Install-From-Source-Guide: outdated instructions (Mac)

In the dependencies section, it says:

macOS:

Install Homebrew, then brew install ffmpeg and brew install homebrew/science/opencv --with-ffmpeg.

The homebrew/science branch was deprecated as all formulae were moved elsewhere. The closest package I could find by name was opencv@2 by simply doing brew install opencv@2 however --with-ffmpeg is an invalid option when I tried substituting with this.

(edit: overlooked package opencv because I’m stupid but same invalid option error thrown)

[thure]

I see references to butterflow all over the internet when frame interpolation comes up, so it’s a bit surprising it’s not just an installable Homebrew formula. If someone can get this working on a contemporary version of macOS, probably worthwhile to make it a formula.

[ManxStef]

Here’s a step-by-step of worked for me on macOS 10.15 Catalina:

Install the Xcode commandline tools if you need to xcode-select --install

note that opencv@2 depends on ffmpeg now so it gets installed automatically - see https://formulae.brew.sh/formula/opencv@2 brew install opencv@2

Install pip, which’ll then let us install virtualenv sudo easy_install pip pip install virtualenv

Note that it’ll give you the following info, which we can ignore for now WARNING: The script virtualenv is installed in ‘/Users/yourusername/Library/Python/2.7/bin’ which is not on PATH. Consider adding this directory to PATH or, if you prefer to suppress this warning, use --no-warn-script-location.

cd to wherever you want to put your code, e.g. cd ~, then clone the butterflow source git clone https://github.com/dthpham/butterflow.git

Create the virtualenv - we’ll just refer to the newly-install virtualenv binary directly instead of adding it to our PATH like the warning above says. Note that python has been renamed to python2 and python3 in Catalina, as far as I know, so we want virtualenv to use python2 ~/Library/Python/2.7/bin/virtualenv -p /usr/bin/python2 butterflow

Navigate into the folder cd butterflow

Tell butterflow where the homebrew python site-packages are by using a .pth file echo "$(brew --prefix)/lib/python2.7/site-packages" > lib/python2.7/site-packages/butterflow.pth

activate the virtualenv source bin/activate

now we’re inside the virtualenv, set the compile flags so the clang compiler knows where things are

export LDFLAGS="-L/usr/local/opt/opencv@2/lib -L/usr/local/opt/openblas/lib"
export CPPFLAGS="-I/usr/local/opt/opencv@2/include"
export PKG_CONFIG_PATH="/usr/local/opt/opencv@2/lib/pkgconfig"
export PYTHONPATH=$PYTHONPATH:$(brew --prefix)/lib/python2.7/site-packages

OK, we’re hopefully ready to install! - sudo python2 setup.py install

test that it works butterflow --help

exit the virtualenv deactivate

NOTE: to use butterflow outside of the virtualenv environment, you’ll need to set the PYTHONPATH permanently for your shell, e.g. something like: echo "export PYTHONPATH=$PYTHONPATH:$(brew --prefix)/lib/python2.7/site-packages" >> ~/.bash_profile

Hope that helps somebody!