[libcamera-devel] [PATCH] libcamera: controls: Add sensor black levels reporting through metadata

[Naushir Patuck]

From: David Plowman <david.plowman at raspberrypi.com>

The black levels will be used when saving RAW data in DNG containers.

Four values are reported, one for each channel, in the order R, Gr, Gb
and B. The values are reported as being out of a 16-bit pixel range
(a fully saturated pixel would be 65535), so may need subsequent
re-scaling, depending on use.

Signed-off-by: David Plowman <david.plowman at raspberrypi.com>
Signed-off-by: Naushir Patuck <naush at raspberrypi.com>
---
 src/libcamera/control_ids.yaml | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/libcamera/control_ids.yaml b/src/libcamera/control_ids.yaml
index b419f8a7..77ebc3f9 100644
--- a/src/libcamera/control_ids.yaml
+++ b/src/libcamera/control_ids.yaml
@@ -230,4 +230,13 @@ controls:
         Specify a fixed saturation parameter. Normal saturation is given by
         the value 1.0; larger values produce more saturated colours; 0.0
         produces a greyscale image.
+
+  - SensorBlackLevels:
+      type: int32_t
+      description: |
+        Reports the sensor black levels used for processing a frame, in the
+        order R, Gr, Gb, B. These values are returned as numbers out of a 16-bit
+        pixel range (as if pixels ranged from 0 to 65535). The SensorBlackLevels
+        control can only be returned in metadata.
+      size: [4]
 ...
-- 
2.17.1