gst: Add pads to the source

This simply adds the boiler plate for pads on the source element. The
design is that we have one pad, called "src", that will always be
present, and then more pads can be requested prior in READY or less
state. Initially pads have one property "stream-role" that let you
decide which role this pad will have.

Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

1 files changed, 102 insertions, 0 deletions

diff --git a/src/gstreamer/gstlibcamerapad.cpp b/src/gstreamer/gstlibcamerapad.cpp
new file mode 100644
index 00000000..ca5c8203
--- /dev/null
+++ b/src/gstreamer/gstlibcamerapad.cpp
@@ -0,0 +1,102 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2019, Collabora Ltd.
+ *     Author: Nicolas Dufresne <nicolas.dufresne@collabora.com>
+ *
+ * gstlibcamerapad.cpp - GStreamer Capture Pad
+ */
+
+#include "gstlibcamerapad.h"
+
+#include <libcamera/stream.h>
+
+#include "gstlibcamera-utils.h"
+
+using namespace libcamera;
+
+struct _GstLibcameraPad {
+	GstPad parent;
+	StreamRole role;
+};
+
+enum {
+	PROP_0,
+	PROP_STREAM_ROLE
+};
+
+G_DEFINE_TYPE(GstLibcameraPad, gst_libcamera_pad, GST_TYPE_PAD);
+
+static void
+gst_libcamera_pad_set_property(GObject *object, guint prop_id,
+			       const GValue *value, GParamSpec *pspec)
+{
+	auto *self = GST_LIBCAMERA_PAD(object);
+	GLibLocker lock(GST_OBJECT(self));
+
+	switch (prop_id) {
+	case PROP_STREAM_ROLE:
+		self->role = (StreamRole)g_value_get_enum(value);
+		break;
+	default:
+		G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
+		break;
+	}
+}
+
+static void
+gst_libcamera_pad_get_property(GObject *object, guint prop_id, GValue *value,
+			       GParamSpec *pspec)
+{
+	auto *self = GST_LIBCAMERA_PAD(object);
+	GLibLocker lock(GST_OBJECT(self));
+
+	switch (prop_id) {
+	case PROP_STREAM_ROLE:
+		g_value_set_enum(value, self->role);
+		break;
+	default:
+		G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
+		break;
+	}
+}
+
+static void
+gst_libcamera_pad_init(GstLibcameraPad *self)
+{
+}
+
+static GType
+gst_libcamera_stream_role_get_type(void)
+{
+	static GType type = 0;
+	static const GEnumValue values[] = {
+		{ StillCapture, "libcamera::StillCapture", "still-capture" },
+		{ VideoRecording, "libcamera::VideoRecording", "video-recording" },
+		{ Viewfinder, "libcamera::Viewfinder", "view-finder" },
+		{ 0, NULL, NULL }
+	};
+
+	if (!type)
+		type = g_enum_register_static("GstLibcameraStreamRole", values);
+
+	return type;
+}
+
+static void
+gst_libcamera_pad_class_init(GstLibcameraPadClass *klass)
+{
+	auto *object_class = G_OBJECT_CLASS(klass);
+
+	object_class->set_property = gst_libcamera_pad_set_property;
+	object_class->get_property = gst_libcamera_pad_get_property;
+
+	auto *spec = g_param_spec_enum("stream-role", "Stream Role",
+				       "The selected stream role",
+				       gst_libcamera_stream_role_get_type(),
+				       VideoRecording,
+				       (GParamFlags)(GST_PARAM_MUTABLE_READY
+					             | G_PARAM_CONSTRUCT
+						     | G_PARAM_READWRITE
+						     | G_PARAM_STATIC_STRINGS));
+	g_object_class_install_property(object_class, PROP_STREAM_ROLE, spec);
+}