GSoC 2018: Port VLC build system to Meson

Mon, Aug 13, 2018

This summer I’ve participated in the Google Summer of Code program, contributing to the VLC media player project by VideoLAN.

My project this year was porting the VLC build system to the Meson Build system.

Motivation

The main reason for this project was that the autotools based build system is not the easiest to maintain, the configure autoconf file which is based on the m4 language is quite complex and hard to debug.

Meson is a modern build system which has it’s own syntax for the build files that is similar to python and therefore for most people relatively easy to understand and learn.

Goal

My initial plan was to port all of VLC in the timeframe of GSoC, but it quickly became clear that this is not a realistic goal, given that it’s quite time consuming to read the old build files and correctly “translate” those to meson build definitions. Additionally building VLC is complex, it has two GUIs, one for macOS based on Cocoa and one for Linux and Windows based on Qt and many other modules for codecs, muxing/demuxing, service discovery and other stuff.

Current state

Now, at the end of GSoC, VLC (libvlc, libvlccore) and about 100 modules are ported to Meson.

Most important missing things are:

  • Proper library versioning
  • Port the two “big” GUI modules
  • Port all other missing modules, most notably the libav modules
  • Correctly use VLCs “contrib” system

The current state can be found in the VLC Gitlab, all my commits are at the top, rebased onto the VLC master branch.

Additionally there are a few trivial contributions to the Meson repository.

Using it

To build VLC with Meson, two dependencies are needed for the build:

  • Python 3
  • Ninja

Meson itself is built as part of VLCs extras/tools so it is not required and currently VLC uses a patched version of Meson due to some upstream bugs that await proper fixes.

Check out the Meson GSoC repository meson branch:

git clone -b meson https://code.videolan.org/GSoC2018/ePirat/vlc.git

Then build the required extras/tools:

( cd vlc/extras/tools/ && ./bootstrap && make )

The run the mesonconfigure helper script with the build directory as argument:

./mesonconfigure build

Now actually build it with Ninja:

ninja -C build