test: gstreamer: Factor out code into a base class

A lot of code used in the single stream test is boiler plate and common
across every gstreamer test. Factor out this code into a base class
called GstreamerTest.

Also update the gstreamer_single_stream_test to use the GstreamerTest
base class.

Signed-off-by: Vedant Paranjape <vedantparanjape160201@gmail.com>
Reviewed-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>

test/gstreamer/gstreamer_single_stream_test.cpp

@@ -14,104 +14,48 @@
 
 #include <gst/gst.h>
 
+#include "gstreamer_test.h"
 #include "test.h"
 
 using namespace std;
 
-extern "C" {
+class GstreamerSingleStreamTest : public GstreamerTest, public Test
-const char *__asan_default_options()
 {
-	/*
+public:
-	 * Disable leak detection due to a known global variable initialization
+	GstreamerSingleStreamTest()
-	 * leak in glib's g_quark_init(). This should ideally be handled by
+		: GstreamerTest()
-	 * using a suppression file instead of disabling leak detection.
+	{
-	 */
+	}
-	return "detect_leaks=false";
-}
-}
 
-class GstreamerSingleStreamTest : public Test
-{
 protected:
 	int init() override
 	{
-		/*
+		if (status_ != TestPass)
-		 * GStreamer by default spawns a process to run the
+			return status_;
-		 * gst-plugin-scanner helper. If libcamera is compiled with ASan
-		 * enabled, and as GStreamer is most likely not, this causes the
-		 * ASan link order check to fail when gst-plugin-scanner
-		 * dlopen()s the plugin as many libraries will have already been
-		 * loaded by then. Fix this issue by disabling spawning of a
-		 * child helper process when scanning the build directory for
-		 * plugins.
-		 */
-		gst_registry_fork_set_enabled(false);
 
-		/* Initialize GStreamer */
+		g_autoptr(GstElement) convert0 = gst_element_factory_make("videoconvert", "convert0");
-		g_autoptr(GError) errInit = NULL;
+		g_autoptr(GstElement) sink0 = gst_element_factory_make("fakesink", "sink0");
-		if (!gst_init_check(nullptr, nullptr, &errInit)) {
+		g_object_ref_sink(convert0);
-			g_printerr("Could not initialize GStreamer: %s\n",
+		g_object_ref_sink(sink0);
-				   errInit ? errInit->message : "unknown error");
+
+		if (!convert0 || !sink0) {
+			g_printerr("Not all elements could be created. %p.%p\n",
+				   convert0, sink0);
 
 			return TestFail;
 		}
 
-		/*
+		convert0_ = reinterpret_cast<GstElement *>(g_steal_pointer(&convert0));
-		 * Remove the system libcamera plugin, if any, and add the
+		sink0_ = reinterpret_cast<GstElement *>(g_steal_pointer(&sink0));
-		 * plugin from the build directory.
-		 */
-		GstRegistry *registry = gst_registry_get();
-		GstPlugin *plugin = gst_registry_lookup(registry, "libgstlibcamera.so");
-		if (plugin) {
-			gst_registry_remove_plugin(registry, plugin);
-			gst_object_unref(plugin);
-		}
 
-		std::string path = libcamera::utils::libcameraBuildPath()
+		if (createPipeline() != TestPass)
-				 + "src/gstreamer";
-		if (!gst_registry_scan_path(registry, path.c_str())) {
-			g_printerr("Failed to add plugin to registry\n");
-			gst_deinit();
 			return TestFail;
-		}
-
-		/* Create the elements */
-		libcameraSrc_ = gst_element_factory_make("libcamerasrc", "libcamera");
-		convert0_ = gst_element_factory_make("videoconvert", "convert0");
-		sink0_ = gst_element_factory_make("fakesink", "sink0");
-
-		/* Create the empty pipeline_ */
-		pipeline_ = gst_pipeline_new("test-pipeline");
-
-		if (!pipeline_ || !convert0_ || !sink0_ || !libcameraSrc_) {
-			g_printerr("Not all elements could be created. %p.%p.%p.%p\n",
-				   pipeline_, convert0_, sink0_, libcameraSrc_);
-			if (pipeline_)
-				gst_object_unref(pipeline_);
-			if (convert0_)
-				gst_object_unref(convert0_);
-			if (sink0_)
-				gst_object_unref(sink0_);
-			if (libcameraSrc_)
-				gst_object_unref(libcameraSrc_);
-			gst_deinit();
-
-			return TestFail;
-		}
 
 		return TestPass;
 	}
 
-	void cleanup() override
-	{
-		gst_object_unref(pipeline_);
-		gst_deinit();
-	}
-
 	int run() override
 	{
-		GstStateChangeReturn ret;
-
 		/* Build the pipeline */
 		gst_bin_add_many(GST_BIN(pipeline_), libcameraSrc_, convert0_, sink0_, NULL);
 		if (gst_element_link_many(libcameraSrc_, convert0_, sink0_, NULL) != TRUE) {
@@ -119,57 +63,16 @@ protected:
 			return TestFail;
 		}
 
-		/* Start playing */
+		if (startPipeline() != TestPass)
-		ret = gst_element_set_state(pipeline_, GST_STATE_PLAYING);
-		if (ret == GST_STATE_CHANGE_FAILURE) {
-			g_printerr("Unable to set the pipeline to the playing state.\n");
 			return TestFail;
-		}
 
-		/* Wait until error or EOS or timeout after 2 seconds */
+		if (processEvent() != TestPass)
-		constexpr GstMessageType msgType =
+			return TestFail;
-			static_cast<GstMessageType>(GST_MESSAGE_ERROR | GST_MESSAGE_EOS);
-		constexpr GstClockTime timeout = 2 * GST_SECOND;
 
-		g_autoptr(GstBus) bus = gst_element_get_bus(pipeline_);
-		g_autoptr(GstMessage) msg = gst_bus_timed_pop_filtered(bus, timeout, msgType);
-
-		gst_element_set_state(pipeline_, GST_STATE_NULL);
-
-		/* Parse error message */
-		if (msg == NULL)
 		return TestPass;
-
-		switch (GST_MESSAGE_TYPE(msg)) {
-		case GST_MESSAGE_ERROR:
-			gstreamer_print_error(msg);
-			break;
-		case GST_MESSAGE_EOS:
-			g_print("End-Of-Stream reached.\n");
-			break;
-		default:
-			g_printerr("Unexpected message received.\n");
-			break;
-		}
-
-		return TestFail;
 	}
 
 private:
-	void gstreamer_print_error(GstMessage *msg)
-	{
-		g_autoptr(GError) err = NULL;
-		g_autofree gchar *debug_info = NULL;
-
-		gst_message_parse_error(msg, &err, &debug_info);
-		g_printerr("Error received from element %s: %s\n",
-			   GST_OBJECT_NAME(msg->src), err->message);
-		g_printerr("Debugging information: %s\n",
-			   debug_info ? debug_info : "none");
-	}
-
-	GstElement *pipeline_;
-	GstElement *libcameraSrc_;
 	GstElement *convert0_;
 	GstElement *sink0_;
 };

test/gstreamer/gstreamer_test.cpp

@@ -0,0 +1,155 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2021, Vedant Paranjape
+ *
+ * libcamera Gstreamer element API tests
+ */
+
+#include "gstreamer_test.h"
+
+#include "test.h"
+
+using namespace std;
+
+extern "C" {
+const char *__asan_default_options()
+{
+	/*
+	 * Disable leak detection due to a known global variable initialization
+	 * leak in glib's g_quark_init(). This should ideally be handled by
+	 * using a suppression file instead of disabling leak detection.
+	 */
+	return "detect_leaks=false";
+}
+}
+
+GstreamerTest::GstreamerTest()
+{
+	/*
+	* GStreamer by default spawns a process to run the
+	* gst-plugin-scanner helper. If libcamera is compiled with ASan
+	* enabled, and as GStreamer is most likely not, this causes the
+	* ASan link order check to fail when gst-plugin-scanner
+	* dlopen()s the plugin as many libraries will have already been
+	* loaded by then. Fix this issue by disabling spawning of a
+	* child helper process when scanning the build directory for
+	* plugins.
+	*/
+	gst_registry_fork_set_enabled(false);
+
+	/* Initialize GStreamer */
+	g_autoptr(GError) errInit = NULL;
+	if (!gst_init_check(nullptr, nullptr, &errInit)) {
+		g_printerr("Could not initialize GStreamer: %s\n",
+			   errInit ? errInit->message : "unknown error");
+
+		status_ = TestFail;
+		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;
+	}
+
+	status_ = TestPass;
+}
+
+GstreamerTest::~GstreamerTest()
+{
+	if (libcameraSrc_ &&
+	    !gst_object_has_as_ancestor(GST_OBJECT(libcameraSrc_),
+					GST_OBJECT(pipeline_)))
+		gst_object_unref(libcameraSrc_);
+	if (pipeline_)
+		gst_object_unref(pipeline_);
+
+	gst_deinit();
+}
+
+int GstreamerTest::createPipeline()
+{
+	g_autoptr(GstElement) libcameraSrc = gst_element_factory_make("libcamerasrc", "libcamera");
+	pipeline_ = gst_pipeline_new("test-pipeline");
+	g_object_ref_sink(libcameraSrc);
+
+	if (!libcameraSrc || !pipeline_) {
+		g_printerr("Unable to create create pipeline %p.%p\n",
+			   libcameraSrc, pipeline_);
+
+		return TestFail;
+	}
+
+	libcameraSrc_ = reinterpret_cast<GstElement *>(g_steal_pointer(&libcameraSrc));
+
+	return TestPass;
+}
+
+int GstreamerTest::startPipeline()
+{
+	GstStateChangeReturn ret;
+
+	/* Start playing */
+	ret = gst_element_set_state(pipeline_, GST_STATE_PLAYING);
+	if (ret == GST_STATE_CHANGE_FAILURE) {
+		g_printerr("Unable to set the pipeline to the playing state.\n");
+		return TestFail;
+	}
+
+	return TestPass;
+}
+
+int GstreamerTest::processEvent()
+{
+	/* Wait until error or EOS or timeout after 2 seconds */
+	constexpr GstMessageType msgType =
+		static_cast<GstMessageType>(GST_MESSAGE_ERROR | GST_MESSAGE_EOS);
+	constexpr GstClockTime timeout = 2 * GST_SECOND;
+
+	g_autoptr(GstBus) bus = gst_element_get_bus(pipeline_);
+	g_autoptr(GstMessage) msg = gst_bus_timed_pop_filtered(bus, timeout, msgType);
+
+	gst_element_set_state(pipeline_, GST_STATE_NULL);
+
+	/* Parse error message */
+	if (msg == NULL)
+		return TestPass;
+
+	switch (GST_MESSAGE_TYPE(msg)) {
+	case GST_MESSAGE_ERROR:
+		printError(msg);
+		break;
+	case GST_MESSAGE_EOS:
+		g_print("End-Of-Stream reached.\n");
+		break;
+	default:
+		g_printerr("Unexpected message received.\n");
+		break;
+	}
+
+	return TestFail;
+}
+
+void GstreamerTest::printError(GstMessage *msg)
+{
+	g_autoptr(GError) err = NULL;
+	g_autofree gchar *debug_info = NULL;
+
+	gst_message_parse_error(msg, &err, &debug_info);
+	g_printerr("Error received from element %s: %s\n",
+		   GST_OBJECT_NAME(msg->src), err->message);
+	g_printerr("Debugging information: %s\n",
+		   debug_info ? debug_info : "none");
+}

test/gstreamer/gstreamer_test.h

@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2021, Vedant Paranjape
+ *
+ * gstreamer_test.cpp - GStreamer test base class
+ */
+
+#ifndef __LIBCAMERA_GSTREAMER_TEST_H__
+#define __LIBCAMERA_GSTREAMER_TEST_H__
+
+#include <iostream>
+#include <unistd.h>
+
+#include <libcamera/base/utils.h>
+
+#include "libcamera/internal/source_paths.h"
+
+#include <gst/gst.h>
+
+using namespace std;
+
+class GstreamerTest
+{
+public:
+	GstreamerTest();
+	virtual ~GstreamerTest();
+
+protected:
+	virtual int createPipeline();
+	int startPipeline();
+	int processEvent();
+	void printError(GstMessage *msg);
+
+	GstElement *pipeline_;
+	GstElement *libcameraSrc_;
+	int status_;
+};
+
+#endif /* __LIBCAMERA_GSTREAMER_TEST_H__ */

test/gstreamer/meson.build

@@ -10,7 +10,7 @@ gstreamer_tests = [
 gstreamer_dep = dependency('gstreamer-1.0', required: true)
 
 foreach t : gstreamer_tests
-    exe = executable(t[0], t[1],
+    exe = executable(t[0], t[1], 'gstreamer_test.cpp',
                      dependencies : [libcamera_private, gstreamer_dep],
                      link_with : test_libraries,
                      include_directories : test_includes_internal)