[gupnp-dlna/wip/meson] build: Add option for default backend

[Jens Georg <jensgeorg src gnome org>]

commit 17e3e6a94c07664b22ab089f7f129c61c78cfcb6
Author: Jens Georg <mail jensge org>
Date:   Thu Oct 31 17:06:43 2019 +0100

    build: Add option for default backend

 meson.build       | 2 +-
 meson_options.txt | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/meson.build b/meson.build
index 1fa4017..0def091 100644
--- a/meson.build
+++ b/meson.build
@@ -12,7 +12,7 @@ metadata_backend_dir = join_paths(get_option('prefix'), get_option('libdir'), 'g
 library_version = '3.0.0'
 
 config = configuration_data()
-config.set_quoted('GUPNP_DLNA_DEFAULT_METADATA_BACKEND', 'gstreamer')
+config.set_quoted('GUPNP_DLNA_DEFAULT_METADATA_BACKEND', get_option('default_backend'))
 config.set_quoted('GUPNP_DLNA_DEFAULT_METADATA_BACKEND_DIR', metadata_backend_dir)
 
 configure_file(output: 'config.h', configuration: config)
diff --git a/meson_options.txt b/meson_options.txt
index 60361a6..5036081 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -1,2 +1,3 @@
 option('gstreamer_backend', type : 'feature', value: 'enabled')
+option('default_backend', type: 'string', value: 'gstreamer')
 option('introspection', type: 'boolean', value: 'true')