[libcamera-devel] [PATCH v8] test: gstreamer: Add test for gstreamer single stream

[Kieran Bingham]

Hi Vedant,

On 13/08/2021 07:37, Vedant Paranjape wrote:
> This patch adds a test to test if single stream using
> libcamera's gstreamer element works.
> 
> Signed-off-by: Vedant Paranjape <vedantparanjape160201 at gmail.com>
> Reviewed-by: Paul Elder <paul.elder at ideasonboard.com>
> ---
>  .../gstreamer_single_stream_test.cpp          | 148 ++++++++++++++++++
>  test/gstreamer/meson.build                    |  19 +++
>  test/meson.build                              |   1 +
>  3 files changed, 168 insertions(+)
>  create mode 100644 test/gstreamer/gstreamer_single_stream_test.cpp
>  create mode 100644 test/gstreamer/meson.build
> 
> diff --git a/test/gstreamer/gstreamer_single_stream_test.cpp b/test/gstreamer/gstreamer_single_stream_test.cpp
> new file mode 100644
> index 00000000..c0d38ff8
> --- /dev/null
> +++ b/test/gstreamer/gstreamer_single_stream_test.cpp
> @@ -0,0 +1,148 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +/*
> + * Copyright (C) 2021, Vedant Paranjape
> + *
> + * ipa_interface_test.cpp - Test the IPA interface
> + */
> +
> +#include <iostream>
> +
> +#include <libcamera/base/utils.h>
> +
> +#include <gst/gst.h>
> +
> +#include "test.h"
> +
> +using namespace std;
> +
> +class GstreamerSingleStreamTest : public Test
> +{
> +protected:
> +	int init() override
> +	{
> +		/* Initialize GStreamer */
> +		GError *errInit = nullptr;
> +		if (!gst_init_check(nullptr, nullptr, &errInit)) {
> +			g_printerr("Could not initialize GStreamer: %s\n",
> +				   errInit ? errInit->message : "unknown error");
> +			if (errInit)
> +				g_error_free(errInit);
> +
> +			return TestFail;
> +		}
> +
> +		/*
> +		* Remove the system libcamera plugin, if any, and add the
> +		* plugin from the build directory.
> +		*/

Oh - excellent, I like this a lot as it will help make sure the test
runs what we expect it to run.

> +		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 = std::string(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;
> +		}
> +
> +		/* Create the elements */
> +		libcameraSrc_ = gst_element_factory_make("libcamerasrc", "libcamera");
> +		convert0_ = gst_element_factory_make("videoconvert", "convert0");
> +		sink0_ = gst_element_factory_make("fakevideosink", "sink0");
> +
> +		/* Create the empty pipeline_ */
> +		pipeline_ = gst_pipeline_new("test-pipeline");
> +
> +		if (!pipeline_ || !convert0_ || !sink0_ || !libcameraSrc_) {
> +			g_printerr("Not all elements could be created.\n");

I still get failures here:

> ./build/test/gstreamer/single_stream_test
> Not all elements could be created.
> 
> (single_stream_test:3346990): GStreamer-CRITICAL **: 09:04:43.279: gst_object_unref: assertion 'object != NULL' failed

Changing this line, makes it clearer what actually has failed, so
perhaps we should be a bit more verbose on this error print.

> -                       g_printerr("Not all elements could be created.\n");
> +                       g_printerr("Not all elements could be created. %p.%p.%p.%p\n",
> +                                       pipeline_, convert0_, sink0_, libcameraSrc_);

So now I can see:

> Not all elements could be created. 0x55d7a51a2100.0x55d7a519db20.(nil).0x55d7a518f0a0

sink0_ has failed on my system. That's ... unexpected and surprising....

gst-inspect-1.0 | grep fakesink
coreelements:  fakesink: Fake Sink

gst-inspect-1.0 | grep fakevideosink
<nothing>

So - my system has a fakesink, but not a fakevideosink.

Is it preferable to use a fakevideosink? Should we always use a
fakesink, or try to make either a fakesink or a fakevideosink, and then
choose the first one we make?

I would ask if we use fakesink, we might not need the videoconvert - but
I actually think having that puts some level of 'make sure the
libcamerasrc' element is configured as a video source, so I think it's
good to have.


> +			gst_object_unref(pipeline_);
> +			gst_object_unref(convert0_);
> +			gst_object_unref(sink0_);
> +			gst_object_unref(libcameraSrc_);

By very definition of entering this conditional section, at least one of
those four lines will cause a null-unref assertion failure.

Anyway, with those issues resolved, I think this is so close, and
certainly a great addition.

So with those issues fixed,

Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>

Looking forward to be able to give a Tested-by: tag too on the next
version ;-)

--
Kieran

> +			gst_deinit();
> +
> +			return TestFail;
> +		}
> +
> +		return TestPass;
> +	}
> +
> +	void cleanup() override
> +	{
> +		gst_object_unref(pipeline_);
> +		gst_deinit();
> +	}
> +
> +	int run() override
> +	{
> +		GstStateChangeReturn ret;
> +		g_autoptr(GstBus) bus;
> +		g_autoptr(GstMessage) msg;
> +
> +		/* Build the pipeline */
> +		gst_bin_add_many(GST_BIN(pipeline_), libcameraSrc_, convert0_, sink0_, NULL);
> +		if (gst_element_link_many(libcameraSrc_, convert0_, sink0_, NULL) != TRUE) {
> +			g_printerr("Elements could not be linked.\n");
> +			return TestFail;
> +		}
> +
> +		/* 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 */
> +		GstClockTime timeout = 2000000000;
> +		bus = gst_element_get_bus(pipeline_);
> +		msg = gst_bus_timed_pop_filtered(bus, timeout,
> +						 GstMessageType((uint)GST_MESSAGE_ERROR | (uint)GST_MESSAGE_EOS));
> +		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)
> +	{
> +		GError *err;
> +		gchar *debug_info;
> +
> +		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");
> +		g_clear_error(&err);
> +		g_free(debug_info);
> +	}
> +
> +	GstElement *pipeline_;
> +	GstElement *libcameraSrc_;
> +	GstElement *convert0_;
> +	GstElement *sink0_;
> +};
> +
> +TEST_REGISTER(GstreamerSingleStreamTest)
> diff --git a/test/gstreamer/meson.build b/test/gstreamer/meson.build
> new file mode 100644
> index 00000000..b99aa0da
> --- /dev/null
> +++ b/test/gstreamer/meson.build
> @@ -0,0 +1,19 @@
> +# SPDX-License-Identifier: CC0-1.0
> +
> +if not gst_enabled
> +    subdir_done()
> +endif
> +
> +gstreamer_tests = [
> +    ['single_stream_test',   'gstreamer_single_stream_test.cpp'],
> +]
> +gstreamer_dep = dependency('gstreamer-1.0', required: true)
> +
> +foreach t : gstreamer_tests
> +    exe = executable(t[0], t[1],
> +                     dependencies : [libcamera_private, gstreamer_dep],
> +                     link_with : test_libraries,
> +                     include_directories : test_includes_internal)
> +
> +    test(t[0], exe, suite : 'gstreamer', is_parallel : false)
> +endforeach
> diff --git a/test/meson.build b/test/meson.build
> index 3bceb5df..d0466f17 100644
> --- a/test/meson.build
> +++ b/test/meson.build
> @@ -11,6 +11,7 @@ subdir('libtest')
>  
>  subdir('camera')
>  subdir('controls')
> +subdir('gstreamer')
>  subdir('ipa')
>  subdir('ipc')
>  subdir('log')
>