Cerbero GStreamer recipes are now built with Meson

[Nirbheek Chauhan]

Hello everyone!

Just a quick note that after extensive testing and porting, all the
GStreamer recipes in Cerbero git master have been moved over to use
Meson on all platforms. The only exception is gst-libav-1.0 which
still uses Autotools, and it is planned to move that to Meson in the
near future. Some of the major advantages of this move:

1. Faster builds on all platforms and toolchains
2. Massively faster and more reliable builds on Windows since Meson
does not use make or shell
3. The future ability to build and ship binaries for Windows built
with Visual Studio, which will allow easier debugging, deployment,
instrumentation, and so on.

This is the second step in the project dropping Autotools in favour of
Meson, the first being gst-build[1], which I hope everyone has been
trying out! This effort involved changes to the GStreamer meson build
files, bug fixes and features to the Meson project, and of course
changes in Cerbero.

Thanks to everyone who contributed to this, particularly Xavier
Claesse and Matthew Waters!

[1] https://cgit.freedesktop.org/gstreamer/gst-build/

I have opened a tracker bug[2] for this change, so please go forth,
test, and report any issues you find or questions you may have.

[2] https://bugzilla.gnome.org/show_bug.cgi?id=797065

Cheers!
Nirbheek

PS: Here's a complete list of recipes that use Meson:

$ grep -rle BuildType.MESON recipes/
recipes/proxy-libintl.recipe
recipes/zlib.recipe
recipes/glib.recipe
recipes/build-tools/glib-tools.recipe
recipes/glib-networking.recipe
recipes/gstreamer-1.0.recipe
recipes/gst-plugins-base-1.0.recipe
recipes/gst-plugins-good-1.0.recipe
recipes/gst-plugins-bad-1.0.recipe
recipes/gst-plugins-ugly-1.0.recipe
recipes/gst-rtsp-server-1.0.recipe
recipes/gst-editing-services-1.0.recipe
recipes/gst-transcoder.recipe
recipes/gst-omx-1.0.recipe
recipes/gst-validate.recipe

Out of these, proxy-libintl, zlib, glib, and glib-networking are built
with Visual Studio on Windows. The rest still use MinGW, but that will
change in the near future.