QT crashes with bad_alloc() when I start the camera and run my application

I have a simple application with a button on the UI.  Before executing the application, I have a camera object instantiated and I start the camera. On clicking the button I just start a while loop, my application crashes with bad_alloc() just after 80k iterations. If I don't start the camera, the application doesn't crash.  I have attached the relevant code snippet below. 

 An important observation is that if I don't start my camera, then the application doesn't crash.