[v6] gstreamer: Plumb camera orientation configuration in libcamerasrc

24979 diff mbox series

Plumb the support for CameraConfiguration::orientation in libcamerasrc.
A new "orientation" property is introduced and mappings for
libcamera::Orientation <> GstVideoOrientationMethod are provided
with helpers.

If the orientation is changed after the CameraConfiguration::validate(),
a GstMessage is sent on the GstBus to report the new orientation
property value.

In case the orientation that was requested cannot be satisfied,
a 'image-orientation' tag is pushed downstream for sinks to rotate
the stream accordingly (those implementing
GSTGST_VIDEO_ORIENTATION_AUTO).

Signed-off-by: Umang Jain <uajain@igalia.com>
---
Changes in v6:
- Use GstMessage to send new property changes if any (like orientation
  after validate())
- send 'image-orientation' tag orientation downstream if orientation
  cannot be satisfied
- Drop 'video-orientation' and restore 'orientation' as property name
- change authorship to myself as patch is reworked significantly

Changes in v5:
- patch scrubbing and cleanup
- If different orientation is returned than requested, update the
  property
- Minor string fixes, append appropriate tags

Link to v4: https://patchwork.libcamera.org/patch/23965/

Note: Checkstyle will complain on this patch on a hunk, but the existing format
is quite read-able IMO, hence ignored.
---
 src/gstreamer/gstlibcamera-utils.cpp | 60 ++++++++++++++++++++++++++++
 src/gstreamer/gstlibcamera-utils.h   |  5 +++
 src/gstreamer/gstlibcamerasrc.cpp    | 58 +++++++++++++++++++++++++++
 3 files changed, 123 insertions(+)

Hi Umang,
  I noticed this patch -really- fell into the cracks..

Is it still valid, still something that hasn't been addressed
otherwise, right ?

On Thu, Nov 06, 2025 at 01:01:33PM +0000, Umang Jain wrote:
> Plumb the support for CameraConfiguration::orientation in libcamerasrc.
> A new "orientation" property is introduced and mappings for
> libcamera::Orientation <> GstVideoOrientationMethod are provided
> with helpers.
>
> If the orientation is changed after the CameraConfiguration::validate(),
> a GstMessage is sent on the GstBus to report the new orientation
> property value.
>
> In case the orientation that was requested cannot be satisfied,
> a 'image-orientation' tag is pushed downstream for sinks to rotate
> the stream accordingly (those implementing
> GSTGST_VIDEO_ORIENTATION_AUTO).
>
> Signed-off-by: Umang Jain <uajain@igalia.com>
> ---
> Changes in v6:
> - Use GstMessage to send new property changes if any (like orientation
>   after validate())
> - send 'image-orientation' tag orientation downstream if orientation
>   cannot be satisfied
> - Drop 'video-orientation' and restore 'orientation' as property name
> - change authorship to myself as patch is reworked significantly
>
> Changes in v5:
> - patch scrubbing and cleanup
> - If different orientation is returned than requested, update the
>   property
> - Minor string fixes, append appropriate tags
>
> Link to v4: https://patchwork.libcamera.org/patch/23965/
>
> Note: Checkstyle will complain on this patch on a hunk, but the existing format
> is quite read-able IMO, hence ignored.
> ---
>  src/gstreamer/gstlibcamera-utils.cpp | 60 ++++++++++++++++++++++++++++
>  src/gstreamer/gstlibcamera-utils.h   |  5 +++
>  src/gstreamer/gstlibcamerasrc.cpp    | 58 +++++++++++++++++++++++++++
>  3 files changed, 123 insertions(+)
>
> diff --git a/src/gstreamer/gstlibcamera-utils.cpp b/src/gstreamer/gstlibcamera-utils.cpp
> index bfb094c9..79fb606b 100644
> --- a/src/gstreamer/gstlibcamera-utils.cpp
> +++ b/src/gstreamer/gstlibcamera-utils.cpp
> @@ -357,6 +357,42 @@ control_type_to_gtype(const ControlType &type)
>  	return G_TYPE_INVALID;
>  }
>
> +static const struct {
> +	Orientation orientation;
> +	GstVideoOrientationMethod method;
> +} orientation_map[]{
> +	{ Orientation::Rotate0, GST_VIDEO_ORIENTATION_IDENTITY },
> +	{ Orientation::Rotate90, GST_VIDEO_ORIENTATION_90R },
> +	{ Orientation::Rotate180, GST_VIDEO_ORIENTATION_180 },
> +	{ Orientation::Rotate270, GST_VIDEO_ORIENTATION_90L },
> +	{ Orientation::Rotate0Mirror, GST_VIDEO_ORIENTATION_HORIZ },
> +	{ Orientation::Rotate180Mirror, GST_VIDEO_ORIENTATION_VERT },
> +	{ Orientation::Rotate90Mirror, GST_VIDEO_ORIENTATION_UL_LR },
> +	{ Orientation::Rotate270Mirror, GST_VIDEO_ORIENTATION_UR_LL },
> +};
> +
> +Orientation
> +gst_video_orientation_to_libcamera_orientation(GstVideoOrientationMethod method)
> +{
> +	for (auto &b : orientation_map) {
> +		if (b.method == method)
> +			return b.orientation;
> +	}
> +
> +	return Orientation::Rotate0;
> +}
> +
> +GstVideoOrientationMethod
> +libcamera_orientation_to_gst_video_orientation(Orientation orientation)
> +{
> +	for (auto &a : orientation_map) {
> +		if (a.orientation == orientation)
> +			return a.method;
> +	}
> +
> +	return GST_VIDEO_ORIENTATION_IDENTITY;
> +}
> +
>  GstCaps *
>  gst_libcamera_stream_formats_to_caps(const StreamFormats &formats)
>  {
> @@ -898,3 +934,27 @@ int gst_libcamera_set_structure_field(GstStructure *structure, const ControlId *
>
>  	return 0;
>  }
> +
> +const gchar *
> +gst_libcamera_transform_to_tag_string(libcamera::Transform transform)
> +{
> +	switch (transform) {
> +	case Transform::Rot90:
> +		return "rotate-90";
> +	case Transform::Rot180:
> +		return "rotate-180";
> +	case Transform::Rot270:
> +		return "rotate-270";
> +	case Transform::HFlip:
> +		return "flip-rotate-0";
> +	case Transform::VFlip:
> +		return "flip-rotate-180";
> +	case Transform::Transpose:
> +		return "flip-rotate-270";
> +	case Transform::Rot180Transpose:
> +		return "flip-rotate-90";
> +	case Transform::Identity:
> +	default:
> +		return "rotate-0";
> +	}
> +}
> diff --git a/src/gstreamer/gstlibcamera-utils.h b/src/gstreamer/gstlibcamera-utils.h
> index 35df56fb..b7983264 100644
> --- a/src/gstreamer/gstlibcamera-utils.h
> +++ b/src/gstreamer/gstlibcamera-utils.h
> @@ -10,7 +10,9 @@
>
>  #include <libcamera/camera_manager.h>
>  #include <libcamera/controls.h>
> +#include <libcamera/orientation.h>
>  #include <libcamera/stream.h>
> +#include <libcamera/transform.h>
>
>  #include <gst/gst.h>
>  #include <gst/video/video.h>
> @@ -32,6 +34,9 @@ libcamera::Rectangle gst_libcamera_gvalue_get_rectangle(const GValue *value);
>  int gst_libcamera_set_structure_field(GstStructure *structure,
>  				      const libcamera::ControlId *id,
>  				      const libcamera::ControlValue &value);
> +libcamera::Orientation gst_video_orientation_to_libcamera_orientation(GstVideoOrientationMethod method);
> +GstVideoOrientationMethod libcamera_orientation_to_gst_video_orientation(libcamera::Orientation orientation);
> +const gchar *gst_libcamera_transform_to_tag_string(libcamera::Transform transform);
>
>  #if !GST_CHECK_VERSION(1, 16, 0)
>  static inline void gst_clear_event(GstEvent **event_ptr)
> diff --git a/src/gstreamer/gstlibcamerasrc.cpp b/src/gstreamer/gstlibcamerasrc.cpp
> index 391b228d..77648e6a 100644
> --- a/src/gstreamer/gstlibcamerasrc.cpp
> +++ b/src/gstreamer/gstlibcamerasrc.cpp
> @@ -141,6 +141,7 @@ struct _GstLibcameraSrc {
>  	GstTask *task;
>
>  	gchar *camera_name;
> +	GstVideoOrientationMethod orientation;
>
>  	std::atomic<GstEvent *> pending_eos;
>
> @@ -152,9 +153,12 @@ struct _GstLibcameraSrc {
>  enum {
>  	PROP_0,
>  	PROP_CAMERA_NAME,
> +	PROP_ORIENTATION,
>  	PROP_LAST
>  };
>
> +static GParamSpec *properties[PROP_LAST];
> +
>  static void gst_libcamera_src_child_proxy_init(gpointer g_iface,
>  					       gpointer iface_data);
>
> @@ -606,6 +610,13 @@ gst_libcamera_src_negotiate(GstLibcameraSrc *self)
>  		gst_libcamera_get_framerate_from_caps(caps, element_caps);
>  	}
>
> +	/* Set orientation in libcamera camera configuration. */
> +	Orientation requestedLibcameraOrientation = gst_video_orientation_to_libcamera_orientation(self->orientation);
> +	{
> +		GLibLocker lock(GST_OBJECT(self));
> +		state->config_->orientation = requestedLibcameraOrientation;
> +	}
> +
>  	/* Validate the configuration. */
>  	CameraConfiguration::Status status = state->config_->validate();
>  	if (status == CameraConfiguration::Invalid)
> @@ -627,6 +638,33 @@ gst_libcamera_src_negotiate(GstLibcameraSrc *self)
>  	gst_libcamera_clamp_and_set_frameduration(state->initControls_,
>  						  state->cam_->controls(), element_caps);
>
> +	/*
> +	 * If the requested orientation isn't possible, report the libcamera-provided orientation
> +	 * on GstBus and send the "image-orientation" tag downstream for elements to apply
> +	 * the final requested orientation.
> +	 */
> +	if (state->config_->orientation != requestedLibcameraOrientation) {
> +		{
> +			GLibLocker lock(GST_OBJECT(self));
> +			self->orientation = libcamera_orientation_to_gst_video_orientation(state->config_->orientation);
> +		}
> +
> +		GValue v = G_VALUE_INIT;
> +		g_value_init(&v, properties[PROP_ORIENTATION]->value_type);
> +		g_object_get_property(G_OBJECT(self), properties[PROP_ORIENTATION]->name, &v);
> +		GstMessage *msg = gst_message_new_property_notify(GST_OBJECT(self), properties[PROP_ORIENTATION]->name, &v);
> +		gst_element_post_message(GST_ELEMENT(self), msg);
> +
> +		Transform toApply = requestedLibcameraOrientation / state->config_->orientation;
> +		const gchar *transform_tag = gst_libcamera_transform_to_tag_string(toApply);
> +
> +		g_autoptr(GstEvent) tag_event =
> +			gst_event_new_tag(gst_tag_list_new(GST_TAG_IMAGE_ORIENTATION, transform_tag, NULL));
> +
> +		for (gsize i = 0; i < state->srcpads_.size(); i++)
> +			gst_pad_push_event(state->srcpads_[i], gst_event_ref(tag_event));
> +	}
> +
>  	/*
>  	 * Regardless if it has been modified, create clean caps and push the
>  	 * caps event. Downstream will decide if the caps are acceptable.
> @@ -934,6 +972,9 @@ gst_libcamera_src_set_property(GObject *object, guint prop_id,
>  		g_free(self->camera_name);
>  		self->camera_name = g_value_dup_string(value);
>  		break;
> +	case PROP_ORIENTATION:
> +		self->orientation = static_cast<GstVideoOrientationMethod>(g_value_get_enum(value));
> +		break;
>  	default:
>  		if (!state->controls_.setProperty(prop_id - PROP_LAST, value, pspec))
>  			G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
> @@ -953,6 +994,9 @@ 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_ORIENTATION:
> +		g_value_set_enum(value, static_cast<gint>(self->orientation));
> +		break;
>  	default:
>  		if (!state->controls_.getProperty(prop_id - PROP_LAST, value, pspec))
>  			G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
> @@ -1162,6 +1206,20 @@ gst_libcamera_src_class_init(GstLibcameraSrcClass *klass)
>  							     | G_PARAM_STATIC_STRINGS));
>  	g_object_class_install_property(object_class, PROP_CAMERA_NAME, spec);
>
> +
> +	properties[PROP_ORIENTATION] = g_param_spec_enum("orientation", "orientation",
> +							 "Property to control flipping and rotation operations of the camera. "
> +							 "If the orientation cannot be satisfied, libcamerasrc will send 'image-orientation' "
> +							 "tag downstream to assist with the orientation that was requested. Sinks that "
> +							 "implement the GST_VIDEO_ORIENTATION_AUTO should rotate the stream accordingly. ",
> +							 GST_TYPE_VIDEO_ORIENTATION_METHOD,
> +							 GST_VIDEO_ORIENTATION_IDENTITY,
> +							 (GParamFlags)(GST_PARAM_MUTABLE_READY
> +							  | G_PARAM_CONSTRUCT
> +							  | G_PARAM_READWRITE
> +							  | G_PARAM_STATIC_STRINGS));
> +	g_object_class_install_property(object_class, PROP_ORIENTATION, properties[PROP_ORIENTATION]);
> +
>  	GstCameraControls::installProperties(object_class, PROP_LAST);
>  }
>
> --
> 2.51.0
>

Hi Jacopo,

On 2026-08-06 08:40, Jacopo Mondi wrote:
> Hi Umang,
>   I noticed this patch -really- fell into the cracks..
> 
> Is it still valid, still something that hasn't been addressed
> otherwise, right ?

I believe this is still valid and needs review. Perhaps needs rebasing
as well.

> 
> On Thu, Nov 06, 2025 at 01:01:33PM +0000, Umang Jain wrote:
>> Plumb the support for CameraConfiguration::orientation in libcamerasrc.
>> A new "orientation" property is introduced and mappings for
>> libcamera::Orientation <> GstVideoOrientationMethod are provided
>> with helpers.
>>
>> If the orientation is changed after the CameraConfiguration::validate(),
>> a GstMessage is sent on the GstBus to report the new orientation
>> property value.
>>
>> In case the orientation that was requested cannot be satisfied,
>> a 'image-orientation' tag is pushed downstream for sinks to rotate
>> the stream accordingly (those implementing
>> GSTGST_VIDEO_ORIENTATION_AUTO).
>>
>> Signed-off-by: Umang Jain <uajain@igalia.com>
>> ---
>> Changes in v6:
>> - Use GstMessage to send new property changes if any (like orientation
>>   after validate())
>> - send 'image-orientation' tag orientation downstream if orientation
>>   cannot be satisfied
>> - Drop 'video-orientation' and restore 'orientation' as property name
>> - change authorship to myself as patch is reworked significantly
>>
>> Changes in v5:
>> - patch scrubbing and cleanup
>> - If different orientation is returned than requested, update the
>>   property
>> - Minor string fixes, append appropriate tags
>>
>> Link to v4: https://patchwork.libcamera.org/patch/23965/
>>
>> Note: Checkstyle will complain on this patch on a hunk, but the existing format
>> is quite read-able IMO, hence ignored.
>> ---
>>  src/gstreamer/gstlibcamera-utils.cpp | 60 ++++++++++++++++++++++++++++
>>  src/gstreamer/gstlibcamera-utils.h   |  5 +++
>>  src/gstreamer/gstlibcamerasrc.cpp    | 58 +++++++++++++++++++++++++++
>>  3 files changed, 123 insertions(+)
>>
>> diff --git a/src/gstreamer/gstlibcamera-utils.cpp b/src/gstreamer/gstlibcamera-utils.cpp
>> index bfb094c9..79fb606b 100644
>> --- a/src/gstreamer/gstlibcamera-utils.cpp
>> +++ b/src/gstreamer/gstlibcamera-utils.cpp
>> @@ -357,6 +357,42 @@ control_type_to_gtype(const ControlType &type)
>>  	return G_TYPE_INVALID;
>>  }
>>
>> +static const struct {
>> +	Orientation orientation;
>> +	GstVideoOrientationMethod method;
>> +} orientation_map[]{
>> +	{ Orientation::Rotate0, GST_VIDEO_ORIENTATION_IDENTITY },
>> +	{ Orientation::Rotate90, GST_VIDEO_ORIENTATION_90R },
>> +	{ Orientation::Rotate180, GST_VIDEO_ORIENTATION_180 },
>> +	{ Orientation::Rotate270, GST_VIDEO_ORIENTATION_90L },
>> +	{ Orientation::Rotate0Mirror, GST_VIDEO_ORIENTATION_HORIZ },
>> +	{ Orientation::Rotate180Mirror, GST_VIDEO_ORIENTATION_VERT },
>> +	{ Orientation::Rotate90Mirror, GST_VIDEO_ORIENTATION_UL_LR },
>> +	{ Orientation::Rotate270Mirror, GST_VIDEO_ORIENTATION_UR_LL },
>> +};
>> +
>> +Orientation
>> +gst_video_orientation_to_libcamera_orientation(GstVideoOrientationMethod method)
>> +{
>> +	for (auto &b : orientation_map) {
>> +		if (b.method == method)
>> +			return b.orientation;
>> +	}
>> +
>> +	return Orientation::Rotate0;
>> +}
>> +
>> +GstVideoOrientationMethod
>> +libcamera_orientation_to_gst_video_orientation(Orientation orientation)
>> +{
>> +	for (auto &a : orientation_map) {
>> +		if (a.orientation == orientation)
>> +			return a.method;
>> +	}
>> +
>> +	return GST_VIDEO_ORIENTATION_IDENTITY;
>> +}
>> +
>>  GstCaps *
>>  gst_libcamera_stream_formats_to_caps(const StreamFormats &formats)
>>  {
>> @@ -898,3 +934,27 @@ int gst_libcamera_set_structure_field(GstStructure *structure, const ControlId *
>>
>>  	return 0;
>>  }
>> +
>> +const gchar *
>> +gst_libcamera_transform_to_tag_string(libcamera::Transform transform)
>> +{
>> +	switch (transform) {
>> +	case Transform::Rot90:
>> +		return "rotate-90";
>> +	case Transform::Rot180:
>> +		return "rotate-180";
>> +	case Transform::Rot270:
>> +		return "rotate-270";
>> +	case Transform::HFlip:
>> +		return "flip-rotate-0";
>> +	case Transform::VFlip:
>> +		return "flip-rotate-180";
>> +	case Transform::Transpose:
>> +		return "flip-rotate-270";
>> +	case Transform::Rot180Transpose:
>> +		return "flip-rotate-90";
>> +	case Transform::Identity:
>> +	default:
>> +		return "rotate-0";
>> +	}
>> +}
>> diff --git a/src/gstreamer/gstlibcamera-utils.h b/src/gstreamer/gstlibcamera-utils.h
>> index 35df56fb..b7983264 100644
>> --- a/src/gstreamer/gstlibcamera-utils.h
>> +++ b/src/gstreamer/gstlibcamera-utils.h
>> @@ -10,7 +10,9 @@
>>
>>  #include <libcamera/camera_manager.h>
>>  #include <libcamera/controls.h>
>> +#include <libcamera/orientation.h>
>>  #include <libcamera/stream.h>
>> +#include <libcamera/transform.h>
>>
>>  #include <gst/gst.h>
>>  #include <gst/video/video.h>
>> @@ -32,6 +34,9 @@ libcamera::Rectangle gst_libcamera_gvalue_get_rectangle(const GValue *value);
>>  int gst_libcamera_set_structure_field(GstStructure *structure,
>>  				      const libcamera::ControlId *id,
>>  				      const libcamera::ControlValue &value);
>> +libcamera::Orientation gst_video_orientation_to_libcamera_orientation(GstVideoOrientationMethod method);
>> +GstVideoOrientationMethod libcamera_orientation_to_gst_video_orientation(libcamera::Orientation orientation);
>> +const gchar *gst_libcamera_transform_to_tag_string(libcamera::Transform transform);
>>
>>  #if !GST_CHECK_VERSION(1, 16, 0)
>>  static inline void gst_clear_event(GstEvent **event_ptr)
>> diff --git a/src/gstreamer/gstlibcamerasrc.cpp b/src/gstreamer/gstlibcamerasrc.cpp
>> index 391b228d..77648e6a 100644
>> --- a/src/gstreamer/gstlibcamerasrc.cpp
>> +++ b/src/gstreamer/gstlibcamerasrc.cpp
>> @@ -141,6 +141,7 @@ struct _GstLibcameraSrc {
>>  	GstTask *task;
>>
>>  	gchar *camera_name;
>> +	GstVideoOrientationMethod orientation;
>>
>>  	std::atomic<GstEvent *> pending_eos;
>>
>> @@ -152,9 +153,12 @@ struct _GstLibcameraSrc {
>>  enum {
>>  	PROP_0,
>>  	PROP_CAMERA_NAME,
>> +	PROP_ORIENTATION,
>>  	PROP_LAST
>>  };
>>
>> +static GParamSpec *properties[PROP_LAST];
>> +
>>  static void gst_libcamera_src_child_proxy_init(gpointer g_iface,
>>  					       gpointer iface_data);
>>
>> @@ -606,6 +610,13 @@ gst_libcamera_src_negotiate(GstLibcameraSrc *self)
>>  		gst_libcamera_get_framerate_from_caps(caps, element_caps);
>>  	}
>>
>> +	/* Set orientation in libcamera camera configuration. */
>> +	Orientation requestedLibcameraOrientation = gst_video_orientation_to_libcamera_orientation(self->orientation);
>> +	{
>> +		GLibLocker lock(GST_OBJECT(self));
>> +		state->config_->orientation = requestedLibcameraOrientation;
>> +	}
>> +
>>  	/* Validate the configuration. */
>>  	CameraConfiguration::Status status = state->config_->validate();
>>  	if (status == CameraConfiguration::Invalid)
>> @@ -627,6 +638,33 @@ gst_libcamera_src_negotiate(GstLibcameraSrc *self)
>>  	gst_libcamera_clamp_and_set_frameduration(state->initControls_,
>>  						  state->cam_->controls(), element_caps);
>>
>> +	/*
>> +	 * If the requested orientation isn't possible, report the libcamera-provided orientation
>> +	 * on GstBus and send the "image-orientation" tag downstream for elements to apply
>> +	 * the final requested orientation.
>> +	 */
>> +	if (state->config_->orientation != requestedLibcameraOrientation) {
>> +		{
>> +			GLibLocker lock(GST_OBJECT(self));
>> +			self->orientation = libcamera_orientation_to_gst_video_orientation(state->config_->orientation);
>> +		}
>> +
>> +		GValue v = G_VALUE_INIT;
>> +		g_value_init(&v, properties[PROP_ORIENTATION]->value_type);
>> +		g_object_get_property(G_OBJECT(self), properties[PROP_ORIENTATION]->name, &v);
>> +		GstMessage *msg = gst_message_new_property_notify(GST_OBJECT(self), properties[PROP_ORIENTATION]->name, &v);
>> +		gst_element_post_message(GST_ELEMENT(self), msg);
>> +
>> +		Transform toApply = requestedLibcameraOrientation / state->config_->orientation;
>> +		const gchar *transform_tag = gst_libcamera_transform_to_tag_string(toApply);
>> +
>> +		g_autoptr(GstEvent) tag_event =
>> +			gst_event_new_tag(gst_tag_list_new(GST_TAG_IMAGE_ORIENTATION, transform_tag, NULL));
>> +
>> +		for (gsize i = 0; i < state->srcpads_.size(); i++)
>> +			gst_pad_push_event(state->srcpads_[i], gst_event_ref(tag_event));
>> +	}
>> +
>>  	/*
>>  	 * Regardless if it has been modified, create clean caps and push the
>>  	 * caps event. Downstream will decide if the caps are acceptable.
>> @@ -934,6 +972,9 @@ gst_libcamera_src_set_property(GObject *object, guint prop_id,
>>  		g_free(self->camera_name);
>>  		self->camera_name = g_value_dup_string(value);
>>  		break;
>> +	case PROP_ORIENTATION:
>> +		self->orientation = static_cast<GstVideoOrientationMethod>(g_value_get_enum(value));
>> +		break;
>>  	default:
>>  		if (!state->controls_.setProperty(prop_id - PROP_LAST, value, pspec))
>>  			G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
>> @@ -953,6 +994,9 @@ 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_ORIENTATION:
>> +		g_value_set_enum(value, static_cast<gint>(self->orientation));
>> +		break;
>>  	default:
>>  		if (!state->controls_.getProperty(prop_id - PROP_LAST, value, pspec))
>>  			G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
>> @@ -1162,6 +1206,20 @@ gst_libcamera_src_class_init(GstLibcameraSrcClass *klass)
>>  							     | G_PARAM_STATIC_STRINGS));
>>  	g_object_class_install_property(object_class, PROP_CAMERA_NAME, spec);
>>
>> +
>> +	properties[PROP_ORIENTATION] = g_param_spec_enum("orientation", "orientation",
>> +							 "Property to control flipping and rotation operations of the camera. "
>> +							 "If the orientation cannot be satisfied, libcamerasrc will send 'image-orientation' "
>> +							 "tag downstream to assist with the orientation that was requested. Sinks that "
>> +							 "implement the GST_VIDEO_ORIENTATION_AUTO should rotate the stream accordingly. ",
>> +							 GST_TYPE_VIDEO_ORIENTATION_METHOD,
>> +							 GST_VIDEO_ORIENTATION_IDENTITY,
>> +							 (GParamFlags)(GST_PARAM_MUTABLE_READY
>> +							  | G_PARAM_CONSTRUCT
>> +							  | G_PARAM_READWRITE
>> +							  | G_PARAM_STATIC_STRINGS));
>> +	g_object_class_install_property(object_class, PROP_ORIENTATION, properties[PROP_ORIENTATION]);
>> +
>>  	GstCameraControls::installProperties(object_class, PROP_LAST);
>>  }
>>
>> --
>> 2.51.0
>>

Hi

2025. 11. 06. 14:01 keltezéssel, Umang Jain írta:
> Plumb the support for CameraConfiguration::orientation in libcamerasrc.
> A new "orientation" property is introduced and mappings for
> libcamera::Orientation <> GstVideoOrientationMethod are provided
> with helpers.
> 
> If the orientation is changed after the CameraConfiguration::validate(),
> a GstMessage is sent on the GstBus to report the new orientation
> property value.
> 
> In case the orientation that was requested cannot be satisfied,
> a 'image-orientation' tag is pushed downstream for sinks to rotate
> the stream accordingly (those implementing
> GSTGST_VIDEO_ORIENTATION_AUTO).
> 
> Signed-off-by: Umang Jain <uajain@igalia.com>
> ---
> Changes in v6:
> - Use GstMessage to send new property changes if any (like orientation
>    after validate())
> - send 'image-orientation' tag orientation downstream if orientation
>    cannot be satisfied
> - Drop 'video-orientation' and restore 'orientation' as property name
> - change authorship to myself as patch is reworked significantly
> 
> Changes in v5:
> - patch scrubbing and cleanup
> - If different orientation is returned than requested, update the
>    property
> - Minor string fixes, append appropriate tags
> 
> Link to v4: https://patchwork.libcamera.org/patch/23965/
> 
> Note: Checkstyle will complain on this patch on a hunk, but the existing format
> is quite read-able IMO, hence ignored.
> ---
>   src/gstreamer/gstlibcamera-utils.cpp | 60 ++++++++++++++++++++++++++++
>   src/gstreamer/gstlibcamera-utils.h   |  5 +++
>   src/gstreamer/gstlibcamerasrc.cpp    | 58 +++++++++++++++++++++++++++
>   3 files changed, 123 insertions(+)
> 
> diff --git a/src/gstreamer/gstlibcamera-utils.cpp b/src/gstreamer/gstlibcamera-utils.cpp
> index bfb094c9..79fb606b 100644
> --- a/src/gstreamer/gstlibcamera-utils.cpp
> +++ b/src/gstreamer/gstlibcamera-utils.cpp
> @@ -357,6 +357,42 @@ control_type_to_gtype(const ControlType &type)
>   	return G_TYPE_INVALID;
>   }
>   
> +static const struct {
> +	Orientation orientation;
> +	GstVideoOrientationMethod method;
> +} orientation_map[]{
> +	{ Orientation::Rotate0, GST_VIDEO_ORIENTATION_IDENTITY },
> +	{ Orientation::Rotate90, GST_VIDEO_ORIENTATION_90R },
> +	{ Orientation::Rotate180, GST_VIDEO_ORIENTATION_180 },
> +	{ Orientation::Rotate270, GST_VIDEO_ORIENTATION_90L },
> +	{ Orientation::Rotate0Mirror, GST_VIDEO_ORIENTATION_HORIZ },
> +	{ Orientation::Rotate180Mirror, GST_VIDEO_ORIENTATION_VERT },
> +	{ Orientation::Rotate90Mirror, GST_VIDEO_ORIENTATION_UL_LR },
> +	{ Orientation::Rotate270Mirror, GST_VIDEO_ORIENTATION_UR_LL },
> +};
> +
> +Orientation
> +gst_video_orientation_to_libcamera_orientation(GstVideoOrientationMethod method)
> +{
> +	for (auto &b : orientation_map) {
> +		if (b.method == method)
> +			return b.orientation;
> +	}
> +
> +	return Orientation::Rotate0;
> +}
> +
> +GstVideoOrientationMethod
> +libcamera_orientation_to_gst_video_orientation(Orientation orientation)
> +{
> +	for (auto &a : orientation_map) {
> +		if (a.orientation == orientation)
> +			return a.method;
> +	}
> +
> +	return GST_VIDEO_ORIENTATION_IDENTITY;
> +}
> +
>   GstCaps *
>   gst_libcamera_stream_formats_to_caps(const StreamFormats &formats)
>   {
> @@ -898,3 +934,27 @@ int gst_libcamera_set_structure_field(GstStructure *structure, const ControlId *
>   
>   	return 0;
>   }
> +
> +const gchar *
> +gst_libcamera_transform_to_tag_string(libcamera::Transform transform)
> +{
> +	switch (transform) {
> +	case Transform::Rot90:
> +		return "rotate-90";
> +	case Transform::Rot180:
> +		return "rotate-180";
> +	case Transform::Rot270:
> +		return "rotate-270";
> +	case Transform::HFlip:
> +		return "flip-rotate-0";
> +	case Transform::VFlip:
> +		return "flip-rotate-180";
> +	case Transform::Transpose:
> +		return "flip-rotate-270";
> +	case Transform::Rot180Transpose:
> +		return "flip-rotate-90";
> +	case Transform::Identity:
> +	default:
> +		return "rotate-0";
> +	}

I'd remove the `default` branch and move the return here so that
the compiler can recognize the incomplete switch if `Transform` changes.


> +}
> diff --git a/src/gstreamer/gstlibcamera-utils.h b/src/gstreamer/gstlibcamera-utils.h
> index 35df56fb..b7983264 100644
> --- a/src/gstreamer/gstlibcamera-utils.h
> +++ b/src/gstreamer/gstlibcamera-utils.h
> @@ -10,7 +10,9 @@
>   
>   #include <libcamera/camera_manager.h>
>   #include <libcamera/controls.h>
> +#include <libcamera/orientation.h>
>   #include <libcamera/stream.h>
> +#include <libcamera/transform.h>
>   
>   #include <gst/gst.h>
>   #include <gst/video/video.h>
> @@ -32,6 +34,9 @@ libcamera::Rectangle gst_libcamera_gvalue_get_rectangle(const GValue *value);
>   int gst_libcamera_set_structure_field(GstStructure *structure,
>   				      const libcamera::ControlId *id,
>   				      const libcamera::ControlValue &value);
> +libcamera::Orientation gst_video_orientation_to_libcamera_orientation(GstVideoOrientationMethod method);
> +GstVideoOrientationMethod libcamera_orientation_to_gst_video_orientation(libcamera::Orientation orientation);
> +const gchar *gst_libcamera_transform_to_tag_string(libcamera::Transform transform);
>   
>   #if !GST_CHECK_VERSION(1, 16, 0)
>   static inline void gst_clear_event(GstEvent **event_ptr)
> diff --git a/src/gstreamer/gstlibcamerasrc.cpp b/src/gstreamer/gstlibcamerasrc.cpp
> index 391b228d..77648e6a 100644
> --- a/src/gstreamer/gstlibcamerasrc.cpp
> +++ b/src/gstreamer/gstlibcamerasrc.cpp
> @@ -141,6 +141,7 @@ struct _GstLibcameraSrc {
>   	GstTask *task;
>   
>   	gchar *camera_name;
> +	GstVideoOrientationMethod orientation;
>   
>   	std::atomic<GstEvent *> pending_eos;
>   
> @@ -152,9 +153,12 @@ struct _GstLibcameraSrc {
>   enum {
>   	PROP_0,
>   	PROP_CAMERA_NAME,
> +	PROP_ORIENTATION,
>   	PROP_LAST
>   };
>   
> +static GParamSpec *properties[PROP_LAST];

If you're creating this, it'd probably be better to initialize all members properly,
not just "orientation".

> +
>   static void gst_libcamera_src_child_proxy_init(gpointer g_iface,
>   					       gpointer iface_data);
>   
> @@ -606,6 +610,13 @@ gst_libcamera_src_negotiate(GstLibcameraSrc *self)
>   		gst_libcamera_get_framerate_from_caps(caps, element_caps);
>   	}
>   
> +	/* Set orientation in libcamera camera configuration. */
> +	Orientation requestedLibcameraOrientation = gst_video_orientation_to_libcamera_orientation(self->orientation);
> +	{
> +		GLibLocker lock(GST_OBJECT(self));
> +		state->config_->orientation = requestedLibcameraOrientation;

Why is the locking needed? `state->config_` is "freely" accessed in this function in other places?
Maybe `self->orientation` is what needs to be guarded?


> +	}
> +
>   	/* Validate the configuration. */
>   	CameraConfiguration::Status status = state->config_->validate();
>   	if (status == CameraConfiguration::Invalid)
> @@ -627,6 +638,33 @@ gst_libcamera_src_negotiate(GstLibcameraSrc *self)
>   	gst_libcamera_clamp_and_set_frameduration(state->initControls_,
>   						  state->cam_->controls(), element_caps);
>   
> +	/*
> +	 * If the requested orientation isn't possible, report the libcamera-provided orientation
> +	 * on GstBus and send the "image-orientation" tag downstream for elements to apply
> +	 * the final requested orientation.
> +	 */
> +	if (state->config_->orientation != requestedLibcameraOrientation) {
> +		{
> +			GLibLocker lock(GST_OBJECT(self));
> +			self->orientation = libcamera_orientation_to_gst_video_orientation(state->config_->orientation);
> +		}
> +
> +		GValue v = G_VALUE_INIT;
> +		g_value_init(&v, properties[PROP_ORIENTATION]->value_type);
> +		g_object_get_property(G_OBJECT(self), properties[PROP_ORIENTATION]->name, &v);
> +		GstMessage *msg = gst_message_new_property_notify(GST_OBJECT(self), properties[PROP_ORIENTATION]->name, &v);
> +		gst_element_post_message(GST_ELEMENT(self), msg);

Is `g_value_unset()` / `g_auto(GValue)` not needed here? I suppose the value is
just an integer, but for the sake of completeness, I'd add it.


> +
> +		Transform toApply = requestedLibcameraOrientation / state->config_->orientation;
> +		const gchar *transform_tag = gst_libcamera_transform_to_tag_string(toApply);
> +
> +		g_autoptr(GstEvent) tag_event =
> +			gst_event_new_tag(gst_tag_list_new(GST_TAG_IMAGE_ORIENTATION, transform_tag, NULL));
> +
> +		for (gsize i = 0; i < state->srcpads_.size(); i++)
> +			gst_pad_push_event(state->srcpads_[i], gst_event_ref(tag_event));
> +	}
> +
>   	/*
>   	 * Regardless if it has been modified, create clean caps and push the
>   	 * caps event. Downstream will decide if the caps are acceptable.
> @@ -934,6 +972,9 @@ gst_libcamera_src_set_property(GObject *object, guint prop_id,
>   		g_free(self->camera_name);
>   		self->camera_name = g_value_dup_string(value);
>   		break;
> +	case PROP_ORIENTATION:
> +		self->orientation = static_cast<GstVideoOrientationMethod>(g_value_get_enum(value));
> +		break;
>   	default:
>   		if (!state->controls_.setProperty(prop_id - PROP_LAST, value, pspec))
>   			G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
> @@ -953,6 +994,9 @@ 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_ORIENTATION:
> +		g_value_set_enum(value, static_cast<gint>(self->orientation));
> +		break;
>   	default:
>   		if (!state->controls_.getProperty(prop_id - PROP_LAST, value, pspec))
>   			G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
> @@ -1162,6 +1206,20 @@ gst_libcamera_src_class_init(GstLibcameraSrcClass *klass)
>   							     | G_PARAM_STATIC_STRINGS));
>   	g_object_class_install_property(object_class, PROP_CAMERA_NAME, spec);
>   
> +
> +	properties[PROP_ORIENTATION] = g_param_spec_enum("orientation", "orientation",
> +							 "Property to control flipping and rotation operations of the camera. "
> +							 "If the orientation cannot be satisfied, libcamerasrc will send 'image-orientation' "
> +							 "tag downstream to assist with the orientation that was requested. Sinks that "
> +							 "implement the GST_VIDEO_ORIENTATION_AUTO should rotate the stream accordingly. ",
> +							 GST_TYPE_VIDEO_ORIENTATION_METHOD,
> +							 GST_VIDEO_ORIENTATION_IDENTITY,
> +							 (GParamFlags)(GST_PARAM_MUTABLE_READY
> +							  | G_PARAM_CONSTRUCT
> +							  | G_PARAM_READWRITE
> +							  | G_PARAM_STATIC_STRINGS));
> +	g_object_class_install_property(object_class, PROP_ORIENTATION, properties[PROP_ORIENTATION]);
> +
>   	GstCameraControls::installProperties(object_class, PROP_LAST);
>   }
>