[libcamera-devel] [PATCH v2] gstreamer: Maintain a control list to track libcamerasrc control properties

[Nicolas Dufresne]

Le lundi 26 juin 2023 à 19:47 +0200, Umang Jain a écrit :
> As more and more libcamera controls get plumbed, more member variables
> get introduced in struct GstLibcameraSrc. Instead of doing that, now
> maintain a single ControlList which is more appropriate to keep track
> of controls that get sets on libcamerasrc.
> 
> This also brings easy validation of controls set on libcamerasrc. If
> the controls are not supported by camera, fail negotiation and report
> what is not supported.
> 
> The current patch migrates previously introduced control,
> auto-focus-mode, to be set directly in control list.
> 
> Signed-off-by: Umang Jain <umang.jain at ideasonboard.com>
> ---
> Changes in v2:
> - Edit commit message 
> - Drop a break; so that all unsupported user-provided controls are
>   reported at once.
> ---
>  src/gstreamer/gstlibcamerasrc.cpp | 44 ++++++++++++++++++++++---------
>  src/gstreamer/gstlibcamerasrc.h   |  6 ++---
>  2 files changed, 35 insertions(+), 15 deletions(-)
> 
> diff --git a/src/gstreamer/gstlibcamerasrc.cpp b/src/gstreamer/gstlibcamerasrc.cpp
> index 47d8ff43..11f15068 100644
> --- a/src/gstreamer/gstlibcamerasrc.cpp
> +++ b/src/gstreamer/gstlibcamerasrc.cpp
> @@ -146,7 +146,7 @@ struct _GstLibcameraSrc {
>  	GstTask *task;
>  
>  	gchar *camera_name;
> -	controls::AfModeEnum auto_focus_mode = controls::AfModeManual;
> +	ControlList *controls;
>  
>  	GstLibcameraSrcState *state;
>  	GstLibcameraAllocator *allocator;
> @@ -462,7 +462,9 @@ gst_libcamera_src_task_enter(GstTask *task, [[maybe_unused]] GThread *thread,
>  	GstLibcameraSrc *self = GST_LIBCAMERA_SRC(user_data);
>  	GLibRecLocker lock(&self->stream_lock);
>  	GstLibcameraSrcState *state = self->state;
> +	const ControlInfoMap &info_map = state->cam_->controls();
>  	GstFlowReturn flow_ret = GST_FLOW_OK;
> +	gboolean supported_ctrl = true;
>  	gint ret;
>  
>  	g_autoptr(GstStructure) element_caps = gst_structure_new_empty("caps");
> @@ -579,18 +581,30 @@ gst_libcamera_src_task_enter(GstTask *task, [[maybe_unused]] GThread *thread,
>  		gst_flow_combiner_add_pad(self->flow_combiner, srcpad);
>  	}
>  
> -	if (self->auto_focus_mode != controls::AfModeManual) {
> -		const ControlInfoMap &infoMap = state->cam_->controls();
> -		if (infoMap.find(&controls::AfMode) != infoMap.end()) {
> -			state->initControls_.set(controls::AfMode, self->auto_focus_mode);
> -		} else {
> +	/*
> +	 * Check the controls set on libcamerasrc is supported by the camera.
> +	 * This can be easily done by CameraControlValidator but it is an internal
> +	 * libcamera class. Hence avoid adding a internal header even though
> +	 * gstreamer links with libcamera-private.

I don't remember why GStreamer links to that, and why we should accept this as a
fact. The longer term plan, when libcamera is stable, was to migrate this
element into GStreamer project, but such thing will prevent it.

> +	 */
> +	for (auto iter = self->controls->begin(); iter != self->controls->end(); iter++) {
> +		if (info_map.find(iter->first) == info_map.end()) {
> +			const ControlIdMap *id_map = self->controls->idMap();
>  			GST_ELEMENT_ERROR(self, RESOURCE, SETTINGS,
> -					  ("Failed to enable auto focus"),
> -					  ("AfMode not supported by this camera, "
> -					   "please retry with 'auto-focus-mode=AfModeManual'"));
> +					  ("Failed to set %s", id_map->at(iter->first)->name().c_str()),
> +					  ("%s not supported by this camera, ", id_map->at(iter->first)->name().c_str()));
> +			supported_ctrl = false;
>  		}
>  	}
>  
> +	if (!supported_ctrl) {
> +		gst_task_stop(task);
> +		flow_ret = GST_FLOW_NOT_NEGOTIATED;
> +		goto done;
> +	}
> +
> +	state->initControls_.merge(*self->controls);
> +
>  	ret = state->cam_->start(&state->initControls_);
>  	if (ret) {
>  		GST_ELEMENT_ERROR(self, RESOURCE, SETTINGS,
> @@ -674,7 +688,8 @@ gst_libcamera_src_set_property(GObject *object, guint prop_id,
>  		self->camera_name = g_value_dup_string(value);
>  		break;
>  	case PROP_AUTO_FOCUS_MODE:
> -		self->auto_focus_mode = static_cast<controls::AfModeEnum>(g_value_get_enum(value));
> +		self->controls->set(controls::AfMode,
> +				    static_cast<controls::AfModeEnum>(g_value_get_enum(value)));
>  		break;
>  	default:
>  		G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
> @@ -693,9 +708,11 @@ gst_libcamera_src_get_property(GObject *object, guint prop_id, GValue *value,
>  	case PROP_CAMERA_NAME:
>  		g_value_set_string(value, self->camera_name);
>  		break;
> -	case PROP_AUTO_FOCUS_MODE:
> -		g_value_set_enum(value, static_cast<gint>(self->auto_focus_mode));
> +	case PROP_AUTO_FOCUS_MODE: {
> +		auto auto_focus_mode = self->controls->get(controls::AfMode).value_or(controls::AfModeManual);
> +		g_value_set_enum(value, auto_focus_mode);
>  		break;
> +	}
>  	default:
>  		G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
>  		break;
> @@ -760,6 +777,7 @@ gst_libcamera_src_finalize(GObject *object)
>  	g_rec_mutex_clear(&self->stream_lock);
>  	g_clear_object(&self->task);
>  	g_free(self->camera_name);
> +	delete self->controls;
>  	delete self->state;
>  
>  	return klass->finalize(object);
> @@ -783,6 +801,8 @@ gst_libcamera_src_init(GstLibcameraSrc *self)
>  	/* C-style friend. */
>  	state->src_ = self;
>  	self->state = state;
> +
> +	self->controls = new ControlList(controls::controls, nullptr);
>  }
>  
>  static GstPad *
> diff --git a/src/gstreamer/gstlibcamerasrc.h b/src/gstreamer/gstlibcamerasrc.h
> index 0a88ba02..2e6d74cb 100644
> --- a/src/gstreamer/gstlibcamerasrc.h
> +++ b/src/gstreamer/gstlibcamerasrc.h
> @@ -26,17 +26,17 @@ gst_libcamera_auto_focus_get_type()
>  	static GType type = 0;
>  	static const GEnumValue values[] = {
>  		{
> -			static_cast<gint>(libcamera::controls::AfModeManual),
> +			libcamera::controls::AfModeManual,
>  			"AfModeManual",
>  			"manual-focus",
>  		},
>  		{
> -			static_cast<gint>(libcamera::controls::AfModeAuto),
> +			libcamera::controls::AfModeAuto,
>  			"AfModeAuto",
>  			"automatic-auto-focus",
>  		},
>  		{
> -			static_cast<gint>(libcamera::controls::AfModeContinuous),
> +			libcamera::controls::AfModeContinuous,
>  			"AfModeContinuous",
>  			"continuous-auto-focus",
>  		},