v4l2src device=/dev/video"+ std::to_string(device_1) + " !" 
" video/x-raw," 
" width=(int)" + std::to_string(capture_width) + "," 
" height=(int)" + std::to_string(capture_height) + "," 
" format=GRAY8," 
" framerate=(fraction)" + std::to_string(framerate) +"/1 !" 
" appsink" 
" v4l2src device=/dev/video"+ std::to_string(device_2) + " !" 
" video/x-raw," 
" width=(int)" + std::to_string(capture_width) + "," 
" height=(int)" + std::to_string(capture_height) + "," 
" format=GRAY8," 
" framerate=(fraction)" + std::to_string(framerate) +"/1 !" 
" appsink";
2

Why don’t you use the included VideoCapture class?

cv::VideoCapture camA(0),camB(1);
if((!camA.isOpened)||(!camB.isOpened)) {
    std::cout<<"Camera error"<<std::endl;
    return;
}
cv::Mat frame1,frameB,frame;
camA>>frameA;
camB>>frameB;

If you want to show them in one window, just concatenate them:

hconcat(frameA,frameB,frame);
imshow("Frame",frame);

Normally your cameras are managed by V4L2 and have the addresses /dev/video0 and /dev/video1.

4

It seems this is what I was looking for.

 " gst-launch-1.0 -e"
            " v4l2src device=/dev/video0 ! videorate !"     
            " video/x-raw,"
            " width=(int)640,"
            " height=(int)400,"
            " format=GRAY8,"
            " framerate=(fraction)50/1 !"
            " m.sink_0"
            " v4l2src device=/dev/video2 ! videorate !"
            " video/x-raw,"
            " width=(int)640,"
            " height=(int)400,"
            " format=GRAY8,"
            " framerate=(fraction)50/1 !"
            " m.sink_1"
            " glvideomixer name=m sink_1::xpos=640 ! video/x-raw, width=(int)1280, height=(int)400, format=GRAY8, framerate=(fraction)50/1 !"
            " appsink max-buffers=1 drop=true sync=false";