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

[Userpc1010]

I have changed the default example opencvcap, but it still only works with one camera?

            " 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";

[Qengineering]

Check with v4l2-ctl --device=/dev/video1 -D --list-formats-ext if you have a video source living at /dev/video1.
If so, try hard-coded " v4l2src device=/dev/video1" instead of " v4l2src device=/dev/video"+ std::to_string(device_1)