[libcamera-devel] [PATCH v2 03/27] gst: Add initial device provider
Laurent Pinchart
laurent.pinchart at ideasonboard.com
Sat Feb 29 14:30:46 CET 2020
Hi Nicolas,
Thank you for the patch.
On Thu, Feb 27, 2020 at 03:03:43PM -0500, Nicolas Dufresne wrote:
> This feature is used with GstDeviceMonitor in order to enumerate
> and monitor devices to be used with the source element. The resulting
> GstDevice implementation is also used by application to abstract the
> configuration of the source element.
>
> Implementation notes:
> - libcamera does not support polling yet
> - The device ID isn't unique in libcamera yet
> - The "name" property does not yet exist in libcamerasrc yet
>
> Signed-off-by: Nicolas Dufresne <nicolas.dufresne at collabora.com>
> ---
> src/gstreamer/gstlibcamera.c | 10 +-
> src/gstreamer/gstlibcameraprovider.cpp | 235 +++++++++++++++++++++++++
> src/gstreamer/gstlibcameraprovider.h | 23 +++
> src/gstreamer/meson.build | 1 +
> 4 files changed, 267 insertions(+), 2 deletions(-)
> create mode 100644 src/gstreamer/gstlibcameraprovider.cpp
> create mode 100644 src/gstreamer/gstlibcameraprovider.h
>
> diff --git a/src/gstreamer/gstlibcamera.c b/src/gstreamer/gstlibcamera.c
> index 7dd94ca..81c7bb1 100644
> --- a/src/gstreamer/gstlibcamera.c
> +++ b/src/gstreamer/gstlibcamera.c
> @@ -6,13 +6,19 @@
> * gstlibcamera.c - GStreamer plugin
> */
>
> +#include "gstlibcameraprovider.h"
> #include "gstlibcamerasrc.h"
>
> static gboolean
> plugin_init(GstPlugin *plugin)
> {
> - return gst_element_register(plugin, "libcamerasrc", GST_RANK_PRIMARY,
> - GST_TYPE_LIBCAMERA_SRC);
> + if (!gst_element_register(plugin, "libcamerasrc", GST_RANK_PRIMARY,
> + GST_TYPE_LIBCAMERA_SRC) ||
> + !gst_device_provider_register(plugin, "libcameraprovider",
> + GST_RANK_PRIMARY,
> + GST_TYPE_LIBCAMERA_PROVIDER))
> + return FALSE;
> +
> return TRUE;
> }
>
> diff --git a/src/gstreamer/gstlibcameraprovider.cpp b/src/gstreamer/gstlibcameraprovider.cpp
> new file mode 100644
> index 0000000..3dcac59
> --- /dev/null
> +++ b/src/gstreamer/gstlibcameraprovider.cpp
> @@ -0,0 +1,235 @@
> +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> +/*
> + * Copyright (C) 2020, Collabora Ltd.
> + * Author: Nicolas Dufresne <nicolas.dufresne at collabora.com>
> + *
> + * gstlibcameraprovider.c - GStreamer Device Provider
> + */
> +
> +#include "gstlibcamera-utils.h"
> +#include "gstlibcameraprovider.h"
> +#include "gstlibcamerasrc.h"
> +
> +#include <libcamera/camera.h>
> +#include <libcamera/camera_manager.h>
> +
> +using namespace libcamera;
> +
> +GST_DEBUG_CATEGORY_STATIC(provider_debug);
> +#define GST_CAT_DEFAULT provider_debug
> +
> +/**
> + * \struct _GstLibcameraDevice
> + * \brief libcamera GstDevice implementation
> + *
> + * This object will be used by GstLibcameraProder to abstract a libcamera
s/GstLibcameraProder/GstLibcameraProvider/
I would already write "is used" instead of "will be used", otherwise
you'll have to change that later.
> + * device. It also provides helpers to create and configure the
> + * libcamerasrc GstElement to be used with this device. The implementation is
> + * private to the plugin.
> + */
Thanks for providing documentation for the structures, it's very useful.
> +
> +enum {
> + PROP_DEVICE_NAME = 1,
> +};
> +
> +#define GST_TYPE_LIBCAMERA_DEVICE gst_libcamera_device_get_type()
> +G_DECLARE_FINAL_TYPE(GstLibcameraDevice, gst_libcamera_device,
> + GST_LIBCAMERA, DEVICE, GstDevice);
> +
> +struct _GstLibcameraDevice {
> + GstDevice parent;
> + gchar *name;
> +};
> +
> +G_DEFINE_TYPE(GstLibcameraDevice, gst_libcamera_device, GST_TYPE_DEVICE);
> +
> +static GstElement *
> +gst_libcamera_device_create_element(GstDevice *device, const gchar *name)
> +{
> + GstElement *source = gst_element_factory_make("libcamerasrc", name);
> +
> + /* Provider and source lives in the same plugin, so making the source
> + * should never fail. */
The comment style should be
/*
* Provider and source lives in the same plugin, so making the source
* should never fail.
*/
I'll try to nerd-snipe Kieran again to add this to checkstyle.py :-)
> + g_assert(source);
> +
> + g_object_set(source, "camera-name", GST_LIBCAMERA_DEVICE(device)->name, nullptr);
> +
> + return source;
> +}
> +
> +static gboolean
> +gst_libcamera_device_reconfigure_element(GstDevice *device,
> + GstElement *element)
> +{
> + if (!GST_LIBCAMERA_IS_SRC(element))
> + return FALSE;
> +
> + g_object_set(element, "camera-name", GST_LIBCAMERA_DEVICE(device)->name, nullptr);
> +
> + return TRUE;
> +}
> +
> +static void
> +gst_libcamera_device_set_property(GObject *object, guint prop_id,
> + const GValue *value, GParamSpec *pspec)
> +{
> + GstLibcameraDevice *device = GST_LIBCAMERA_DEVICE(object);
> +
> + switch (prop_id) {
> + case PROP_DEVICE_NAME:
> + device->name = g_value_dup_string(value);
> + break;
> + default:
> + G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
> + break;
> + }
> +}
> +
> +static void
> +gst_libcamera_device_init(GstLibcameraDevice *self)
> +{
> +}
> +
> +static void
> +gst_libcamera_device_finalize(GObject *object)
> +{
> + GstLibcameraDevice *self = GST_LIBCAMERA_DEVICE(object);
> + gpointer klass = gst_libcamera_device_parent_class;
> +
> + g_free(self->name);
> +
> + G_OBJECT_GET_CLASS(klass)->finalize(object);
> +}
> +
> +static void
> +gst_libcamera_device_class_init(GstLibcameraDeviceClass *klass)
> +{
> + GstDeviceClass *device_class = GST_DEVICE_CLASS(klass);
> + GObjectClass *object_class = G_OBJECT_CLASS(klass);
> +
> + device_class->create_element = gst_libcamera_device_create_element;
> + device_class->reconfigure_element = gst_libcamera_device_reconfigure_element;
> +
> + object_class->set_property = gst_libcamera_device_set_property;
> + object_class->finalize = gst_libcamera_device_finalize;
> +
> + GParamSpec *pspec = g_param_spec_string("name", "Name",
> + "The name of the camera device", "",
> + (GParamFlags)(G_PARAM_STATIC_STRINGS | G_PARAM_WRITABLE |
> + G_PARAM_CONSTRUCT_ONLY));
> + g_object_class_install_property(object_class, PROP_DEVICE_NAME, pspec);
> +}
> +
> +static GstDevice *
> +gst_libcamera_device_new(const std::shared_ptr<Camera> &camera)
> +{
> + g_autoptr(GstCaps) caps = gst_caps_new_empty();
> + const gchar *name = camera->name().c_str();
> + StreamRoles roles;
> +
> + roles.push_back(StreamRole::VideoRecording);
> + std::unique_ptr<CameraConfiguration> config = camera->generateConfiguration(roles);
> +
> + for (const StreamConfiguration &stream_cfg : *config) {
> + GstCaps *sub_caps = gst_libcamera_stream_formats_to_caps(stream_cfg.formats());
> + if (sub_caps)
> + gst_caps_append(caps, sub_caps);
> + }
> +
> + return GST_DEVICE(g_object_new(GST_TYPE_LIBCAMERA_DEVICE,
> + /* \todo Use a unique identifier instead of camera name. */
> + "name", name,
> + "display-name", name,
> + "caps", caps,
> + "device-class", "Source/Video",
> + nullptr));
> +}
> +
> +/**
> + * \struct _GstLibcameraProvider
> + * \brief libcamera GstDeviceProvider implementation
> + *
> + * This GstFeature will be used by GstDeviceMonitor to probe the available
s/will be used/is used/
> + * libcamera devices. The implementation is private to the plugin.
s/ / /
> + */
> +
> +struct _GstLibcameraProvider {
> + GstDeviceProvider parent;
> + CameraManager *cm;
> +};
> +
> +G_DEFINE_TYPE_WITH_CODE(GstLibcameraProvider, gst_libcamera_provider,
> + GST_TYPE_DEVICE_PROVIDER,
> + GST_DEBUG_CATEGORY_INIT(provider_debug, "libcamera-provider", 0,
> + "libcamera Device Provider"));
> +
> +static GList *
> +gst_libcamera_provider_probe(GstDeviceProvider *provider)
> +{
> + GstLibcameraProvider *self = GST_LIBCAMERA_PROVIDER(provider);
> + CameraManager *cm = self->cm;
> + GList *devices = nullptr;
> + gint ret;
> +
> + GST_INFO_OBJECT(self, "Probing cameras using libcamera");
> +
> + /* \todo Move the CameraMananger start()/stop() calls into
> + * GstDeviceProfiler start()/stop() virtual function when CameraMananger
s/GstDeviceProfiler/GstDeviceProvider/
With those small issues fixed,
Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> + * gains monitoring support. Meanwhile we need to cycle start()/stop()
> + * to ensure every probe() calls return the latest list.
> + */
> + ret = cm->start();
> + if (ret) {
> + GST_ERROR_OBJECT(self, "Failed to retrieve device list: %s",
> + g_strerror(-ret));
> + return nullptr;
> + }
> +
> + for (const std::shared_ptr<Camera> &camera : cm->cameras()) {
> + GST_INFO_OBJECT(self, "Found camera '%s'", camera->name().c_str());
> + devices = g_list_append(devices,
> + g_object_ref_sink(gst_libcamera_device_new(camera)));
> + }
> +
> + cm->stop();
> +
> + return devices;
> +}
> +
> +static void
> +gst_libcamera_provider_init(GstLibcameraProvider *self)
> +{
> + GstDeviceProvider *provider = GST_DEVICE_PROVIDER(self);
> +
> + self->cm = new CameraManager();
> +
> + /* Avoid devices being duplicated. */
> + gst_device_provider_hide_provider(provider, "v4l2deviceprovider");
> +}
> +
> +static void
> +gst_libcamera_provider_finalize(GObject *object)
> +{
> + GstLibcameraProvider *self = GST_LIBCAMERA_PROVIDER(object);
> + gpointer klass = gst_libcamera_provider_parent_class;
> +
> + delete self->cm;
> +
> + return G_OBJECT_GET_CLASS(klass)->finalize(object);
> +}
> +
> +static void
> +gst_libcamera_provider_class_init(GstLibcameraProviderClass *klass)
> +{
> + GstDeviceProviderClass *provider_class = GST_DEVICE_PROVIDER_CLASS(klass);
> + GObjectClass *object_class = G_OBJECT_CLASS(klass);
> +
> + provider_class->probe = gst_libcamera_provider_probe;
> + object_class->finalize = gst_libcamera_provider_finalize;
> +
> + gst_device_provider_class_set_metadata(provider_class,
> + "libcamera Device Provider",
> + "Source/Video",
> + "List camera device using libcamera",
> + "Nicolas Dufresne <nicolas.dufresne at collabora.com>");
> +}
> diff --git a/src/gstreamer/gstlibcameraprovider.h b/src/gstreamer/gstlibcameraprovider.h
> new file mode 100644
> index 0000000..bdd19db
> --- /dev/null
> +++ b/src/gstreamer/gstlibcameraprovider.h
> @@ -0,0 +1,23 @@
> +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> +/*
> + * Copyright (C) 2020, Collabora Ltd.
> + * Author: Nicolas Dufresne <nicolas.dufresne at collabora.com>
> + *
> + * gstlibcameraprovider.h - GStreamer Device Provider
> + */
> +
> +#ifndef __GST_LIBCAMERA_PROVIDER_H__
> +#define __GST_LIBCAMERA_PROVIDER_H__
> +
> +#include <gst/gst.h>
> +
> +G_BEGIN_DECLS
> +
> +#define GST_TYPE_LIBCAMERA_PROVIDER gst_libcamera_provider_get_type()
> +G_DECLARE_FINAL_TYPE(GstLibcameraProvider, gst_libcamera_provider,
> + GST_LIBCAMERA, PROVIDER, GstDeviceProvider)
> +
> +G_END_DECLS
> +
> +#endif /* __GST_LIBCAMERA_PROVIDER_H__ */
> +
> diff --git a/src/gstreamer/meson.build b/src/gstreamer/meson.build
> index f409107..a57dd85 100644
> --- a/src/gstreamer/meson.build
> +++ b/src/gstreamer/meson.build
> @@ -1,6 +1,7 @@
> libcamera_gst_sources = [
> 'gstlibcamera-utils.cpp',
> 'gstlibcamera.c',
> + 'gstlibcameraprovider.cpp',
> 'gstlibcamerasrc.cpp',
> ]
>
--
Regards,
Laurent Pinchart
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