Building Essentia's Python extension on Windows

Python.org Windows binaries are compiled against an MS Visual C++ (MSVC) runtime, which version differs with different Python versions. Essentia's Python extension should be built with MSVC too because the MinGW C++ library builds won't be compatible with MSVC.

In this guide we use a VirtualBox Windows machine. The instructions are for a x64 build, but they can be modified together with the scripts accordingly.

Preparing build environment

• Download Dev Virtual Machine: https://developer.microsoft.com/en-us/windows/downloads/virtual-machines
• Remove Visual Studio 2017 Community as we won't use it
• Install Build Tools for Visual Studio 2017: https://www.visualstudio.com/downloads/#build-tools-for-visual-studio-2017
• Make sure VC++ v140 toolset is installed: Visual Studio Build Tools 2017 preferences --> check "VC++ 2015.3 v140 toolset for desktop (x86,x64)"
• Make sure Win10 SDK is also installed
• Install Python 3 x64, add path to python.exe to %PATH% variable
• Patch distutils/msvc9compiler.py and distutils/msvccompiler.py (they are inside C:\Users\User\AppData\Local\Programs\Python\Python36\lib\distutils\ folder): add a line import setuptools
• Force upgrade of the setuptools package: python -m pip install -U pip setuptools
• Install pkg-config-lite (https://sourceforge.net/projects/pkgconfiglite/files/) to C:\workspace and add this path to %PATH% variable

Building Essentia

• Download pre-built dependencies (http://essentia.upf.edu/documentation/downloads/packaging/win/) and unpack them into the packaging\win32_3rdparty folder.
• Open "x64 Native Tools Command Prompt for VS 2017"
• Configure Essentia: python waf configure --with-python --msvc_targets="x64"
• Compile and install:

python waf
python waf install

By default waf script will install:

• library binary and headers to C:\Users\User\AppData\Local\Temp\include\essentia\ and C:\Users\User\AppData\Local\Temp\lib\
• Python extension to C:\Users\User\AppData\Local\Programs\Python\Python36\Lib\site-packages\essentia

You can specify your own path to install using the --prefix flag (see python waf --help for help). In the case of import error in python due to missing DLLs, use Dependency Walker to find out missing dependencies.

Prebuilt library

essentia.lib 750MB https://drive.google.com/file/d/1qtwMW-D94za2lG65r5KcWhW-XTCPBrhl/view?usp=sharing