How to install OpenCV in Qt on macOS

This tutorial explains how to install OpenCV in Qt on macOS (OSX). I hope this can help you.

Include the following "code" on your .pro file, inside Qt:
Change USERNAME to your user name, or define another path that you find adequate.

INCLUDEPATH += "/Users/USERNAME/opencv/build/install/include/opencv4"
LIBS += -L"/Users/USERNAME/opencv/build/install/lib" -l"opencv_world"

[AltairIV]

One of few tutorials in my life that everything works, thank you.

[roryhill]

Everything worked without a hitch. Great tutorial. Many thanks!!

[jishada.v]

Nice video. Saved my hours. Neatly explained. Please do more videos.

[emirhan]

make command throws errors. it think this is happening because i'm using an arm64 macbook(m1)

[isenseven]

Thx a lot for the video! 
I had the error "The file was generated by an older version of protoc" do you have an idea how to solve that?

[an_gorniy]

You did not use Xcode, so why it need? And also I would like to ask what flags need to set in qt installer ? thanks in advance

[SaeedDev]

After I checked build_opencv_world
I got the error:
CMake Warning at (message):
IPPICV: Download failed: 28;"Timeout was reached"

I downloaded that manually but do not know where to put it.
Any Idea?