[v3] libcamerasrc: Report camera properties as device properties

23741 diff mbox series

Iterate over all libcamera camera properties and report them as
device properties. The values are reported as strings, including the ones
which enum types, for better readability.

Signed-off-by: Umang Jain <uajain@igalia.com>
---
Changes in v3:
- Iterate over all camera properties and report everything.
---
 src/gstreamer/gstlibcameraprovider.cpp | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

Hi Umang,

Thank you for the patch.

On Fri, Jul 04, 2025 at 11:04:24AM +0530, Umang Jain wrote:
> Iterate over all libcamera camera properties and report them as
> device properties. The values are reported as strings, including the ones
> which enum types, for better readability.
> 
> Signed-off-by: Umang Jain <uajain@igalia.com>
> ---
> Changes in v3:
> - Iterate over all camera properties and report everything.
> ---
>  src/gstreamer/gstlibcameraprovider.cpp | 24 ++++++++++++++++++++++++
>  1 file changed, 24 insertions(+)
> 
> diff --git a/src/gstreamer/gstlibcameraprovider.cpp b/src/gstreamer/gstlibcameraprovider.cpp
> index 5da96ea3..237baeb2 100644
> --- a/src/gstreamer/gstlibcameraprovider.cpp
> +++ b/src/gstreamer/gstlibcameraprovider.cpp
> @@ -12,6 +12,7 @@
>  
>  #include <libcamera/camera.h>
>  #include <libcamera/camera_manager.h>
> +#include <libcamera/property_ids.h>
>  
>  #include "gstlibcamerasrc.h"
>  #include "gstlibcamera-utils.h"
> @@ -130,6 +131,7 @@ gst_libcamera_device_new(const std::shared_ptr<Camera> &camera)
>  {
>  	static const std::array roles{ StreamRole::VideoRecording };
>  	g_autoptr(GstCaps) caps = gst_caps_new_empty();
> +	g_autoptr(GstStructure) props = gst_structure_new_empty("camera-properties");

You can move this just before the for loop below.

>  	const gchar *name = camera->id().c_str();
>  
>  	std::unique_ptr<CameraConfiguration> config = camera->generateConfiguration(roles);
> @@ -144,12 +146,34 @@ gst_libcamera_device_new(const std::shared_ptr<Camera> &camera)
>  			gst_caps_append(caps, sub_caps);
>  	}
>  
> +	for (const auto &[key, value] : camera->properties()) {
> +		const ControlId *id = properties::properties.at(key);
> +
> +		g_autoptr(GString) prop_str = g_string_new("api.libcamera.");
> +		g_string_append(prop_str, id->name().c_str());
> +
> +		/* Use string names for enum values for better readability */

s/readability/readability./

> +		if (value.type() == ControlTypeInteger32) {
> +			int32_t val = value.get<int32_t>();
> +			const auto &it = id->enumerators().find(val);
> +			if (it != id->enumerators().end()) {
> +				gst_structure_set(props, prop_str->str, G_TYPE_STRING,
> +						  it->second.c_str(), nullptr);
> +				continue;
> +			}
> +		}
> +
> +		gst_structure_set(props, prop_str->str, G_TYPE_STRING,
> +				  value.toString().c_str(), nullptr);

Instead of using a libcamera-specific internal string representation of
the value, it should be converted to native GStreamer types. Numerical
properties should use a numerical type, rectangles should be converted
to the native GStreamer representation, ...

Nicolas, any opinion on this ?

> +	}
> +
>  	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",
> +				       "properties", props,
>  				       nullptr));
>  }
>