[libcamera-devel] [PATCH v2] test: gstreamer: Add a test for gstreamer multi stream

[Vedant Paranjape]

This patch adds a test to test if multi stream using libcamera's
gstreamer element works.

We need to work around one issue with ASan when enabled in the
build:

- glib has a known leak at initialization time. This is covered by the
  suppression file shipped with glib, but it's not clear how to use it
  automatically. For now, disable leak detection to avoid test failures.

Signed-off-by: Vedant Paranjape <vedantparanjape160201 at gmail.com>
---
 .../gstreamer/gstreamer_multi_stream_test.cpp | 225 ++++++++++++++++++
 test/gstreamer/meson.build                    |   1 +
 2 files changed, 226 insertions(+)
 create mode 100644 test/gstreamer/gstreamer_multi_stream_test.cpp

diff --git a/test/gstreamer/gstreamer_multi_stream_test.cpp b/test/gstreamer/gstreamer_multi_stream_test.cpp
new file mode 100644
index 00000000..e32b07a4
--- /dev/null
+++ b/test/gstreamer/gstreamer_multi_stream_test.cpp
@@ -0,0 +1,225 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2021, Vedant Paranjape
+ *
+ * gstreamer_single_stream_test.cpp - GStreamer single stream capture test
+ */
+
+#include <iostream>
+#include <unistd.h>
+
+#include <libcamera/base/utils.h>
+
+#include <libcamera/libcamera.h>
+
+#include "libcamera/internal/source_paths.h"
+
+#include <gst/gst.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";
+}
+}
+
+class GstreamerSingleStreamTest : public Test
+{
+protected:
+	int init() override
+	{
+		/*
+		 * 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");
+
+			return TestFail;
+		}
+
+		/*
+		 * Remove the system libcamera plugin, if any, and add the
+		 * 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()
+				 + "src/gstreamer";
+		if (!gst_registry_scan_path(registry, path.c_str())) {
+			g_printerr("Failed to add plugin to registry\n");
+			gst_deinit();
+			return TestFail;
+		}
+
+		/* Check if platform support multistream output */
+		libcamera::CameraManager cm;
+		cm.start();
+		if (cm.cameras()[0]->streams().size() <= 1) {
+			cm.stop();
+			return TestSkip;
+		}
+		cm.stop();
+
+		/* Create the elements */
+		libcameraSrc_ = gst_element_factory_make("libcamerasrc", "libcamera");
+		convert0_ = gst_element_factory_make("videoconvert", "convert0");
+		convert1_ = gst_element_factory_make("videoconvert", "convert1");
+		sink0_ = gst_element_factory_make("fakesink", "sink0");
+		sink1_ = gst_element_factory_make("fakesink", "sink1");
+		queue0_ = gst_element_factory_make("queue", "camera_queue0");
+		queue1_ = gst_element_factory_make("queue", "camera_queue1");
+
+		/* Create the empty pipeline_ */
+		pipeline_ = gst_pipeline_new("test-pipeline");
+
+		if (!pipeline_ || !convert0_ || !convert1_ || !sink0_ ||
+			!sink1_ || !queue0_ || !queue1_ || !libcameraSrc_) {
+			g_printerr("Not all elements could be created. %p.%p.%p.%p.%p.%p.%p.%p\n",
+						pipeline_, convert0_, convert1_, sink0_,
+						sink1_, queue0_, queue1_, libcameraSrc_);
+			if (pipeline_)
+				gst_object_unref(pipeline_);
+			if (convert0_)
+				gst_object_unref(convert0_);
+			if (convert1_)
+				gst_object_unref(convert1_);
+			if (sink0_)
+				gst_object_unref(sink0_);
+			if (sink1_)
+				gst_object_unref(sink1_);
+			if (queue0_)
+				gst_object_unref(queue0_);
+			if (queue1_)
+				gst_object_unref(queue1_);
+			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_, queue0_, queue1_,
+							convert0_, convert1_, sink0_, sink1_, NULL);
+		if (gst_element_link_many(queue0_, convert0_, sink0_, NULL) != TRUE
+				|| gst_element_link_many(queue1_, convert1_, sink1_, NULL) != TRUE) {
+			g_printerr("Elements could not be linked.\n");
+			return TestFail;
+		}
+
+		g_autoptr(GstPad) src_pad = gst_element_get_static_pad(libcameraSrc_, "src");
+		g_autoptr(GstPad) request_pad = gst_element_get_request_pad(libcameraSrc_, "src_%u");
+		GstPad *queue0_sink_pad = gst_element_get_static_pad(queue0_, "sink");
+		GstPad *queue1_sink_pad = gst_element_get_static_pad(queue1_, "sink");
+
+		if (gst_pad_link(src_pad, queue0_sink_pad) != GST_PAD_LINK_OK
+				|| gst_pad_link(request_pad, queue1_sink_pad) != GST_PAD_LINK_OK) {
+			if (queue0_sink_pad)
+				gst_object_unref(queue0_sink_pad);
+			if (queue1_sink_pad)
+				gst_object_unref(queue1_sink_pad);
+			g_printerr("Pads could not be linked.\n");
+			return TestFail;
+		}
+		gst_object_unref(queue0_sink_pad);
+		gst_object_unref(queue1_sink_pad);
+
+		/* 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;
+		}
+
+		/* 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:
+			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 *queue0_;
+	GstElement *queue1_;
+	GstElement *convert0_;
+	GstElement *convert1_;
+	GstElement *sink0_;
+	GstElement *sink1_;
+};
+
+TEST_REGISTER(GstreamerSingleStreamTest)
diff --git a/test/gstreamer/meson.build b/test/gstreamer/meson.build
index b99aa0da..e28225b2 100644
--- a/test/gstreamer/meson.build
+++ b/test/gstreamer/meson.build
@@ -6,6 +6,7 @@ endif
 
 gstreamer_tests = [
     ['single_stream_test',   'gstreamer_single_stream_test.cpp'],
+    ['multi_stream_test',   'gstreamer_multi_stream_test.cpp'],
 ]
 gstreamer_dep = dependency('gstreamer-1.0', required: true)
 
-- 
2.25.1