[libcamera-devel,v2] test: gstreamer: Add a test for gstreamer multi stream
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Message ID 20210828173753.336859-1-vedantparanjape160201@gmail.com
State Superseded
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Series
  • [libcamera-devel,v2] test: gstreamer: Add a test for gstreamer multi stream
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Commit Message

Vedant Paranjape Aug. 28, 2021, 5:37 p.m. UTC 
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@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

Comments

Laurent Pinchart Aug. 29, 2021, 1:09 a.m. UTC | #1 
Hi Vedant,

Thank you for the patch.

On Sat, Aug 28, 2021 at 11:07:53PM +0530, Vedant Paranjape wrote:
> 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@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;
> +		}

There's quite a bit of duplicated code between this and the single
stream test. Could you refactor the single stream test to create a base
class that can be shared with this one ?

> +
> +		/* Check if platform support multistream output */
> +		libcamera::CameraManager cm;
> +		cm.start();
> +		if (cm.cameras()[0]->streams().size() <= 1) {
> +			cm.stop();
> +			return TestSkip;
> +		}
> +		cm.stop();

Is there a guarantee that libcamerasrc will pick the same camera ? It
seems quite fragile to me. Isn't there a way to instead query the
libcamerasrc element for the number of pads it supports ? More than
that, as not all cameras support multiple streams, it would be nice if
the test could iterate over all cameras to find one that does.

> +
> +		/* 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");

Looks like there's room to make the code more generic, posibly storing
the elements in containers.

> +
> +		/* 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)
>
Vedant Paranjape Aug. 29, 2021, 5:23 a.m. UTC | #2 
Hi Laurent,
Thanks for the review.
On Sun, Aug 29, 2021 at 6:39 AM Laurent Pinchart <
laurent.pinchart@ideasonboard.com> wrote:

> Hi Vedant,
>
> Thank you for the patch.
>
> On Sat, Aug 28, 2021 at 11:07:53PM +0530, Vedant Paranjape wrote:
> > 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@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;
> > +             }
>
> There's quite a bit of duplicated code between this and the single
> stream test. Could you refactor the single stream test to create a base
> class that can be shared with this one ?
>

Yes, I am going to do this, but can we go about it as follows, merge this
patch with duplicated code,
then I think over it a bit and then submit new patch which refactors a lot
of the duplicated code,
also I don't think going ahead with making a base class is a good idea as,
there's much functional difference between two codes,
they rather have isolated code that repeats, but no so much as to roll it
into a class.

> +
> > +             /* Check if platform support multistream output */
> > +             libcamera::CameraManager cm;
> > +             cm.start();
> > +             if (cm.cameras()[0]->streams().size() <= 1) {
> > +                     cm.stop();
> > +                     return TestSkip;
> > +             }
> > +             cm.stop();
>
> Is there a guarantee that libcamerasrc will pick the same camera ? It
>

Yes, it is guaranteed if we don't pass it a camera-name which we aren't see
here:
https://git.linuxtv.org/libcamera.git/tree/src/gstreamer/gstlibcamerasrc.cpp#n237


> seems quite fragile to me. Isn't there a way to instead query the
> libcamerasrc element for the number of pads it supports ?


I think this won't be possible unless we add code to the
gstreamer-element, @Nicolas
Dufresne <nicolas@ndufresne.ca> can
you answer this please, I am not sure :)

More than
> that, as not all cameras support multiple streams, it would be nice if
> the test could iterate over all cameras to find one that does.
>

This sounds like a nice idea, I could store the camera-name of the specific
camera and set the camera-name property
of the libcamera element and start on it, but now I don't a multicamera
setup.

> +
> > +             /* 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");
>
> Looks like there's room to make the code more generic, posibly storing
> the elements in containers.
>

Okay something like a vector to hold the elements and then a map to hold
<element name, unique name>.
But this is a test code, is this fancy stuff really needed ? !!

> +
> > +             /* 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)
> >
>
> --
> Regards,
>
> Laurent Pinchart
>

Regards
*Vedant Paranjape*
Laurent Pinchart Aug. 29, 2021, 9:25 a.m. UTC | #3 
Hi Vedant,

On Sun, Aug 29, 2021 at 10:53:34AM +0530, Vedant Paranjape wrote:
> On Sun, Aug 29, 2021 at 6:39 AM Laurent Pinchart wrote:
> > On Sat, Aug 28, 2021 at 11:07:53PM +0530, Vedant Paranjape wrote:
> > > 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@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;
> > > +             }
> >
> > There's quite a bit of duplicated code between this and the single
> > stream test. Could you refactor the single stream test to create a base
> > class that can be shared with this one ?
> 
> Yes, I am going to do this, but can we go about it as follows, merge this
> patch with duplicated code,
> then I think over it a bit and then submit new patch which refactors a lot
> of the duplicated code,

Why ? :-) I'm fine merging work in progress when there's a reason (for
instance to split very large partch series in chunks, or to avoid
blocking development when other developers depend on that code), but in
this case I think a refactoring before merging the second test is
better.

> also I don't think going ahead with making a base class is a good idea as,
> there's much functional difference between two codes,
> they rather have isolated code that repeats, but no so much as to roll it
> into a class.

I don't agree, I think the tests are very similar. diffstat agrees with
me.

$ diff -u gstreamer_single_stream_test.cpp gstreamer_multi_stream_test.cpp | diffstat
 gstreamer_multi_stream_test.cpp |   62 +++++++++++++++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 55 insertions(+), 7 deletions(-)

> > +
> > > +             /* Check if platform support multistream output */
> > > +             libcamera::CameraManager cm;
> > > +             cm.start();
> > > +             if (cm.cameras()[0]->streams().size() <= 1) {
> > > +                     cm.stop();
> > > +                     return TestSkip;
> > > +             }
> > > +             cm.stop();
> >
> > Is there a guarantee that libcamerasrc will pick the same camera ? It
> 
> Yes, it is guaranteed if we don't pass it a camera-name which we aren't see
> here:
> https://git.linuxtv.org/libcamera.git/tree/src/gstreamer/gstlibcamerasrc.cpp#n237
> 
> > seems quite fragile to me. Isn't there a way to instead query the
> > libcamerasrc element for the number of pads it supports ?
> 
> I think this won't be possible unless we add code to the
> gstreamer-element, @Nicolas
> Dufresne <nicolas@ndufresne.ca> can
> you answer this please, I am not sure :)

The GstElement documentation mentions a numsrcpads field. I have little
experience with GStreamer, but it sounds like something that could help.
Have you tried it ?

> > More than
> > that, as not all cameras support multiple streams, it would be nice if
> > the test could iterate over all cameras to find one that does.
> 
> This sounds like a nice idea, I could store the camera-name of the specific
> camera and set the camera-name property
> of the libcamera element and start on it, but now I don't a multicamera
> setup.
> 
> > +
> > > +             /* 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");
> >
> > Looks like there's room to make the code more generic, posibly storing
> > the elements in containers.
> 
> Okay something like a vector to hold the elements and then a map to hold
> <element name, unique name>.
> But this is a test code, is this fancy stuff really needed ? !!

Test code doesn't mean that it has to be dirty and throw away all
software development good practices. Tests are first class citizens.
It's not about "fancy stuff", it's about making the code more readable
and maintainable.

> > > +
> > > +             /* 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)
> > >
Vedant Paranjape Aug. 29, 2021, 10:04 a.m. UTC | #4 
Hello Laurent,

On Sun, Aug 29, 2021 at 2:56 PM Laurent Pinchart <
laurent.pinchart@ideasonboard.com> wrote:

> Hi Vedant,
>
> On Sun, Aug 29, 2021 at 10:53:34AM +0530, Vedant Paranjape wrote:
> > On Sun, Aug 29, 2021 at 6:39 AM Laurent Pinchart wrote:
> > > On Sat, Aug 28, 2021 at 11:07:53PM +0530, Vedant Paranjape wrote:
> > > > 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@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;
> > > > +             }
> > >
> > > There's quite a bit of duplicated code between this and the single
> > > stream test. Could you refactor the single stream test to create a base
> > > class that can be shared with this one ?
> >
> > Yes, I am going to do this, but can we go about it as follows, merge this
> > patch with duplicated code,
> > then I think over it a bit and then submit new patch which refactors a
> lot
> > of the duplicated code,
>
> Why ? :-) I'm fine merging work in progress when there's a reason (for
> instance to split very large partch series in chunks, or to avoid
> blocking development when other developers depend on that code), but in
> this case I think a refactoring before merging the second test is
> better.
>

Because that will make reviewing difficult.

> also I don't think going ahead with making a base class is a good idea as,
> > there's much functional difference between two codes,
> > they rather have isolated code that repeats, but no so much as to roll it
> > into a class.
>
> I don't agree, I think the tests are very similar. diffstat agrees with
> me.
>
> $ diff -u gstreamer_single_stream_test.cpp gstreamer_multi_stream_test.cpp
> | diffstat
>  gstreamer_multi_stream_test.cpp |   62
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++-------
>  1 file changed, 55 insertions(+), 7 deletions(-)
>

Other than the code that loads gstreamer libcamera library, none of the
other code can be modularized. small blocks of code are similar
in between, but "similar" not "same". I am unable to comeup with a way to
refactor it more.

> > +
> > > > +             /* Check if platform support multistream output */
> > > > +             libcamera::CameraManager cm;
> > > > +             cm.start();
> > > > +             if (cm.cameras()[0]->streams().size() <= 1) {
> > > > +                     cm.stop();
> > > > +                     return TestSkip;
> > > > +             }
> > > > +             cm.stop();
> > >
> > > Is there a guarantee that libcamerasrc will pick the same camera ? It
> >
> > Yes, it is guaranteed if we don't pass it a camera-name which we aren't
> see
> > here:
> >
> https://git.linuxtv.org/libcamera.git/tree/src/gstreamer/gstlibcamerasrc.cpp#n237
> >
> > > seems quite fragile to me. Isn't there a way to instead query the
> > > libcamerasrc element for the number of pads it supports ?
> >
> > I think this won't be possible unless we add code to the
> > gstreamer-element, @Nicolas
> > Dufresne <nicolas@ndufresne.ca> can
> > you answer this please, I am not sure :)
>
> The GstElement documentation mentions a numsrcpads field. I have little
> experience with GStreamer, but it sounds like something that could help.
> Have you tried it ?
>

No, this won't work. An element by default will generate a single source
pad, after that I'd need
to explicitly request a request pad, which will map to a new stream. I
guess this variable stores the
the number of active source pads and not the theoretical supported pads.

> > More than
> > > that, as not all cameras support multiple streams, it would be nice if
> > > the test could iterate over all cameras to find one that does.
> >
> > This sounds like a nice idea, I could store the camera-name of the
> specific
> > camera and set the camera-name property
> > of the libcamera element and start on it, but now I don't a multicamera
> > setup.
> >
> > > +
> > > > +             /* 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");
> > >
> > > Looks like there's room to make the code more generic, posibly storing
> > > the elements in containers.
> >
> > Okay something like a vector to hold the elements and then a map to hold
> > <element name, unique name>.
> > But this is a test code, is this fancy stuff really needed ? !!
>
> Test code doesn't mean that it has to be dirty and throw away all
> software development good practices. Tests are first class citizens.
> It's not about "fancy stuff", it's about making the code more readable
> and maintainable.
>

I am not sure what is the ideal way for you to do it, please let me know.
Just adding all these elements in
a struct ?

> > > +
> > > > +             /* 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)
> > > >
>
> --
> Regards,
>
> Laurent Pinchart
>

Regards,
*Vedant Paranjape*
Laurent Pinchart Aug. 30, 2021, 11:18 a.m. UTC | #5 
Hi Vedant,

On Sun, Aug 29, 2021 at 03:34:46PM +0530, Vedant Paranjape wrote:
> On Sun, Aug 29, 2021 at 2:56 PM Laurent Pinchart wrote:
> > On Sun, Aug 29, 2021 at 10:53:34AM +0530, Vedant Paranjape wrote:
> > > On Sun, Aug 29, 2021 at 6:39 AM Laurent Pinchart wrote:
> > > > On Sat, Aug 28, 2021 at 11:07:53PM +0530, Vedant Paranjape wrote:
> > > > > 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 > he
> > > > >   suppression file shipped with glib, but it's not clear how to use > t
> > > > >   automatically. For now, disable leak detection to avoid test > ailures.
> > > > >
> > > > > Signed-off-by: Vedant Paranjape <vedantparanjape160201@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 > /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 > apture 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 > nitialization
> > > > > +      * leak in glib's g_quark_init(). This should ideally be > andled by
> > > > > +      * using a suppression file instead of disabling leak > etection.
> > > > > +      */
> > > > > +     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 > ith ASan
> > > > > +              * enabled, and as GStreamer is most likely not, this > auses the
> > > > > +              * ASan link order check to fail when > st-plugin-scanner
> > > > > +              * dlopen()s the plugin as many libraries will have > lready been
> > > > > +              * loaded by then. Fix this issue by disabling > pawning of a
> > > > > +              * child helper process when scanning the build > irectory 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 > he
> > > > > +              * 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 = > ibcamera::utils::libcameraBuildPath()
> > > > > +                              + "src/gstreamer";
> > > > > +             if (!gst_registry_scan_path(registry, path.c_str())) {
> > > > > +                     g_printerr("Failed to add plugin to > egistry\n");
> > > > > +                     gst_deinit();
> > > > > +                     return TestFail;
> > > > > +             }
> > > >
> > > > There's quite a bit of duplicated code between this and the single
> > > > stream test. Could you refactor the single stream test to create a base
> > > > class that can be shared with this one ?
> > >
> > > Yes, I am going to do this, but can we go about it as follows, merge this
> > > patch with duplicated code,
> > > then I think over it a bit and then submit new patch which refactors a lot
> > > of the duplicated code,
> >
> > Why ? :-) I'm fine merging work in progress when there's a reason (for
> > instance to split very large partch series in chunks, or to avoid
> > blocking development when other developers depend on that code), but in
> > this case I think a refactoring before merging the second test is
> > better.
> 
> Because that will make reviewing difficult.

Being on the reviewer side, I respectfully disagree :-)

> > also I don't think going ahead with making a base class is a good idea as,
> > > there's much functional difference between two codes,
> > > they rather have isolated code that repeats, but no so much as to roll it
> > > into a class.
> >
> > I don't agree, I think the tests are very similar. diffstat agrees with
> > me.
> >
> > $ diff -u gstreamer_single_stream_test.cpp gstreamer_multi_stream_test.cpp | diffstat
> >  gstreamer_multi_stream_test.cpp |   62 +++++++++++++++++++++++++++++++++++++++++++++++++++++++-------
> >  1 file changed, 55 insertions(+), 7 deletions(-)
> 
> Other than the code that loads gstreamer libcamera library, none of the
> other code can be modularized. small blocks of code are similar
> in between, but "similar" not "same". I am unable to comeup with a way to
> refactor it more.
> 
> > > +
> > > > > +             /* Check if platform support multistream output */
> > > > > +             libcamera::CameraManager cm;
> > > > > +             cm.start();
> > > > > +             if (cm.cameras()[0]->streams().size() <= 1) {
> > > > > +                     cm.stop();
> > > > > +                     return TestSkip;
> > > > > +             }
> > > > > +             cm.stop();
> > > >
> > > > Is there a guarantee that libcamerasrc will pick the same camera ? It
> > >
> > > Yes, it is guaranteed if we don't pass it a camera-name which we aren't see
> > > here:
> > >
> > https://git.linuxtv.org/libcamera.git/tree/src/gstreamer/gstlibcamerasrc.cpp#n237
> > >
> > > > seems quite fragile to me. Isn't there a way to instead query the
> > > > libcamerasrc element for the number of pads it supports ?
> > >
> > > I think this won't be possible unless we add code to the
> > > gstreamer-element, @Nicolas
> > > Dufresne <nicolas@ndufresne.ca> can
> > > you answer this please, I am not sure :)
> >
> > The GstElement documentation mentions a numsrcpads field. I have little
> > experience with GStreamer, but it sounds like something that could help.
> > Have you tried it ?
> 
> No, this won't work. An element by default will generate a single source pad, after that I'd need
> to explicitly request a request pad, which will map to a new stream. I guess this variable stores the
> the number of active source pads and not the theoretical supported pads.

Good point. I'll defer to Nicolas on this topic.

> > > > More than
> > > > that, as not all cameras support multiple streams, it would be nice if
> > > > the test could iterate over all cameras to find one that does.
> > >
> > > This sounds like a nice idea, I could store the camera-name of the specific
> > > camera and set the camera-name property
> > > of the libcamera element and start on it, but now I don't a multicamera
> > > setup.
> > >
> > > > +
> > > > > +             /* Create the elements */
> > > > > +             libcameraSrc_ = > st_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");
> > > >
> > > > Looks like there's room to make the code more generic, posibly storing
> > > > the elements in containers.
> > >
> > > Okay something like a vector to hold the elements and then a map to hold
> > > <element name, unique name>.
> > > But this is a test code, is this fancy stuff really needed ? !!
> >
> > Test code doesn't mean that it has to be dirty and throw away all
> > software development good practices. Tests are first class citizens.
> > It's not about "fancy stuff", it's about making the code more readable
> > and maintainable.
> 
> I am not sure what is the ideal way for you to do it, please let me know.
> Just adding all these elements in
> a struct ?

I'll review the patch you've sent, it's easier to discuss it in that
context.

> > > > +
> > > > > +             /* 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 > reated.> %p.%p.%p.%p.%p.%p.%p.%p\n",
> > > > > +                                             pipeline_, convert0_, > onvert1_, sink0_,
> > > > > +                                             sink1_, queue0_, > ueue1_, 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_, > ueue0_, queue1_,
> > > > > +                                                     convert0_, > onvert1_, sink0_, sink1_, NULL);
> > > > > +             if (gst_element_link_many(queue0_, convert0_, sink0_, > ULL) != TRUE
> > > > > +                             || gst_element_link_many(queue1_, > onvert1_, sink1_, NULL) != TRUE) {
> > > > > +                     g_printerr("Elements could not be linked.\n");
> > > > > +                     return TestFail;
> > > > > +             }
> > > > > +
> > > > > +             g_autoptr(GstPad) src_pad = > st_element_get_static_pad(libcameraSrc_, "src");
> > > > > +             g_autoptr(GstPad) request_pad = > st_element_get_request_pad(libcameraSrc_, "src_%u");
> > > > > +             GstPad *queue0_sink_pad = > st_element_get_static_pad(queue0_, "sink");
> > > > > +             GstPad *queue1_sink_pad = > st_element_get_static_pad(queue1_, "sink");
> > > > > +
> > > > > +             if (gst_pad_link(src_pad, queue0_sink_pad) != > ST_PAD_LINK_OK
> > > > > +                             || gst_pad_link(request_pad, > ueue1_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_, > ST_STATE_PLAYING);
> > > > > +             if (ret == GST_STATE_CHANGE_FAILURE) {
> > > > > +                     g_printerr("Unable to set the pipeline to the > laying 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 = > st_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), > rr->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)
> > > > >

Patch
diff mbox series 

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)