Chief Delphi - Switching Camera Views

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- Java (http://www.chiefdelphi.com/forums/forumdisplay.php?f=184)

- - Switching Camera Views (http://www.chiefdelphi.com/forums/showthread.php?t=154213)

Switching Camera Views

I would like to know if it is possible to change the current camera display programmatically. What I would like to achieve as the end result is having two cameras, one forward, one backward, that switch based on the direction the robot is currently moving (with a manual override).

I currently am able to manually change the view by selecting the desired view from the drop-down menu on the dashboard, and may display both simultaneously if I wish.

Re: Switching Camera Views

You can do something like this (edited from the screensteps page):

Code:

public void robotInit() {

            new Thread(() -> {

                UsbCamera camera1 = CameraServer.getInstance().startAutomaticCapture(0);

                camera1.setResolution(640, 480);

                UsbCamera camera2 = CameraServer.getInstance().startAutomaticCapture(1);

                camera2.setResolution(640, 480);

                

                CvSink cvSink1 = CameraServer.getInstance().getVideo(camera1);

                CvSink cvSink2 = CameraServer.getInstance().getVideo(camera2);

                CvSource outputStream = CameraServer.getInstance().putVideo("Switcher", 640, 480);

                

                Mat image = new Mat();

                

                while(!Thread.interrupted()) {

                    if(/*switcher button logic*/){

                      cvSink1.grabFrame(image);

                    } else{

                      cvSink2.grabFrame(image);

                    }

                    

                    outputStream.putFrame(image);

                }

            }).start();

    }

I'm tired, so this is all I can think of now. The code may not be entirely right, but the general idea should work. There probably is a much better/simpler/more efficient way that I have no clue about.

Re: Switching Camera Views

The above code gets you about 90% of the way their, but still runs into USB bandwidth issues. I modified the code slightly and now have switching cameras working very well, with the occasional error message, but nothing fatal.

Code:

public void robotInit() {

            

            Thread t = new Thread(() -> {

                    

                    boolean allowCam1 = false;

                    

                    UsbCamera camera1 = CameraServer.getInstance().startAutomaticCapture(0);

            camera1.setResolution(320, 240);

            camera1.setFPS(30);

            UsbCamera camera2 = CameraServer.getInstance().startAutomaticCapture(1);

            camera2.setResolution(320, 240);

            camera2.setFPS(30);

            

            CvSink cvSink1 = CameraServer.getInstance().getVideo(camera1);

            CvSink cvSink2 = CameraServer.getInstance().getVideo(camera2);

            CvSource outputStream = CameraServer.getInstance().putVideo("Switcher", 320, 240);

            

            Mat image = new Mat();

            

            while(!Thread.interrupted()) {

                    

                    if(oi.getGamepad().getRawButton(9)) {

                            allowCam1 = !allowCam1;

                    }

                    

                if(allowCam1){

                  cvSink2.setEnabled(false);

                  cvSink1.setEnabled(true);

                  cvSink1.grabFrame(image);

                } else{

                  cvSink1.setEnabled(false);

                  cvSink2.setEnabled(true);

                  cvSink2.grabFrame(image);     

                }

                

                outputStream.putFrame(image);

            }

            

        });

        t.start();

Re: Switching Camera Views

When I attempt to add the switcher, I get a large number of errors and warnings. Something like unable to set FPS or unable to set resolution. It's really irritating, the errors go away when I comment out the switching code, but the dashboard still shows >30 FPS for both cameras, and higher resolution (even though my code sets the resolution and FPS lower).

I am using two Lifecam 3000s if it matters.

Re: Switching Camera Views

On the dashboard are you streaming the Switcher? If you try to stream just the default USB cameras, you will get errors.