test: gstreamer: Use env instead of registry edit

Instead of editing the registry, use gst_env variable provided by the plugin and
already used as part of the devenv shell. This reduces the complexity of the
C++ test code.

Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

test/gstreamer/gstreamer_test.cpp

@@ -51,23 +51,6 @@ GstreamerTest::GstreamerTest(unsigned int numStreams)
 		return;
 	}
 
-	/*
-	 * Remove the system libcamera plugin, if any, and add the plugin from
-	 * the build directory.
-	 */
-	GstRegistry *registry = gst_registry_get();
-	g_autoptr(GstPlugin) plugin = gst_registry_lookup(registry, "libgstlibcamera.so");
-	if (plugin)
-		gst_registry_remove_plugin(registry, plugin);
-
-	std::string path = libcamera::utils::libcameraBuildPath() + "src/gstreamer";
-	if (!gst_registry_scan_path(registry, path.c_str())) {
-		g_printerr("Failed to add plugin to registry\n");
-
-		status_ = TestFail;
-		return;
-	}
-
 	/*
 	 * Atleast one camera should be available with numStreams streams,
 	 * otherwise skip the test entirely.

test/gstreamer/meson.build

@@ -17,5 +17,5 @@ foreach test : gstreamer_tests
                      link_with : test_libraries,
                      include_directories : test_includes_internal)
 
-    test(test['name'], exe, suite : 'gstreamer', is_parallel : false)
+    test(test['name'], exe, suite : 'gstreamer', is_parallel : false, env : gst_env)
 endforeach