gstreamer: Add enable_auto_focus option to the GStreamer plugin

Cameras such as the PiCam 3 support auto-focus, but the GStreamer plugin
for libcamera does not enable auto-focus. With this patch auto-focus can
be enabled for cameras that support it. By default it is disabled, which
means default behaviour remains unchanged. For cameras that do not
support auto-focus, an error message shows up if auto-focus is enabled.

This was tested on cameras that do not support auto-focus (e.g. PiCam2)
and was tested on a camera that does support auto-focus (PiCam3). The
test involved setting the focus to AfModeContinous and observing it.
However, by not setting "auto-focus-mode" or using AfModeManual as
the "auto-focus-mode" both resulting in auto-focus being disabled.

Bug: https://bugs.libcamera.org/show_bug.cgi?id=188
Signed-off-by: Cedric Nugteren <cedric@plumerai.com>
Reviewed-by: Maarten Lankhorst <dev@lankhorst.se>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>
Tested-by: Umang Jain <umang.jain@ideasonboard.com>
Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>

1 files changed, 31 insertions, 0 deletions

diff --git a/src/gstreamer/gstlibcamerasrc.h b/src/gstreamer/gstlibcamerasrc.h
index fdea2f10..0a88ba02 100644
--- a/src/gstreamer/gstlibcamerasrc.h
+++ b/src/gstreamer/gstlibcamerasrc.h
@@ -8,6 +8,8 @@
 
 #pragma once
 
+#include <libcamera/control_ids.h>
+
 #include <gst/gst.h>
 
 G_BEGIN_DECLS
@@ -17,3 +19,32 @@ G_DECLARE_FINAL_TYPE(GstLibcameraSrc, gst_libcamera_src,
 		     GST_LIBCAMERA, SRC, GstElement)
 
 G_END_DECLS
+
+inline GType
+gst_libcamera_auto_focus_get_type()
+{
+	static GType type = 0;
+	static const GEnumValue values[] = {
+		{
+			static_cast<gint>(libcamera::controls::AfModeManual),
+			"AfModeManual",
+			"manual-focus",
+		},
+		{
+			static_cast<gint>(libcamera::controls::AfModeAuto),
+			"AfModeAuto",
+			"automatic-auto-focus",
+		},
+		{
+			static_cast<gint>(libcamera::controls::AfModeContinuous),
+			"AfModeContinuous",
+			"continuous-auto-focus",
+		},
+		{ 0, NULL, NULL }
+	};
+
+	if (!type)
+		type = g_enum_register_static("GstLibcameraAutoFocus", values);
+
+	return type;
+}