[libcamera-devel] [PATCH 09/10] android: camera_device: Use Camera properties for static Metadata

[Laurent Pinchart]

Hi Jacopo,

Thank you for the patch.

On Wed, Dec 04, 2019 at 02:21:05PM +0100, Jacopo Mondi wrote:
> Construct two example static metadata to be reported to the Android
> framework using the properties reported by the Camera.
> 
> Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
> ---
>  src/android/camera_device.cpp | 29 +++++++++++++++++++++++++++--
>  1 file changed, 27 insertions(+), 2 deletions(-)
> 
> diff --git a/src/android/camera_device.cpp b/src/android/camera_device.cpp
> index 065e0292e186..674867d313ac 100644
> --- a/src/android/camera_device.cpp
> +++ b/src/android/camera_device.cpp
> @@ -7,6 +7,9 @@
>  
>  #include "camera_device.h"
>  
> +#include <libcamera/controls.h>
> +#include <libcamera/property_ids.h>
> +
>  #include "log.h"
>  #include "utils.h"
>  
> @@ -97,6 +100,8 @@ camera_metadata_t *CameraDevice::getStaticMetadata()
>  	if (staticMetadata_)
>  		return staticMetadata_->get();
>  
> +	const ControlList &properties = camera_->properties();
> +
>  	/*
>  	 * The here reported metadata are enough to implement a basic capture
>  	 * example application, but a real camera implementation will require
> @@ -261,9 +266,15 @@ camera_metadata_t *CameraDevice::getStaticMetadata()
>  	staticMetadata_->addEntry(ANDROID_SENSOR_INFO_EXPOSURE_TIME_RANGE,
>  				  &exposureTimeRange, 2);
>  
> +	/*
> +	 * Android reports orientation as clockwise correction, while Linux
> +	 * uses counter-clockwise.

What Linux does isn't relevant I think, what matters here is what
libcamera does.

Android defines the rotation as

"Clockwise angle through which the output image needs to be rotated to
be upright on the device screen in its native orientation."

I have to say I have a hard time parsing the description of the
libcamera rotation property:

"Camera mounting rotation expressed as counterclockwise rotation degrees
towards the axis perpendicular to the sensor surface and directed away
from it."

I can't figure out what this means :-S Is it just me ?

> +	 */
>  	int32_t orientation = 0;
> -	staticMetadata_->addEntry(ANDROID_SENSOR_ORIENTATION,
> -				  &orientation, 1);
> +	if (properties.contains(properties::Rotation))
> +		orientation = (360 - properties.get(properties::Rotation))

This could be made slightly more efficient if you used .find() to avoid
the double lookup. Same below.

> +			    % 360;
> +	staticMetadata_->addEntry(ANDROID_SENSOR_ORIENTATION, &orientation, 1);
>  
>  	std::vector<int32_t> testPatterModes = {
>  		ANDROID_SENSOR_TEST_PATTERN_MODE_OFF,
> @@ -310,6 +321,20 @@ camera_metadata_t *CameraDevice::getStaticMetadata()
>  				  lensApertures.size());
>  
>  	uint8_t lensFacing = ANDROID_LENS_FACING_FRONT;
> +	if (properties.contains(properties::Location)) {
> +		int32_t location = properties.get(properties::Location);
> +		switch (location) {
> +		case CAMERA_LOCATION_FRONT:
> +			lensFacing = ANDROID_LENS_FACING_FRONT;
> +			break;
> +		case CAMERA_LOCATION_BACK:
> +			lensFacing = ANDROID_LENS_FACING_BACK;
> +			break;
> +		case CAMERA_LOCATION_EXTERNAL:
> +			lensFacing = ANDROID_LENS_FACING_EXTERNAL;
> +			break;
> +		}
> +	}
>  	staticMetadata_->addEntry(ANDROID_LENS_FACING, &lensFacing, 1);
>  
>  	std::vector<float> lensFocalLenghts = {

-- 
Regards,

Laurent Pinchart