Connecting 2 camera for stereo vision

edit

Hello. I do not know what to do when one camera is connected is working perfectly. But when I connect the second camera, the system outputs one frame and freezes.

    OpenCV Error: Assertion failed (size.width>0 && size.height>0) in imshow, file /opt/opencv/modules/highgui/src/window.cpp, line 331
terminate called after throwing an instance of 'cv::Exception'
  what():  /opt/opencv/modules/highgui/src/window.cpp:331: error: (-215) size.width>0 && size.height>0 in function imshow


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

#include "opencv2/opencv.hpp"
/*
git clone https://github.com/opencv/opencv.git
mkdir build
cd build
cmake
make -j
sudo make install
*/

int main(int argc, char **argv)
{
    //const char *pipeline = "tcambin serial=10710002 ! video/x-raw, format=GRAY8, framerate=30/1, width=640, height=480  ! videoconvert ! appsink";
    //const char *pipeline = "v4l2src ! video/x-raw, format=GRAY8, width=640, height=480, framerate=30/1 ! videoconvert ! appsink";
    //const char *pipeline = "videotestsrc ! appsink";
    const char *pipeline_left =  "tcamsrc serial=19710151 ! video/x-bayer,width=640, height=480 ! bayer2rgb ! videoconvert ! appsink";
    const char *pipeline_right = "tcamsrc serial=19710152 ! video/x-bayer,width=640, height=480 ! bayer2rgb ! videoconvert ! appsink";

    cv::VideoCapture *cap_1 = new cv::VideoCapture(pipeline_left);
    cv::VideoCapture *cap_2 = new cv::VideoCapture(pipeline_right);

    if (!cap_1->isOpened())
    {
        printf("Error can't create video capture left");
        return 1;
    }
    if (!cap_2->isOpened())
    {
        printf("Error can't create video capture right");
        return 1;
    }

    cv::namedWindow("Left",1);
    cv::namedWindow("Right",1);

    for(;;)
    {
        cv::Mat frame_left;
        cv::Mat frame_right;

        *cap_1 >> frame_left; // get a new frame from camera
        *cap_2 >> frame_right;

        cv::imshow("Left",  frame_left);
        cv::imshow("Right", frame_right);


        char c= cv::waitKey(20);
        if(c ==' ')
        break;
    }
    delete cap_1;
    delete cap_2;

    cv::destroyWindow("Left");
    cv::destroyWindow("Right");

}