OpenCV stream from raspberry pi

display.cpp

#include "opencv2/highgui/highgui.hpp"

#include <iostream>
#include <stdio.h>

using namespace std;
using namespace cv;


int main( int argc, const char** argv )
{
    cout << "Starting..." << std::endl;
    CvCapture* URL= cvCreateFileCapture("/path/to/my/pipe/here");
    cout << "loaded pipe" << std::endl;
    Mat image;
    while (true) {

        image = cvQueryFrame(URL);
        if(! image.data )                              // Check for invalid input
        {
            cout <<  "Could not open or find the image" << std::endl ;
            return -1;
        }
    
        namedWindow( "Display window", CV_WINDOW_AUTOSIZE );// Create a window for display.
        imshow( "Display window", image );                   // Show our image inside it.
    
        cvWaitKey(1);                                          // Wait for a keystroke in the window
    }
    return 0;
}

Instructions.md

1. Build display.cpp
2. Set up pipe on Linux VM
3. Run display application
4. Run proxy/passthrough on Mac
5. Start streaming from Raspberry Pi

On Linux VM Shell 1

# On Linux VM
rm my_pipe; mkfifo my_pipe; nc -q 5 -l 5001 > my_pipe

On Linux VM Shell 2

./display

On Mac

# On Mac
nc -l 5002 | nc <your VM's ip> 5001

On Raspberry Pi

# On Raspberry Pi

# ssh pi@ipaddress
# password is 'raspberry'

# -t 0 => stream infinitely.  (t is in milliseconds)
# -fps 12 => stream at 12 fps
# -o - => output to stdout
raspivid -fps 12 -t 0 -o - | nc <your Mac's ip> 5002

To build display.cpp

g++ display.cpp -lopencv_core -lopencv_highgui -o display